Pushing the limits of TDA1543 NOS DAC

[Peter Daniel]

Preferably, you would need 1x 8V and 2x 5V regulators.

[manollo]

Thanks Peter

[maartentje]

Hi guys,

Having a hard time getting the BSP129, you think the 2sk2836 would be okay?

Thanks

[maartentje]

never mind the 2sk2836 is hard to get as well.

[le´flu]

Hi Peter,
did you ever tried reclocking with your DAC?

Greetings Ulf

[Peter Daniel]

Yes, I did, and never liked it.

[maartentje]

I'm trying to get the voltage regulator to working. For some reason the BSP129 Current source does not work. The BSP129 are new but give zero current.

Also tried to connect the gate and source together with 15v at the drain still same problem.

Pin 1 is gate
Pin 2 is drain
Pin 3 is source

[Bobken]

Originally Posted by maartentje

I'm trying to get the voltage regulator to working. For some reason the BSP129 Current source does not work. The BSP129 are new but give zero current.

Also tried to connect the gate and source together with 15v at the drain still same problem.

Pin 1 is gate
Pin 2 is drain
Pin 3 is source

Hi,

If as you suggest here there is is no output after the depletion mosfet, unless the connections are not correctly arranged, this implies that the mosfet is damaged.
This arrangement with a resistor and a depletion mosfet is a text-book implementation for restricting currents, and being so simple and with merely 2 components involved it is difficult to understand how it can go wrong otherwise.

I have been using variations of this circuit for maybe 10 yrs now and never experienced any problems with these mosfets, nor with DN2540 which are also frequently used to regulate currents in a circuit like this.

By way of encouragement, when you overcome the problem I believe you will like the results. For this particular DAC circuit it is the finest-sounding regulator out of a great many I experimented with during the past 4+ yrs, and Peter seems to like the results as well.

I hope that you are able to resolve the problem soon.

Regards,

[maartentje]

Originally Posted by Bobken

Hi,

If as you suggest here there is is no output after the depletion mosfet, unless the connections are not correctly arranged, this implies that the mosfet is damaged.
This arrangement with a resistor and a depletion mosfet is a text-book implementation for restricting currents, and being so simple and with merely 2 components involved it is difficult to understand how it can go wrong otherwise.

I have been using variations of this circuit for maybe 10 yrs now and never experienced any problems with these mosfets, nor with DN2540 which are also frequently used to regulate currents in a circuit like this.

By way of encouragement, when you overcome the problem I believe you will like the results. For this particular DAC circuit it is the finest-sounding regulator out of a great many I experimented with during the past 4+ yrs, and Peter seems to like the results as well.

I hope that you are able to resolve the problem soon.

Regards,

Hi Bob,

Thanks for your input. The fets are out of a reel of 50 i tried 2 with the same result. I just connected as followed now: 15v at the Drain, 10ohm between gate and source, then 220ohm from the gate to ground. There is 0Volt over the 220ohm resistor.

If connect the 220ohm resistor at the source and then to the ground. and i hold my finger on the gate then there voltage of around 8volt over the 220ohm.

Can't figure out what the problem is yet.

thanks

[Peter Daniel]

This is how I have it connected.