Effect of split cathode R values on parallel V1

[MORE_Guitar_Solos]

Hello all,


I have a half-AC30ish amp with a parallel 12AX7 for the preamp. Right now it's got a shared cathode resistor (I believe 820 ohm), and I've been considering switching in a 1.5k to get a higher plate voltage option to listen to. But then I wondered if it might be possible to have a different cathode R value on each half of the paralleled V1. Has anyone tried this? How does it sound/does it work?


Thanks!

[ALBATROS1234]

I built a 1965 Supro 24 clone and instead of putting separate inputs and using 4 jacks were I could jumper the channels i wired it to be permanently parallel with one input jack and I used 2 different kathode bias resistors and if I remember right I only bypassed one triode because I wanted each triode of the V1 12AX7 to have different characteristics. In the Supro 24 each channel has a volume and tone. I really love this amp because I can use the volumes and tones to dial in so many tones with so many levels of gain. One channel I bias hotter and thats the volume and tone which has the bite and the other triode has much more bass and different mids. I have 4 knobs 2 volumes and 2 tones to dial in the perfect tone. oddly one of the tones somehow increases gain when I bleed off treble so I am able to seriously dial in an amazing tone depending on which guitar I use etc. So in my opinion you cant go wrong with a parallel stage with separate controls. It really gives me alot of control over gain and tone in this amp. I was going to do a Supro lite like slucky posted where you use a switch to select each channel or jumper them but then I decided I would likely jumper channels all the time so I wired it that way and with the two triodes set up differently I feel I get a depth and texture I would not get with the channels separated.

[MORE_Guitar_Solos]

Albatros1234, thanks for the reply. This amp is basically a 2-el84 version of the Hoffman AC30, without the normal channel. The free 1/2 12ax7 is used up paralleling the preamp. So there's a single input jack and single volume control. No mixing would be possible, but I'm just curious what would happen if I had differing cathode situations on a parallel 12ax7, for example one half 1.5k/25uF and the other 2.7k/.68uF. Anybody done this?