To learn about electronics in a different and very effective way, check out my Patreon page. Many of my designs are released there as well. Click this Link: www.patreon.com/MrCarlsonsLab
@HalfSpeedMastering -- In this particular case it certainly is same, since the FET in question has a pure and very brief pop-suppression function and is otherwise pretty close to a piece of wire in the signal chain. I would trust Paul 100 percent to avoid degrading or otherwise altering the audio performance of any gear he works on.
Gotta love this old school equipment. Very stylish scientific look to the dials, markings, and solid cabinetry. Reliable circuitry, and easy to work on. 🎛🎚🎚🎚🎚 👌😙
Quick question where did you get you desoldering tool. And or what is the brand name/ what is it called. Thank you for your time and have yourself a grate day. 😁
its funny you might be right. i put on mr carleson to relax and go on adventures into vintage troubleshooting land. youre right. its an awesome quality and i hope he never changes. im gonna subscribe to his patreon i think
Hi Paul, I am very excited to see your first repair video of the New Year. Nice to see you use the SuperProbe and the 224. I love both very much I have a Mod 222 which I think is very useful, yet not as useful as the SuperProbe I built using your brilliant design. Thanks again for all that you do and sharing your bottomless knowledge, along with your ingenious electronic inventions with us! Take care my friend and please never stop sharing your vast and practical knowledge with the electronics repair community. "Why be a rockstar when you can be a god?" applies to Mr. Carlson's Lab. It's funny, you have the youthful appearance of someone in their late 30's or early 40's and yet you posses 125 years worth of electronics knowledge and experience.
@@sferg9582 Still have my ~40 year old one, a SS110 Mk. II, that I had given to me back when I was 14. That was in 1991. Just fixed it today, now it works right :)
Amen brother. Don't know how many times someone sent in a radio saying xxx was wrong with it and the instant it got set on my bench it started to work again. Having been a heavy truck mechanic also many years ago I speak from experience when I say they suffer from the same problem to.
@@Mariano.Bernacki For me the opposite happens. I test the damn computers for 2-3hours and the next day the client calls me that the thing stopped working.
The effect also happens with desktop support. Arriving at customers desk will sometimes solve the problem. I always used to say I was so good my mere presence solved the problem.
Truck driver to Radio tech: "It's the finals". Truck driver to Mechanic: "It's the EGR". -Former, recovering truck driver turn technician. Other favorites: "No, I bought it brand new! Nobody has ever been in there!(Covered in pry marks, stripped screw heads, missing screws, splatter-box, solder balls rolling around, cut diodes, over-sized caps...). "It just needs caps". (Burnt PCB around through holes, smoked resistors, some weird residue all over, is that a bobby pin? What is that smell? Is...is that urine? How the hell...). "I'll be back Thursday".(11 months later..)
As an industrial electrician, that spent literally weeks fault finding and eventually repairing a marantz vintage amplifier, as a hobby at home, this was very humbling to watch and follow. Thankyou sir !
Same, I'm an industrial electrician and don't know as much about electronics as I should mainly because my PA system has 10, 15 band eq's and 2, 31 band eq's. Atleast one of them has an issue in rotation.
Great job! Once again, making it look all too easy! And once again thinking I need to build that Super Probe. I built a probe(with an actual germanium diode) and it works well, but the idea of a non-contact probe where one can just wave it close to the board and not having to locate and contact an emitter at some absurd angle is blissful. Curve tracer first, though. Op Amps are coming in from Digi-key as we speak. Your Patreon page has been the single best tool on my bench. I have been using your transistor tester, matching, biasing circuit for a while now and it never fails. I just let your videos play while I work and always learn something new, even if I have heard the video a couple of times.
Wow, freakin' awesome video. My first equalizer was an ADC Sound Shaper Two (with the VU meter) in 1978. Worked great but with three tape decks I eventually wanted a dubbing feature on the EQ. So in 1982 I purchased this model ($213). With bidirectional dubbing, large LED meters, a good subsonic filter (18dB/oct@15hz), THD and IM of 0.02% and great layout of controls I was pleased. My original EQ was given to my brother-in-law and he still uses it today. That's over forty years. My SS2 IC still functions perfectly and is used every time the hifi is on. Not bad for thirty six years old. Some folks just don't understand how useful an equalizer can be. This video is very interesting and a definite keeper. The SS2 IC is an excellent EQ, functional and pleasing to the eye with that "industrial" look. Remember their first EQ?? The ADC 500??? Well worth an hour of my time to view this. Nicely done, sir.
Is it possible for this whole "porn" nonsense to be dropped, when referring to an area of interest which one likes? It sounds SO crude and ignorant, not to mention that it's just... unoriginal in the utmost. Maybe...?
I agree with unlokia, there is nothing pornographic about this. To be frank Penfold8, I would like to quote Inigo Montoya, "I don't think that word means what you think it means." This is pure electronics nerdvana, not something dirty at all and I would kindly ask that you refrain from referring to it as something it is not.
Repairmans syndrome: I had case just before Christmas- dead guitar amp , guy supplied guitar and curly lead , but not the lead he was using apparently!
Been an auto tech 30+ years.....my favorite: customer calls, gives symptoms, schedules to drop off. They come in the door with a confused look on their faces, "You're not gonna believe this but it just started running fine about a half-mile back." I reply, "Yep. Happens often, cars are terrified of me."
some one set a guitar amp out to the curb and I grabbed it. got it home, plugged in and played through it for about half an hour. Came back a few weeks later to play again and it was dead. Electronics are voodoo
Repairman's syndrome is REAL! My grandfather worked for Dictaphone way back in the day. He had been called to a particular piece of equipment 8 times but had never found a problem when testing it. After the ninth call he did something odd...he taped a picture of himself on the underside of the cover. He retired 14 years later...having NEVER been recalled to work on that piece of equipment in all that time.
I’m sure this is going to be another great video and I’m looking forward to enjoying it over the next hour. It looks like nice unit, and these things could be useful in the right hands. Unfortunately, back in the day equalizers seemed to attract those that wanted overly-booming bass and overly-sizzling highs and not those that wanted to subtly correct for a room aberration or poor recording. I wish they had been designed with only +/- 4 dB of gain and not the typical 12. That’s more than enough, really, and would have kept people from destroying the careful sound that engineers take time to mix, while also saving amps, speakers and ears from damage. I can’t tell you how many times I got in a car back in the 80s and 90s, and was tempted to zero-out a friend’s equalizer. Nowadays, I’m still tempted, but the equalizer is buried in ten layers of GUI!
