I was a Marshall dealler from 2000 to 2005. I must say about half of them didn't sound bad. They couldn't, because they didn't make any sound at all. It was up to us to pay for repairs, then *hope* future invoices would be adjusted. Funny that we could also order cheap Asian imports like Kustom and they would always work-shipping amps doesn't have to destroy them. The Classic Peaveys were a constant money-losing headache for us as well-same shitty PCB layout that costs more to work on than the amp cost. (At least Peavey was supportive of their dealers.) The Amp in this video is a showcase for manufacturers' contempt for their customers. On tube amps, cap replacement is just maintenance, and if you MUST design a PCB amp (for point-to-point retail prices), the caps should be easy to change. The ability to keep it working should be built right into the amp. Replacing an entire PCB just to do basic maintenance? Excuse me? Marshall had lost their minds by the time these amps were designed. Lost their flipping minds. The workmanship on that replacement is an embarassment, and God knows how long it's been in storage-those new caps may already be half done for. If' I'm going to own a PC board amp, I'm going to buy a cheap one. Because that PC board is there so it can be cheap. That is what the designer was after. If all I was allowed to play was Marshalls, I'd quit playing electric guitar.
This was a defective board material problem that caused cross conduction, manifesting over time with heat, most likely supplier QC. I have repaired many. A lot of techs tried to lift bias circuitry off the board which did solve the bias drift issue. Usually the next thing to happen was ingress of hum. This was cross talk from DC heater bridge rectifier to adjoining high impedance circuitry. There is only one fix - a new board.
A turd with an input jack. Wrong grid stoppers on the power tubes, d.c.heater supply that fails , shorting jack ground for 4 and 8 ohm output that gets hot and fails and to top it all off pcb that conducts . Add that to a 4-12 cab with a pcb with 2 jacks and a switch that breaks loose and burns up . A rig designed to fail . I still love your video . Your a brave man to service this stuff.
After watching 15+ of your excellent videos the top two takeaways I have are 1. Tighten up yer connectors/nuts/wires etc... and 2. Be vigilant about heat damage. Yup.
That is smart to change the whole board because you will be going down a rabbit hole if you don"t.I see you have been there before like I have this is a great vid for the young / new amp teck.
I realize this is an older video, but I've been watching you a while now, and going back through your old catalog of videos. It has been eye opening. Thank you.
Back in the early 1990's, I used to design switching mode power supplies for telcos. The only way to achieve long life, high mean time between failures greater than 20 years of continuous operation, was to seriously limit both the thermal and voltage stresses on those electrolitic capacitors. Obviously, tube amps are not operated 24/7, so they should last many years. Another rule was to use the highest quality parts for the job. Yet aluminium electrolitic capacitors will fail if they operate in a hot environment, i.e. next to tubes without any cooling, or too close to their operating voltage limit, simply because their non-solid electrolite tends to dry up eventually, or worse boil away. Hense, servicing them is a must. I agree with the comments about improving PCB layout to ease their replacement. Some amps like EVH have more free flowing air available around hot components.
Just wanted to say how much I continue to enjoy your content! Thanks I’ve been recapping a lot of my gear from the 90’s. It’s amazing how some will go and some will last longer - but as you say in the early part of the video - it’s often not obvious the cap is bad from bulging or external leakage. Thank god caps are cheap
My 2¢ -- just THANK YOU for your posts & sharing your experience. Recently bought a used AC15C1 and was able to make a better-informed choice because of your videos. Cheers!
There might be some controversy about this, but I definitely recommend cleaning the flux off circuit boards after any rework. I've seen solder joints severely damaged by flux, though it's often a slow process that could take a decade or two. Spray-can flux remover is especially easy to use when the board is completely out of the chassis.
HAHAHA! Hysterical! You call that grumpy? You should see me when a DSL/TSL or Triple rectifier lands on my bench! I am inconsolable. Thanks for that C46 tip. It will be added to my ever-growing note book called "Lyle's Tips".
