Regulated vs. Traditional

[roibm]

Why should I peak one over the other?


This is a new forum, isn't it?

[Mark25]

TNT - Solid State Power Amplifier Supply, Regulated or not?

I followed this guy's advice when building a PSU for my ESP p3a SS amp. It's head and shoulders above what ESP specify and much better than a commercial fully regulated Integrated i use.

[acenovelty]

More from Dejan V. Veselinovic at http://zero-distortion.com/start.htm

Prosit

[Circlotron]

I say use a fully regulated supply, but have really *big* filter capacitors at the supply output where it connects to your amp. These capacitors will be able to supply the current peaks the amplifier may draw on transients just like an unregulated supply with these same size caps, yet the whole thing will have the normal advantages of a regulated supply too.

[jleaman]

Regulated is best i'm building some regulated psu's for my blue amps and my gain clone's

[cunningham]

Originally posted by Circlotron
I say use a fully regulated supply, but have really *big* filter capacitors at the supply output where it connects to your amp.

Or better yet, use multiple smaller caps in paralell, 4700uF, 6800uF.....

[sam9]

My opinions - by no means authoritative, but mine nonetheless:

For small signal applications -- preamps, signal processors, instrunentation, perhaps even for the opamp in power amps using an opam based input section -- go regulated. In each case, the principal advantage being supression of ripple and noise.


For power amps -- unregulated. More efficient, potentially more headroom from a given transformer, simpler. And since regulated supplies involve a feedback loop, avoids the possability of two feedback loops in conflict. The exception is amps with poor PSRR wich tends to include single ended designs.

I would say there are trade-off's involved: On one hand to get some desired qualities you may have to accept a design that is sensative to power supply noise which argues for a regulated supply, but if you don't feel a need for those qualities then a design with high PSRR may make a regulated supply superfluous.

-----
Of course some people just are turned on by power supplies. As an example I'm thinking of a particularly expensive commercial headphone amp (which I'll leave nameless) I once saw the inside of. About 3/4 of the space (and it seemed like a rather large enclosure for a headphone amp) was taken up by the power supply. The amps boards themselves seemed to be little more than a single opamp with current boot, which can make an excellent headphone amp. The opamps were good units, probably OPA134s, and while a regulated supply was appropriate, the one used was way more elaborate for what was needed. The quality of construction was very good, but nontheless I failed to see the rational (as oppossed to marketing) rationale.

[Sch3mat1c]

Or a combo: unregulated for the power amp and regulated for anything that needs stability or extreme ripple rejection: input stages and screen supplies for instance.

Tim

[markp]

I've done both fully regulated and just the input/driver regulation and find that just doing the input/driver is 90% as good as full regulation. Full regulation is also much more costly and takes up a lot of room. Another good idea is to use two transformers on for input and one for output, that way you can use a higher voltage and regulate it down for the input/driver.

[dutch diy]

Hi, although I've built my J-amps with fully regulated ps both times
one thing that I've noted is that no COTS regulators are available for voltages over 35v with a decent Amp rating.

My J-amps are Class A so adding a regulated ps isn't nice for the overall efficiency but it' seemed a good idea to have. Sound wise I have not made a comparison with unregulated psu's.

I have some ideas about a setup which will be able to regulate over 70V at 5Amps but these are waiting on my next diy project.

A disadvantage of using a lot of buffer caps after the regulator is the current limitation in the regulator itself. The regulator might shutdown on the in-rush current.