So ive been trying to build this pwr supply and i can seem to find the transformers it calls for … anyone know of any 1 to 1 replacements? (the transformer is a Jameco 102154)
/ there is the schematic im following /
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You can use any transformer at the right votlage and current rating, shouldn’t be too hard to find.
I see it says 12.6v, tube heaters are often 6.3v or 12.6v.
A 12v transformer should work just fine, 5% deviation for the filament voltage is perfectly acceptable.
Or are you referring to the center tapped primary coil?
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It’s hard to recommend sources unless we know where you’re located…
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Oh ok that’s what I thought. I was just a bit confused when looking at the schematic.
Also are you asking whether it has to be center tapped?
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You’ve got a dual power supply design from the vacuum tube era (we call them thermionic valves in the UK.). Transformer-based designs aren’t used with transistor circuits any more, hence the relative rarity of transformers in component supplier stock. The notation on the left hand side instructs you how to adapt this 110V circuit to a 220-240V supply, by using the entire primary instead of just the centre tap.
There are two stages, obviously. The first is a step-down which provides a heater (“filament”) voltage to keep the cathodes hot and make those electrons dance. The second stage takes the secondary of the first and feeds it to a step-up transformer (identical part number). After that comes a bridge rectifier (the four 1N4007 diodes.) to give a DC +150V, 0V, -150V supply. The 470 microFarad capacitors form a reservoir for smoothing. The discharge pushbutton is a safety feature, discharging the dangerous stored charge from the smoothing capacitors. You’d press that button before touching any component in the circuit and before turning the power on. Note the high (2W) rating of the resistors on the discharge circuit.
I hope this helps you to choose the right parts. Do be careful.
One alternative to this design would be to use two separate tube power amp supplies in series. For Eurorack power (+12V, 0V, -12V) there is a design that wires two Mean Well 12VDC power supplies together and, with caution, it should be possible to produce a similar arrangement using tube power amp supplies. I have not tried this.
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Thank you so much ! I thought it worked like you described but I wasn’t confident… and yes this is for a tube synth im making out of thyratron tubes
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A synth using thyratrons? There should be a name for the aesthetic. Not steampunk. Not dieselpunk. Radiopunk? Tubepunk?
Wikipedia informs me that thyratrons have a quite sizable discharge hysteresis which can be controlled by the grid voltage, and this property was exploited to produce a sawtooth wave in oscilloscope sweep circuits. A pair of them can make a flip-flop (pulse generator). So there’s your oscillator. Sawtooth and square wave all taken care of.
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Yup it’s pretty great !
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Here’s somebody’s thyratron synth. I post this photo to draw your attention to the two power supply enclosures–those large oblong grilles just behind the front panel. These are likely commercial PSUs with a high tension output, wired as I suggested earlier so as to produce a dual power supply.
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Tip: Don’t look up the prices of Metasonix modules 
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Ah, ok I’ll look into it… doing that will probably be easier than building a psu from scratch lol
It’s still not easy. Looking at Eric Barbour’s original article, he shows a design using a non-centre-tapped filament transformer and cites the Radio Shack 273-1511. This also seems to rather scarce nowadays. It doesn’t help that the brand is defunct.
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Here we are on Mouser. I found a 115V-6.3V 3.0A filament transformer as specified by Barbour in Fig. 2, called the Triad F-16X. Nice and reasonable price in the UK, but check availability and price in yours.
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yeah ur right, I think now that I look at it imma go with the second design that barbour did, it’s not my ideal but I mean it certainly is a start!
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