1960's Rauland-Borg 32W Amp Conversion.......Resistance is Futile ;)
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- Опубліковано 16 чер 2019
- In this video, a 1960's Rauland-Borg Model RA32 PA amp is converted into a guitar amplifier. The conversion is quite challenging, requiring re-engineering of the input, volume, and pre-amp circuits; mapping of the output transformer, wiring of 4 and 8-Ohm speaker jacks, removal of three extraneous sockets, replacement of all electrolytic caps, conversion of the fixed negative DC grid bias circuit to adjustable bias, addition of an adjustable NFB loop, and replacement of the 3-wire power cord, as well as several cosmetic improvements. After all the modifications are completed, the amplifier receives a thorough audio testing at the paws of Jack and Ollie.
Extra features include a brief visit from both Jack and KC, as well as a seismic, high-decibel audio demonstration of the Legend Rock & Roll 50 amp from a previous video.
If you enjoy advertising-free videos such as this, then please subscribe to our channel and consider becoming a Patreon patron at / uncledougsvintageamps or making a PayPal donation to dldcam@aol.com. Donations of vintage tube gear are also welcome, possibly to be featured in future videos, as this donated amp was.
Thanks for watching !!!
It has been brought to my attention that in my hand-drawn input circuit diagram, I show the 1Meg grid leak beside the 12AX7 grid rather than connected to the input jack itself, as I actually wired it. In practice, it is best to keep the grid-blocker (not grid-leak) as close as possible to the grid. I guess this is a good, slightly modified, example of the old saying: "Do as I do, not as I draw" :)
I think most or us meant what you know(8-). I was thinking about when you hooked up the signal to the wiper of the volume control...then later changed that by
hooking the grid to the wiper. "Hmmm, I wonder if that will screw up the fact that it's a log taper pot and not a linear taper." But the thought occurred to you
before I could type anything(8-).
As for the volume control existing right off the git go...I was of a mind that it was probably application driven. Like, there was something else up stream of that amp.
Musac (elevator music vendor) tuner or some other source for annoying racket, maybe(8-). Oh...just looking below at Norm's comment...(8-)
@@tomfrye9037 ...That pot was most surely a replacement (Gibson?? LOL). All of those institutional application amps used a screwdriver to adjust levels, so somebody had their fingers in there prior to your sending it to Doug. Fortunately, as you mentioned, the right guy ended up with it! :-) With experience as my guide, I probably would have welded a chain to one of the rack mount holes and used it to keep my fishing boat from drifting!! Kudos to Uncle Doug for patience and willingness to accept a challenge!
@@normjacques6853 I replaced the pot, added the input jack and tried a 3 wire cord grounded to the chassis. I got a lot of hum, so I cut the green wire. I did not
ground the internal "bus" to the chassis (which would have cured the hum) because I wasn't finished with poking around in the rest of the circuitry. I never
got much chance to do that...too may people pestering me...so I sent it to Uncle Doug without further alterations. U.D. can dive head first, ankle deep into
something like that amp...and come up smelling like....soldering flux(8-).
Uncle Doug, series resistance or parallel resistance, grounded or not, "resistance is futile. You will be assimilated!" Sorry, that is a Star Trek joke. I haven't even watched the video yet, but the Borg thing was just too good to pass up!
Thanks for all the great comments, guys. I try to show the entire repair/conversion process, and it rarely goes exactly as planned. It's important for budding electronics techs to realize that you have constantly double check your work and make changes as needed. The most important thing is not to rush through the job, but to optimize the final outcome.
I ejected most of a previously tasty sip of coffee through my nose when I saw the topic of your latest video!! I spent more years than I care to count servicing and installing Dukane and Rauland systems and components in hospitals and schools. That one, if memory serves, came form a school intercom system, and served as a program and/or 'all-call' amp. They operated strictly with a 600-ohm line input, but had outputs for 4, 8, or 16 ohms, and 70- or 25-volt distributed (most often 25V, in school intercom) outputs. The octal receptacle was for speaker (impedance) selection, and the 'mystery' plug provided for external switching, usually to interrupt ongoing announcement or program by a higher-priority signal. These things were full of special little 'trick' circuits of that sort, and were sometimes integrated with fire alarm systems. Since retiring, the nightmares are slowly going away. :-)
Wow.....thanks so much for your very detailed and informative input, Norm. It's always great to hear from you :)
I feel for you on the coffee spewing issue, Norm. Been there, done that...makes a great mess(8-/. I too thought the bundled output wires may have been options for
"long haul" noise and racket distribution. I did google Rauland Borg...as Uncle Doug did. So I knew about their products. I just have no good place or enough peace
and quiet to work on the thing...so I left it to the man who can turn a toaster into a damned fine amp...our Guru to the Gurus, Uncle Doug.