I had a TSL. It sounded great on the clean but the gain channel was terrible. I returned it after the first show at the ampitheater in Dallas Texas. Very disappointed. I traded my 2210 for it and my amp sold before I got back. I was sick, but the store helped me on a puchase on a Mesa Triple rec. I hated that amp and traded for a jcm800 2203, but still didnt sound as good as my 1982 2210 and no clean channel. So I used my fender 65 black face and the 2203. UGH! Jod video
I gigged a tsl 100h for six years it was a great amp blew a ht fuse once at a gig changed it and it was fine, up graded to a JVM 100 h the fuses and bias pot are inside!! I turned the tsl on one day at home and it went pop, two valves were cold, I suspected it was the dreaded conductive PCB malady, so I changed the mother board, £120 and it's fine now, but I don't use it anymore, or the JVM, can't be bothered lugging it all about anymore, I use boss katanas now excellent for what I'm doing now
Circuit board construction seems to put most amp building companies on an even playing field. They all use pretty much the same assembly machines and wave soldering machines. It’s not the point to point or tag board of yesteryear. I have more respect for the companies that at least do hand wired tube sockets and not direct board mounted sockets.
Circus board deluxe. I have a newer dsl40 combo. Boat anchor my dsl100s from the 90s are still holding up and doing well even though they too are circus board deluxes.
You know you can't own one marshall. You have to have one you're using, one in the shop, and one that's the backup for when the one you're gigging breaks again.
That's why the big name, arena acts have two or three full stacks on stage. In most cases, they're only using one at a time and the others are backups.
It's a good job you didn't mention the flappy vibration PCB with no standoff supports being held up only by the terribly made potentiometers fixed to the front chassis panel. Marshall designed built in failure.
I bought brand new a 1998 JCM 602. The amp was complete garbage. After the 1st time it failed (2 years in) it was just never right and would break down at least once a year or two. The Tech blamed poor design due to horizontal tubes. I then bought a 2004 DSL 100 W off a friend who upgraded some caps to better ones just cause that's what he does lol. Never had one issue ever. Owned it for over 12 years now hundreds of shows. Love that amp.
I guess ive been lucky my dsl 100 was i think 2 nd year of production i worked it hard on the road it went to the amp hole in burbank every 6 months for a check up and its still fine a good workhorse loud as hell ha ha i would tell the sound man get youre mike outta here man i got this ha ha
As a PCB designer(up to like 24VDC) I find it weird that so many of the PCBs used look like something out of a 80's keyboard. But I am curious to know what sort of priorities one have to make, and subsequently compromise somethings, when doing PCB for tube guitar amps. Do you have any resources on PCBs in tube amps?
It’s almost 100% cost driven in mass produced amps. All other rules as far as PCB layout still apply. You’re frequently dealing with high voltage, relative to other audio frequency devices, so dielectric parameters and trace spacing are your top concerns. Be mindful of trace width and routing when it comes to heater circuits. Use tools available to generate the DRC parameters in your ECAD software and guide your component placement and routing. Be mindful of thermals, too.
I have a dsl 100 the second year i think but an early one it was my road amp i had it serviced every 6 months it never let me down and i drove that amp hard vol at 8 sound guys hated me i would just say dont mike it im good ha ha this amp geys a bad rap but serviceing it is the key i still have it and plxi marshalls to never had a problem cheers
Years ago I had a tsl 100 combo ,it sounded pretty good until the board went bad.I had Marshall do the repair because I don’t live too far from the factory,that amp worked after the repair but sounded like shit .bought a jvm and had 3 replaced under warranty for various faults.never touched a Marshall since .utter junk.
Hoping maybe you could enlighten me on something. I just got a DSL100H and researching hasn't gotten me very far. All functions fine except the footswitch has issues. I have a DSL40 C as well and first tried it's footswitch on the 100H. It stays locked into one setting and won't make any changes. I had also ordered the 6 button switch and when it arrived I got the same result. Both work fine on the 40C. The only thing research has led me to is replacing the footswitch jack which I'm about to start prepping for. I thought you may know if there could be some other cause I should inspect before proceeding. Any help is GREATLY appreciated, Thank You.
