Balanced stages seem popular these days, so i am tinkering with the idea, but i have not put in any serious calculator time on it yet. i imagine that I am looking for something simple and clean, maybe an opamp differential splitter feeding two BUF634 into an XLR output?? Anyone else toy with the idea?
aletheian said:
Yes. I do, and it works extremely well. As a hint, you can see the Audio Buffer on my web.
We compared it to transformer output, and prefered the BUF stage. Of course it is not the "true" balanced output, if you short one of the outputs the second does not double. But we compared it sonically, and the BUF beated transformers.
Contrary to Steve, I do not like transformers at all.
Steve,
you would not know them, as they are produced here. Very similar parameters to corresponding Jensen link transformers. I do not remember type numbers, it was 2 years ago.
For me, the biggest issues are sensitivity to external magnetic fields (heard), a lot of HF noise (measured, IMHO responsible for worsen sound) and higher LF distortion, possibly LF saturation at high voltage levels. That is why I do not like them.
Cheers,
Pavel
you would not know them, as they are produced here. Very similar parameters to corresponding Jensen link transformers. I do not remember type numbers, it was 2 years ago.
For me, the biggest issues are sensitivity to external magnetic fields (heard), a lot of HF noise (measured, IMHO responsible for worsen sound) and higher LF distortion, possibly LF saturation at high voltage levels. That is why I do not like them.
Cheers,
Pavel
Hello Mr.PMA,
I have question for you.I want use your buffer in DAC and do little test(measure).And my question is which version is best for you?50 Ohm at output and 50 Ohm in cable to
r without 50 Ohm in cable.And what this alternation do with sound?I remember you tested this.I hope so...
I look on PCB and this I must make alone.And you now why.
I have question for you.I want use your buffer in DAC and do little test(measure).And my question is which version is best for you?50 Ohm at output and 50 Ohm in cable to
r without 50 Ohm in cable.And what this alternation do with sound?I remember you tested this.I hope so... I look on PCB and this I must make alone.And you now why.
I remember this discussion between you and OPA.And I now your choice.There is much difference in sound?And last time you promise new DAC.Which buffer you plan use?I think Mark Levinson use same topology (OPA627+BUF634) and this player is not bad.
Of course I show you my DPS and tell you which output configuration is best for me.
thanks
Of course I show you my DPS and tell you which output configuration is best for me.
thanks
PMA said:
Not sure what you mean by the Jensen "link" transformers. Can you be a bit more specific?
Interesting. I've never experienced anything like that with any of the Jensen or CineMag transformers I've used. I can't help thinking maybe something was amiss in your case. Perhaps the wrong transformer for the job (i.e. an input transformer being used as an output transformer), something wired up wrong, or maybe even just crappy transformers.
se
Here is my experience:
I tested opa627 +BUF634 and it sounded decent, not bad, little bit dry and I would say clinical. Than I dropped instead Lundahl transformer. Much better, cleaner and it didn't add anything to the sound. I would absolutely prefer that. Unfortunately I needed more gain, so I tested X-Bosoz and I was very happy. X was much more natural and warmer than opa627 +BUF634 and much better sounding. Since I was running all this after DAC chip that has DC output I have Lundahl in front of X Bosoz that takes care of DC and as well transmit pure ballanced signal.
All three units are very good and the differences between them are as I described in my system. I would absolutely prefer just Lundahls and nothing else behind as they provide the maximum transparency and resolution. If I didn't need gain that will be the answer for me. If you do need gain than Mosfets are better than opamps.
I remember testing just BUF634 as well as INA134 (I could be wrong with numbers)and it was minimal influence to the sound, but still little bit dry but much less than with opa627 in combination.
I hope this help you.
AR2
I tested opa627 +BUF634 and it sounded decent, not bad, little bit dry and I would say clinical. Than I dropped instead Lundahl transformer. Much better, cleaner and it didn't add anything to the sound. I would absolutely prefer that. Unfortunately I needed more gain, so I tested X-Bosoz and I was very happy. X was much more natural and warmer than opa627 +BUF634 and much better sounding. Since I was running all this after DAC chip that has DC output I have Lundahl in front of X Bosoz that takes care of DC and as well transmit pure ballanced signal.
All three units are very good and the differences between them are as I described in my system. I would absolutely prefer just Lundahls and nothing else behind as they provide the maximum transparency and resolution. If I didn't need gain that will be the answer for me. If you do need gain than Mosfets are better than opamps.
I remember testing just BUF634 as well as INA134 (I could be wrong with numbers)and it was minimal influence to the sound, but still little bit dry but much less than with opa627 in combination.
I hope this help you.
AR2
Hello Pasul,
X - Bosoz is MOSFET pre amp designed by Nelson Pass. You will learn more about it if you visit:
http://www.passdiy.com/
or just go to Pass Lab section of this board.
I didn't try different opamps, just the ones that I mentioned. I agree with you that one bill doesn't fit all and certainly everyone should test and try what works in their system. I maybe wasn't clear enough but I haven't meant that MOSFETS are warm, but warmer sounding comparing to opamps. Just like if you are matching certain speakers to certain amps and you find a great combination that doesn't mean that other amps or speakers are bad, it means that that particular combination works well for you. In my set up that was the case. I am glad that I did try all above mentioned which provided me of pleasure making it, learning and being able to select what fits me the most. I have to stress one more time - none of mentioned is bad - far away from that, it is best in its class, but is certanly different from each other. I beleive Pavel Macura sells boards with opa637 and BUF634, and I would strongly advise you to give it a shot. The beauty is that it is not too expensive to put it together and you could judge for your own.
AR2
X - Bosoz is MOSFET pre amp designed by Nelson Pass. You will learn more about it if you visit:
http://www.passdiy.com/
or just go to Pass Lab section of this board.
I didn't try different opamps, just the ones that I mentioned. I agree with you that one bill doesn't fit all and certainly everyone should test and try what works in their system. I maybe wasn't clear enough but I haven't meant that MOSFETS are warm, but warmer sounding comparing to opamps. Just like if you are matching certain speakers to certain amps and you find a great combination that doesn't mean that other amps or speakers are bad, it means that that particular combination works well for you. In my set up that was the case. I am glad that I did try all above mentioned which provided me of pleasure making it, learning and being able to select what fits me the most. I have to stress one more time - none of mentioned is bad - far away from that, it is best in its class, but is certanly different from each other. I beleive Pavel Macura sells boards with opa637 and BUF634, and I would strongly advise you to give it a shot. The beauty is that it is not too expensive to put it together and you could judge for your own.
AR2
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.