decent psu

Has anyone a schem for a decent psu? Ive got my latest one up and running for the phono but it needs refining, any ideas?

 

use rechargeable batterys

 

What kind of PSU are you building? I might be able to help or point you in the right direction.

 

T-Bone,

One of These and a super reg will get you as close as it gets for DIY sir. Wm
The N/C.s are available seperately (single or dual rail)

 

What's a super reg?

 

A very high quality regulator that has the ability to create a very stable voltage, unlike the standard units that litter 99% of all electronics
Check out Andy L Weeks website for instructions on constructing his good DIY units, the dungeons and dragon forum (PFM) is litted with them.
WE use some a little different, however Andys regs are infinatley better then the vast majority of the stuff that is secreated into todays gear.
A quality psu is nothing with out them imho.

 

Have you seen my super regulators? I have a complete PSU (JSR04), just add AC but I have made also separate regulators.

The advantage is that a super regulator is very fast which means low output impedance over a wide bandwidth, much more than 20-20000 Hz AND it has a very low noise, we are talking less than 10 uV's.

http://home.swipnet.se/~w-50719/hifi/jsr03
http://home.swipnet.se/~w-50719/hifi/jsr04

 

Cheers Wm, Ive looked over Andrews website many times and I think I might be best mailing him. At the moment I just need to get the dam thing running so Im looking for something simple. One problem I may have is the lack of any centre taps on my transformer. I have the 2 AC leads and 2 x 12v DC windings, any help on this??

 

Use two rectifiers bridges, or one bridge and make a centertap. A centeratpped treanaformer is the same thing as two separate widnings except that you can't separate the windings.

Just check my QRV-01 headphone amp and check how the transformers are connected.

http://home.swipnet.se/~w-50719/hifi/qrv01

 

If I use two bridges (which I have made some), use one DC + from one bridge and one DC - from the second bridge and connect the remaining DC + & - I will have my centre tap?? The only thing I was planning to feed each channel with its own power supply from the secondaries.

 

Hi,

What power supply requirements has your circuit got? I find it amusing that everyone runs to offer their pet choices without even knowing what is needed.

For what it's worth, the Phonostage may be Valve based, may be discrete needing a single supply or dual rail and so on.

Some general hints, if you can use batteries.

If you cannot stick to passively filtered supplies (a 6 cell 33R/1,000uF filter chain will knock any 100Hz noise down by nearly 160db, with no transient problems, no complex distortion and so on. ANYONE (including Mr Jung) will have a hard time building a regualtor to match this.

If you cannot do that use Shunt regulators (TL431 is a pretty good choice if applied correctly).

Active series regulated supplies, including the much vaunted "Super Regulators" have so far failed to convince me of their value, they measure very well but sonically they are far from optimal. Often a simple "3-Pin" regulator followed by a simple RC circuit (say a pair of 33R/1,000uF filter cells) sound miles better, subjectively speaking.

Note the above is merely my own experience, no claims of the only truth are implied, merely that of what I tried (and I tried a lot) the above results where obtained using my ears and my own system.

Ciao T

 

Nice one, Per. I haven't seen your site before.

 

I know what is required, the phono uses 2 x single op amp, at the moment OP27. This needs a 12v supply. At the moment everything is a straight copy from the schems Ive got and all is working fine Im just experimenting with as much as possible. I could just box it up as it is, it easily beats on-board phonos Ive tried and those that have heard say its a big improvement over the usual budget fare of pro-ject ect. Im using a 50Va transformer which should be more than enough for a phono supply.

Before I play around with different makes of caps and resisitors etc I want to make sure the power supply is of a decent quality. The problem Im finding is that there are so many different designs when it comes to psu's, everyone seems to have a different preference.

 

Thanks

T-Bone, check closely how I have done, check also the amps QRV-04 and QRV-07 . There you have two windings (from separate transformers) and two rectifier bridges.

 

Hi,

I would have thought that 12V is WAY too low for a Phonostage. The OP27 is not such a bad choice otherwise, but a 24V single rail or a +/-12V supply seems a better choice in terms of overload margin.

There are two basic schools really and the rest are variations. One I'll call the "active" and the other the "passive".

The active school aims at making better and better regulators (which implies negative loop feedback), with a exponential increase in complexity and often not or little attendant sonic benefit (highly dependent on the circuit supplied by the PSU).

The passive school aims at making simple and effective supplies that get it right inherently, instead of trying to fix errors after they occoured. Typhically the most extreme passive solution are batteries.

Among commercial gear you find that many Valve Gear makers favour passive approaches, paramount among the SS crowd is Sutherland, his "PhD" Phonostage is batteries only (not even rechargable!)....

For myself, for a Phonostage I would simply get down to Maplin and pick up "On Sale" bulk packs of AA size 2000mAH NIMH Batteries up, altogether 20 Batteries, together with suitable holders (usually available for 4pcs or more AA Cells). Then build a suitable charger (plans here

http://tangentsoft.net/audio/ppa/bb/

Ciao T

 

simplest (and cheapest) way to get a split rail psu

 

Thanks for the replies. Is that from the rjm site hippy?

Per, I understand what you saying, I saw the power side of your amp when I downloaded page two.

I also found this which is along the same lines:

http://www.zero-distortion.com/techno/x1.htm

I think I know where Im going now.