Well, first, the DSL100H is a different (much better) amp than the older JCM2000 model here. So that’s good. But I don’t know what’s going on in the switching of your model. Contact Marshall to get the suitable foot controller.
I have a pair of those Pana-Vise type PCB holders that have detents at 0-90-180 & 270 degrees and back at 0 degrees. It holds the board securely above the bench. Pull out, twist it and the board locks back into place, only upside down. I HATE THE TSL and DSL amps. THEY ARE TRASH! Garbage like the TSL and DSL are why I started building my own stuff. When Marshall stops making the replacement boards where will we be with those amps? At the landfill, or doing major surgery. The whole board gets conductive from heat around the bias circuit.
Yes ! There are so many things wrong with Marshalls made after 1985 up until now. This one is WAY TOO complicated ! It has more interconnect cables than a marshall superlead (circa 1974) had components! The boards are laid out as though they are handling 5 Volts ! What with the tenth inch spacing between component holes,.. that means less than 1/20th inch between the copper lands around component leads from different parts in the circuit with potentially 460 volts! Combine that with EU solder that is lead free non-eutectic 98 % tin, that grow tin whiskers, and they are bound for imminent demise. Great for saving land fills from having lead leach into the ground water. but previous to the EU regulations no one threw away their Marshalls into the land fill , because the good old amps didn't have massive solder failures (within 5-10 years) due to tin whiskers/ film on the boards. Good they fixed the issue with the little blue plate/screen cap but why did they not replace the CRAPPY samwha power filter caps with something decent ???
Isn't the wiggle around the cap supposed to be a good thing? because the vibration won't stress the component too much, instead most of it is dissipated as heat in the lead. I read in nasa soldering technique, stress releive is important
In most amps I would have. But the earlier DSL boards have drifting bias issues due to substandard board materials. The original board here was one of those. The replacement board doesn't have the faulty fiberglass. This should have been a worldwide recall under warranty.
@@PsionicAudio How can I identify if mine has the old or new board? Mine is the DSL100H, not the older JCM2000 dual super lead. Getting ready to open mine up for maintenance.
@@g3ultra If you have a DSL100H,you dont have anything to worry about.This amp is the JCM2000 series of amps.Made from 1998-2005.There were a small number of late 1997 amps too.The new board fixes the problem.But they recommend replacing the tubes at the same time because they might be damaged from the drifting bias.
I think they revised the board in 2006 to solve the drift issue.... was the complaint crackling or bias drift with this amp... its unclear the way you spoke on this
the sanwa caps 315v 330uf They are really bad capacitors Do not hold for many years Especially Inside an tube amplifier . I would replace them now Instead of waiting for problems later on because of them
Shit board on these amps. I had one that kept doing the runaway bias thing and red plating my tubes and popping the fuse. Turns out Marshall used cheap shit boards that would become conductive over a short period of time. Had the board replaced. After 2 months, same thing. They didn’t change to a better board. Eventually they made a replacement board with a better one. But by that time, that piece of crap became a nice boat anchor.
Also, regardless of the material used, circuit boards can become conductive, perhaps permanently, if a capacitor leaks. Tube circuits, being high impedance, are particularly susceptible to noise and bias drift from conductive boards (and double-sided boards are the worst). Solid-state circuit boards are more forgiving ---- I have successfully scrubbed cap leakage off of the (single-sided) PCB's for many vintage solid-state hifi receivers and amplifiers, and replaced the electrolyte-corroded parts, and gotten them working again, reliably. I don't know how old that failed Marshall DSL is, but if it's less than 6 to 8 years old, I would have recommended upgrading the new board before installation by changing out (at minimum) the two large filter caps which had obviously bulged and leaked on the the old board. Find another better-made brand of electrolytic cap to put in there, perhaps with a higher-voltage rating, if that's possible. Checking the rest of the old electrolytic caps with an ESR meter would identify any others that ought to be prophylactically changed on the replacement board. BTW, the only solid-state hifi gear I've ever worked on where merely cleaning capacitor leakage off of the circuit board isn't sufficient to fix the amp is some older models of Adcom amplifiers; the tarry brown leakage from the stock capacitors resembles tobacco juice, smells like fish when heated by the soldering iron, and is not only conductive but highly corrosive---- and it seeps into all the component-lead holes in the board and corrodes the solder joints where you can't see it. Plus, it causes leakage paths around an input IC, and after fixing all the other problems you had to cut a bunch of circuit board foils and lift several IC pins and associated resistors off of the board and reroute the circuit with flying leads.
