Maida tracking preregulator?

[kacernator]

Hi,

is it possible to implement LM317 tracking preregulator as high voltage maida tracking preregulator? Is the schematic correct?

 

[kacernator]

I have Maida tracking regulator running up. Works fine and it sounds better! Highly recommended for maida builders as this is very easy mod.

 

[merlin el mago]

What are the benefits, subjective & objective speaking? could I use with Salas SSHV2?

 

[kacernator]

Subjectively I hear clearer sound, better resolution. Objectively you have more ripple rejection (not quite sure, but I think 8 times more).

I dont understand how you want to use this regulator with Salas shunt reg. Maybe before Salas reg?

 

[merlin el mago]

Yes, before Salas reg.

 

[kacernator]

Sure, why not. But I recommend you to try traciking preregulator wihtou Salas first, you maybe pleasently surprised.

 

[tomchr]

Do yourself a favor and use a more modern part than the LM317. While the LM317 was excellent in its day, modern regulators don't require as much current to regulate so you don't have to use the big honking power resistors.

The newer regulators also give you much better ripple rejection. In my setup, I ran a test with 50 Vpp ripple into the regulator. This resulted in 20 uV of ripple (+noise) on the output. 20 uV as in micro-volt. You can see my regulator here: Neurochrome.com : : Audio : 21st Century Maida Regulator

~Tom

 

[kacernator]

Well, it is hard to get LT3080 in my country and LM317 is ten times cheaper. Any suggestion for LT3080 alternative?

I would be very curious about your results trying pretracking regulator with your 21st century maida regulator circuit.

 

[merlin el mago]

tomchr have you compared your reg vs SSHV2 about subjective sound & ripple reduction & noise?

 

[kacernator]

I have tried SSHV1 and it sounds good, but too much heat. I am totally happy with TPR as subjective sound performance is concerned.

 

[merlin el mago]

Well, it is hard to get LT3080 in my country and LM317 is ten times cheaper. Any suggestion for LT3080 alternative?

I would be very curious about your results trying pretracking regulator with your 21st century maida regulator circuit.

I also have problems to get LT3080.

I have tried SSHV1 and it sounds good, but too much heat. I am totally happy with TPR as subjective sound performance is concerned.

What's TPR?

 

[kacernator]

TPR is abbreviation for "tracking preregulator".

 

[merlin el mago]

Thanks.

 

[tomchr]

I haven't compared against the SSHVx. However, the ripple rejection of my regulator is so good that I can't see any ripple on the output even with 50 Vpp ripple on the input. Furthermore, the output impedance is very low across the entire audio band. It's better than Jan Didden's T-reg regulator. So I'm confident it's the best I can do with the components available today.

Farnell in Europe should be able to help you out with the LT3080. I can also help you out with an assembled module. Just PM me.

~Tom

 

[kacernator]

I have found that LT1085 is available in my country, which should be better than LM317.

 

[kacernator]

Cap needed?

I have looked at more maida regulator implementations and sometimes there is cap after the 47R which bypasses first reg´s input to ground. In the LB-47 application there is no cap. Do I need this cap for stability?

 

[kacernator]

Adjust pin bypass?

Can I also bypass adjust pin of the second LM317 to improve ripple rejection or it is already bypassed with 1uF? If it can be bypassed, then whrer should I connect the bypass cap? From adjust pin to ground?

Thanks.