Tri-Valvecaster Circuit Diagram Questions

[Deude_Band]

So I am new here but I have been reading and reading and listening to youtube vids of various overdrive setups and think I know what I want to build. After watching this video, I am convinced I can hear a difference in the 'richness' of the overdrive sound as each of the three gain stages are activated (in series)
https://www.youtube.com/watch?v=7KLEQwUm5Pw

I looked around and have seen comments on a tri-valvecaster, including comments on the video above, but no schematics. So I have drawn up a schematic in LTSpice (as bast I can) and am posting it here for some feedback on whether the wiring scheme is correct and on component value selection. Here are a few comments and questions:

1. The way this is set up is each of the three stages is added in series via the three SPDT switches S1, S2, and S3. In the top position the switch sends the input into its respective preamp stage (to the right). In the bottom position it sends the input to the output 'bus'.
2. At the end of the output bus is a volume adjustment that will adjust the overall volume for however many preamp stages are connected.
3. Note that the preamps only work in series. For example, if S1 is in the OUTPUT position (straight to the output) then it does not matter if S2 or S3 are in the PREAMP position... The output will still be straight through; S2 and S3 have no effect.
4. All of the three preamp stages are the same. I believe this will work from what I have read about other multistage valvecasters but let me know if this is not correct.
5. Note that I am showing this with a drive (?) voltage of 48V. I have read here and there that even though this is still below where the tube is designed to operate (200-300V) that it still makes a difference vs say 9V. I have used 48V since this is normally considered intrinsically safe and unlikely to present a safety issue.
6. Now, on the heaters.... I have not shown the heaters wired here even though I know they need to be wired. I have seen it done two ways, that is with the heater voltage wired across pins 4 and 5, and with 4 and 5 wired separately and then grounded to pin 9. The former seems to be common practice, but the latter seems to be recommended as a means for common mode rejection of noise that might be in the heater voltage source. Comments? Recommended voltage? Does the pin 4 to 5 scheme require 12V, and the 4 to ground and 5 to ground scheme require 6V (half the resistance)?
7. I plan on building this into a 1U rack mount case due to the way I have my bass guitar set up. I am running it through some other effects that are also 1U rack mounts and it would be nice to have it all together. If I decide I need to have stomp switches I'll add those later.
8. This is for a bass guitar. I am using passive pickups (EMG Geezer Butlers on J and P) which are on the hotter side from what I can tell. I am looking for something from light overdrive to full metal crunch. Think Chris Squire on the low end and Dan Lilker (S.O.D.) on the other end. If anything I would like to err on the lower side of overdrive, so please let me know if my component values are at least in the ball park.

As an aside I bought a Behringer VT999 and am playing around with that for now with the stock tube and some different ones on the way.   

OK, I think that is enough. Please excuse my newbness and point me in the right direction. Thanks in advance

[Deude_Band]

Here is my schematic... ***NOTE THIS SCHEMATIC IS INCORRECT. I have only left it for reference***

[Deude_Band]

For those who have no idea what Chris Squire and Dan Lilker sound like (even though both sold a ton of records) here is some info:

Dan Lilker attributes his sound to a Tech 21 SansAmp GT2 pedal, even on SS amps. Here is an example:
https://youtu.be/qZSTfGIoPLc?t=85

From what I have read, Chris Squire (RIP) played a custom Rickenbacker with split outputs going to two different amps. One output he ran with low tones with distortion. The other output was run high with no distortion. That is how he got that great growl sound but still had the attack that let his virtuosity come through.
https://youtu.be/0vNcgL9Fi4w?t=30

I have set my bass up with dual outputs via a 1/4" TRS jack. I have the mix from the EMG Geezer J and P on one channel and a DIY piezo bridge setup on the other channel. All three pickups have their own volume on the guitar so I can adjust the mix on the fly. There is tons of attack from the piezo channel as it sounds almost acoustic. I run the J and P pickups through the distortion and run the piezo clean with tone mods.

[mozz]

Not quite right, the second cathodes are floating. C1, C7, C13 you don't need. I only see use for 1 tone control, your last stage would be the one to use tone if you picked only 1 gain stage. You also may not need the cathode cap on second cathodes.
Middle stage i would run a .68 maybe on both sections?

[Deude_Band]

Oh crud... I see what I did on the second cathode. I'll fix that now, and simplify it per your suggestions. Stand by...


OK here we go...
1. C1, C7 and C13 were removed
2. C2, C8, and C14 all changed to 0.068uF or 68 nF (assuming that is what you meant, or did you mean .68uF?).
3. I put the tone control on the FIRST stage since it will always be used no matter what. If it were on the third stage, then it would only work when all three stages were connected, correct?

[Deude_Band]

And hopefully this simplification does not complicate matters, but this, if I have it right, would be a bare-bones, all-in, 'three stage' Valvecaster with no tone controls or volume output, just three gain adjustments. If I understand things correctly, this could be ganged with another overdrive pedal, though I suppose a volume pot on the output might still be desirable. I have also added the heater wiring.

Is this workable?

[Deude_Band]

Here is a google drive link if that uploaded PDF does not expand out. Someone else told me it did not work for them.

https://drive.google.com/file/d/1d5l1UYwHamGhZPUPyegHK5yrsR9Z8YGH/view?usp=sharing

[mozz]

The 0.047 can stay, I meant one of the stages to use .68 on the cathode caps, ala marshall. I'd run 12v heaters as you only need 150ma each, total of .450a. Running 6v you need 900ma almost 1amp power supply. It would be easier to find 12v/450ma.