I would have thought that if the capacitors were wonky when the board was made, the glue would hold them wonky. I suspect the board was dropped on the side, pushing the caps over, pulling out the leads a few mm on one side, damaging the seal, maybe more. Reseating them upright fixes nothing. The capacitors are more or less damaged and will likely fail early.
Funny, brand new board, and you have set it up before you install it. Maybe it may have been better to redo the original. The board looks good. The Fender boards are just awful. Cheers
There is an aftermarket bias kit you can buy which involves isolating the G1 pins from the board (cutting the pcb around the pin) and flying leads to them. That is the only way to make the existing board reliable again. Mar$hall could just not build chintzy junk and we wouldn't need to resort to such tactics...
@@Gtrtech It seems more prevalent the amp companies are having to skimp in order to make a buck, but others do that just because they can. It doesn't leave repair techs with nice thoughts about some of their products.
Why replace the board if you need to do all that to a new one plus it has crap components like the original. You could fix the issues that original board has and put in quality components
@@shckltnebay I agree. I was never a fan of that line. The Dual Calibur (DC5 & 10, not the DC3) series and .50 Cal, which came before those were much better made.
All those passive components are cheapest Chinese made garbage!. Marshall should be ashamed putting out this low quality made with a quick pick and place machine quick wave soldering techniques no care or craftsmanship ! as a electronics technician and engineer i use NICHICON ,ELNA,CDE,PRP,HOLCO,VISHAY,WIMA. There is NO QUALITY British or German made components stuffed here.
Heck I like Marshall amps but the company? I've emailed them twice in the past year with questions about my $1200 Marshall amps that I own and they won't even give me the time of day. Besides, unless you're blind how could anyone look at that pathetic cap job on that replacement board and not understand your criticism lmao
I was a Marshall dealler from 2000 to 2005. I must say about half of them didn't sound bad. They couldn't, because they didn't make any sound at all. It was up to us to pay for repairs, then *hope* future invoices would be adjusted. Funny that we could also order cheap Asian imports like Kustom and they would always work-shipping amps doesn't have to destroy them. The Classic Peaveys were a constant money-losing headache for us as well-same shitty PCB layout that costs more to work on than the amp cost. (At least Peavey was supportive of their dealers.)
The Amp in this video is a showcase for manufacturers' contempt for their customers. On tube amps, cap replacement is just maintenance, and if you MUST design a PCB amp (for point-to-point retail prices), the caps should be easy to change. The ability to keep it working should be built right into the amp. Replacing an entire PCB just to do basic maintenance? Excuse me? Marshall had lost their minds by the time these amps were designed. Lost their flipping minds. The workmanship on that replacement is an embarassment, and God knows how long it's been in storage-those new caps may already be half done for.
If' I'm going to own a PC board amp, I'm going to buy a cheap one. Because that PC board is there so it can be cheap. That is what the designer was after. If all I was allowed to play was Marshalls, I'd quit playing electric guitar.
This was a defective board material problem that caused cross conduction, manifesting over time with heat, most likely supplier QC. I have repaired many. A lot of techs tried to lift bias circuitry off the board which did solve the bias drift issue. Usually the next thing to happen was ingress of hum. This was cross talk from DC heater bridge rectifier to adjoining high impedance circuitry. There is only one fix - a new board.
A turd with an input jack. Wrong grid stoppers on the power tubes, d.c.heater supply that fails , shorting jack ground for 4 and 8 ohm output that gets hot and fails and to top it all off pcb that conducts . Add that to a 4-12 cab with a pcb with 2 jacks and a switch that breaks loose and burns up . A rig designed to fail . I still love your video . Your a brave man to service this stuff.