I don't think a lot of people understand the proper use of an EQ also. I use it more to remove frequencies rather than boost. Most people boost the crap out of it!
In theory, but not in practice... I've come across equipment in the past where left and right have been reversed in TRS jacks (usually Chinese origin, but not always). I've also recently come across numerous 3.5mm TRS to RCA leads with the colours reversed on the RCA jacks.
so true as Long as everybody uses them the conventional way… but Standards are if everybody does what he wants noone what he should but everyone is part of the game
TRS...reminds me of when I first worked for the Telephone company...1969...Tip was +, ring -, sleeve ground...that was a 48 volt DC situation...still is on landlines... most all telephone stuff is 48 volt DC and is powered by batteries, and diesel generator for back-up...
I'd like to know how Paul got so heavily into vintage as his specialty. It's really what sets this channel apart because much of the knowledge he presents is no longer taught and is slowly being lost. And yet, he doesn't come off as some nostalgic curmudgeon but rather he makes everything seem timely and relevant. They say with everything being so digital today, it's often the analog aspects of a circuit that are most half-assed and overlooked. This is where the tricks of the past could serve us well.
Hello, Paul, and a very Happy 2019 to you! I trust you're not enduring ice-laden cables, and continuously cracking trees, this year? God bless you my friend. Matthew. 🙂
Love your channel! You are an incredible tech. I used to calibrate analog aircraft instruments mostly rate of climbs and altimeters and we used to call it technician proximity syndrome. I haven't commented yet but have been binge watching your channel. I am also a ham. 67 yrs old and been a ham for 35 yrs. You have more knowledge about things than most people have forgotten. You and Nicola Tesla would have been the team to change the world. 73 de KB7ICI.
I had a very annoying fault with a Toshiba 29N5DXA flat screen crt that I've owned 20 years since new. When it was brand new it would randomly produce a loud high voltage crack and the tv would shut off. It would turn on again just fine. I took it back to the store where I bought it and they kept it for a couple of weeks sitting on a shelf running and of course it ran perfectly well, because if it failed they would have gave me a replacement. So I took it home and it ran fine for another few weeks before failing in the same way again. So off to the service man it went, where he could find no fault, so also kept it for a couple of weeks running without fault before returning it. A day later the tv did the same thing again, and I was told the only thing left to do was to keep using it until it finally failed properly and stopped working completely, because they were powerless to help if they couldn't witness the failure with the manufacturers warrenty. So the tv ran like that for a few more months until one day it made a much louder electrical crack, there was a wisp of smoke but this time the tv didn't shut down, and its never produced the fault again or had any problem since. It went back to the service man who again found no trace of the fault or replicate it. I can only assume a faulty solder joint somewhere got welded back into service.
Many years ago I had a 25" Sony console that did the same thing... a loud crack then shut down. Turned out the set had a safety circuit that activated when the HV exceeded 25 KV. This was supposed to prevent the CRT from emitting X-rays. Plugging the tv into a variac set to 115V solved the problem, but it tied up my variac. Sounds like that last loud crack may have pooched your tv's safety circuit, if that was the cause.
Thank you for uploading extremely informative videos that inspire, help, motivate, and bring pleasure to people all over, and in a professional, calmly hypnotic manner. You deserve a lot more subs!
Paul, I am not a repairman, just a very long term interested bystander. Rather than apologise you should promote the use of a signal injector and tracer. Back in the day that was all that many amateurs, and indeed some shops, could afford. I've still got mine - though they aren't as well designed or as capable as yours. regards Dave
There's really no way to say why it failed. If there was a power supply problem, it would have shown up during his other tests, and if one of the caps or resistors had died it would have shown up too. It basically comes down to the device being 30+ years old, and that component just got tired and stopped working.
Dan Todd, Good premise, but it would be a guess. Paul deals in facts. If the circuit promoted the failure, I'm sure he would have pointed it out. It was a low level failure, and an odd one, at that.
Dan, there's the what else in the circuit caused it to fail in this case probably nothing or what failed in the fet. There are very spendy x-ray strip the epoxy and sem type services when you really need to know. They'd show you things like esd causing a latent defect etc.
Given enough time in service, EVERY electrical component will fail. It's just a matter of when and with what severity. So....the question isn't why a part failed as much as it is when the remaining components are likely to go.
Well, while viewing the entire video I also wondered why he did not spend time explaining- or looking for- why it failed. In general, capacitors can die of old age, resistors (especially old ones from way before this thing was made) too, but when "a little FET" like this fails there usually is an external reason for it. That reason can be lots of things, but "getting tired" or "lifetime" is usually not it.
I learned alot from this video here. I learned how to divide a schematic to break it down to areas of concern. Also about Jfets and what the signals mean. I'm headed over to the pahtheon page to check it out. Thanks again.
A practical approach to audio or video equipment troubleshooting/repair: I think the determination of a (the) faulty channel could be done much quicker by a simple "audio in and out" setup. With a cheap mp3/music player, a powered speaker (I have one on my bench always ready to rumble) and a set of RCA cables this would take literally 20 seconds. No need to disassemble anything. From there the search could go on. Or you could determine a properly working EQ, with the only defect a faulty VU meter. It IS "audio" so it can be prechecked audibly :-). I recommend also to changes the state of all of the switches and sliders while testing (aka listening to the test sound/music), so a "rotten" switch or bad contact can be traced immediately. And what I missed in your video was a final check of audio. Only after that step, I would do a thumbs up, not before :-)
great job, well explained. another bit of gear saved from the recycler one thing tho. i would recap it just do to it's age, and it should last many years make owner happy camper :)
man im so keen on making a carelson super probe now. and a curve tracer. ive been obsessed with clipping & saturation shapes recently and i cant believe i didnt know what a curve tracer was. its such a straight forward bit of gear too, but it tells you so much. and the super probe is genius. non-coupled signal sniffing. what a ripper idea. thanks mate you do an amazing job.
You can determine R and L channel on the schematics starting from the S.L.M. Jack. Tip is the left channel, so the right channel is the lower one in the schematics.