@@UncleDoug One of the benefits to having a great channel...having guys like Norm who're willing to risk spraying coffee all over to provide more great data.
Makes sense, I suspected it would be supporting a 25V and/or 75V wired intercom system.
@@tomfrye9037 ...Only downside is cleaning it up! LOL It's kind of oddball equipment, and there aren't many that work on it routinely, so any help I can lend is given with a huge smile! :-) Uncle Doug is the real 'Wiz' for getting to the bottom of it!
Hi Uncle Doug! I am an old frustrated guitarist who had the bright idea of turning an old Knight 3235 PA amp into a guitar amp. I wasn’t sure how to do it since I knew very little about electronics. Then serendipity happened and I found your channel. I began to understand a little and eventually saw this Rauland Borg conversion. It’s practically the same design and was also made in Chicago. Same tubes and a can capacitor. I pulled the can and ordered four caps to replace it. I don’t know if I’ll need all of them but I will try it out and see if it works. Thanks for the inspiration! You’re a great teacher.
You're quite welcome, Ed. Best of luck with your conversion project.
I finally got all the parts and got into the amp. I modified the input and replaced the filter caps, adding a new power cord. I plugged it in and tried it out. It works! Now to figure out the source of the annoying hum and find a better speaker. My current limiter lights up a bit but the 2 amp fuse doesn’t blow. Thanks for your videos!
@@edrushbrook Congratulations on your early success, Ed. Keep at it and you'll end up with a great amp. The slight glow sounds appropriate for the wattage of the amp.
Bless you Uncle Doug for sharing your wisdom with us all!!! You are part of our family. We all look forward to hearing you explaining how things work and you always make us happy hearing you play the guitar. We also love watching you use your detective skills to find problems. Your amazing.
Wow, thanks so much, F1. We really appreciate your kind words :)
I have just "tried out" about ten of your videos by now. The first came recommended by Y-T and so I gave it a shot; and I'm glad I did. What makes your channel good I M O, is the slow pace, interspersing the videos with some theory, cats and whatnot. I'm a computer/electronics/electrical engineer both by trade and private and also like technical history so your channel is now something I enjoy every now and then along with 'mr Carlsons lab'. A very genuine channel you have here!
A friendly hello from me (in Sweden) and keep up the good work!
Greetings and welcome to our channel, Matthias. We appreciate your kind words and hope you continue to enjoy our videos.
Uncle Doug! You loved and grew this baby into a wonderful adult. The ugly duckling becomes a swan.
Your gigantic experience and knowledge brought this project to an awe inspiring conclusion.
Wow, thanks so much, IL :)
Doug, You are amazing, Your knowledge of old valve amps/equipment is mind boggling....Thank you for sharing your knowledge.
Thanks so much, O. It's a pleasure to do so :)
I learn so much every video of yours I watch. Your knowledge level of vintage electronics is nothing short of astounding.
Thanks so much, Bill. You are more than kind :)
Great video. Your knowledge and experience really show in this conversion. Really great work. A real joy to watch. Thanks once again for posting such great content.
You're quite welcome, Ima. Thanks !!!
What a fantastic PA to guitar amp conversion, Uncle Doug !
That is a great sounding amp you created, very Bassman 5F6-A/ JTM -45 like in its tone .
You knocked this one out of the ball park, Uncle Doug, super video !
Thanks so much, Jay. We really appreciate it.
UD, great job, great looks and most importantly great sound. I've seen similar conversions placed in a milk crate and set up for easy portability and easy 1x12 speaker switch outs (something to consider) keep up the great work.
Thanks so much, Paul. We will :)
Uncle Doug is a genius and an artist! This was an especially impressive and interesting episode. And the aesthetics of the final amp are beautiful.
Uncle Doug, your skill and knowledge are second to none and your taste is impeccable!
Wow....thanks so much Steven. You are too kind :)
As we have now come to expect an absolute class act conversion from you Doug,the PA amp sounds amazing ,with only a volume control ! And the Legend ,pure Rock and Roll, its a privilege to be watching your channel !
