Im hoping to build a low voltage tube preamp module for my existing modular preamp that uses lm317/337 regulators for the psu. As part of the design constraint i need a way to increase the voltage coming out of the 317 regulator which means a voltage multiplier will have to go AFTER the regulator. Seems not likely since the multiplier is a passive circuir but will i risk oscillation regardless? And if so what are some better alternatives?
A voltage multiplier works on AC, and the output of your reg is DC, so that wouldn't work.
Depending on the voltage and current you need, you can do a voltage multiplier on the transformer AC output, followed by a high voltage regulator, like this one Linear Audio T-reg V5 – diyAudio Store
Jan
Depending on the voltage and current you need, you can do a voltage multiplier on the transformer AC output, followed by a high voltage regulator, like this one Linear Audio T-reg V5 – diyAudio Store
Jan
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30v for ecc86 in a white cathode follower mode for one. Im open to suggestions however. Im only at an idea gathering stage
30V for B+ ? That sound rather low. And you wouldn't need any voltage multiplier for that.
You have a schematic?
Jan
You have a schematic?
Jan
The most logical solution if you just begin to examine your options is to provision the supply accordingly: a dedicated transformer winding for example.
It could make sense to use a common supply: you could use the 6.3V AC of the heaters to drive a 4-stages voltage multiplier. The current draw of your tubes is probably minimal, a few mA, and it is a perfectly viable option.
If you want to use a single DC supply, you will need some kind of DC/DC converter.
You have a wide choice of modules "Traco power" etc available from the usual sources.
You can also brew your own: for a low power level, and with efficiency largely irrelevant (the heaters power will always be vastly larger), a single-transistor LC oscillator will work quietly and reliably, unlike cheap DC/DC modules.
You can also look at the application examples of converter ICs: all major manufacturers have some in their portfolio, and if you follow the guidelines, it is a safe option; probably vastly over-dimensioned for your needs, as they will be able to supply a few watts, but who cares?
It could make sense to use a common supply: you could use the 6.3V AC of the heaters to drive a 4-stages voltage multiplier. The current draw of your tubes is probably minimal, a few mA, and it is a perfectly viable option.
If you want to use a single DC supply, you will need some kind of DC/DC converter.
You have a wide choice of modules "Traco power" etc available from the usual sources.
You can also brew your own: for a low power level, and with efficiency largely irrelevant (the heaters power will always be vastly larger), a single-transistor LC oscillator will work quietly and reliably, unlike cheap DC/DC modules.
You can also look at the application examples of converter ICs: all major manufacturers have some in their portfolio, and if you follow the guidelines, it is a safe option; probably vastly over-dimensioned for your needs, as they will be able to supply a few watts, but who cares?
Not mentioned is the DC source voltage available?
The previous posts are speculations without all the facts.
The previous posts are speculations without all the facts.