I have a Marshall 9200 poweramp (Dual mono-bloc) that I am having problems with. Channel A works fine, but when I turn on Channel B, I get no output, but rather I get this low pitched buzzing sound that becomes louder and louder. (Both channels work independently of each other, as in Channel A runs 4 6L6GC tubes and Channel B runs another 4 tubes)
Also, Channel B's tubes glow blue when it is turned on. (I never turn Channel B longer than 30 seconds after that buzzing sound starts) I was wondering whether it was a blown tube or whether it is something more sinister at work, i.e. a blown transformer.
FYI, the amp doesn't trip the fuse, but rather the tubes just immediately glow blue, like the gas in the tubes is on fire or something.
Thanks for your help guys.
Have a few questions about attenuator usage with SC20H amp.
1. Do I need two attenuators? My cabinet has two speakers (8 Ohm each), and SC20H has two separate outputs for each speaker, so does it mean I have to buy two attenuators, one for each speaker? I didn't manage to find SC20H schematics, so I'm not sure if those two amp outputs are connected in parallel internally, and I can just use one attenuator.
2. Do I need attenuator(s) at all? I want to run the amp with overdriven tubes, thus I have to set max level, right? Consultant at my local store told me it's enough to reduce "Master" volume, and EL34 will still be overdriven, if I set "Pre-amp" volume to max. But folks at Marshall forum say that it's still better to use attenuator, even in 5W mode. Again, I don't have SC20H schematic, so it's hard to tell who is right.
3. What if my cabinet only have one 4 Ohm input (2 x 8 Ohm speakers inside)? Is it enough to connect it to the amp with only one cable? Or I have to rework my cabinet to have two different inputs (separate input for each speaker)?
Where I can buy the Marshall Dsl40c's fuses?
I've had a hard time finding them. My Marshall went silent and I replaced all the tubes.
Running out of ideas.
I am a recent ower of a Marshall Origin 20, which I got in July. I've really enjoyed the amp until I plugged in last night and got out absolutely no sound out of it. I couldn't figure out why, as nothing as happened to it and it worked fine two days ago. I took it apart to do some trouble shooting and found that when I have all the knobs max'd and output on 20 watts, I can hear a whisper of my guitar signal (nicely saturated, presumably by the preamp tubes) through the speaker. This sound is affected by all of the knobs. However, if I plug my guitar directly into the return of the effects loop, and activate the effects loop I get no sound whatsoever; no guitar, no hum, nothing. Because of this, I'm sure my speaker is not the problem. These things led me to think it was a power amp section issue, so I went down and purchased a new set of matched EL34's, threw them in there, and nothing changed. I'd really like to know if there's anything I can do to fix this, because this amp is not even a year old and I should not be having these kinds of problems with completely normal bedroom use.
I have a DSL 100h that has been fading in and out and crackling for quite some time. It seems to only happen on the clean channel and makes no difference, if I have my pedal board plugged in or not. I have the fx loop turned off, so I believe that that part of the circuit is out of the equation. I just swapped out the tubes because I suspected the pre amp tubes were bad from some other things I read and still no luck. Has anyone else experienced this?
I've noticed the outputs 2 & 3 differ, while the specifications on the speakers but the back of the cab (ORI212A) says x2 8ohms. Should I use the 16ohm output? And if not, which of the ohm outputs on the Origin 20H is the ideal one? The 16 ohm, the 8ohm or the 16x2 one?
I just bought a DSL5CR,
its "classic gain" channel has no gain at all, and one tube of the pre amp don't glow as the other, it glows, but not like the other pre amp tube.
Maybe there is a problem with it?
Can someone tell me why the JMP1 that Geoff Whitehorn and many other guitarist used on guitar cds sounds so different from the 4 that I've recorded with? There is a warm fuzzy present quality on these recordings that the JMP1s I've tried don't have. All the ones I've tried sound the same, so I'm sure I don't have a faulty unit. It sounds great though an amp and cab. I've changed the tubes a few times, but it hasn't made any difference. Cheers.
So i have had this amp since 2016 and i play it a lot. mostly at home on the 5 watt mode. Today as i turned on my rig and put the amp on from stanby(around 20 min) i start playing and the volume starts fluctuating from loud to soft and back on its own. I investigted some patch cables in my pedal board to see if one was faulty and finally just went direct guitar to amp. The fluctuations kept happening. eventually i turned it off and now am writing this!
Now where i live the mains are at 220 and this amp is a US voltage amp so 110. I run it through a power transformer and its worked fine for the last 4 odd years. Never ever had this problem.
Do you guys think a tube is busted? or something else is the culprit. Guitar pots are fine no problem there. the cable and input are all fine. It has to be the amp. Do i need to change out the tubes, have these ones worn out or do you think its my electricity thats irregular?