Wow, what a treat! There's always something cooking at Mr Carlson's Lab, but today you coincidentally covered the same model of equalizer my dad gave me which has a similar problem! I can't wait to work on it after seeing this video. I like the curve tracer you were using and the Super Probe was pretty cool. Your channel is an inspiration to me, the way you explain things make electronics fun and less daunting to learn. As always, keep posting awesome repair videos :)
Great video, man I have to build the super probe and curve tracer asap. Thanks Mr Carlson. Love your channel and being a patreon is a must! Best money I spend every month
What jerk would give this video a thumbs down? Someone sharing their valuable knowledge like this does not deserve a dislike. Anyway, thanks Paul as always for sharing with us. Good stuff pal.
What an excellent example and tutorial on the most useful devices for quick repairs! Many thanks Paul, for taking the time going along the schematics with us step by step. You're an awesome teacher!
So cool to watch you diagnose and repair this graphic equalizer ! You are quite the expert and I thank you for sharing your outstanding skills for others to learn from and enjoy on UA-cam.
Today you can get a small LCD oscilloscope for low frequency for like 20-40 dollars including shipping. It would be nice to make a curve tracer with one of those, but unfortunately they do not do X-Y mode... Usually they lack even an external trigger. Should someone find a little scope like that, but with X-Y mode and/or trigger input I would be very interested...
Thanks Paul. More invaluable coaching and instruction. I also agree with others in that you should bring the SuperProbe to market either in DIY kit form or finished product.
All thanks and credit to you Paul and 1/2 dozen excellent guys like w2aew, AA5R, Afrotech, Andreas, Andy Davis & a few other subject matter experts, who constantly share your wealth of knowledge and experiences with us.
Repairman's Syndrome is likely a loose connection. When being carried to the repairman, it gets tilted, bumped, shaken, and finally delivered. It's random whether the movement results in a good or bad connection each time.
Never heard it called repair man syndrome. But I work on cars and that happens all the time as soon as they bring it by the shop it quits acting up. Yes experience it many times now I know what to say to customers. Makes you sound like a doctor 👨⚕️. Excuses me sir I have to inform you your car has repairman syndrome. I’m gonna see what kinds of reactions I get. I hope that they don’t take it the wrong way.
At min 24: HP taught that was the "half/split method." I was a technician for 38 years at Raytheon and then an engineer for up to year 50 and it worked for me
Respected sir, I have seen lots of audio repairs uploads on UA-cam. BUT your upload is top of all those .In my opinion you well described, relaxed,well speech,through, well repaired videos.
this reminds me of when i fixed a DVR that refused to stay turned on - only had to open it up and reseat the front panel connector and it workes again perfectly :D
Another wonderful video. Almost root against you solving the problem because that's where it concludes. All of what was presented was fantastic but how much fun and learning it would have been had we made it into the equalizer sections? I don't think anyone could explain it better! Thanks for taking the time to make it I enjoyed every second.
On the circuit board I see oct 24 19?? Is it 1981 or 1987 ? I'm guessing 1981 judging from those old looking elna caps. Great video as always. You've got a great sense of humour most of what I enjoy about your videos and not to mention the clever work you show us.
Great vid. Love your non-intrusive test tools. With regards to which channel is which, there are a few conventions that can help people make good educated guesses. they all follow the convention left comes first, then right; - the channel drawn on the top is usually Left - if all the component numbers are odd numbers (eg TR101, R113), and the other even (TR102, R114) then the odd channel is usually Left. - if the channel component numbers all differ by a hundred (eg TR511, R512, C518 one side) vs (TR611, R612, C618 the other) then the lower hundred series is usually Left - if only one channel has signal path, component values, voltages all drawn in, and the other doesn't, the channel with the extra info is usually Left - if only one channel is fully drawn (and the other is only partially drawn, if at all), the channel drawn properly is usually Left. Awesome vid. Really enjoyed.
Hi Paul Happy New Year, It's great to see the Super probe in action,I'm about half way through the build, I look forward to the release of the mods to the block on Patreon. Paul
I must be having a slow day, or my brain is on vacation.....I saw what appears to be a signal tracer output (2 pins only, hence a mono signal) connected through a "Y" splitter to some "it does not matter which ones" RCA jacks on the back of a piece of audio gear that has inputs and outputs. No mention of WHICH RCA jacks were being connected to, but I assumed they were the left and right stereo inputs to the equalizer. The next thing I see is a knob being twiddled and a pronouncement made that, yes, the left channel is dead. Maybe I missed something, or maybe that signal tracer works differently from what I thought, but how to determine that the left channel of an audio device is dead only by checking the input, and also when both inputs are shorted together by the "Y" splitter? Mr. Carlson, please enlighten me!
Love this video Paul just the way you pursue a problem and solve it is just incredible I have to say this but you are so young but you have acquired so much knowledge and the equipment you have is just wonderful It's always a pleasure to watch you solve a problem and in such detail repair it
I have what is probably a previous version of that very EQ. It is simply called Sound Shaper Two and it has analog/mech level indicators. Aside from some of the switches needing cleaning, I use it to this day and and after around 40 years, I still like it! Glad to see with very little effort, they can be repaired! Thanks!
@@BruceNitroxpro Ha! I would if I could figure out a way to recap my ears! Sadly I can't hear any highs anymore! But along those lines, I do have a couple old Heath Kit amps and pre-amps that I used as a stereo years ago that definitely need recapping. No idea what kind to use though.
I worked at a job troubleshooting printer PCBs years ago. I miss the Huntron Tracker (dual trace curve tracer). Great tool. Very necessary as the manufacters would not release schematics to our company. Info on a lot of the printers was still confidential.
Thanks again Paul for another great video and for your Patreon course. I have learned a great deal and have been able to understand how different parts work together.
We used to sell and service SoundShaper equaliser back i n The early 70' and this one you repaired is so simpler than the first ones they designed! The had the power supply completely shielded from the rest of the circuitry and used at the first models germanium transistors, but I see their basic or original design hasn't changed to much. Keep videos like these coming , they are a pleasure to watch for a retired old engineer like me! :)
My Soundcraftsmen PE2217 Preamp-Equalizer is due for an overhaul. Time to get my hands in there and have some fun. Sliders have gotten sticky, and some electrolytic caps are on their last leg and thus are affecting the bandwidth at the low end.
