Marshall DSL100 Part 2 : Putting It All Back Together. Better.
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- เผยแพร่เมื่อ 2 ต.ค. 2024
- Remember when Marshalls were great amps? Anyone?
I do my best to undo more of Marshall's mistakes...
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Howdy Lyle. I do enjoy your channel.
I earned my BSEE degree in 1980. Even at that early date, those of us who were interested in analog radio or audio engineering using those old-style, unreliable, and imprecise "transistors in a bottle," had to learn on our own time using the school library.
Having gone to school a few dozen miles north of the Silicon Valley, there were only two of us in the program who were so inclined, even in the late 1970's. Still, there were plenty of analog houses utilizing tubes at the time, mostly instrumentation builders, but Ampex was just down the 101 in Redwood City, probably making 16-track tape recorders for Les Paul by then.
Any of our talented younger viewers with an interest in earning an EE degree with a focus in analog and digital music engineering design should look into a great program they run out of Georgia Tech. There's a full professor over there who has an excellent TH-cam channel. Aaron Lanterman is how I believe he spells his name. His channel provides an excellent preview of what one might expect to learn as a "Rambling Wreck."
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 !
Yes I remember when Marshalls were great ... from the 1960's until the 1980's ( early ). When there were was one board, about 70 components, and the techs who helped layout the boards and amp at least understood basic tube amp theory , and practice.
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.
I have been in the Electrical and Electronic Industry as a Designer and Field Operations Technician for Industrial
Applications and Systems Integration.
Here is My Rules to Understanding Engineered Problems
Rule One: Engineering Degrees do not directly produce Competent Engineers.
Rule Two: Computer Modeling is not the Same as Real World prototyping and Testing and the Feed back from Testing.
Rule Three: "Bean Counters" and Some Business types worry about "The flow of Money" not what Should Produce that
Positive Money Flow first, Customer Satisfaction from reasonable quality and Value.
Rule Four: Engineering Management does not want to be responsible for Engineering Failings.
Rule Five: New Ideas do not always improve things if they come from low understanding of the Real World Environments.
Really Like Your Channel You Always Seem Real and your Reasoning is Logical and Rational.
As a former military avionics tech, mechanic, and tinkerer, I couldn't agree with you or Lyle more...😎
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 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!
You are rapidly becoming the best amp tech to watch.
Between him, uncle doug, granville guitars etc there is some excellent stuff around now. I don't think I could have gotten into it myself without channels like this
@@kbkman7742 Thanks, I didn't know about granville guitars. Any more channels to suggest? I also already follow the Guitologist, D-lab Electronics, Fazio Electrics, the Guitar Amp Tech.
@@GiuBernardi not really, although as far as guitar tech and repair goes twoodfrd is the finest channel on youtube
@@kbkman7742 big d guitars as well
@@GiuBernardi " Mr. Carlsons Lab " for electronics theory and testing , repair practices. He knows more about Hi End audio than guitar amps, but he does go through a couple.
The same problems exist in construction of buildings. Engineers do the dumbest stuff. They Engineer 10 pounds of crap into a five pound bucket, deni any wrong doing and tell all the trades "make it work". Engineers lay the turds and the rest of us waste time polishing.
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.
10:36 The Line 6 Spider has its uses - I used the cab and chassis of a dead one to build a tweed Princeton!
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.
Now I feel like an idiot for buying one of these, or is ut better in the DSL100HR? Still love the sound of that amp..
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
Wow! Look how the fat traces necks down to the impedance switch, and they didn't even use the switch contacts in parallel (like you are modifying). I guess Marshall amps were good back when they wired it up in "radio days" (that is components mounted on the tube pins - no circuit boards) style, they don't seem to have good PWB designers... too many mistakes that never get corrected. Radial lead Electrolytic Capacitors in a high vibration evenvironment... nope!
a new one is $1200...that had to be 600-800 invoice?
Man I wish I'd studied electronics back in the days ! so interesting ! Thank you for your great videos !
Any mechanical component (switch/pot/jack) that is mounted directly to a PWB is a poor design practice... the solder joints and traces will crack. Such components should be mechanically mounted to the chassis and connections made to the PWB via short wires to take up the vibration.
