Would u choose Buf634T?

[PederBass]

Hi!
Didn't get that much on searching so....


Just wonder what ur opinions are on Buf634T? I will use it as a output buffer in a closed loop circuit (in a headphone amp).

It doesn't seems to be popular on some headphone - forums , therefore I felt that I must ask u people here...and yes I know that Carlos seems happy with it, but how about the rest of u?

And, doesn't Mark Levinson use it in their dac's?

I feel that it can't be that bad but it cost a lot..however it's nice to hear so many opinions that's possible before deciding on the pcb-layout...

Thanx!

________________________

/Peder

[analog_sa]

I feel that it can't be that bad

Not that bad. Just not great.

[Peter Daniel]

Originally posted by PederBass
And, doesn't Mark Levinson use it in their dac's?

They only use it in ML37 player. Their other DACs use discreet buffer.

[peranders]

Originally posted by PederBass
Just wonder what ur opinions are on Buf634T? I will use it as a output buffer in a closed loop circuit (in a headphone amp).

It doesn't seems to be popular on some headphone - forums , therefore I felt that I must ask u people here...and yes I know that Carlos seems happy with it, but how about the rest of u?

I at least am very pleased with BUF634 and the "F" model (SMD, TO220). Together with OPA627, AD8610 and OPA134 I think it's an excellent combination. I have also tested the buffer in "medium speed" and "high speed" without any big differences. Medium speed is to have 3.9 kohms from BW pin to V-.

Picture here

[peranders]

Originally posted by PederBass
I feel that it can't be that bad but it cost a lot..however it's nice to hear so many opinions that's possible before deciding on the pcb-layout...

Note that this buffer is an industrial part and the sound quality has nothing to do with it's price. It has to do with demand from the industry and how hard it's to make.

[PederBass]

"Note that this buffer is an industrial part and the sound quality has nothing to do with it's price. It has to do with demand from the industry and how hard it's to make."

Yes, I totally agree about that soundquality has nothing to do with price, just ment that high price would be a negative factor when u choose ur amp...

So ur happy with then? Have u compared it to other buffers, like those Intersil HA-5002 or HA-5033 buffers?


/Peder

[peranders]

You can try to get samples, cost you nothing but you can also build a diamond buffer quite easily with very good results. Check my designs for inspiration. All of these are "high speed, low distortion versions" with cascodes but you can make it. QRV-03 is made of ordinary parts and the other two are made of SMD parts.

QRV03
QRV05
QRV06

Good reading can befound here
http://www.elecdesign.com/Globals/Pl...tent/2800.html
http://www.linear.com/prod/datasheet.html?datasheet=315
http://www.national.com/an/AN/AN-227.pdf
http://focus.ti.com/lit/an/sboa071/sboa071.pdf

[mandat]

In WWW exist very often cited audio buffers.
http://www.pha.inecnet.cz/macura/buffer_en.html

[Upupa Epops]

I had compared this type with similar discrete one ( something as Jung's diamond buffer ). Both was connected to feedback loop of opamp ( OPA 134, OPA 627 ), both was set up to the same BW ( 1 MHz ), both had the same load impedance ( 50 Ohm ). I bias of 634 was 15 mA, discrete was cca 25 mA. In discrete was used normal cheap transistors ( BC 546 / BC 556, BD 139 / BD 140 ), not any " exotic " high speed types. And results ? Discrete win " two horse lenhg " in all aspects, mainly in much more firm bass. Interesting of this solution is also price - it is ten times lower .

[PAM]

I did build a buffer with the BUF 634 and compared it with the Misical Fidality X10D. I did used battery powersupply from a drilling machine and add some capacitors. The 634 did easy win this from the X10D.