Hi, just came across your channel. This is off subject sorry for that. My brother has a ICOM IC-746 that he lost all transmit , (not sure if he is able to RX) Have you come across a common issue with these rigs having such a break down? Any help would be appreciated. Thanks, WD9DWQ
@@MrCarlsonsLab OK very good I will pass that along we were theorizing that maybe it is the finals the 1st question I would have does that unit use the same finals for HF and VHF?
Absolutely amazing troubleshooting Mr Paul. This is the first I saw testing jfets, how great the curve tracer see inside the device. Wow, I really enjoyed. Best of the best video only in this channel👈👏👏👏👍👍
Hahah. Yup. Repairman Syndrome or The Magic Touch … I've a number of different test signal generators but my favourite AF sine source is an old analogue synthesizer's resonant filter (Roland SH-101). The self oscillation of the VCF gives a lovely smooth wave.
Dear Mr Carlson, Love your videos ! I'm catching up with them and learning a lot in the process, i was wondering, what radio would you suggest to find as a starter project that is not too hard to work on ? Thanks !
We can se that you are a great engineer. Congratulations for that wonderful scenario. People like you make the world a better place. Wish I had 1% of your capabilities. Thank you for your videos.
I had an Apple tech brake tabs off and leave pry bar marks on an Apple IIc computer because he did not know the proper way to open the case. It really got my goat. I love the channel. Keep up the great work. Wish I knew one tenth as much as you about electronics. I learned just enough to get a ham licence. Love the old equipment (boat anchors).
I feel as if I've learned more watching your videos than I did during the handful of mandatory EE courses I had to take at uni (I studied SE). Wonderful content.
Awesome video Mr. Carlson! Really appreciate the time you take to spread your knowledge. Watched the entire video with immense interest. Learn a lot. Looking forward to taking your course very soon. Cheers!
To say Bravo, great job, is redundant. You know, I know you are brilliant! It's the be brave to open the cover and troubleshoot the problem and don't give up creed! If you follow the signal, you will find where it starts and where it stops you will find the faulty component. Happy 2019, a great video to start the new year. Thanxz
Great video, Paul. Thank you very much! About addressing the L-R, 1-2 part on the schematic; Firstly if the manufacturer doesn't label this on the front plate, it doesn't help much if they label it on the schematic. A possible explanation can be that in a professional environment, "a stereo" EQ most of the time isn't used on the stereo output chain. Perhaps one EQ is inserted on the console channel 16 before recording and the second EQ is used on return 4 to the vocalist's headphone, as this often is a dual mono signal. Nevertheless, you are right, for troubleshooting it is unacceptable not to address the two parts especially if these aren't electronically identical. Heck, name it Anne & Rose if L-R, 1-2 can be confusing.
Where do you find your schematics? I've tried to find schematics for somethings I want to repair a few times and I'm never able to find what I'm looking for. I have an old Philips SBC 345 soldering station I would like to repair but I can't find a schematic to repair it. I do know it's a rebranded xytronic (the identification on the PCB). I have three issues to deal with to repair it, 1) I have a burned out resistor going to the LM324N op-amp (the resister has been removed so no chance to try to attempt to figure it's value out by other methods), 2) the is a trace which has lifted off the PCB 3) I need to get a new iron since the tip has fused to the old iron (should be a standard 24v 60w xytrontic replacement).
I appreciate you making these videos with a high megapixel camera. That way we can really see what's going on with the circuitry and individual components.
To learn about electronics in a different and very effective way, check out my Patreon page. Many of my designs are released there as well. Click this Link: www.patreon.com/MrCarlsonsLab
@HalfSpeedMastering -- In this particular case it certainly is same, since the FET in question has a pure and very brief pop-suppression function and is otherwise pretty close to a piece of wire in the signal chain. I would trust Paul 100 percent to avoid degrading or otherwise altering the audio performance of any gear he works on.
Gotta love this old school equipment. Very stylish scientific look to the dials, markings, and solid cabinetry. Reliable circuitry, and easy to work on. 🎛🎚🎚🎚🎚 👌😙
Could you help or enlighten me with component VSHPS1437_040050680, your help will be highly appreciated sir....thanks
May you should make a video about the carlson super probe instead, if it is so easy to use.
Quick question where did you get you desoldering tool. And or what is the brand name/ what is it called.
Thank you for your time and have yourself a grate day. 😁
This guy is the Bob Ross of the electronic world... "Let's put a happy little TRIAC right here."
:) lol
Interestingly, his voice is also similar...
@@Rob2 you are right, had to listen again. Very much like Bob. lol
@@Rob2 The voice of interminable patience.
its funny you might be right. i put on mr carleson to relax and go on adventures into vintage troubleshooting land. youre right. its an awesome quality and i hope he never changes. im gonna subscribe to his patreon i think
A super probe on a super channel.........Beautiful explained and implemented, simply the best tech/designer/teacher on UA-cam .
I don't find it tedious watching you take screws out because you always talk about interesting things while you do it!
Hi Paul, I am very excited to see your first repair video of the New Year. Nice to see you use the SuperProbe and the 224. I love both very much I have a Mod 222 which I think is very useful, yet not as useful as the SuperProbe I built using your brilliant design. Thanks again for all that you do and sharing your bottomless knowledge, along with your ingenious electronic inventions with us! Take care my friend and please never stop sharing your vast and practical knowledge with the electronics repair community. "Why be a rockstar when you can be a god?" applies to Mr. Carlson's Lab. It's funny, you have the youthful appearance of someone in their late 30's or early 40's and yet you posses 125 years worth of electronics knowledge and experience.
Thanks for sharing another electronic tutorial Paul. That was fun to watch.
Wow, I have the same ADC Equalizer that I bought in the mid 80's. still works great. Thanks for the video.
Me too. Love it.
@@sferg9582 Still have my ~40 year old one, a SS110 Mk. II, that I had given to me back when I was 14. That was in 1991.
Just fixed it today, now it works right :)
The sliders on mine does light up and no sound it hasn't been used in years
Amen brother. Don't know how many times someone sent in a radio saying xxx was wrong with it and the instant it got set on my bench it started to work again. Having been a heavy truck mechanic also many years ago I speak from experience when I say they suffer from the same problem to.
Ditto for computers and electrical installations.
@@Mariano.Bernacki For me the opposite happens. I test the damn computers for 2-3hours and the next day the client calls me that the thing stopped working.
The effect also happens with desktop support. Arriving at customers desk will sometimes solve the problem. I always used to say I was so good my mere presence solved the problem.
