Hi all,
I'm a NEWB - so apologies for my ignorance in advance - I'm just starting out.
I'm looking to build a DAC with a tube rectified power supply. The DAC board I'm considering needs 7-9V AC or 12V DC (see here) or this snippet on power input from the manual:
Power input 7-8V AC or +-7-15V DC max 5W
So my question is - how do I design a tube rectified power supply to deliver 12V DC? I found this tube rectified kit and they recommend the input transformer - I guess I'm just not clear on the output voltage of this unit and how to get that (presumably much higher) voltage down to 12V DC.
(Also, clearly, I'm not sure of a lot of things - but I'm trying haha!)
I'm a NEWB - so apologies for my ignorance in advance - I'm just starting out.
I'm looking to build a DAC with a tube rectified power supply. The DAC board I'm considering needs 7-9V AC or 12V DC (see here) or this snippet on power input from the manual:
Power input 7-8V AC or +-7-15V DC max 5W
So my question is - how do I design a tube rectified power supply to deliver 12V DC? I found this tube rectified kit and they recommend the input transformer - I guess I'm just not clear on the output voltage of this unit and how to get that (presumably much higher) voltage down to 12V DC.
(Also, clearly, I'm not sure of a lot of things - but I'm trying haha!)
Tube rectifiers drop a lot of voltage, so they are seldom used for low voltage supplies.
The Tubecad board's tube rectifier is for a HV supply, typically several hundred VDC.
The Tubecad board's tube rectifier is for a HV supply, typically several hundred VDC.
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My inspirations for the projet are from the PSU stage of the Boarder Patrol DAC (here) which uses a tube/hybrid PSU (I think you can switch the PSU from SS to tube rectified), and from the Denefrips R2R DAC...
I was thinking I could source a DIY/OEM R2R board and mate it to a tube rectified PSU.
Am I dreaming too big?
I was thinking I could source a DIY/OEM R2R board and mate it to a tube rectified PSU.
Am I dreaming too big?
That´s not a dream but a nightmare, wake up quick.
Absolute nonsense, snake oil, b*ll sh*t, con game, ridiculous, you-name-it.
And in any case, impossible since it allready has built-in solid-state rectifiers,solid-state regulators and is, of course, a solid-state DIGITAL board, so tube rectification will add NOTHING to sound, and only work as a not-too-visible pilot lamp.
Be sure to provide a chassis-cabinet cutout so it can be seen from outside.
Or give it its own open top coffin, like in your examples.
Almost forgot, only power the filaments for the magic orange glow to appear, do not even *think* about using it for any kind of rectification duty.
I am certain your cherished examples do not, by the way.
They are snake oil salesmen, not fools.
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So, I've heard some interesting things about the tube rectifier in the power supply of the DAC... Steve Guttenburg did a good review on youtube of the Border Patrol. How much a tube in the power supply makes a difference, I agree, not much right - it's more just about the fun of the design that appeals to me.
Your other point on there being a PSU built into this board is completely fair though, and I was wondering how that would work if I fed it DC voltage.
Your other point on there being a PSU built into this board is completely fair though, and I was wondering how that would work if I fed it DC voltage.
If you want a tube rectifier for aesthetics, it might be easiest to just aim to build a low voltage supply, say something like a 25VAC transformer, try whatever you might have handy, and then just burn off any excess voltage with a 3 pin regulator. It might not be an efficient solution, but at least a DAC is low current and you will not be burning off huge amounts of heat.
Some amplifiers do use a solid state rectifier, with a series tube rectifier added as a soft start mechanism.
This will drop significant voltage, burn power, require an extra secondary winding for the filament,
and have poorer voltage regulation at higher currents. Musicians often seem to like very much this sag
under heavy load in their PA amplifiers, and that's fine.
This will drop significant voltage, burn power, require an extra secondary winding for the filament,
and have poorer voltage regulation at higher currents. Musicians often seem to like very much this sag
under heavy load in their PA amplifiers, and that's fine.
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As 'JMFahey' just wrote, it matters not whether you provide 7-9V AC or 12V DC. The actual DC supply is part of the circuit board. Maybe you should stop reading writers like Steve Guttenburg, as they are misguided.
Your trying to use a spanner to undo a screw.
The tube rectifier is completely the wrong method by any stretch of the imagination.
They work great at high inaccurate voltages but for low voltages you need to go solid state.
If someone tells you different they are seriously treating you like a plonker.