Caldo71
Active member
Okay @vigilante398 and everyone else, I need to preface this post by pointing out that I am posting build pics for you guys to examine (I know it's the first thing requested for troubleshooting, always) but you guys are going to find them to be an absolutely crazy-looking jumbled, inexplicable hot mess. And, well: it is.
So let me explain what you are looking at in the pics:
SO HERE IS THE WEIRD PROBLEM:
For whatever reason, this things sounds just fine with these NOS RCA tubes I've had sitting around the studio forever. Its what I first put in when I built the circuit, and it's stayed in there after deciding to incorporate the buffer and all that. Cool, fine. Never knew there was some underlying issue...it always worked.
HOWEVER: recently I decided to try some different tubes in it, and I bought myself some new production Mullards and Tung-Sols from Sweetwater, and they don't work! So weird. The filaments barely glow at the tips, and they never get to "full glow". And no sound comes out at all.
I first suspected bunk tubes, so I tried the new ones in all my tube amps, and they were just fine! Likewise, I pulled a really rando selection of new and vintage tubes (yes they are all 12AX7s) from those amps and stuck 'em into the Space Heater, and had the same issue: literally no tube in my arsenal will pass sound in the Space Heater except for these RCAs.
So what makes these RCAs different? And is something in my "exotic" build—i.e. the buffer or the power splitter—somehow keeping my Space heater from supplying all these other tubes with the juice they need?
it's a weird issue...any solid answers or even theories would be hugely appreciated. Sorry if any of my schemes and strategies verge on mental illness.
EDIT: thought I should mention that the 9V power supply I'm using provides a full 3A, in case anyone was concerned that I was not giving the pedal enough juice. Unless (again) splitting that out to the buffer is the issue?
So let me explain what you are looking at in the pics:
- I mount my stomp box circuits in rackmount enclosures, jutting out horizontally inside 'em, with the potentiometers facing the front face of the enclosure, extended out on little ribbon wire+pin header thingies. Back connections for in/out/power are on Molexes. So that gray plastic thing you see that looks like an oil rig? That's the armature that screws into the face of the rack enclosure and holds everything in place. it's designed and 3D printed by yours-truly.
- I found that the Space Heater was giving me weird volume drops when I put other pedals AFTER it, so you'll see a little "mini shelf" built into the 3D print on the left-hand strut? That's actually a @PedalPCB Simple Jfet Buffer....the Space Heater hits that on the way outta town, and it works to solve that problem. Impedance mismatch on the tube gear I guess? Anyhow it worked so I incorporated it.
- In tandem with that I have another little "mini shelf" built into the right-hand strut that holds a pedalpcb DC Jack Breakout Board, so I can split power as cleanly as possible to the Space heater and Buffer, and give myself some more grounding points.
SO HERE IS THE WEIRD PROBLEM:
For whatever reason, this things sounds just fine with these NOS RCA tubes I've had sitting around the studio forever. Its what I first put in when I built the circuit, and it's stayed in there after deciding to incorporate the buffer and all that. Cool, fine. Never knew there was some underlying issue...it always worked.
HOWEVER: recently I decided to try some different tubes in it, and I bought myself some new production Mullards and Tung-Sols from Sweetwater, and they don't work! So weird. The filaments barely glow at the tips, and they never get to "full glow". And no sound comes out at all.
I first suspected bunk tubes, so I tried the new ones in all my tube amps, and they were just fine! Likewise, I pulled a really rando selection of new and vintage tubes (yes they are all 12AX7s) from those amps and stuck 'em into the Space Heater, and had the same issue: literally no tube in my arsenal will pass sound in the Space Heater except for these RCAs.
So what makes these RCAs different? And is something in my "exotic" build—i.e. the buffer or the power splitter—somehow keeping my Space heater from supplying all these other tubes with the juice they need?
it's a weird issue...any solid answers or even theories would be hugely appreciated. Sorry if any of my schemes and strategies verge on mental illness.
EDIT: thought I should mention that the 9V power supply I'm using provides a full 3A, in case anyone was concerned that I was not giving the pedal enough juice. Unless (again) splitting that out to the buffer is the issue?
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