Truck driver to Radio tech: "It's the finals". Truck driver to Mechanic: "It's the EGR". -Former, recovering truck driver turn technician. Other favorites: "No, I bought it brand new! Nobody has ever been in there!(Covered in pry marks, stripped screw heads, missing screws, splatter-box, solder balls rolling around, cut diodes, over-sized caps...). "It just needs caps". (Burnt PCB around through holes, smoked resistors, some weird residue all over, is that a bobby pin? What is that smell? Is...is that urine? How the hell...). "I'll be back Thursday".(11 months later..)
@@sobolanul96, you mean the client failed to tell you that the computer was being used in a sauna? LOL
As an industrial electrician, that spent literally weeks fault finding and eventually repairing a marantz vintage amplifier, as a hobby at home, this was very humbling to watch and follow. Thankyou sir !
Same, I'm an industrial electrician and don't know as much about electronics as I should mainly because my PA system has 10, 15 band eq's and 2, 31 band eq's. Atleast one of them has an issue in rotation.
Meanwhile Mr. Carlson in the background still restoring Vedolyzer Supreme to GigaHertz capability... ;-)
Ulrich Frank, Pul-ease! You are cracking me up! [Rohde and Schwartz, beware!]
Great job! Once again, making it look all too easy! And once again thinking I need to build that Super Probe. I built a probe(with an actual germanium diode) and it works well, but the idea of a non-contact probe where one can just wave it close to the board and not having to locate and contact an emitter at some absurd angle is blissful. Curve tracer first, though. Op Amps are coming in from Digi-key as we speak. Your Patreon page has been the single best tool on my bench. I have been using your transistor tester, matching, biasing circuit for a while now and it never fails. I just let your videos play while I work and always learn something new, even if I have heard the video a couple of times.
Wow, freakin' awesome video. My first equalizer was an ADC Sound Shaper Two (with the VU meter) in 1978. Worked great but with three tape decks I eventually wanted a dubbing feature on the EQ. So in 1982 I purchased this model ($213). With bidirectional dubbing, large LED meters, a good subsonic filter (18dB/oct@15hz), THD and IM of 0.02% and great layout of controls I was pleased. My original EQ was given to my brother-in-law and he still uses it today. That's over forty years. My SS2 IC still functions perfectly and is used every time the hifi is on. Not bad for thirty six years old.
Some folks just don't understand how useful an equalizer can be. This video is very interesting and a definite keeper. The SS2 IC is an excellent EQ, functional and pleasing to the eye with that "industrial" look. Remember their first EQ?? The ADC 500??? Well worth an hour of my time to view this. Nicely done, sir.
This channel is one of my favorite YT channels. I love the vintage electronics porn.
Is it possible for this whole "porn" nonsense to be dropped, when referring to an area of interest which one likes? It sounds SO crude and ignorant, not to mention that it's just... unoriginal in the utmost.
Maybe...?
unlokia I agree 100%!
I agree with unlokia, there is nothing pornographic about this. To be frank Penfold8, I would like to quote Inigo Montoya, "I don't think that word means what you think it means."
This is pure electronics nerdvana, not something dirty at all and I would kindly ask that you refrain from referring to it as something it is not.
How about obscene or titillating or sexy? That okay Mom?
penfold8 - did you trigger somebody? bad penfold8.
Repairmans syndrome: I had case just before Christmas- dead guitar amp , guy supplied guitar and curly lead , but not the lead he was using apparently!
Sometimes we would joke, that the gear just needed a car ride to make it happy again...lol
Been an auto tech 30+ years.....my favorite: customer calls, gives symptoms, schedules to drop off. They come in the door with a confused look on their faces, "You're not gonna believe this but it just started running fine about a half-mile back." I reply, "Yep. Happens often, cars are terrified of me."
some one set a guitar amp out to the curb and I grabbed it. got it home, plugged in and played through it for about half an hour. Came back a few weeks later to play again and it was dead. Electronics are voodoo
Repairman's syndrome is REAL! My grandfather worked for Dictaphone way back in the day.
He had been called to a particular piece of equipment 8 times but had never found a problem when testing it.
After the ninth call he did something odd...he taped a picture of himself on the underside of the cover.
He retired 14 years later...having NEVER been recalled to work on that piece of equipment in all that time.
Love it!
I had the same EQ back in the day. I miss those component systems.
I’m sure this is going to be another great video and I’m looking forward to enjoying it over the next hour. It looks like nice unit, and these things could be useful in the right hands. Unfortunately, back in the day equalizers seemed to attract those that wanted overly-booming bass and overly-sizzling highs and not those that wanted to subtly correct for a room aberration or poor recording. I wish they had been designed with only +/- 4 dB of gain and not the typical 12. That’s more than enough, really, and would have kept people from destroying the careful sound that engineers take time to mix, while also saving amps, speakers and ears from damage. I can’t tell you how many times I got in a car back in the 80s and 90s, and was tempted to zero-out a friend’s equalizer. Nowadays, I’m still tempted, but the equalizer is buried in ten layers of GUI!
I don't think a lot of people understand the proper use of an EQ also. I use it more to remove frequencies rather than boost. Most people boost the crap out of it!
Flux Condenser, I have one with built in Spectrum Analyzer, which makes the unit a hoot to use.
Superbly efficient troubleshooting, very informative narration, and excellent video/audio clarity -- IOW, A+++! Thanks very much.
You can also figure out left vs right channels from that TRS jack on the left side of the schematic... 🤔
In theory, but not in practice... I've come across equipment in the past where left and right have been reversed in TRS jacks (usually Chinese origin, but not always). I've also recently come across numerous 3.5mm TRS to RCA leads with the colours reversed on the RCA jacks.
@@chrisg6597 well with those you must squint your eye's when testing! ;-p
@@kenhancock8931, B-b-b-aaad!
so true as Long as everybody uses them the conventional way… but Standards are if everybody does what he wants noone what he should but everyone is part of the game
TRS...reminds me of when I first worked for the Telephone company...1969...Tip was +, ring -, sleeve ground...that was a 48 volt DC situation...still is on landlines... most all telephone stuff is 48 volt DC and is powered by batteries, and diesel generator for back-up...
Mr. Carlson, the audio on your channel is outstanding, damn near the best on you tube.
I was just thinking that myself. Would love to see an episode where you give a tour of your audio video recording setup.
