STEREO FET BUFFER on ebay

[mudihan]

How is this buffer (ebay item 120230964247)? How is its design (the schematic is on the page)? It's very cheap.

No relationship to the seller.

[lineup]

Originally posted by mudihan

How is this buffer (ebay item 120230964247)?
How is its design (the schematic is on the page)?
It's very cheap.

No relationship to the seller.

It is a very good buffer.
It has even got Cascoding with 2SC2240 and 2SA970.

You should be able to use some other JFET pairs, too.
2SK246 + 2SJ103 is not the easiest to find everywhere.

Here is link + The JFET Buffer Circuit as attachment.
http://cgi.ebay.co.uk/STEREO-FET-BUF...742.m153.l1262

[poynton]

Originally posted by lineup


It is a very good buffer.
It has even got Cascoding with 2SC2240 and 2SA970.

You should be able to use some other JFET pairs, too.
2SK246 + 2SJ103 is not the easiest to find everywhere.

.............

It comes ready assembled so sourcing parts is not a problem.

Quick delivery, too .............



Andy

[lineup]

Originally posted by poynton
It comes ready assembled so sourcing parts is not a problem.
Quick delivery, too .............
Andy

Great, Andy

If I could afford it and had some payment method for use in other country,
I would buy 10 pieces of that Audio Kit .. right way!!!
Such a good STEREO FET BUFFER with complementary 2SK246 / 2SJ103
is very useful, in many cases. When we are into diyaudio.

In UK the seller of this stuff at ebay is tubeshunter
http://stores.ebay.co.uk/tubeshunter

[sharpi31]

Has anyone tried one of these? Any comments on the schematic?

I've ordered one to try as a buffer after a pot (a la Pass B1).





The price is $9.99 plus $5 delivery to the UK

[sharpi31]

more info...

[jonners]

The circuits are not quite identical, but there has been a bit of discussion on something similar here: http://www.diyaudio.com/forums/showt...07#post1549507

[sharpi31]

I received two of these buffers and installed one in my dac/preamp.

The system had been TDA1541A S1 > 2x LM49710 > 3.3uF Epcos MKV > 10K stepped attenuator > 75cm interconnect cables > UCD180HG (input cap bypassed).

I added the buffer after the stepped attenuator and a second pair of coupling caps after the buffer (if I don't have a DC offset after a few days I'll remove these caps).

My system had sounded very good before adding the buffer. As the UCDs have a 100K input impedance, I hadn't worried about using a 10K attenuator as a passive pre. After adding the buffer the sound became slightly richer with better resolved lower mids & upper bass. There is less HF sparkle, which I don't mind. Voices sound more real and everything seems a bit more solid and weighty. The slight loss in detail seems very acceptable given the increased body and real-ness of the the sound.

I ran the buffer from the same (over-spec'd) +15/-15V supplies feeding the opamps. I added a 22uF conductive polymer cap on each rail on each channel of the buffer.

Well worth a play for $10 :-)

[john curl]

I would remove the ceramic 100pf cap at the input, and replace it with 100pf mica or polystyrene. This is the only real problem with this buffer.

[rlim]

What are the bipolars there for? Aren't the fets followers?