Tubes for Synthesizers

Woah, Wendy Carlos vibes. Real synth head stuff right there.

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By the way, let’s all wish Wendy belated happy 81st birthday. She celebrated her birthday last Saturday, November 14th.

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Im just going to leave this here:

Sorry for not being able to continue the thread! Might take me a bit. I may or may not have lost my job so I’m trying to sort out the mess. Thanks all :slight_smile:

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I totally hear you. Feel free to vent in the “How’s everybody holding up?” thread.

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To avoid bulky mains transformers a smallish DC/DC converter can do the trick:
HV DC/DC converter
Note that 250V is still 250V even from a low-voltage to high-voltage converter. :skull_and_crossbones:

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Hey everyone! Sorry for running off like that - Life, ugh.

Anyway, I’m going to have a crack at making a few standalone tube filter modules which can be used either on a synth or with a guitar or anything else. I’m still validating the design and waiting for parts to arrive so it’ll probably be a couple more months before I can start making them.

The first thing it needs is a power supply, so I designed this one. It’s about 80% efficient (which is pretty poor) but at least it’s simple. This has enough kick to power eight tubes. The transformer is a Myrra 74060 and is readily available from RS or Element14. The smaller 74030 works fine too and gives about half the power. Watch out though, the output is about 210V (schematic updated with voltages and warning)

Here’s a rendering of the PCB too. The power supply bolts to it with standoffs. The whole thing only has two transistors (in the power supply). All active elements other than those are tubes.


The idea is to attach it all in this aluminium box available from Hammond Manufacturing


Here’s the box on the Hammond website. Be warned if you want to get one - the back panel and screws are sold separately!

A distraction too… they also have ones with wood panelling on them here

Cheers!

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Hopefully nobody who doesn’t know what they’re doing will try to build high-voltage [1] supplies, but I’d add a note to the schematics and spell out the cap ratings and connector voltages as well.

1) well, technically this is low voltage but that’s just because safe levels are defined as extra-low voltage.

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Done. Thanks for the tip!

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Got a video of the board working. Just a shame the PSU is under powered. Argh. I’ll make a new one. I’ve left a tube out that handles the LFO because of that.

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Returning to this thread to assist in a rapid descent down the tetriode rabit hole.
(ariving sunday)

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