Wow, thanks so much, Meirion. We're really glad you enjoyed it.
Uncle Doug,
You've officially become my favorite person. God bless whatever part in you that decided to record and document your work. I'm probably half way through all of your videos and have learned a great deal about amplification, and a great deal about how to approach problems with a good sense of humor. I'd still love to see you work on a Dynaco hi-fi amplifier, but I know I know. I found you through the one and only Fazio amp repair, shout out to Fazio.
Thanks, Jules. We're glad you found us and enjoy our videos :)
hello uncle Doug,
thanks so much for taking the time of producing so many educating videos in vintage electronics and for taking the time of explaining the circuits and they work, i really appreciate it. God bless you sir!
You're quite welcome, 4H. Likewise on the blessing.
Amazing job on this one, Uncle Doug! I love the tone. You were born to mod and I was born to rack my brain trying to follow your thought process and figure out how you know so much, in spite of the excellent job you do explaining it all. Guess I better just keep watching...
Thanks, Greg.
Great video Doug. Conversion amps can be jewels in the making,and this one is just that.Thanks buddy!😎🎸🔌
You're welcome, Bob. Thanks !!!
Just before I thought I'd seen it all. That was a great conversation. I've learned so much from your channel. Thank you Uncle Doug.
You're quite welcome, Bill. That's great to hear.
Really nice conversion. Thanks for walking us through!
You're welcome, Daniel.
Wonderful journey on this one. So much good information Doug, hopefully there are some young(er) folk coming on board for these excursions. Guitar amps are rather like the last vestiges of the tube era. As you've been doing with guitar amps, I've been revamping old tube mic preamps for use in today's project and home studios. The way I see it, there are so many electronic amps of the past that can gain new life and service - pretty good for something made so long ago that it's on the downward slope towards a century of existence!! Love the videos!
That Rauland-Borg has a tuneful, smooth voicing! 33watts is plenty of horsepower for most situations. Always a great way to start the day! Thanks Doug!
You're welcome, KM. I agree with your assessment of the tone.....it is very warm and pleasant......unlike the Legend monster-amp :)
@@UncleDoug
Not to sound like Mister Rodgers Neighborhood but I wish you were my neighbor. Would love for you to see my big '65 Maggie built Lyric 260/262. It still has its 6L6 RCA power tubes and compliment of original preamp/rectifier tubes. It is with great shame that I have to report that it hasn't the ubiquitous white paint dots that make it professionally qualified though :(
I would love the opportunity to see and hear any Magnatone 260, KM, white spots or not :) They are one of the best amps ever made, in my opinion.
Very clear tone. Nice job Uncle Doug!
Thanks, Ken.
I just want to say I really appreciate your videos. I'm trying to troubleshoot some issues with my tube amp and your videos have been a wonderful resource. Thank you!
You're welcome, Brandon. We're glad the videos are helpful.
Hi Uncle Doug,
Here I am tardy again, been a busy week. I had to run the scoreboard at a Tee-Ball game for 5 year olds again, always fun watching my grandson stomp on home plate. Great conversion video. Unusual amp to start with. I seem to remember seeing a photo with similar amps in a 19” rack (about eight amps in the rack) with the inputs sort of in a daisy chain arrangement (in actuality they would be paralleled) from top to bottom, with the bottom amp’s 2nd input having a phono plug with a termination resistor in it. It was a public address system for an Air Force base, each amp fed speakers for different buildings and hangers at 70 or 100 volt speaker line voltage. Each amp also had a local speaker output that went through a multi-position selector switch to allow setting levels and checking for distortion. That might explain the extra set of secondaries, or they could have been there for driving a tape recorder input who knows? The 6AV6 was a very often used detector/audio tube in AM receivers. Would have also been a common tube on an Air Force base spare parts inventory. High gain like a 12AX7 just only one triode. Definitely, an odd design, purpose built amp, no doubt. Your redesign of the circuit was great. The addition of the adjustable bias and negative feedback really elevated the over all design. One question, would splitting the negative bias with two pots for individual bias controls for each 6L6 GT have given you the ability to balance the plate dissipation of the tubes?
I just loved the finished look.
I also love the cabinet of the Legend amp. The only thing about it is, it makes me laugh when I look at the speaker grill. I swear I have parked my butt on many a kitchen chair with that same ratan cane covering on the seat. Got to admit it is durable. Great video, superb conversion, love that Supro speaker cabinet that you saved from ending up in a landfill it turned out beautiful and sounds wonderful. Have a great weekend!
