It is so nice to see a video by a repair tech who knows guitar amps , How they work, and how they fail. I have just been watching Brad the Guitologist search aimlessly for why a Marshall 100 DSL had runaway bias problems. He has made several video's on the same amp that keeps coming back for repairs, and it is frustrating to see that after several years of comments going back and forth , he still has not availed himself of the opportunity to check the veracity of many commentors (including my) suggestions. And You have addressed all these issues in a brief but very succinct and TO THE POINT video! BRAVO !

I have been in the Electrical and Electronic Industry as a Designer and Field Operations Technician for Industrial

You are rapidly becoming the best amp tech to watch.

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Howdy Lyle. I do enjoy your channel.

Man I wish I'd studied electronics back in the days ! so interesting ! Thank you for your great videos !

Thanks for your honesty. Keep it coming.

You note that the pick and place machines can't space the rectifier off the board, but shortly thereafter, your camera pans back across the board showing a variety of cement and carbon film resistors standing proud of the board. I think it's possible that the cement resistors have feet so that they're technically flat against the board, but that's definitely not true of the carbon film ones. So someone's been in there doing some manual work at the factory. They could easily have that same person solder in the raised rectifier. They just choose not to.

I personally don't know a single tech that would argue your point about some amps these days. Just completely disposable, overly complicated, under engineered crap.

The joke among amp techs is exactly what Lyle said, "Engineers are the worst techs". Hands-on is super important. When I was a kid, I thought I knew a lot about cars without any hands-on, my mentor called us "magazine mechanics". Same when I was a sales rep, I was just "parroting" what was the current "rap" on a product, when I actually started working as an amp tech, a whole world opened up to me and I realized how much my friends and sales buddies did NOT know!!

I totally agree with you on what you're saying about these companies They Don't Care About Us they just care about their bottom line but unfortunately we have all these Fanboys out here religiously want to defend them I like Marshall don't get me wrong but I have to totally agree with what you're saying thank you sir

You’re great Lyle.

I have two TLS60s. And I have played a DSL50. Both amps sound great when there's nothing wrong with them. I believe they just made them too complicated. There's too many buttons, knobs, switches and features. On my TSLs I tend to just use the high gain channel without the reverb, deep or tone shift. I also don't use the effects loop. They're my favorite sounding Marshalls. The plexis don't have enough gain for me.

Bogner, Boogie, Marshall, Friedman. They all use board mounted tube sockets, potentiometers, input output jacks. Built in obsolescence, and failure...

I am tempted to buy a $400 working JCM 2000 DSL 100 with the BIAS problem. How much would labor cost? The new PCB costs between $210 to $250, and I already have a matched EL34 quad. I have seen both videos and I assume that the repair will be the same. Old tubes show overheating, the amp sounds good though. T hanks for sharing your knowledge!

Watching these kind of videos, you would think that an amp manufacturer with multiple decades of experience would know better than to design a PCB with so main single points of failure, especially as dumb as skipping GND trace between the 16 ohm jack sleeves. Really makes you realize that these things are not designed to run forever like old amplifiers. Also explains why a lot of people believe that P2P amps are better than PCB amps, when in reality it's just the execution of the PCB based amps is much worse, not the technology itself. Shame on today's manufacturers.

I know 3 guys in my area that ran out and bought a DSL 100 and every one of them had a problem with tubes red plating and runaway bias. I don’t claim to know a thing about amp repair and electronics. But it was told to them that there was a problem with the boards used. They would become conductive over time from heat and cause runaway bias. Again, I don’t know how accurate that info is, but all 3 guys were told that from 3 separate repairmen.

Yeah, I use something between 3K3 and 10K for a grid stopper, but never anything like a 220K. I get those bridge rectifiers off the board completely and screw them to the can. The can acts as a heat sink. I hate the DSL TSL Marshall stuff. Andy Fuch's makes pretty nice PCB amps. I came out of Phoenix Music & TV, radio & CRT analog television repair. I fix Line 6. Usually the Line 6 failures are simple stupid things like jax, bad solder, & encoders instead of the SHARC chip. After that there is a class D amp. There are some glaring problems with the SM and some timing caps. A few pennies in parts makes the class D amp a lot more stable.

Binge watching into week 3

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