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!!
Bogner, Boogie, Marshall, Friedman. They all use board mounted tube sockets, potentiometers, input output jacks. Built in obsolescence, and failure...
Tired of the B. S. and marketing campaigns.
No wonder why Grumpy Tech is such a Grump. 😡
Thanks for all this.
Cheers 🍻
At 10:30: I saw Buddy Guy play some years back and he was using Cyber Twins. Inbetween each song, a roadie or guitar tech came out and *adjusted the amplifier for him*. I love his voice but I really don't care for his guitar tone.
These amps came out around the time they were switching over to lead free solder. Some amp manufacturers switched over early, was Marshall one?
Early lead free solder was awful causing bad solder joints and there’s also tin whiskers etc.
In the UK so I have to send my DSL50H to Marshall directly for repair. Would you recommend including s link to this video and asking them to apply the same error-proofing or do you think that would provoke a reaction/give me a headache?
I doubt they would watch it, let alone implement it. Clock watchers.
@@PsionicAudio If they work for Marshall, currently, there seems to be a culture of arrogant ignorance in place already that would discourage such things.
Mine is a 2014 which revision board would it have?
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.
Hey boss, former military avionics and mechanic here in the valley! I've retired from trucking, and wondering if there are shops that would take in an entry level tech in the amplification/ effects world?
Thanks in advance, and stay kewl!😎
Binge watching into week 3
Thanks for your honesty. Keep it coming.
Hey Lyle, this is not about this video but......where do you source your replacement transformers? Classic tone are no more so I need a source for iron. I can get them from several sites, but I’m looking for the best deals. Love the channel and congrats on your subs! Love from NW Colorado. Thanxz
Thanks!
I use Mercury and Heyboer - I am a dealer for each. I've heard that CT has been bought and may start up again, but...
Nothing wrong with Hammond either.
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.
They were right, which is why I replaced this board with the last version. Marshall should have replaced EVERY board out there for free.
Question I have a Marshall modal 1987 which I believe is from the year 1971. The power tubes that are in it are 6550's and not EL34. I believe Marshall used both but I'm not sure maybe you know? Also the pilot light is not in the middle like most Marshall Ive seen but up high. Thanks
Marshal shipped amps to the US market with 6550s starting in '72. I'd have to see your amp to know more.
You’re great Lyle.
Have you ever worked on any Dr. Z amps? I am really liking his new EMS.
Many. While I disagree with some of his design choices, and wish that he used lock washers on his jacks, overall they are well built amps that sound good. Just avoid the Maz amps with reverb - his reverb circuit is horribly noisy. The non-reverb Maz amps are very good.
@@PsionicAudio I heard that from another post somewhere that the reverb MAZ had problems. I think he discontinued that.
I replaced the bridge diode and glued a small cooling fin which worked well.
Stanley, bolting a heatsink onto the bridge rectifier, with some heatsink grease between them, would be a better way to go about it. Of course, this is only practical if you install a new bridge rectifier with longer leads, raised up off the board slightly, which I presume you did anyway when you replaced it. (Or, you could drill a hole through the board for the through bolt, if there aren't any foil traces in the way ---- but lifting the rectifier off the board would be better for both heat dissipation and preventing the solder joints from cracking due to expansion and contraction). I don't know what type of glue you used, but unless it was a thermally conductive epoxy and you roughed up the surface of both the bridge rectifier and the underside of the heat sink, I would worry about the heatsink falling off and shorting something inside the amplifier. Most ordinary adhesives such as superglue, silicon RTV and so on are not very good at conducting heat. (JB Weld contains powdered steel, that might be a good choice.).
@@goodun2974 Thank you. Good points. I used thermal glue and raised it from the board. Your right, we don't want the components to rattle loose and short out the amp. Appreciate the videos and info.
Is it normal for the solder to have all the flux left around it?
Leo Fender and the other early amp builders who came out of radio repair businesses knew how to solder; they also knew the importance of making a good mechanical connection before soldering. Nor were they hamstrung by the legal requirement to use lead free solder; plus they had access to a huge variety of American made parts and components, and if they didn't like what they were getting from one manufacturer or vendor they had lots of others to choose from.