And they sound incredible 👍🏻
Between brad the guitaroligist Stuart uk amp guy and this fella is three great techs who’s work is just perfect . Great channel
After watching 15+ of your excellent videos the top two takeaways I have are 1. Tighten up yer connectors/nuts/wires etc... and 2. Be vigilant about heat damage. Yup.
I just bought the brand new dsl100hr I'm glad they solved these problems
I overwhelmed by your old school craftsmanship. Great to see it still exists in 2022.
That is smart to change the whole board because you will be going down a rabbit hole if you don"t.I see you have been there before like I have this is a great vid for the young / new amp teck.
I like your honesty and quality of work. I used to build boards for a living and you are doing things the old school way and I like it. Cheers 🍻
I realize this is an older video, but I've been watching you a while now, and going back through your old catalog of videos. It has been eye opening. Thank you.
Back in the early 1990's, I used to design switching mode power supplies for telcos. The only way to achieve long life, high mean time between failures greater than 20 years of continuous operation, was to seriously limit both the thermal and voltage stresses on those electrolitic capacitors. Obviously, tube amps are not operated 24/7, so they should last many years. Another rule was to use the highest quality parts for the job. Yet aluminium electrolitic capacitors will fail if they operate in a hot environment, i.e. next to tubes without any cooling, or too close to their operating voltage limit, simply because their non-solid electrolite tends to dry up eventually, or worse boil away. Hense, servicing them is a must. I agree with the comments about improving PCB layout to ease their replacement. Some amps like EVH have more free flowing air available around hot components.
Just wanted to say how much I continue to enjoy your content! Thanks
I’ve been recapping a lot of my gear from the 90’s. It’s amazing how some will go and some will last longer - but as you say in the early part of the video - it’s often not obvious the cap is bad from bulging or external leakage. Thank god caps are cheap
Appreciate your honesty. So many brands only care about profits and not the product that carries their namesake.
My amp tech hates modern Marshalls, I’m beginning to understand why.
My 2¢ -- just THANK YOU for your posts & sharing your experience. Recently bought a used AC15C1 and was able to make a better-informed choice because of your videos. Cheers!
Very educational video !
There might be some controversy about this, but I definitely recommend cleaning the flux off circuit boards after any rework. I've seen solder joints severely damaged by flux, though it's often a slow process that could take a decade or two. Spray-can flux remover is especially easy to use when the board is completely out of the chassis.
Oh, you're quite right. I mentioned that I would after the rework is done, though I didn't show if.
For what it's worth I really like how the TSLs and DSLs sound. Especially the two EL34 ones.
they are good sounding amps that gig well especially the tsl with three channels
HAHAHA! Hysterical! You call that grumpy? You should see me when a DSL/TSL or Triple rectifier lands on my bench! I am
inconsolable. Thanks for that C46 tip. It will be added to my ever-growing note book called "Lyle's Tips".
Haha we all have a Lyle chapter in our troubleshooting notebooks.
@@luthiervandros I've seen you lurking. Your username always gives me a chuckle.
@@IamtheFerryMan 🤜🏼🤛🏼😂
Just say no to rack mount boogies
I had a TSL. It sounded great on the clean but the gain channel was terrible. I returned it after the first show at the ampitheater in Dallas Texas. Very disappointed. I traded my 2210 for it and my amp sold before I got back. I was sick, but the store helped me on a puchase on a Mesa Triple rec. I hated that amp and traded for a jcm800 2203, but still didnt sound as good as my 1982 2210 and no clean channel. So I used my fender 65 black face and the 2203. UGH! Jod video
Thanks for this vid. I note that DSL20HRs are all on backorder as of May 22. I wonder if they made another revision...
Thank you !
I gigged a tsl 100h for six years it was a great amp blew a ht fuse once at a gig changed it and it was fine, up graded to a JVM 100 h
the fuses and bias pot are inside!!