I connect the head into 2 different 'cabinets' basically 2 combo amps have that im connecting to the speakers of directly. both are at 8 ohm. again, ive run this setup and play almost everyday and this volume thing has never happened.
Any help is much appreciated!
Hello I want to exchange valves in my Origin 20h, ordered some aol login from Tube Amp Doctor. After I exchange them do I have to rebias it? Is there a manual for rebiasing? I wasn't able to find anything which would give me even slight bit of a hint about it .
Hi Marshall team,
so now I know I can use my origin 20 head without any cabinet connected, taking the sound from the DI out.
But my question is...can I use it with the master volume at 6-7 (1-2 o'clock), to get tube breakup point and creamy sound, like I usually do when the head is connected (through an attenuator) to the cabinet?
Is it safe to crank the volume (max 6-7) when using just the internal dummy load?
Please let me know, THANKS
Should i connect my wah pedal and tube screamer to the fx loop of my dsl20 combo or directly to the input? Can you tell me the difference and if it's possible of causing any damage? Thanks
Does 5w combo 5C need rebiasing when replacing tubes?
It´s a Class A amp?
Hello friends at marshall
Just bought a new DSL20 combo and i would like to ask if i can install my AMT S-11 tube preamp pedal to the amp without causing damage.
Thanks in advance
I am getting a high pitch squeal out of my amp but only in the OD1, and OD2, channels in anything above green channel. Tubes have checked out fine. I am using a pedal board through the FX loop but I also use a Voodoo Labs isolated power supply. And I have pulled each pedal out of the loop, one at a time to see if it was a specific pedal that was causing the issue. Still squeals even without pedal board. It is becoming frustrating to try and determine what the issue is. Any suggestions or advice?
Where I can buy the Marshall Dsl40c's fuses?
I've had a hard time finding them. My Marshall went silence and I replaced all the tubes.
Running out of ideas.
What brand does Marshall recommend for replacement tubes? I would like to know what would be the best tubes to replace both the ECC83 and EL34 tubes with. I recently had the power tubes replaced under warranty and they used Groove Tubes. To me, they don't sound as warm as the original tubes. I play mostly blues and rock. I like the warm rich sound. I use the overdrive channel, but don't get into the metal sound.
Anyway, I figure I should ask the experts. If you could tell me where I might be able to purchase the tubes you recommend that would be a plus. I'm in the USA.
I recently acquired an Origin 50c. I love this amp and am very happy with it. I have been looking for info regarding tube replacement. I have found several places that indicate the Origin 20 is self biasing, but have seen conflicting info on the 50c. Does the 50c need rebiasing when replacing tubes?
I have a DSL15 that is humming a 120 Hz tone, even with all controls down. This tells me the trouble is in the power section. I checked the bias voltage of both 6V6 tubes, and they are there. However, when I checked the voltage across the plate current sensing resistors, one is around 24 mV, and the other is virtually zero. I swapped the tubes, and the voltage values on the resistors went the other way round. It looks I have a bad 6V6 tube, but I'dlike to confirm before I go buying a new one. Any thoughts?
Hello everyone i hope your all doing well
I recently we are talking the last 4 days purchesed my dream amp a marshall DSL100HR. I was very excited to finally be able to get my hands on a marshall super lead series amp. The dream has become a bit of a nightmare as currently i am the proud owner of a fancy paper weight. I handled the amp head with extreme care when i got it. I let it acclimate to my house temp befor even taking it out of the shipping packiging then when i did i was baby gental in doing so i set it up correctly and double checked so befor even powering up the amp. When i did power on the amp i let the tubes warm up like i read to do so i did this for 15m when i switched the amp to power low mode on i think that its 50watt in that mode. I heard a loud pop pop pop buzz and everything died the amp became unresponsive and the only thing that seemed to be working was that the tubes were lighting up properly and i could run the amp in standby thats it. the front panel was dead the foot switch was dead but the amp could still power on does anybody know what the hell happand ?
what did i do wrong did i just get a lemon ?
is this common with this amp range ?
I am not rich it took a lot of financial planning to be able to afford this amp i am so bummed out. I did speak to the place i bought it from and there sending me a return label and when they get it they will ship a new DSL to me but this whole situation sucks. Thanks for any insite and help i wish everyone well !
(update) I got the return label sent the amp head back there processing a new DSL100HR order for me i wont get it till tuesday/wensday hope the one they send me works ! If the new DSL100HR also has issues i will most likely swear off tube amps forever not at all pleased with my initial experience at all.
(update 2) I have the new DSL100HR and this one works so i guess i got a lemon befor all is well now enjoy your lives people stay metal ! stay rock and roll ! most important stay safe out there !