Welcome • User Guide
ToS • Privacy • Canary
Donate • Bugs • License

©2024 Poal.co

1.4K

This is a 1960s external power supply that was very common. It supplied +830 Vdc, +300/+250 Vdc switchable, -130 Vdc bias, adjustable ~50 Vdc bias, +6 Vac filament, +12 Vac filament via a crazy 11-socket plug. It featured external on/off, a "circuit breaker", and could optionally fit inside the company's speaker enclosure.

Older poaler bears (@Owlchemy) will recall fondly the Heathkit phenomenon, whereby inexpensive (relative to others on the market) kits were made for adults and older children to put together themselves! Think of it... soldering, deadly voltage... could never do it today.

As with any old electronics, as @sporkulon can attest to, capacitors will probably be bad, and given the price to replace, worth doing. In the case of this power supply, it was so common that a couple folks have made printed circuit board replacements for the direct point-soldering method of circuit construction, and everything fits in a smaller space (while still using the transformer, choke (inductor), switches, and mounting points.

  1. Comparison of my grandfather's work vs. mine (picinfinity.co) (he had lead solder probably!) soldered all diodes, resistors, capacitors to the PCB
  2. Old unit didn't have the cover that came with it; wasn't a big deal before but now there would be exposed 800 Vdc so good idea to get a cover off eBay (picinfinity.co) and spruce it up (picinfinity.co) with some matching paint.
  3. Hardest part was doing the point-soldering of old wires to the underside of the PCB; several needed extensions. OLD (picinfinity.co) NEW (picinfinity.co)
  4. Outside view, OLD (picinfinity.co) NEW (picinfinity.co)
  5. Finished, with cover (picinfinity.co)

I hereby declare this as the coolest thing any of us faggots did today

This is a 1960s external power supply that was very common. It supplied +830 Vdc, +300/+250 Vdc switchable, -130 Vdc bias, adjustable ~50 Vdc bias, +6 Vac filament, +12 Vac filament via a crazy 11-socket plug. It featured external on/off, a "circuit breaker", and could optionally fit inside the company's speaker enclosure. Older poaler bears (@Owlchemy) will recall fondly the Heathkit phenomenon, whereby inexpensive (relative to others on the market) kits were made for adults and older children to put together themselves! Think of it... soldering, deadly voltage... could never do it today. As with any old electronics, as @sporkulon can attest to, capacitors will probably be bad, and given the price to replace, worth doing. In the case of this power supply, it was so common that a couple folks have made printed circuit board replacements for the direct point-soldering method of circuit construction, and everything fits in a smaller space (while still using the transformer, choke (inductor), switches, and mounting points. 1. [Comparison of my grandfather's work vs. mine](http://picinfinity.co/d/c4247ab5-e3e9-4ff7-855a-07bb4ccd231f.jpg) (he had lead solder probably!) soldered all diodes, resistors, capacitors to the PCB 2. Old unit didn't have the cover that came with it; wasn't a big deal before but now there would be exposed 800 Vdc so good idea to get a [cover off eBay](http://picinfinity.co/d/6baf1c5a-14d9-43c5-b89e-3d4d5018f1f5.jpg) and [spruce it up](http://picinfinity.co/d/32a46305-5c04-4384-a717-361d85a2f602.jpg) with some matching paint. 3. Hardest part was doing the point-soldering of old wires to the underside of the PCB; several needed extensions. [OLD](http://picinfinity.co/d/773d32d2-e4d2-45c0-9f52-70577a5f49a7.jpg) [NEW](http://picinfinity.co/d/d8267eec-c9bd-4615-bad6-b6ce873a42ae.jpg) 4. Outside view, [OLD](http://picinfinity.co/d/fe9df325-40ee-4d5a-89cb-e8756f522906.jpg) [NEW](http://picinfinity.co/d/38211039-a7a4-44ed-80c4-7d3462c2687f.jpg) 5. [Finished, with cover](http://picinfinity.co/d/11591e15-c161-4b25-8fd8-444629886522.jpg) I hereby declare this as the coolest thing any of us faggots did today

(post is archived)

You are currently inside a comment thread.
Click here to see all the comments (8).
[–] • 1 pt

Another thought. You could try and source switching power transformers and go all out. Those old linear types suck the juice and make heat like no tomorrow. Just replaced a 16 volt transformer in a 1955 GE tube radio and it went down to 72 degrees operation @ 69 degrees ambient from 147 degrees, the thing ran so hot it had dried up the vent holes carved in the wood.

[–] • 1 pt

Interestingly, a lot of the old radio equipment with crystal oscillators are designed to operate hot, to avoid temperature variations from affecting the frequency stability & noise. The oscillator is built into a purposely hot "oven" part of the radio. Idea is if it's ALL really hot, then variations in ambient don't affect measurably affect the signal

[–] • 1 pt

That is a fact, I wrap stuff in heat tape to hold temperature in. Losses some of the "Warmth" in the sound from less heat due to it being switching and giving just the power needed instead of the full current at all times as well as the waste heat of a linear supply. Even analogue sound interfaces for computers sound waaaay better hot like the c64 SID or Apple II mockingboard, but then they are hot and die faster. It is a line to balance I suppose.