@@HarvardBob Good idea! I think he uses a Zoom H2 from memory for Audio
I'd like to know how Paul got so heavily into vintage as his specialty. It's really what sets this channel apart because much of the knowledge he presents is no longer taught and is slowly being lost. And yet, he doesn't come off as some nostalgic curmudgeon but rather he makes everything seem timely and relevant. They say with everything being so digital today, it's often the analog aspects of a circuit that are most half-assed and overlooked. This is where the tricks of the past could serve us well.
Near the best? No, Mr, Carlson is the best! Give me your superior reference.
Hello, Paul, and a very Happy 2019 to you! I trust you're not enduring ice-laden cables, and continuously cracking trees, this year? God bless you my friend.
Matthew. 🙂
Thank You Matthew!
Very intuitive video... Will check out your Patrion Page.... Thanks for sharing this professional troubleshooting techniques.... God Bless....
Welcome aboard!
Love your channel! You are an incredible tech. I used to calibrate analog aircraft instruments mostly rate of climbs and altimeters and we used to call it technician proximity syndrome. I haven't commented yet but have been binge watching your channel. I am also a ham. 67 yrs old and been a ham for 35 yrs. You have more knowledge about things than most people have forgotten. You and Nicola Tesla would have been the team to change the world. 73 de KB7ICI.
I had a very annoying fault with a Toshiba 29N5DXA flat screen crt that I've owned 20 years since new. When it was brand new it would randomly produce a loud high voltage crack and the tv would shut off. It would turn on again just fine. I took it back to the store where I bought it and they kept it for a couple of weeks sitting on a shelf running and of course it ran perfectly well, because if it failed they would have gave me a replacement. So I took it home and it ran fine for another few weeks before failing in the same way again. So off to the service man it went, where he could find no fault, so also kept it for a couple of weeks running without fault before returning it. A day later the tv did the same thing again, and I was told the only thing left to do was to keep using it until it finally failed properly and stopped working completely, because they were powerless to help if they couldn't witness the failure with the manufacturers warrenty. So the tv ran like that for a few more months until one day it made a much louder electrical crack, there was a wisp of smoke but this time the tv didn't shut down, and its never produced the fault again or had any problem since. It went back to the service man who again found no trace of the fault or replicate it. I can only assume a faulty solder joint somewhere got welded back into service.
Many years ago I had a 25" Sony console that did the same thing... a loud crack then shut down. Turned out the set had a safety circuit that activated when the HV exceeded 25 KV. This was supposed to prevent the CRT from emitting X-rays. Plugging the tv into a variac set to 115V solved the problem, but it tied up my variac.
Sounds like that last loud crack may have pooched your tv's safety circuit, if that was the cause.
Jedda73 I wonder if you had a lot of flies in your home? Wink, wink!
Those old Sony's were notorious for having bad H-stat blocks which would cause intermittent shutdown problems.
A pleasure to see a master at work.
Thank you for uploading extremely informative videos that inspire, help, motivate, and bring pleasure to people all over, and in a professional, calmly hypnotic manner. You deserve a lot more subs!
Paul,
I am not a repairman, just a very long term interested bystander.
Rather than apologise you should promote the use of a signal injector and tracer. Back in the day that was all that many amateurs, and indeed some shops, could afford. I've still got mine - though they aren't as well designed or as capable as yours.
regards
Dave
ADC one of the best sounding EQ ever made !
You did not explain the reason the part failed. A reason explained or understanding could lead to any future returnes for the same reason.
There's really no way to say why it failed. If there was a power supply problem, it would have shown up during his other tests, and if one of the caps or resistors had died it would have shown up too. It basically comes down to the device being 30+ years old, and that component just got tired and stopped working.
Dan Todd, Good premise, but it would be a guess. Paul deals in facts. If the circuit promoted the failure, I'm sure he would have pointed it out. It was a low level failure, and an odd one, at that.
Dan, there's the what else in the circuit caused it to fail in this case probably nothing or what failed in the fet. There are very spendy x-ray strip the epoxy and sem type services when you really need to know. They'd show you things like esd causing a latent defect etc.
Given enough time in service, EVERY electrical component will fail. It's just a matter of when and with what severity. So....the question isn't why a part failed as much as it is when the remaining components are likely to go.
Well, while viewing the entire video I also wondered why he did not spend time explaining- or looking for- why it failed.
In general, capacitors can die of old age, resistors (especially old ones from way before this thing was made) too, but when "a little FET" like this fails there usually is an external reason for it.
That reason can be lots of things, but "getting tired" or "lifetime" is usually not it.
I learned alot from this video here. I learned how to divide a schematic to break it down to areas of concern. Also about Jfets and what the signals mean. I'm headed over to the pahtheon page to check it out. Thanks again.
A practical approach to audio or video equipment troubleshooting/repair: I think the determination of a (the) faulty channel could be done much quicker by a simple "audio in and out" setup. With a cheap mp3/music player, a powered speaker (I have one on my bench always ready to rumble) and a set of RCA cables this would take literally 20 seconds. No need to disassemble anything. From there the search could go on. Or you could determine a properly working EQ, with the only defect a faulty VU meter. It IS "audio" so it can be prechecked audibly :-). I recommend also to changes the state of all of the switches and sliders while testing (aka listening to the test sound/music), so a "rotten" switch or bad contact can be traced immediately. And what I missed in your video was a final check of audio. Only after that step, I would do a thumbs up, not before :-)
great job, well explained. another bit of gear saved from the recycler
one thing tho. i would recap it just do to it's age, and it should last many years make owner happy camper :)
You are truly gifted in electronics. I'm envious. Thank you for all of your videos.
You are very welcome!
man im so keen on making a carelson super probe now. and a curve tracer. ive been obsessed with clipping & saturation shapes recently and i cant believe i didnt know what a curve tracer was. its such a straight forward bit of gear too, but it tells you so much. and the super probe is genius. non-coupled signal sniffing. what a ripper idea. thanks mate you do an amazing job.
the super probe we already have in electrical installations ..we call it a fuse finder..
You can determine R and L channel on the schematics starting from the S.L.M. Jack. Tip is the left channel, so the right channel is the lower one in the schematics.