I always look forward to your analysis of a video, Mark. Your discussion of the Air Force PA system was quite interesting, and I appreciate your nice comments regarding the R-B conversion. Yes, I could have provided two bias adjustment pots to permit virtually perfect matching of the 6L6's. Perhaps I'll do that in a future video. Thanks again for your time, interest, and input.
So, so impressive. Man, I wish I had your knowledge of electronics Uncle Doug.
Thanks, John.
Another great video UD!! Perfect timing as well, I just this past week picked up a Bogen Challenger CHB 50 PA amp on ebay for like 40ish dollars! The case while looking a little worse for wear is not dented or warped just a little grungy and rusty., I was just yesterday thinking I needed to go back through your old videos to find a conversion tutorial and here you upload exactly what I was looking for! Thank you so much for sharing your vast knowledge with us on all things tube related!! Also, the Legend is awesome! Very cool amp, they both sound amazing! And yes...resistance is futile...or voltage divided by current, lol
Thanks so much, Jack. Best of luck with your Bogen project.
Cool amp rebuild thanks. I have an old Bogen P.A. amp to convert. I use a Roland Blues Cube on stage. Works really well for what we play these days but still having a tiny tube amp is fun.
You're welcome, David. Best of luck with your project.
Great job with the conversion. the legend is a very cool amplifier, from what I know it's the amplifier that Billy F. Gibbons used on the eliminator album. I pulled up a few of the songs while the cats were playing and it does sound very similar. Great video once again.
Thanks for your comments and observations, Stephen.
Thanks hope you and the little 1's have a great day!!!!
You're welcome, Ken. We do.....every day :)
That is one GREAT-sounding amp! Rich and full, bright and clear! Uncle Doug, you've done it yet again.
Thank you kindly, Dave.
I bet on my favorite guitar - The Borg-Queen would be very amused! :-)
Very nice conversion, looks great and sounds fantastic. Thanks for taking time to document the work. The Legend is ready for a smokey bar, very raunchy (in a good way).
You're welcome, Andrew. Thanks !!! I agree :)
Another awesome Dan-O-sonic has been born ! Doug, that was really nice work. And it sounds really good too !
Thanks so much, Jason :)
Wow, that was one of the best tone amps I've heard in a long time, I'm jealous. Excellent video! I also liked when you hit that old Beetles "Come together" riff. Man, talk about bringing back old memories. I have completely forgot about that song. As a matter of fact, I think I still have the 45RPM laying around here somewhere. God bless you man, and keep these interesting videos coming. I look forward to everyone.
Thanks so much PJ. We're glad you enjoyed the video and the demo. Likewise on the blessing.
Kudos UD another interesting video, thanks for sharing your bountiful knowledge!
You're welcome, James :)
Doug: *thanks*! I finally managed to understand something about how to determine the correct impedance of a speaker based on reflected impedance! Awesome contribution as usual!
You're welcome, Fabio. I'm glad the video was helpful.
Loved the video Doug, this amp sounds like one of the best you've played on the channel.
I would also have loved to see more of how you fabricated the hardware or even the soldering work, even if it needed to be split into two videos.
Thanks so much, Darren. I'll keep your requests in mind.
Wow. Whow wouldnt love to play through this amp. Very nice job Uncle Doug
Thanks, Monty :)
Great video Doug. Thanks for posting.
Great video! So full of info, it’s basically a review of “how an amp works”. 👏🏼👏🏼👏🏼
Glad you enjoyed it, 2T :)
A very interesting rebuild! Thanks one more time!
You're welcome, Michael.
Another video with great info! Thanks and greetings Uncle Doug!
You're quite welcome, Janne.
Wow, this one sounds awesome! More crisp and clear than dedicated guitar amps. I love the new riffs.
Thanks so much, JG :)
Nice tubes! Their technological distinctiveness has been added to our own.
Thanks, TP :)
Nice one young man, keep tinkering, and we'll keep watching.
Thanks, JJ. It's a deal :)
Hi Doug, wow just in time, bought a new monitor, and now testing it using your video...great! :)
I hope you like it, TC :)
@@UncleDoug of course i do....as always :) :) :)
You are most kind, TC. Thanks :)
As always learning from and loving your video, man that tube data binder looks sweet! Thanks for another swell video U D!
You're welcome, Gao :)
Listening to the amp makes me feel as if the amp isn't getting to do more. I was envisioning that puppy pushing 4 eight inch speakers. Great video UD!
