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Poindexter's Musical Machine:Tube Power Supply Schematic

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Mr_Zenith

Mr_Zenith

Member
Joined 2009
#1
I'd be most grateful if anybody here could provide a copy of the 5AR4 power supply schematic for Poindexter's Musical Machine. The web is rife with the sand version, but the "new and improved" schematic seems to be lost to the sands of time (and yes, I've already searched this forum). The Wayback Machine has numerous references to his old site, but many of the schematics are missing - including that one.

And while I'm thinking of it: was there ever a specific schematic for the 6V6/6GK5 version of the MM, or was the builder just supposed to take the 6GK5 stage from the EL34 PP schematic?

Enquiring minds want to know... 😀
 
#2
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#3
Thank you, Leadbelly! I'm grateful. Embarrassed, but grateful. 😱

I've previously looked at all the links you provided on a new PC I just built, but with no luck. This morning I opened them using the browser on my phone and voila - the schematics on the links magically appeared! It turns out my PC's browser isn't happy with my OS, and that was preventing many of the graphics from being loaded.

D'oh!:cuss:
 
#4
#5
nerdorama said:
There are newer versions of the MM circuit, specifically using 6GK5 as the long tailpair and including a CCS as the tail load. I built this one on a breadboard a few years ago and it sounds really nice.
https://www.diyaudio.com/forums/tubes-valves/149211-6v6-music-machine-build-help.html#post1904511

There are also versions using EL34 and 2A3 output tubes. I built mine with 6B4G which is a 2A3 relative.

Good luck with you project,
John
Click to expand...

Could you point me to the 2A3/6B4 version? I'm curious.

Thanks,
Jim
 
#6
Here are a few links:
an early DIYaudio discussion: New project; Musical Machine

You should be able to adapt the triode 6V6 version for 6B4G or 2A3 with the addition of an appropriate filament transformer for each channel. I dropped the B+ on mine to 300V. Can't find the official 6B4/2A3 version right now.

Am attaching my schematics. You don't need the grid chokes on the output stage. Just use an appropriate grid resistor based on 6B4 or 2A3 data sheets or maybe the 6V6 original schematic.
John
 

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#7
I think VERSION is being laughably used here. Every amp that consists of an LTP driving PP finals, with drastic differences such as SS CCS or choke loading is not a VERSION of the Musical Machine. Or is my Ford a version of a Ferrari because it has 4 wheels?
 
#8
Kind of a silly waste of time argument. I used the exact driver stage from the later "versions" posted by Poindexter. There is a 2A3 or 6B4G schematic out there somewhere that gave me my original impetus to build it. So the only real difference is the grid chokes. This is the DIY tube forum after all so the terms used to give attribution to the original idea are just trivial semantics.
 
#11
I think your amp is great. That's the one that was a real hit at planet10's get together, right?

My pet peave is people who "discover" tube circuits, that can easily be found in textbooks, and put some flashy name or acronym on them as if it was their IP.
 
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