Marshall Artiste / Artist 2040 channel volume question

[tfb]

Hi, I'm asking this just in case anyone has one of these, and because people were so helpful previously.

I have one of these which, surprisingly given their reputation, I don' t hate.  It's a fairly early (tag-strip not PCB) combo one.  I don't use it that much because I'm terrified it's going to go horribly and expensively wrong (also it's way too loud, but I have a powersoak now).  And now I am worried that it has.

It has two channels which are very (have always been very) different: one is a bit traditonally-Marshally, while the other has less top and sounds, to me, a bit Supro-y (certainly nothing like a sound you'd associate with a Marshall).  I suspect the Suproish channel was originally intended for organ or something, but I like it a lot.

So, something that I'm pretty sure used to be the case was that the channel gains were kind of the same (but I don't use it that much so I'm not sure sure).  But the Marshally channel is now a lot quieter than the Suproish one.  Good thing is that this can't be power valves (tubes) since they're shared.

So the question really is: can preamp tubes lose a lot of gain if they get sickly?  If they can, then I think my strategy will be to get some ECC-83s (I think I have a stash in fact) and just swap them in to see if it makes it better.

Alternatively, if someone has one of these, and knows that the channel gains really are wildly different, that would ease my mind.

Thanks

[Steiner]

I've never experienced that magnitude of loss in pre-amp tubes (valves).  Experimenting with 12AX7s is child's play.  You can swap them out while in standby mode.  Get a bunch of small containers, line them up nearby and transfer the original tubes into the containers.  In that fashion, you'll never loose the original order of the amp's 12AX7s (ECC83).

[kbp810]

It is plausible, and def worth swapping around some 12AX7's for troubleshooting before diving any deeper into it. 

[tbonesullivan]

When is the last time it was given a full service? Swapping preamp tubes and cleaning the sockets would be a good start if things aren't working right.

[tfb]

On 2/1/2021 at 8:38 PM, Steiner said:

I've never experienced that magnitude of loss in pre-amp tubes (valves).  Experimenting with 12AX7s is child's play.  You can swap them out while in standby mode.  Get a bunch of small containers, line them up nearby and transfer the original tubes into the containers.  In that fashion, you'll never loose the original order of the amp's 12AX7s (ECC83).

That's a good idea: I've got some newish ones (might actually be new) and I'll have a go at swapping individual tubes in and out.

On 2/4/2021 at 11:51 PM, tbonesullivan said:

When is the last time it was given a full service? Swapping preamp tubes and cleaning the sockets would be a good start if things aren't working right.

Well, before I bought it, anyway, so maybe twenty years (but I'm pretty sure someone had looked at it previously as it looks suspicously clean inside, although possibly it's just led a charmed life).  I think swapping tubes and reseating things generally would be a good approach.  I also need to look at the connections for the powersoak I have for it anyway (I seriously can't understand now how people use a 50W amp with no master volume without one, but long ago even I did...).

(As an aside, I looked at prices for these things and ... ouch.  What must good early 70s Marshall's cost?)

PS sorry for not reading replies till just now: I thought the thing mailed me when people commented but it seems not to.  I wasn't intentionally being rude, anyway!

[pressure]

5 hours ago, tfb said:

(I seriously can't understand now how people use a 50W amp with no master volume without one, but long ago even I did...).

We used those for practice. Fender Twin Reverbs were for performances. When I saw Johnny Winter he was playing through 2 Fender Twin Reverbs (with JBL speakers) stacked upon each other in a small venue. Ahhh that was the sound of Rock and Roll.