Thanks, JJ. Heck, it could push four 10" speakers ala Fender Bassman, and probably sound wonderful doing it.....but I just didn't have such a speaker cabinet handy.
Really enjoyed this video. Lots to learn. Very informative.
That's good to hear, Alastair.
Very interesting, I wish I could or had time to do the fantastic work that you and others do.👍
Thanks, Ralph. Sometimes you just have to take the time :)
Nice work as always Uncle Doug!
Thanks, GS.
Thank you so much for all these great videos .
You're welcome, KC.
great video Doug! installing a jewel light for power would be the finishing touch on this amp
Thanks, Ash. I thought the tubes themselves were the simplest, best pilot light(s).
Beautiful work uncle Doug.
Thanks, John.
You are an amazing human being Uncle Doug!
Wow.....thanks, Kenny. We appreciate it :)
You were having way too much fun with that Legend.
The cats went nuts with it. The volume and power are intoxicating.
Excellent Doug, You're an inspiration.
Thanks, Michael.
Brilliant work sir! strip it down leaving the bare bones and add a bias control pot! very very nice!
Thanks, David. I'm glad you enjoyed it.
It sounds great very nice job Doug 😎👍
Thanks, Mike :)
I love the silk-screen on the chassis. Classy chassis are my thing now I've been exposed to a few nice examples.
I just picked up one of the Denis Cornell hand-built 18/20 Plexi heads from a guy in France. What a stunning piece of kit. Totally silent, and I haven't found a setting that sounds less than stellar, and I haven't even got anywhere close to cranking it yet. After turning it on the first time it was a half hour before I changed a knob, it sounded so sweet. Cornell uses polished stainless chassis, only toggles for switching (no rockers), full valve retainers and optimized tapers on the pots. He also learned his wiring style from one of Harry Joyces disciples, which is to say it's a thing of beauty. I'm so glad i went used boutique, rather than vintage Marshall, in this case, anyway. There is no way I'd have a got a vintage Plexi anywhere near as good as this one for three or four times the price (£750).
That sounds like a wonderful amp, Gerry. I hope you enjoy it for many years to come.
@@UncleDoug Thanks! It's the next best thing to owning an Uncle Doug Special, I think.
UD, You are killin me! Borg would make an excellent platform for pedals. And the Legend sounds tres ZZ! Another triumph!
Thanks twice, UB. I told you that resistance is futile :)
Holy mother of rock and roll that legend amp sounds amazing!
Thanks, William. It's sort of a poor-man's vintage Marshall :)
You're on a proper roll Uncle D... Been away a week and now it's a whole afternoon fest... Haven't even got any munchies..
I hope you enjoy it, SR :)
@@UncleDoug I love the one's where there's very little info.. It teaches you far more than just a follow the schematic type... Kinda like the first time you put your finger on the B+ .... LOL
That's true, SR. You do tend to learn more when "flying by the seat of your pants" :)
I’d add a nifty, red pilot light near the power switch, and maybe put the volume control on the front face near the input jack (no, not that Jack...). 😻 You’ve got a real winner, there. Give Jack and Ollie some treats for “testing” your amp. ❤️❤️
I will, William. Thanks for your suggestions.
I'm always amazed by how good a converted PA amp can sound.
Thanks, VCF. This one seemed to turn out quite well, largely due to it's good DNA :)
@Frank Heuvelman Obviously they are two different kinds of circuit topologies. Not all guitar amps are made to intentionally distort. Not all of them use negative feedback. All kinds of different speakers are used in guitar amps. The method of rectification also makes a difference. I prefer tube rectifiers myself. Heck, even the specific brand tubes you use can make a difference, to a point.
Another great video Uncle Doug!!
Thanks so much, Big Joe :)
Very nice sounding amp.
Both amps sound supervolous... have mercy! 🐈✨🙋🏻♂️🍻
No mercy, RH. You must face the music ;)
@@UncleDoug 👍👍
A single input grid stopper can be half of the standard Fender double input values. A 33k resistor is fully capable of preventing RF interference. Frequency response is still above human hearing at 33k BUT a 68k will chop off a bit of the very highest frequency range.
The standard Fender values are PARALLEL when using the HI input. On a 2 input Fender amp, plug in a cable, measure the resistance between pin 2 of V1A and the tip of the cable. It should read in the 30k-ish range (depending on the resistor tolerance).