I turned the tsl on one day at home and it went pop, two valves were cold, I suspected it was the dreaded conductive PCB malady, so I changed the mother board, £120
and it's fine now, but I don't use it anymore, or the JVM, can't be bothered lugging it all about anymore, I use boss katanas now
excellent for what I'm doing now
Circuit board construction seems to put most amp building companies on an even playing field. They all use pretty much the same assembly machines and wave soldering machines. It’s not the point to point or tag board of yesteryear. I have more respect for the companies that at least do hand wired tube sockets and not direct board mounted sockets.
i have this amp. I chucked the pcb and put in a 2203 circuit on a turret board
Circus board deluxe. I have a newer dsl40 combo. Boat anchor my dsl100s from the 90s are still holding up and doing well even though they too are circus board deluxes.
You cracked me up with the Blind Melon Chitlin reference...
Sad that you have to do all the work to a brand new circuit board. You do great work!!
You know you can't own one marshall. You have to have one you're using, one in the shop, and one that's the backup for when the one you're gigging breaks again.
That's why the big name, arena acts have two or three full stacks on stage. In most cases, they're only using one at a time and the others are backups.
Nice way of putting Marshall and all product manufacturers on notice! Just OK ain’t good enough!
we got to give marshall some credit,they went to 12 year olds making them instead of 10 year olds
These amps drive me nuts. They sound awesome when they’re working though.
It's a good job you didn't mention the flappy vibration PCB with no standoff supports being held up only by the terribly made potentiometers fixed to the front chassis panel. Marshall designed built in failure.
I bought brand new a 1998 JCM 602. The amp was complete garbage. After the 1st time it failed (2 years in) it was just never right and would break down at least once a year or two. The Tech blamed poor design due to horizontal tubes. I then bought a 2004 DSL 100 W off a friend who upgraded some caps to better ones just cause that's what he does lol. Never had one issue ever. Owned it for over 12 years now hundreds of shows. Love that amp.
Are there better quality caps that can be used . I have a TSL
I guess ive been lucky my dsl 100 was i think 2 nd year of production i worked it hard on the road it went to the amp hole in burbank every 6 months for a check up and its still fine a good workhorse loud as hell ha ha i would tell the sound man get youre mike outta here man i got this ha ha
Is this the newer Chinese DSL or the JCM 2000 DSL.
As a PCB designer(up to like 24VDC) I find it weird that so many of the PCBs used look like something out of a 80's keyboard. But I am curious to know what sort of priorities one have to make, and subsequently compromise somethings, when doing PCB for tube guitar amps. Do you have any resources on PCBs in tube amps?
It’s almost 100% cost driven in mass produced amps. All other rules as far as PCB layout still apply. You’re frequently dealing with high voltage, relative to other audio frequency devices, so dielectric parameters and trace spacing are your top concerns. Be mindful of trace width and routing when it comes to heater circuits. Use tools available to generate the DRC parameters in your ECAD software and guide your component placement and routing. Be mindful of thermals, too.
I have a dsl 100 the second year i think but an early one it was my road amp i had it serviced every 6 months it never let me down and i drove that amp hard vol at 8 sound guys hated me i would just say dont mike it im good ha ha this amp geys a bad rap but serviceing it is the key i still have it and plxi marshalls to never had a problem cheers
"Lead solder might end up in landfills." Well, build repairable amps that won't end up there! 🙄
From what I'm reading it's verified that Marshall did correct the bias in 2004, I hope i am I correct, because I just purchased a 2005
Years ago I had a tsl 100 combo ,it sounded pretty good until the board went bad.I had Marshall do the repair because I don’t live too far from the factory,that amp worked after the repair but sounded like shit .bought a jvm and had 3 replaced under warranty for various faults.never touched a Marshall since .utter junk.
Hoping maybe you could enlighten me on something. I just got a DSL100H and researching hasn't gotten me very far. All functions fine except the footswitch has issues. I have a DSL40 C as well and first tried it's footswitch on the 100H. It stays locked into one setting and won't make any changes. I had also ordered the 6 button switch and when it arrived I got the same result. Both work fine on the 40C. The only thing research has led me to is replacing the footswitch jack which I'm about to start prepping for. I thought you may know if there could be some other cause I should inspect before proceeding.
