[morsel]

We are working on a capacitance multiplier power supply for the PPA. Here are a couple of links for reference:

http://sound.westhost.com/project15.htm
http://www.gmweb.btinternet.co.uk/jlhcapmult.htm

There are 3 versions: single, dual, and single with dual darlingtons. Two current sources and a zener have replaced a resistor or pi filter from the original circuit to limit the maximum output voltage. The dual darlington versions use complimentary pairs for better negative rail performance. The bridge rectifiers are bypassed with capacitors for reduced noise.

 

[morsel]

 

[jamont]

Does this design perform better than one using IC regulators (LM317/337 or similar)?

 

[morsel]

We expect it will. A capacitance multiplier is simple, quiet, efficient, and responsive to dynamic current requirements.

 

[Whit]

Will the capacitance multiplier be able to compete with something like a Jung superregulator or a Borbely regulator?

 

[jamont]

Do you plan to use 1N4007 (or similar) diodes in the rectifier bridge or something more exotic?

 

[morsel]

Since many people feel strongly about their pet rectifiers, we decided to go with discrete barrel types so you can use whatever you want. Generic silicon should work just fine. PPL favors Schottkys.

Testing and refinement must take place before we can comment on the specs of the power supply. Requests and suggestions are welcome.

 

[eric343]

Why did you decide to design your own p/s as opposed to using a Jung SuperRegulator or similar?

 

[aos]

You need to do simulations at the very least, and then build this and measure it to see how it compares to modern integrated regulators (which are cheaper and take less space).

Jung superregulator has space and power requirements that would not make it portable friendly, though space requirements are probably similar to this discrete design (at least if you only use positive regulator and then rail-split).

 

[Whit]

Here's a very informative link about the noise produced by various 3pin and discrete regulators for anyone interested.

Reducing noise in voltage regulators

 

[yejun]

why not use IC regulator + capacitor multiplier?

 

[morsel]

Eric: PPL and I are fond of capacitance multipliers. We want a power supply that will play nicely with the PPA and other amps. Aos: don't worry, we will test it extensively. Whit: nice thread, thanks for the pointer. Yejun: PPL wanted to do as you suggest, but I said it would be too big and expensive. If we can't get the results we want then we will reconsider.

 

[Possum]

Wasn't the PPA supposed to be an amp done ppl's way?

 

[puppyslugg]

Quote:

Originally posted by Possum Wasn't the PPA supposed to be an amp done ppl's way?

Maybe the next one.

 

[yejun]

i think the problem with pure capacitance multipliers is unable to adjust output voltage. Though opamp have a very wide range operation voltage, i think it will be best to adjust power supply to the most optimal voltage.