A higher value won’t hurt anything besides gain and high frequency response. That may be desirable for some people. A lower value than ~30k can permit high frequency oscillations to pass, which can kill tubes. I know it can because IVE DONE IT!
Uncle Doug, Jack, Ollie and Kasey, you guys are a joy to watch, as always.
Excellent comments, Matt. I agree with your analysis and will keep it in mind for the future.
As usual an excellent job!
Thanks, Russell.
What an AMAZING BONUS he sent with that cigar box! It looks as well-crafted as any tube amplifier - complete with latch, even.
KC's looking quite happy and well-fed these days - Good! And very glad to see Jack carrying on Rusty's legacy of eagerly jumping in to help you. What a guy!
That amp is even better than expected - nice, clear highs, and a full bottom end (Didn't Sir Mix A Lot have something to say about that?) Thanks so much, Uncle Doug!
My wife has already commandeered the cigar box, put felt on the inside bottom, and is using it as an auxiliary jewelry box, Dave. Yes, KC is flourishing like a little piranha in an aquarium full of guppies :) Jack, on the other hand is not only the "master of concealment" but also the "feigner of deafness" whenever there is work to be done. Thanks for your nice amp assessment.
Man oh man that came out nice. You really had to do your homework on this one. I would go on to imagine that you went to the
" Uncle Doug " channel and watched the series on power and audio transformers. That info comes in so handy.
I actually did refer to my notes (from previous videos) prior to mapping the OPT, Carl. Thanks so much :)
@@UncleDoug oh, hey, I resemble that! I get myself in trouble when I resort to memory. Always best to consult my notes and various reference books and refresh my memory.
Another Great Job Doug
Thanks, Evan.
Sweet, another cool conversion. Going to fire up the MA-620 Monarch tube amp project, and jam along with ya :)
Thanks, Sean. You're always welcome :)
Unk nice job on your Zeppelin guitar chops and the amp sounds nice too👍
Thanks, Ron. Jack & Ollie outdid themselves on the demo, I thought.
Masterful work, as always. You make it look easy! That front panel strip is simply brilliant. My first thought at seeing that 4-pin chassis connector for the speaker was a connection for an electrodyne speaker. I realize the speaker field coil is usually between the first and second filter capacitors, but considering all the other oddities in this thing, maybe? My kitty Angus also likes those fuzzy blankets, and I think you're right on it reminding them of their mother, because Angus often grooms his fuzzy blanket to the point where it's disgustingly moist with kitty saliva.
Thanks, RPP, for your input and nice comments. Regards to Angus from all his furry bretheren in Texas.
Glad to see KC's appetite is still healthy.
No kidding, Sean. She is like a little piranha :)
I have no idea what you are talking about but I found this very interesting.
Keep watching, William, and it will start to make sense.
I started working maintenance at a hospital in 1980, and they had a small communication room full of tube amplifiers for music and P.A. The room was so hot from all the tubes. About a year later they replaced the system with solid state, and threw away all the old tube amps. If I had only known.
No kidding, Exciter. I would love to have been hanging out at the dump when that load of "junk" arrived :)
Thanks man I had a Rauland pa a long time ago.I wish i wtill had it
You're welcome, Ed.
Jack and Ollie certainly know their rock classics!!
I heard that Brian May takes guitar lessons from them!
@@Bishka100 LOL! That is spectacular!
They are rock historians as well as excellent musicians, AG......a deadly combination :)
Sounds great thanks for another great video!
You're welcome, Prof.
You got me! When you said "Legend 50" amp, I thought you were saying " Legend 50-amp" Now, that would be a project!
Trust me, the Legend is a monster no matter what you call it :)
Another nice video. Thanks for sharing!
You're welcome, Kirk.
very interesting uncle doug thank you
Our pleasure, James.
The conversion had a distinct clarity to the tone. I think it would be ideal for a clean Telecaster player. The late Don Rich would love it. Miss his Tele work and harmony with Buck.
Thanks, TM. Some have questioned my omission of tone controls, but I believe the addition of any passive tone modification would only hamper the overall fidelity and clarity.
@@UncleDoug I wondered about that, too. After I heard how it sounded, I thought it would be like ketchup on a good steak; not a good idea.
Excellent video !!!
Thanks, Stefan.
Another great addition to the library UD. It would appear when it comes to stressing the brain and doing any sort of physical labor that Jack and Rusty prefer to participate with equal enthusiasm...