Wow, what a treat! There's always something cooking at Mr Carlson's Lab, but today you coincidentally covered the same model of equalizer my dad gave me which has a similar problem! I can't wait to work on it after seeing this video. I like the curve tracer you were using and the Super Probe was pretty cool. Your channel is an inspiration to me, the way you explain things make electronics fun and less daunting to learn. As always, keep posting awesome repair videos :)
Great video, man I have to build the super probe and curve tracer asap. Thanks Mr Carlson. Love your channel and being a patreon is a must! Best money I spend every month
"stranger things have happened here"
Is it Mr Carlson's lab, or the Hawkins National Laboratory? :)
What jerk would give this video a thumbs down? Someone sharing their valuable knowledge like this does not deserve a dislike.
Anyway, thanks Paul as always for sharing with us. Good stuff pal.
The people who designed it.
haters be hatin'
"No cats?! Thumbs down!" LOL
@@TheHermitHacker, FUNNY you were thinking exactly what I was thinking! LOL
and i thought i got alot of thumbs down, just for my channel name,lol, Carlson seems like one of the smartest electronic guys on YT !!!!!
What an excellent example and tutorial on the most useful devices for quick repairs! Many thanks Paul, for taking the time going along the schematics with us step by step. You're an awesome teacher!
Thanks for your kind comment Ralf!
So cool to watch you diagnose and repair this graphic equalizer ! You are quite the expert and I thank you for sharing your outstanding skills for others to learn from and enjoy on UA-cam.
Today you can get a small LCD oscilloscope for low frequency for like 20-40 dollars including shipping.
It would be nice to make a curve tracer with one of those, but unfortunately they do not do X-Y mode...
Usually they lack even an external trigger.
Should someone find a little scope like that, but with X-Y mode and/or trigger input I would be very interested...
Thanks Paul. More invaluable coaching and instruction. I also agree with others in that you should bring the SuperProbe to market either in DIY kit form or finished product.
Thanks for your input!
All thanks and credit to you Paul and 1/2 dozen excellent guys like w2aew, AA5R, Afrotech, Andreas, Andy Davis & a few other subject matter experts, who constantly share your wealth of knowledge and experiences with us.
*ah yes.. the EQUALIZER, that 1980s 'must have' audio component that EVERYONE set to the "V" standard....*
Repairman's Syndrome is likely a loose connection. When being carried to the repairman, it gets tilted, bumped, shaken, and finally delivered. It's random whether the movement results in a good or bad connection each time.
You da man paul! Hope you have a great day!! ;-)
Never heard it called repair man syndrome. But I work on cars and that happens all the time as soon as they bring it by the shop it quits acting up. Yes experience it many times now I know what to say to customers. Makes you sound like a doctor 👨⚕️. Excuses me sir I have to inform you your car has repairman syndrome. I’m gonna see what kinds of reactions I get. I hope that they don’t take it the wrong way.
At min 24: HP taught that was the "half/split method." I was a technician for 38 years at Raytheon and then an engineer for up to year 50 and it worked for me
Respected sir, I have seen lots of audio repairs uploads on UA-cam. BUT your upload is top of all those .In my opinion you well described, relaxed,well speech,through, well repaired videos.
this reminds me of when i fixed a DVR that refused to stay turned on - only had to open it up and reseat the front panel connector and it workes again perfectly :D
Another wonderful video. Almost root against you solving the problem because that's where it concludes. All of what was presented was fantastic but how much fun and learning it would have been had we made it into the equalizer sections? I don't think anyone could explain it better! Thanks for taking the time to make it I enjoyed every second.
On the circuit board I see oct 24 19?? Is it 1981 or 1987 ?
I'm guessing 1981 judging from those old looking elna caps.
Great video as always.
You've got a great sense of humour most of what I enjoy about your videos and not to mention the clever work you show us.
1981 for sure.
Another great video Paul...love the super probe...uber cool
73
Jeff de WD8JM
I am completely naive to the world of electronics but you present in such a way that makes it easy to understand.
Greetings from Sweden Mr. Carlson . And it´s always great fun & joy to watch your channel . . . :o) .
Great vid. Love your non-intrusive test tools.
With regards to which channel is which, there are a few conventions that can help people make good educated guesses. they all follow the convention left comes first, then right;
- the channel drawn on the top is usually Left
- if all the component numbers are odd numbers (eg TR101, R113), and the other even (TR102, R114) then the odd channel is usually Left.
- if the channel component numbers all differ by a hundred (eg TR511, R512, C518 one side) vs (TR611, R612, C618 the other) then the lower hundred series is usually Left
- if only one channel has signal path, component values, voltages all drawn in, and the other doesn't, the channel with the extra info is usually Left
- if only one channel is fully drawn (and the other is only partially drawn, if at all), the channel drawn properly is usually Left.
Awesome vid. Really enjoyed.
Great job Mr. Carlson. Old school gear lives on. I've had a smaller version ADC EQ forever and it still works.
Wait, I have this exact EQ in my basement right now... I’m definitely glad I saw this video, thank you for posting it!
I don't understand any of this, but dang, I love this channel!
Hi Paul Happy New Year, It's great to see the Super probe in action,I'm about half way through the build, I look forward to the release of the mods to the block on Patreon.
Paul
You're welcome Paul, and Happy New Year!
One of the best channels on UA-cam! Thanks for a great video!
Great video, excited to start my classwork on filters after watching this.
I suggest always using the CARLSON PROBE on the 2nd video of fixing the same type of system you already fixed in a previous video
Keep on suggesting! :^)
Very watchable, educational and inspiring vid - as usual. Thanks.
Hi Mr. carson, i love your videos! they are just great! My question: Could you say someting about why these components fail?
this is amazing. World Radio Repair Championships are needed
I must be having a slow day, or my brain is on vacation.....I saw what appears to be a signal tracer output (2 pins only, hence a mono signal) connected through a "Y" splitter to some "it does not matter which ones" RCA jacks on the back of a piece of audio gear that has inputs and outputs. No mention of WHICH RCA jacks were being connected to, but I assumed they were the left and right stereo inputs to the equalizer. The next thing I see is a knob being twiddled and a pronouncement made that, yes, the left channel is dead. Maybe I missed something, or maybe that signal tracer works differently from what I thought, but how to determine that the left channel of an audio device is dead only by checking the input, and also when both inputs are shorted together by the "Y" splitter? Mr. Carlson, please enlighten me!