Any help is GREATLY appreciated, Thank You.
Well, first, the DSL100H is a different (much better) amp than the older JCM2000 model here.
So that’s good.
But I don’t know what’s going on in the switching of your model. Contact Marshall to get the suitable foot controller.
I have a pair of those Pana-Vise type PCB holders that have detents at 0-90-180 & 270 degrees and back at 0 degrees. It holds the board securely above the bench. Pull out, twist it and the board locks back into place, only upside down. I HATE THE TSL and DSL amps. THEY ARE TRASH! Garbage like the TSL and DSL are why I started building my own stuff. When Marshall stops making the replacement boards where will we be with those amps? At the landfill, or doing major surgery. The whole board gets conductive from heat around the bias circuit.
Yes ! There are so many things wrong with Marshalls made after 1985 up until now. This one is WAY TOO complicated ! It has more interconnect cables than a marshall superlead (circa 1974) had components! The boards are laid out as though they are handling 5 Volts ! What with the tenth inch spacing between component holes,.. that means less than 1/20th inch between the copper lands around component leads from different parts in the circuit with potentially 460 volts! Combine that with EU solder that is lead free non-eutectic 98 % tin, that grow tin whiskers, and they are bound for imminent demise. Great for saving land fills from having lead leach into the ground water. but previous to the EU regulations no one threw away their Marshalls into the land fill , because the good old amps didn't have massive solder failures (within 5-10 years) due to tin whiskers/ film on the boards. Good they fixed the issue with the little blue plate/screen cap but why did they not replace the CRAPPY samwha power filter caps with something decent ???
Isn't the wiggle around the cap supposed to be a good thing? because the vibration won't stress the component too much, instead most of it is dissipated as heat in the lead. I read in nasa soldering technique, stress releive is important
No. Vibration has nothing to do with heat. It stresses the leads/solder joints.
i would probarly have replaced all the caps on the old PCB. its quickly done with a desoldering station (and used 105 C caps)
In most amps I would have. But the earlier DSL boards have drifting bias issues due to substandard board materials. The original board here was one of those. The replacement board doesn't have the faulty fiberglass.
This should have been a worldwide recall under warranty.
@@PsionicAudio ooh yes forgot about that problem... Not much to do, other than New pcb
@@PsionicAudio How can I identify if mine has the old or new board? Mine is the DSL100H, not the older JCM2000 dual super lead. Getting ready to open mine up for maintenance.
@@g3ultra If you have a DSL100H,you dont have anything to worry about.This amp is the JCM2000 series of amps.Made from 1998-2005.There were a small number of late 1997 amps too.The new board fixes the problem.But they recommend replacing the tubes at the same time because they might be damaged from the drifting bias.
Hi. I have a jcm2000 dsl 50. Do I need to pull c46?
If it's a 500V cap, yes. 1KV, probably not.
@@PsionicAudio thank you. Love your content. Really great info and watching you wrestle the camera is a great time!
I think they revised the board in 2006 to solve the drift issue.... was the complaint crackling or bias drift with this amp... its unclear the way you spoke on this
For sure I heard him say one of the complaints was crackling.
the sanwa caps 315v 330uf
They are really bad capacitors
Do not hold for many years
Especially
Inside an tube amplifier .
I would replace them now
Instead of waiting for problems later on because of them
I'll stick with my Friedmans
Shit board on these amps. I had one that kept doing the runaway bias thing and red plating my tubes and popping the fuse. Turns out Marshall used cheap shit boards that would become conductive over a short period of time. Had the board replaced. After 2 months, same thing. They didn’t change to a better board. Eventually they made a replacement board with a better one. But by that time, that piece of crap became a nice boat anchor.
