Marshall JCM800 2210 questions

[ruepselrum]

Hello everybody,

I have a long-time love/hate relationship to my 2210, fortunately it is turning more and more into love.

The main problem is that the clean channel is too low volume compared to the boost channel, moreover it's not really clean and sometimes produces some not so nice distortion, especially on attacks. This is, of course, bcause of the fact that I use Distortion Humbuckers and how I adjust the Boost channel, namely Volume on 10 and Gain on 8-9 (if Gain is further increased some kind of strange hissing is added, I suppose that's because of the clipping diodes).
But that way I like the distortion sound, even though that's not the intended mode of operation...

Now I heard about so-called tube-rolling, meaning that one or more tubes, preferably the input tube, to be exchanged with similar tubes of less amplification; e.g. 12AY7 or ECC832 replaces 12AX7. Could this solve my clean channel problem?
Has anyone done something like this at a similar amp and how was the result?

I'm also interested in mods
Sascha

[Pedro Vecino]

Now I heard about so-called tube-rolling, meaning that one or more tubes, preferably the input tube, to be exchanged with similar tubes of less amplification; e.g. 12AY7 or ECC832 replaces 12AX7. Could this solve my clean channel problem?

No. What you get changing tubes in that aspect is irrelevant.

Has anyone done something like this at a similar amp and how was the result?
I'm also interested in mods.

The only really good solution I have found is to reconfigure the clean channel (practically make a new one) and rearrange the phase splitter circuit if necessary.
You have information here:

http://music-electronics-forum.com/t36647/

[ruepselrum]

Hi Pedro,

you're my man!!!!!

I really appreciate your article about Split Channels, but there are still some questions I'd like to ask just for more clarity.

When you say it's preferable to assign V3 to the boost channel and V4 to reverb, is it just for "logical" reason or is there any technical aspect?

Writing of classical or asymmetric driver circuit, I assume you're talking about Phase Inverters and the depicted (with 82k and 100k plate resistors) is the assymetric one. Am I right? What then is the classic circuit?

Although channel bleeding isn't an issue with my 2210, I'd like to know which value would be better for the three muting capacitors instead of 0.22µF.

Where is the "100n capacitor added to avoid DC voltage in the new circuit". To the plate of V2a?

In which case do you recommend altering values of R41,44,45 an C32,34 as depicted?

Is clipping out C24 and increasing value of R29 an overall recommendation?

Did you do any mods to the boost channel?

Would you mind giving me some kind of extra advice concerning signal flow in the peamp, in other words, which tube belongs to which channel? I just had a look into the schematic and was a little confused about it. I think it's because of the channel switching circuitry and related cross connections.


I'd like to obtain a Twin-like Clean Channel and think your mod could do the job!

I recently watched a YT video where a guy presented the 2210 he bought from a Marshall tech, who also modded the amp. The main feature was bypassing the Master Volume for the Clean Channel, thus obtaining much more volume in the Clean Channel and therefore better balance control between channels.
Do you have any ideas of how to achieve this?


I'm looking forward to your reply
Sascha