recommend me a buffer (bi polar supply)

[adamus]

Hi,

Can anyone recommend me a simple buffer to run off a +/- 15v reulated supply. I have a spare supply, and need a buffer for a preamp i am building.

This will be built on perf board - so simple is good.

thinking Source > r2r vol control > buffer > valve amp (baby huey to be precise).

I have searched, but its pretty overwhelming, and i'll be honest and say my solid state electronics isnt great!

Thanks

Adamus.

 

[sharpi31]

Ebay FET buffer

It's very good! I added after a passive pot before my UCD180HG power amp.

See this thread for more info...

STEREO FET BUFFER on ebay

I bought two and replaced all the resistors on one with 0.1% matched carbon films. Didn't change the sound much (possibly a shade smoother) but did reduce output offset voltage.

 

[Thomo]

I built a buffer based on the Pedja Rogic buffer, which I found the info for on this forum.

Sounds incredible, far superior to just a "passive pre".

Cheers, Lee.

 

[adamus]

the fet buffer looks good and cheap. Any issue with offset on turn on, would i need a delay circuit or output caps (which i would prefer to avoid).

Thanks

 

[juma]

I built a buffer based on the Pedja Rogic buffer, which I found the info for on this forum.
Sounds incredible, far superior to just a "passive pre".
Cheers, Lee.

IMHO, it's superior to any other popular buffer circuit and Pedja is always glad to help. His site:
http://diy.audialonline.com/modulelab/
http://diy.audialonline.com/modulelab/buffer.php

 

[homemodder]

Superior in what way ??? Sound, specs, for 280 euro the parts and board better be goldplated.

 

[marc brown]

I'd either build Pedja's or the Pass B1.

 

[dodo]

recommend me a bufer

search for the JISBOS ?
Well documented design in the net

If you want high quality design , look at Mr Borbely web-side
and his product called SUPER Buffer , he will charge you only 80-100EUR , which is more resonably price , compared to the
280 EUR

 

[homemodder]

80 Euros is more reasonable, in some east european countries the minimum wage is below 280 euros. Adamus wants simple so I suggest just 4 transistors and excellent performance, a buffer used by the old master JL Hood. Wire with current gain, what comes in is what comes out and can even drive headphones pretty well. For 0 V output offset adjust R1 R2 values, R3 should be around 100 ohms. Thd levels of -130db mostly 2nd, attainable by tweaking resistor values for particular load.

BTW the circuit shown by sharp is pretty good too. If you build them yourself they will maybe set you back 15 pounds or so for stereo.

 

[mjf]

hello.
annother easy amp.
ic = ne5532(bip),opa2604(fet) or something else.....
you may test this circuit with a tl072.............
if you have a cap at the input of your poweramp you can c leave away (it is for safety,to block the offset from the ic).
47n.......100n nearby the pins of the opamp.
greetings.............

 

[AndrewT]

all of those discrete buffer solutions are good.

B1 by Pass, The Pedja Rogic and the JLH.

All can be run from a low noise +-15Vdc supply.

The buffer part is so cheap you could build all three and compare them.
the main cost is in the PSU and casing.

All can be built up easily on a plug board and then compressed to fit on to a tiny bit of perforated board.

 

[adamus]

the b1 schematics i have seen look like there are for a 24vdc single supply. I'll have a look through the beast of a thread for the bipolar version.

Cheers

Adam.

 

[marc brown]

the b1 schematics i have seen look like there are for a 24vdc single supply. I'll have a look through the beast of a thread for the bipolar version.

Cheers

Adam.

Here's a link to a schematic


link

Ignore the other mods if want to keep the caps.

 

[adamus]

An externally hosted image should be here but it was not working when we last tested it.

I can get parts for this from my local supplier. Any views?

 

[homemodder]

Thats the JLH buffer I proposed, it will work, I built them with those parts back in 1992, the Jfets are not of the best quality though and the resistor setup I proposed takes out the adjustable one wich is noisy.