I have been using my El84 20/20 with a 2x12 1936 cab in stereo for 5 years.

Resently the right side has started to  intermitently  go quite compared to left.

Ive had it looked at by my local repair shop but they cant find the issue

and I ve changed the power tubes on the right side only to see if that sorts it.

It didnt.

I cant find much about the same problem online so I guess its not common.

Any thoughts?

Cheers

Hello,

I recently purchased a Marshall Origin 20 Head and I am experiencing a rattling sound. Could this be the tubes or could it possibly be something else? Is there anything I can check on my own to narrow down the problem? 

Thanks,

D

Hi

Can any one suggest what preset and adjustments to get a Tube Screamer sound from my code 50

Thanks in advance

Hi - 

  I wanted to change the power tube in my DSL1HR Head.  Will it need Re Biasing ? or I can go ahead and just swap the tube and no problems it is good to go. 

Thank You

So I have a 1977 JMP 50 watt 4 hole amp. S# 474j.  Model says M2100. I was told when I bought it used it was a special order amp. It was not available at any dealer. It was a 212 combo. I took it out of the combo box and got a mojotone headshell for it. It is all original except for the case/box. It still had Marshall branded pre amp tubes when I got it. It has GE 6550 power tubes. I am thinking of selling it. Does anyone know the value of an amp like this. The Doyle book doesn't talk much about it, he says no bother, very few people will have one. Well I do but don't know anything about it.  

So I thank you for the reply. I tried to send pictures to the link in your email but I kept getting them returned.  Is there another way to get pictures to you? I tried the insert tab here but it just says link? I am technically challenged,  sorry bout that.

Any help would be much appreciated. 

Erik

5702298697

My 1974x amp is quiet when nothing is plugged into it, but as soon as I plug my intrument cable into the non-tremolo channel, I get this awful cyclic noise.  Does anyone know what to do?   I replaced the ECC83 tubes one by one (testing it between each tube replacement), but it didn't fix the problem.

Here's a video of my problem.

https://youtu.be/lN_lhUAu7jA

Is the DSL5CR Combo cathode bias or will I need to bias the amp after swapping tubes? Pre-amp and power amp tubes? Thanks in advance

Amp is a little over a year old was fine then past few weeks after warmup the volume would dump. All cables, inputs were checked and new JJ tubes put in which seemed like it fixed the issue However when I engaged the Tone Shift button the volume dumped again and when manipulating this button it caused the amp to crackle and seemed to be shorting out the power which intern was dumping the volume.. My tech replaced the Tone Shift curcuit but still when pushing the button in it causes the same issue, we are at a lost..and frustrated...Any Comments or Suggestions greatly appreciated

Dear,

I have a new Marshall DSL1CR and it make a popping noise when changing channels from the Ultra gain to Classic gain while playing.

If I mute the guitar, or changing channels from the Classic gain to Ultra gain or using the emulated out there is no pop.

There is same noise when switching off it.

Is it normal or somethings wrong with my combo?

Thanks & best regards.

I need a new circuit board for my Marshall 20/40 combo amp. I turn the amp on and it will play for a little while and then all sound ceases until I turn it back on. I've change out tubes to no avail and I broke out my old amp mod equipment and tested circuits. That's the only piece I am unfamiliar with so I'm thinking that's the issue. My vendor tells me they can't order it because the amp is discontinued. Where can I order one so I can fix my amp?

Hello everyone,,

I know that turning a "TUBE" amp on without a speaker load on the output will damage the amp.

(the no-load condition will cause the output voltage to increase until the output tubes burn out, which can then lead to other component  damage)

Is this also true for a CODE 100 amp?  Is there a risk of damage to the output section, with turning the unit on without a speaker cab load connected?

Would it be safe to operate the amp with just headphones connected instead of a speaker cab?

Would it be safe to operate the amp without either a speaker cab or headphones connected?

I ask because my computer (which is a desktop) is in a different location in my house than my amp.

