Express Gain Stages/EQ pots

[EtherealWidow]

Ok, so maybe I totally don't understand how the different gain stages work, but I'm wondering if the different stages and triodes apply to one of the EQ settings. I know that all the channels go V2, V1, V3, and then I don't know if the driver is before the reverb. What I'm wondering is: if I change out the V2 tube, will that affect the gain and treble? If I change out V1, will it affect the mids? Same thing with V3 and the bass. I know V5 will affect reverb and V4 will affect the dynamics of the amp. Any help is appreciated.

 

[J.J]

The Eq (Bass, Mid and trebble) is a package, and can be thought of as a stage in itself. None of the gain stages will effect just one of the eq ranges. Changing any of the pre tubes will effect gain and tone with V2 being the most sensitive to change. V5 will have the least effect as it is only mixing the reverb signal in. The reverb sound however can be changed significantly with tube changes.

One thing I have found that wasn't expected is that V4 can also have a significant effect on the tone. Other amps I have played with were not nearly as sensitive to driver/PI stage changes.

 

[EtherealWidow]

Ohhh alright. That makes sense then because when I charted out the signal path through the tubes it didn't quite add up. The clean channel was the odd ball. Thank you though. This helps a lot and actually de-complicates things a bit.

 

[ddmeburger]

I looked for this in the other threads, saw some references to it, but not the complete picture. I tried to chart out the preamp path for all four modes, and found a couple of description inconsistencies in the manual.
a) V2A is the 1st gain stage, and V2B is the 1st gain stage for Clean. They both can't be first, can they?
b) Ch 1 and Ch 2 are mentioned, as well as Clean and Overdrive. It seems Clean and Overdrive equate to Ch1 and Ch2, but do they, or are they relating to the Clean and Burn modes and not the two channels?

So in my attempt to chart all four modes, I assumed that Clean equates to the channel (not the mode), Clean and Blues have three gain stages, Crunch and Burn have four, and V2B's description is incorrect for the Clean channel. That leads me to the following.

GAIN.....Stg1..Stg2..Stg3..Stg4
Clean....V2A...V1B...V2B
Crunch..V2A...V1B...V2B...V3A
Blues.....V2A...V2B...V1A
Burn......V2A...V2B...V1A...V3A

Please refute at will and point out my flawed assumptions and deductions!

By the way, just picked up a 5:50 1x12 combo a couple of weeks ago. I had tried a Trem-o-Verb years ago, and felt the liquidity of the gain would make everyone sound like everyone else. This seems more expressive (no pun intended), with a more open and organic feel to it. Sounds great so far, and I'm sure there's a LOT more in there I have to experiment with in order to elicit it. Looking forward to the hunt!

 

[Don]

Both channels go through V3A.

I believe that the clean channel is-
V2B, gain control, tone controls, V1B, V3A

And the dirty channel is-
V2A, gain control, V2B, tone controls, V1a, V3A

Maybe.

 

[Mark 63]

The tube task chart in the manual is confusing, especially with regard to V2A/B and V3A.

Do both the Clean/Crunch and Blues/Burn channels have 4 gain stages as the task chart implies? It looks like Clean/Crunch has 3: V2A or V2B, V1B and V3A.

Maybe this explains why Clean/Crunch is a quieter channel overall.



BTW, this is my first post. Purchased a used 5:50 2x12 before Thanksgiving and really loving it.

 

[FXR]

I sat down and did this with all 4 bias' using 4 stages and came up with the following. I never posted it though since I have no clue if it's correct. But WTH, we can discuss it I guess.


GAIN......Stg1...Stg2...Stg3..Stg4
Clean.....V2A....V2B....V1B....V3A
Crunch...V2A....V2B....V1B....V3A
Blues.....V2A....V2B....V1A....V3A
Burn......V2A....V2B....V1A....V3A

 

[Don]

They might have thrown us a curve on purpose!