Also, regardless of the material used, circuit boards can become conductive, perhaps permanently, if a capacitor leaks. Tube circuits, being high impedance, are particularly susceptible to noise and bias drift from conductive boards (and double-sided boards are the worst). Solid-state circuit boards are more forgiving ---- I have successfully scrubbed cap leakage off of the (single-sided) PCB's for many vintage solid-state hifi receivers and amplifiers, and replaced the electrolyte-corroded parts, and gotten them working again, reliably.
I don't know how old that failed Marshall DSL is, but if it's less than 6 to 8 years old, I would have recommended upgrading the new board before installation by changing out (at minimum) the two large filter caps which had obviously bulged and leaked on the the old board. Find another better-made brand of electrolytic cap to put in there, perhaps with a higher-voltage rating, if that's possible. Checking the rest of the old electrolytic caps with an ESR meter would identify any others that ought to be prophylactically changed on the replacement board.
BTW, the only solid-state hifi gear I've ever worked on where merely cleaning capacitor leakage off of the circuit board isn't sufficient to fix the amp is some older models of Adcom amplifiers; the tarry brown leakage from the stock capacitors resembles tobacco juice, smells like fish when heated by the soldering iron, and is not only conductive but highly corrosive---- and it seeps into all the component-lead holes in the board and corrodes the solder joints where you can't see it. Plus, it causes leakage paths around an input IC, and after fixing all the other problems you had to cut a bunch of circuit board foils and lift several IC pins and associated resistors off of the board and reroute the circuit with flying leads.
I would have thought that if the capacitors were wonky when the board was made, the glue would hold them wonky. I suspect the board was dropped on the side, pushing the caps over, pulling out the leads a few mm on one side, damaging the seal, maybe more.
Reseating them upright fixes nothing. The capacitors are more or less damaged and will likely fail early.
Funny, brand new board, and you have set it up before you install it. Maybe it may have been better to redo the original. The board looks good. The Fender boards are just awful. Cheers
There is an aftermarket bias kit you can buy which involves isolating the G1 pins from the board (cutting the pcb around the pin) and flying leads to them. That is the only way to make the existing board reliable again. Mar$hall could just not build chintzy junk and we wouldn't need to resort to such tactics...
@@Gtrtech It seems more prevalent the amp companies are having to skimp in order to make a buck, but others do that just because they can. It doesn't leave repair techs with nice thoughts about some of their products.
Why replace the board if you need to do all that to a new one plus it has crap components like the original. You could fix the issues that original board has and put in quality components
The original board was made of conductive material. It was not salvageable.
Marshall should do a lot better by their customers.
Mesa love is probably the most undeserved
Depends on the era. I've been a tech for 25 years and a MKIII owner for +30...its never needed not1 single repair. It's still on the original caps!
@@dan_perry Have you seen the inside of newer Mesas?
@@shckltnebay yes, I have. That's why I said certain era Boogies are better than others.
@@dan_perry Bought two Express series 550 and 525 with issues recently and no way is a normal tech going to be able to work one them
@@shckltnebay I agree. I was never a fan of that line. The Dual Calibur (DC5 & 10, not the DC3) series and .50 Cal, which came before those were much better made.
Good grief.
I don't think this video is "boring."
I got one I kinda hate it
this thing just looks so hideous compared to the old ‘82 2203 you worked on, such a tragic decline in quality for Marshall.
That is really a crap solution and poor work. Why do they mount tube sockets on PCB?
All those passive components are cheapest Chinese made garbage!. Marshall should be ashamed putting out this low quality made with a quick pick and place machine quick wave soldering techniques no care or craftsmanship ! as a electronics technician and engineer i use NICHICON ,ELNA,CDE,PRP,HOLCO,VISHAY,WIMA. There is NO QUALITY British or German made components stuffed here.
so much for quality control...pretty damn pathetic!....this would not cost Marshall a lot of $ to check over each pcb!
Nothing wrong whatsoever about calling them out on their junk man.
Heck I like Marshall amps but the company? I've emailed them twice in the past year with questions about my $1200 Marshall amps that I own and they won't even give me the time of day. Besides, unless you're blind how could anyone look at that pathetic cap job on that replacement board and not understand your criticism lmao