Doing firmware updates or testing out patches requires either moving my computer or my amp, both of which are very inconvenient.

It would be much easier if all I had to move was the head.

Hello

I want to exchange valves in my Origin 20h, ordered some 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

iosman

Currently my JVM410HJS squeals periodically.  Initially this would only happen occasionally and I was still able to gig with it, but now it has become to frequent to use.  It will do this even if unplugged from a guitar and will do it no matter which channel it is on.  Channel switching does not stop it.  I am not sure where to start.  Am going to change out the tubes and reset the MIDI switch, but otherwise will have to travel a good distance to find a qualified tech.  Anyone else ever had this issue?

Ive started playing guitar again later in life after first playing at the age of 10. My skill level is probably moderate but I enjoy playing again. I don’t gig or plan to be in a band. I’m either playing at home by myself or I have a buddy that I will go play with at his house. I have a couple nice Epiphone’s and 2 Yamaha DG60 amps. Theses amps are pretty good and have allot of different adjustments for different sounds. They both have an intermittent issue where something cuts out like the gain or reverb. I’ve though about taking them to get looked at but that’s another decision other then my request. 

Lately I’ve been kicking around getting a new amp. The more research I do the more I get confused. Get another solid state amp, a modeling amp or a tube amp. I’ve never had a Marshal and out of pure envy I’d like to get a Marshall but only if it’s the right amp for me. Money isn’t a deterrent. I’ve worked my way up to looking at a Marshall combo 2x12 100 watt. JVM210C. 

The reallity is I don’t think a 100W tube amp is a smart choice for me. Currently I play my 60W no more then 50% volume. And from what I’ve been told is you need to turn up a tube amp to saturate the tubes to get the most out of the sound. I’d probably only turn a 100Watt up past 50% on rare occasions like when I’m drunk and think I sound better then I really do. 

Is there a 1x12 or 2x12 Marshall tube amp that you can switch between 50W and 100W? That might satisfy my needs? What about the JVM215C? What about the code 50?

I should note I like to play classic rock/rock and metal, Led Zeppelin, Black Sabbath, AC/DC, Kiss, Jimi Hendrix, UFO, OZZY, Pantera..... 

I want something that sounds great played quite or LOUD! I don’t want something that needs a bunch of pedals for different sounds. But I don’t want an amp that has a bunch of effects but just has that fake/cheap sound. I know I’m asking allot. I just need some good advice from someone that has been around music allot and has knowledge about amps. Then I can narrow down some choices and then go to a guitar center or somewhere  and play a couple!

Thank you in advance,

signed “confused” Jeff

Hey Mates,

Having issues with a clients amp, seems that after a retube that i did, he was playing and after about 30 min, it gradually started losing sound and then cut sound completely.  I did the re-tube myself, and biased it properly and i was able to play it for about 40 min with absolutely no issues.  List of troubleshooting steps i have done:

tried a different speaker cable

tried a different guitar cabinet

tried a different guitar and guitar cable

tried the old tubes, additionally bought a 12ax7 and tested each pre-amp tube

tried a different power source

Have tried different power tubes

have checked and replaced the fuses

Now this is what i am THINKING is the problem, I think it might be something with either the heater curcuit fuse, or i think it's called a BRT1 Rectifier?  I did alot of research and it seems that the people having MY issue, explain the same symptoms of what i am having.

Now i have to make this clear, I AM NOT A PROFESSIONAL TECH, just a guy helping bands out with tech stuff that they don't know how to do.  So any help is appreciated.

Thanks!

Hi. I have bought the Marshall Code 212 cabinet with 8OHM. Now I want to buy Marshall DSL1HR tube head with 16OHM. Can I connect 16 OHM head to 8 OHM cabinet? Thanks in advance

So I've been thinking about buying a Celestion F12-X200 speaker for my code 50 and was wondering it this would work. The reason I need to know this is because even though I know you can use an 8ohm speaker on a 4ohm tube amp, I'm not sure about a digital amp. Could anyone tell me if this is possible.