Thanks, Scott. Jack will spend 20 minutes leaping around to catch a moth, but when it comes to the workshop......he needs a nap.
From Leo: Nice touch with the negative feedback.
It helped a little in the demos.......keeping things reasonably clean and clear.
Im 15 years old and I have autism I love restoring old cars and I'm still perfecting my home theater system in my bedroom
Keep up the good work, BC. When I was your age I was barely able to operate a can opener :)
Great Uncle Doug!
Thanks, CdK.
wow, it really turned out well. great video! again, the way you go wire to wire is extraordinary. i'm working on a stromberg carlson au29 pa that is giving me 120cycles hum. unfortunately, someone was in there prior to me so it is difficult to figure out. thanks,
Thanks, Michael. A 120 Hz hum virtually always originates in the power supply, due to faulty filter caps.
@@UncleDoug someone had been in there prior to me and had weird re-routings and sizes of caps. i've taken it back to stock as far as i can and have replaced all the caps but still have the 120. i'm now thinking that one of the new caps is bad or i've missed some of their weird re-routings.
My head is exploding! I will be going to electronic swap meets and looking for this kind of amps to convert! Mainly for the transformers and tubes. You gave us "Ampaholics" a clear, step by step tutorial on amp conversion. Thank you so much for this video. I in no way would second quests you, no tone controls? I suppose you thought tone controls, be it a single or multiple controls were needed. The amp does sound great. My reasoning was different pickups could benefit from tone controls, but you knew that! I am just so happy to get up early in the morning and grab a stout cup of dark roast and watch you preform electronic wizardry! If the company who made this amp, are aware of this conversion, they would be happy you brought it back to life as a worthy guitar amp! Someone could build an appropriate cabinet for this beauty to take to a gig to become the next guitar hero we are so in need of! Thanxz
Greetings, ATL. I have changed my stance regarding on-board tone controls in certain (i.e. small to medium-size) amps. I've found that by experimenting with different pickups (humbucker and single-coil) and the volume and tone controls on the guitar, it is possible to achieve much more dynamic tone variations than ever possible with all but the most sophisticated on-board TC's. Watch Jeff Beck, not that I am in the same musical universe as he, and see how often he adjusts his amp's tone controls.
I concur! I set my amp's tone controls and forget it! I do use the guitar tone controls a lot. There is something to be said about simple, shortest path of the signal to the amp. I have guitars and basses that have no tone control, one has no volume control, just an off and on switch. Thanxz
That sounded really good! After turning a Hammond Ao-29 into a Princeton Reverb for a friend, I have a Rauland 3035(?) I believe it is to convert for another friend. It has the same weird rectifier. 6L6’s too. Very similar to this one but it’s newer I think. Has a lot of eq controls. A shell over the chassis in great shape. Can’t wait to open it up and see what I can do with it!
Good luck with your project, William.
Great work !!!
Thanks, SP :)
The wiggling input cord attests to the fact that no tricks or overdubs were used in demoing the Legend... just real live albeit furry musicians. It's not easy picking on such a cool vid but here goes: I wuz dyin' to hear a demo of the NFB loop and also wondered where volumes were set... at. ...thanx for yet another piece of gold Uncle Doug... you made a really tough gutting/rewire look so easy... amazing!
You're welcome, Jonny. The NFB was used in the audio demos. It's really only beneficial at high volumes, to de-flub and tighten up the sound. The R-B volume was pleasantly loud around 5, while the Legend was absolutely deafening at only 4.
the thing about the volume right at the input jack is to prevent saturation, with guitars there is a control on the guitar but with music could be different levels and may lead to saturation and distortion (clipping)
watts waves and more wizardry than anyone can shake a stick at uncle doug,
that legend r/r 50 has to be your signature amp , it sounds luscious,,
Thanks so much, William :)
Amazing work Uncle Doug. A couple cosmetic suggestions from my side would be addition of a pilot light, a grommet for the power cord (I couldn't see one if there was) and using a sort of adhesive for the front panel that you have wonderfully placed, since the unsupported middle section looked already separated from the chassis.
I believe the power cord did have a grommet, but the rest are excellent suggestions, LS. Thanks !!!
HI Uncle Doug,hope you are doing well?This amp reminds' of a Leslie(#122,#147).Beautiful work and finished amp,as usual!Nice,little "Hendrix" performance!
We are indeed, Charles. Thanks. Yes, other viewers said the same.