Love this video Paul just the way you pursue a problem and solve it is just incredible I have to say this but you are so young but you have acquired so much knowledge and the equipment you have is just wonderful It's always a pleasure to watch you solve a problem and in such detail repair it
Have a adc equalizer similar to that one the difference is the spectrum analyizer
I have what is probably a previous version of that very EQ. It is simply called Sound Shaper Two and it has analog/mech level indicators.
Aside from some of the switches needing cleaning, I use it to this day and and after around 40 years, I still like it!
Glad to see with very little effort, they can be repaired!
Thanks!
Throw Me Back, You may consider recapping it, also. That is a circuit long in the tooth.
@@BruceNitroxpro Ha! I would if I could figure out a way to recap my ears! Sadly I can't hear any highs anymore! But along those lines, I do have a couple old Heath Kit amps and pre-amps that I used as a stereo years ago that definitely need recapping. No idea what kind to use though.
The modest demeanor is incredible. Awesome work!
The Super Probe is incredible. Thanks for making this video.
Nice scope! I have a little Tektronix 212. Great scopes!
Professor Carlson, I got my snack... let's do this!
I worked at a job troubleshooting printer PCBs years ago. I miss the Huntron Tracker (dual trace curve tracer). Great tool. Very necessary as the manufacters would not release schematics to our company. Info on a lot of the printers was still confidential.
Thanks again Paul for another great video and for your Patreon course. I have learned a great deal and have been able to understand how different parts work together.
We used to sell and service SoundShaper equaliser back i n The early 70' and this one you repaired is so simpler than the first ones they designed! The had the power supply completely shielded from the rest of the circuitry and used at the first models germanium transistors, but I see their basic or original design hasn't changed to much. Keep videos like these coming , they are a pleasure to watch for a retired old engineer like me! :)
Thanks for sharing your story!
My Soundcraftsmen PE2217 Preamp-Equalizer is due for an overhaul. Time to get my hands in there and have some fun.
Sliders have gotten sticky, and some electrolytic caps are on their last leg and thus are affecting the bandwidth at the low end.
Hi, just came across your channel. This is off subject sorry for that. My brother has a ICOM IC-746 that he lost all transmit , (not sure if he is able to RX) Have you come across a common issue with these rigs having such a break down? Any help would be appreciated. Thanks, WD9DWQ
Yes it is, but it could be a number of things. If it still receives, it may be the RF finals.
@@MrCarlsonsLab OK very good I will pass that along we were theorizing that maybe it is the finals the 1st question I would have does that unit use the same finals for HF and VHF?
Absolutely amazing troubleshooting Mr Paul. This is the first I saw testing jfets, how great the curve tracer see inside the device. Wow, I really enjoyed. Best of the best video only in this channel👈👏👏👏👍👍
Thanks Roy!
Hahah. Yup. Repairman Syndrome or The Magic Touch …
I've a number of different test signal generators but my favourite AF sine source is an old analogue synthesizer's resonant filter (Roland SH-101).
The self oscillation of the VCF gives a lovely smooth wave.
Dear Mr Carlson, Love your videos ! I'm catching up with them and learning a lot in the process, i was wondering, what radio would you suggest to find as a starter project that is not too hard to work on ?
Thanks !
We can se that you are a great engineer. Congratulations for that wonderful scenario. People like you make the world a better place. Wish I had 1% of your capabilities. Thank you for your videos.
Man, you are fantastic. Amazing good video. Thank's a lot. Don't forget to mark the L and R channel on the schematic :D
I “totally resonate” with you. This channel is great.👍
Holy moly! Look at the lab this mad alien being has! wow!
Mr Carlson generates very high quality spoken word Sound, I understand he uses an Australian made valve Rode Microphone Rode make great quality Mics!
love vintage electronics n Jesus educational videos
I had an Apple tech brake tabs off and leave pry bar marks on an Apple IIc computer because he did not know the proper way to open the case. It really got my goat. I love the channel. Keep up the great work. Wish I knew one tenth as much as you about electronics. I learned just enough to get a ham licence. Love the old equipment (boat anchors).
I feel as if I've learned more watching your videos than I did during the handful of mandatory EE courses I had to take at uni (I studied SE). Wonderful content.
Great to hear!
“Repairman syndrome” is a THING ? I have been in computer repairs for 30 years, and I always thought it happened to me alone ! 😱
Awesome video Mr. Carlson! Really appreciate the time you take to spread your knowledge. Watched the entire video with immense interest. Learn a lot. Looking forward to taking your course very soon. Cheers!
To say Bravo, great job, is redundant. You know, I know you are brilliant! It's the be brave to open the cover and troubleshoot the problem and don't give up creed! If you follow the signal, you will find where it starts and where it stops you will find the faulty component. Happy 2019, a great video to start the new year. Thanxz
Great video, Paul. Thank you very much! About addressing the L-R, 1-2 part on the schematic; Firstly if the manufacturer doesn't label this on the front plate, it doesn't help much if they label it on the schematic. A possible explanation can be that in a professional environment, "a stereo" EQ most of the time isn't used on the stereo output chain. Perhaps one EQ is inserted on the console channel 16 before recording and the second EQ is used on return 4 to the vocalist's headphone, as this often is a dual mono signal. Nevertheless, you are right, for troubleshooting it is unacceptable not to address the two parts especially if these aren't electronically identical. Heck, name it Anne & Rose if L-R, 1-2 can be confusing.
Where do you find your schematics? I've tried to find schematics for somethings I want to repair a few times and I'm never able to find what I'm looking for.
I have an old Philips SBC 345 soldering station I would like to repair but I can't find a schematic to repair it. I do know it's a rebranded xytronic (the identification on the PCB). I have three issues to deal with to repair it, 1) I have a burned out resistor going to the LM324N op-amp (the resister has been removed so no chance to try to attempt to figure it's value out by other methods), 2) the is a trace which has lifted off the PCB 3) I need to get a new iron since the tip has fused to the old iron (should be a standard 24v 60w xytrontic replacement).
You are so technical good :)
Genius. That signal probe thingamajig is genius.
Repairman's syndrome is a real thing! I've had shit magically fix itself just on the trip to the workbench.
In the 80s, I had *Mr. Wizard's World.* Today, I have *Mr Carlson's Lab.* Life is good! 🤗🎙️📻
You are a great instructor and do an excellent job producing your videos, keep up the great work.
I appreciate you making these videos with a high megapixel camera. That way we can really see what's going on with the circuitry and individual components.