where to put my pot?

[shooter]

I'm finishing up my 4th build which has basically a volume for treble n one for bass each after the filter circiuts.  I can add a master volume on the signal in or just in front of the PA stage, Parallel EL84's.
i find schematics with master volumes driving the PA stage but i also read where it causes "issues".  I don't have a traditional preamp in front of the PA, i'm useing v2 as a combiner/preamp.  Anyway, thanks for any help info

dave

[HotBluePlates]

Hard to say without seeing the rest of the amp schematic.

Basically, you want the volume pot to be in a position where it might help control the possible distortion in the preamp. That means looking at the circuit, estimating stage gains and guitar input level, and seeing where the preamp may run out of headroom and into distortion.

The volume control would then naturally go at or just before that point in the circuit, so you can actually turn down the volume control and get a clean signal (otherwise, you'd be required to turn your guitar down for clean, and depending on circumstances that may change the guitar's tone).

[embotone]

Don't put your pot anywhere where grownups can see it.

[shooter]

at 55yrs old i'm finding that grownup is something i still aspire NOT 2b.

i think my pot's ok , the amp still has kinks i'm workin thru, one question i have;  i'm using a weber PT, the 550v taps vs the 600v taps but i'm having a hard time knocking B+ down below 300vdc for the parallel EL84's  I have plate voltage at 288, screen at 255 but the plate resistor and tubes are both runnin hot, my fluke ain't measuring cuurent!!!!  but i'm using about 500ohms on each cathode so i'm thinking max I will be ok.  The B+ rail starts with a 250r and 40uf(tap A), then 10k and 20uf(tap B).  I had to add a 1k in series with the OT wire at tap A in order to get plate voltage on the EL's to 288 and that resistor, the 1K is runnin hot.  anyway, thanks for the help

dave

[HotBluePlates]

i'm using a weber PT, the 550v taps vs the 600v taps but i'm having a hard time knocking B+ down below 300vdc for the parallel EL84's ...

If you want your B+ to be at 300v, you need a transformer providing about 300v/1.414 = 212vac; that's a "212-0-212v" or "424v CT".

Realistically, you won't find that, so something like 220-0-220v or 440v CT is what you need.

I had to add a 1k in series with the OT wire at tap A in order to get plate voltage on the EL's to 288 and that resistor, the 1K is runnin hot.

I bet! Probably dissipating 10w or so, and if not a 25w resistor, it's probably crispy. 

You really don't want to do it this way. Best bet is a lower-voltage PT or bigger output tubes (or accept a B+ well over 300v).