Muddy Orange channel: Dual Rec. 2 Channel serial# R0264

You said it was muddy before the retube and I'm assuming it didn't change much. With the Presence high, does it make a difference? Could you put Orange to Modern and see if it still does the same? Also, try silicon diode so the top end is crisper while you play with it.

You might try swapping out the preamp tubes one at a time with that new tube and reinstall V2 while you do so. That would at least eliminate the possibility of a failed tube. If the pin holes are dirty or corroded, you might clean them with contact cleaner. Another option is to open it up and look for blackened or broken parts and burns on the board.

Thanks for your reply, I thought more people might have had similar issue but I guess not.

I exchanged each pre-amp tube for the new one 1 by 1 testing each time and they were all good, same sound
I checked each of the pin holes they all look to be fine. I know this amp in it's like has almost no hours on it from knowing it's history.

I'll have to check inside the amp next and get some contact spray.

It's just the treble channel that makes the issue i think. When I turn it all the way down as it's coming down 5, 4, 3, 2, 1 it's getting louder then
when I turn it up it just sounds dumpy garbled. It's just not the sound I know from these 2 channels and never have heard an amps treble gain in
volume when it's turned down so I'm thinking it's there where the problem lies.

If anyone knows of what that is or means Id appreciate it. Is it a pot that could be it?

Thanks Guys
and Thanks afu I'll write back after I check the inside.

I was wondering about Modern cloned to Orange, because there's a filter between the Treble and Volume pots. If LDR 7 is stuck on, that filter will be darker than normal. The 10k resistor produces a boost in the filter's shelf for Vintage. Its function is like turning the Presence nearly halfway up with Modern Red; It brightens the sound. When Modern cloned Orange is used, LDR 7 turns on and bypasses the resistor. This is change is similar to turning the Presence all the way down with Modern Red.

Of course, there are other differences between the two modes and channels which will affect the sound, but that's what it does. You might even try going back and forth with the cloning switch a few times to see if it can reestablish a connection with that LDR (if that's the problem). Otherwise, the switching matrix might need a looksie.

Wow....All that would need a looksie brother your speakin a different language I wish I understood and not just for this situation.
I'll try the going back and forth with the cloning switch and see if has any effect on it. Past that I live about an hour from Mesa Boogie
and Gary is really cool but $250 is entry level diagnostics if I remember correctly so I'll try and see if there are any other amp repair guys
that are any good in the Sacramento Area.
Maybe I'll look here on the forum for that.

Thanks so much afu
Dave

If switching it around doesn't work, tell me if Red cloned to Vintage sounds right. That whole thing I described isn't happening there.

Ok, found something!

when switching from Bold To Spongy I notice the power light get dimmer likewise the switch from spongy to bold light gets brighter and I get bit more volume. This seams normal voicing going to bold
but the light was interesting.

More importantly, I did the cloning Red channel to Vintage and seemed to be somewhat normal with a bit more volume and each step of the way vintage to modern ect. upon switching the black rocker switch
In the back (just to make sure you know or I know what were talking about here). BUT, when I did the Orange channel to clean the amp totally cuts out. Nothing. switch it to the opposite (being it's only 2 poss. rocker switch) and it comes back on. I also switched btw modes of silicone vac. as well as bold and spongy just in case and nothing. Also on the Orange channels master or Gain knob when I crank it either way back and forth there's some scratching going on so I'm not a tech but new pot I'm thinking there.

let me know what you think but you got me in the right direction. Should have caught that before now just never go to that channel so didn't think about it.

Thanks Dave

Each switch in the amp uses a LDR (light dependent resistor) to open or close. It could either be a failure of an LDR or a problem in the circuit that turns them on and off. When Orange is Clean, LDR 16 seems to be one of the only placed where a problem could cut the sound. If LDR 16 (OR MV bright cap) isn't working correctly, it could affect the switches for 15 (OR MV path to next stage) and the LED for OR Clean. It might also affect the sound when OR Vintage is being used by drawing some signal away. This, instead of LDR 7, is where I would first look.

The lights dimming and become brighter with different rectifier and power settings is normal.

Does Vick or Third Age Amps or anyone else have input?