Post pics of your builds....

[rickcr42]

Nice job tyre.reelly good to see someone "wing it' and do their own layout for a change

Kudos from the rickmeister

[tyre]

Originally Posted by rickcr42

Nice job tyre.reelly good to see someone "wing it' and do their own layout for a change

Kudos from the rickmeister

Thanks. It's definitely more fun to do it without a pcb. I plan on making most of my amps on protoboard if possible. Sijosae's amps are pretty inspiring.

[Banfi T.]

I never saw that site before. Quite impressing...

[Anthrax]

the multi-hybrid, heres my go at sijosaes tube amp.




and the in the dark shot, which every tube amp needs

[cetoole]

Originally Posted by Anthrax

the multi-hybrid, heres my go at sijosaes tube amp.


[IMG]http://home.swiftdsl.com.au/~robert1234/tubeamp1.jpg/IMG]

and the in the dark shot, which every tube amp needs

[IMG]http://home.swiftdsl.com.au/~robert1234/tubeamp2.jpg/IMG]

Looking good, what tube is that?

[Anthrax]

Originally Posted by cetoole

Looking good, what tube is that?

from OCAU arnt you?

its a EI 6DJ8 with gold pins

[luften]

I´m pretty new to this forum, but I thought I could post you some pics

To begin with, my OPA627 + BUF634 headphoneamp, built almost as the sample in the BUF634 datasheet.

Front picture:


Rear picture:


Internal amp:


Internal powa:


And at last, a picture with my Senns:

[~n00beR]

Nice layout luften :600smile:
I've been working on something similar using the BUF634T as a preamp, i havent got round to making some boards up yet , and was thinking of using a 3rd channel as a ground.

Anway back on topic, nice layout, well done

Originally Posted by luften

I´m pretty new to this forum, but I thought I could post you some pics

To begin with, my OPA627 + BUF634 headphoneamp, built almost as the sample in the BUF634 datasheet.

Front picture:


Rear picture:


Internal amp:


Internal powa:


And at last, a picture with my Senns:

[luften]

Originally Posted by ~n00beR

Nice layout luften :600smile:
I've been working on something similar using the BUF634T as a preamp, i havent got round to making some boards up yet , and was thinking of using a 3rd channel as a ground.

Anway back on topic, nice layout, well done

Thank you!

If someone is interested, I also have a couple of measurements performed with an AudioPrecision 2522. The load at measurement time is 300ohm, to show how they work with Sennheiser HD650.

Frequency Response
This is measured at two different levels, and as you can see, one channel is a little bit higher than the other, because of the Alps RK09 potentiometer.
At 20khz, the signal is at -0.3 dB.

THD + N and N
Here you can see that THD+N (yellow line) is lesser than 0.003% from 10hz - 20khz. The red line is only N, wich shows a little peak at 50hz.

THD vs Power in 300ohm
This shows that the THD+N is very low all the way until ~290mW where the clipping point seems to be.

Conclusions, it could be done better, but, this is good enough for me at this time! :600smile:

[~n00beR]

Originally Posted by luften
This shows that the THD+N is very low all the way until ~290mW where the clipping point seems to be.

Isn't the maximum continuious output current for the 634 250mA, and the short circuit current is 350mA.

The clipping is probably because you are driving it beyond the max cont current recomendations , you've done pretty well to get it to run at that level :basshead:

Just a thought

n00b