Hello, 

I recently found a JCM900 4500 series hi-gain dual reverb in mint condition. The serial is Y38091---I know that it was made in 1990, I was just curious past the "Y" what the remaining five digits might pertain to? I was really just intrigued by reading the history of these and was wondering if mine is one of the first few produced and if it would be possible to find out what tubes and components were used on this one. Also, is it possible to get a copy of the original manual? 

Thanks for any and all help! I love my 900.

hi , can I swap out the ecc83 preamp tube in V1 for a ecc81 in a SC20H? I’m just trying to lower gain to a much cleaner sound - preferably to the origin clean . 

Any suggestions - outside of “ buy an Origin “ ;) 

thanks 

p.s REISSUE THE JMD:1 heads !

Hi. I'm having a problem with my DSL5CR. When plugged direct into the amp and switched to the Classic gain channel it works perfectly. However, when switched to the Ultra gain channel, the guitar is very faint and what can be heard is a weak-fuzzy sound. When I first noticed the problem, I thought it was a case of the tubes needing to warm up, as after 30 seconds the level would gradually increase, unfortunately the problem has got worse. Could it be the pre-amp tubes at fault? 

Thanks,
Steve

Are there instructions on how to bias Origin 50 power tubes? A schematic?

I have a DSL40C i purchased in September. After a few weeks it started to emmit an arcing sound when in standby. I returned it to the supplier who found nothing wrong. It has been ok since except for a  wooshing sound when it is first turned on that stays at the same volume even if I turn the volume up but slowly dissapears over time (I assumed this was just the valves heating up and settling and happened in both normal and low power modes) Today it started the arcing again and it would not turn the volume off in standby mode, then standby mode started working correctly and now if i put the amp in low power mode the volume starts decreasing and eventually disappears after about 10 seconds. Normal power mode seems to be OK though. Does this point to defective tubes already?

I purchased a new DSL40CR  a few months ago. I think I need to replace some of the tubes/valves. The product is still under original manufacturer warranty, so I would like to take it to someone qualified to work on Marhsall amps, rather than change them myself. I have never owned a brand new amp before, so I don't want to void any warranty. How can I locate a proper amp technician in my area (Buffalo, NY) to help me with this? Appreciate any help. Thanks .

Dave

Hello,

can I use my JTM60 speaker with a Marshall Origin 20H Head?

Also, my JTM60 has suffered some damage when my nephew tried to power on the amplifier, she cranked everything up but didn't succed, when I got home I didn't noticed it was all cranked up and powered it, it blew tubes and some more, I had it repaired but it didn't get back to the same sound as before... I'd like to have it checked by qualified personnel, can you indicate someone in Italy, please?

Thanks a lot,

Marco

Got myself what i thought could be the greatest idea of an amp,Origin 20h.  looks awesome , plenty of clean , Too much clean , i can t seem to get gain and dirt out of it , i tried with Humbuckers seymour"s Pearly gates, and Aph-1 ( little gain but just to mention )  and with my strat with ssl-1 and ssl-5 it was cleaner than my fender Blues junior  ??  is there a way i can get it to growl more , change tubes? what should i put in  to get it the meanest ? i reallythought i could drive it better , oh yes and the treble, mid , bass, no big difference there also .  Not sure i want to invest to much in case there is no significative results.  what should i do to get real gainy dirt, please don t answer me to by a jcm900. cheers

Somewhere on the internet it was mentioned that replacing the power tube of a DSL5CR does not require to re-bias as the DSL5CR is a "self bias" system.
Can anyone confirm this?

Other question what would be the best brand to have for my DSL5CR power tube?

Hi all, i’m looking to buy a new marshall sc20c jcm800 tube amp and get payday loans 24/7 and it doesn’t have a headphone jack . Could i plug headphones into the jack called “DI OUT” or not and what does this do?

Hi,

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.

darmowe dzwonki na telefon

Hi,

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)?

Thanks!

Hello,

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.

thanks

alexsunny

Hello,

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.

Thanks,

Alex

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?

Kind regards,
Leonardo Bortolin

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. 

Hey 

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 .

thanks