BUF634 vs HA5002 buffers in headphone amp ? - diyAudio
Go Back   Home > Forums > Amplifiers > Headphone Systems

Headphone Systems Everything to do with Headphones

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 29th July 2003, 05:18 PM   #1
diyAudio Member
 
Join Date: Jul 2003
Location: Dayton, OH USA
Default BUF634 vs HA5002 buffers in headphone amp ?

Guys,
What are your thoughts on these two buffers ?
I see that HA5002 is used a lot in headphone amps.
What about BUF634 ? It has a nice specs, at least on paper.
Is HA5002 really much better sounding IC then BUF634 ?
Let me know what you think. Thanks

BUF634 is easity available from digikey.com
HA5002 is harder to source.

Thanks
Sergey
  Reply With Quote
Old 1st August 2003, 08:37 PM   #2
mlloyd1 is offline mlloyd1  United States
diyAudio Member
 
mlloyd1's Avatar
 
Join Date: Feb 2001
Location: illinois
I just ordered some from Arrow Electronics

mlloyd1
  Reply With Quote
Old 1st August 2003, 08:44 PM   #3
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
If you really want quality, just make a discrete push-pull class A buffer from Fets or bipolar devices. The only other alternative is tubes. Trust me. ;-)
  Reply With Quote
Old 2nd August 2003, 08:50 AM   #4
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally posted by john curl
If you really want quality, just make a discrete push-pull class A buffer from Fets or bipolar devices. The only other alternative is tubes. Trust me. ;-)
There might be more kinds of "trust" .
I have the best experience with BUF634T, both parameters and sonic quality (you can visit my www to see an example of a circuit design). I am very sure that it is practically impossible to reach the same parameters by several discrete transistors, monolithic technology is superb for this purpose. The speed, thermal junction between components, repeatability ... And with BUF634 inside feedback loop you are able to reach THD of 0.0001% with OPA627, for example. You'll hear the result when listening to great philharmonic orchestra, violin, organ, trumpets ...
  Reply With Quote
Old 2nd August 2003, 09:07 AM   #5
diyAudio Moderator Emeritus
 
jean-paul's Avatar
 
Join Date: Sep 2002
Location: Germany
Don't trust your website, the link on your www site to the audio-buffer is broken.

At the moment it is:

file:///C:/Dokumenty/HIGHEND/MAC_hifi_publish/pokusny/buffer_en.html

This one works:

http://www.pha.inecnet.cz/macura/buffer_en.html

I would take advice of John Curl serious. He has some experience with preamps to say the least.
__________________
It's only audio. Official member of the Norske Brillegeit Gang.
  Reply With Quote
Old 2nd August 2003, 09:29 AM   #6
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
have the best experience with BUF634T, both parameters and sonic quality (you can visit my www to see an example of a circuit design). I am very sure that it is practically impossible to reach the same parameters by several discrete transistors, monolithic technology is superb for this purpose. The speed, thermal junction between components, repeatability ... And with BUF634 inside feedback loop you are able to reach THD of 0.0001% with OPA627, for example. You'll hear the result when listening to great philharmonic orchestra, violin, organ, trumpets ...
I have only used the dip BUF634 and have been consistently underwhelmed. As i don't care one bit about thd, the zeroes fail to impress me. Outside fb loop i find the sound pathetic; inside it's much better but you can always hear the presense of the BUF and not necessarily in a pleasant way. I haven't touched opamps for more than 10 years and only recently spent some time investigating how far have the little chips progressed. Well, in some respects the best are now truly better than the 5534 - a good design conveys a degree of a sense of space, delicacy and PRAT, but in respect of genuine, lifelike, startling dynamics they still have a long, long way to match the sonics of discretes, be that valves or SS. For the record my experiments have included a phono in which a opa637 is followed by a buf634 driving a fb type riaa network and a opa627 with a buf634 as a line stage.

cheers
peter
  Reply With Quote
Old 2nd August 2003, 11:12 AM   #7
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally posted by jean-paul
Don't trust your website, the link on your www site to the audio-buffer is broken.

You are right, thank you very much. I have just repaired it.

Pavel
  Reply With Quote
Old 2nd August 2003, 11:22 AM   #8
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally posted by analog_sa


As i don't care one bit about thd, the zeroes fail to impress me. Outside fb loop i find the sound pathetic; inside it's much better but you can always hear the presense of the BUF and not necessarily in a pleasant way.
Hi Peter,

yes, low thd is not the only sufficient parameter , but necessary (in case that the whole audio chain is perfect , otherwise it may emphasize another flaws). From my experience - low THD, IMD and perfectly stable design (to any load - this must be measured) are absolutely necessary in case that I want to listen to all the details of symphonic orchestra. Valves are fine for a jazz quartet or single saxophone, but I do not prefer to hear new colorations. Valve itself is further musical instrument in the audio chain

Pavel
  Reply With Quote
Old 2nd August 2003, 03:11 PM   #9
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
Valves are fine for a jazz quartet or single saxophone, but I do not prefer to hear new colorations. Valve itself is further musical instrument in the audio chain
Valves require an incredible amount of care to sound good with complex music. In my experience each amplification stage has to have its own independent power supply, or at least dedicated regulator. The results can be truly rewarding but there is a price to be paid in size and weight. Of course microphony is another curse... To my ears, though, valves ultimately win as far as dynamic expression is concerned.
Have you compared the sonics of the dip BUF634 to BUF634T? Is there a substantial difference (assuming both are driving easy loads, far from max current)?

cheers
peter
  Reply With Quote
Old 2nd August 2003, 03:44 PM   #10
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally posted by analog_sa



Have you compared the sonics of the dip BUF634 to BUF634T? Is there a substantial difference (assuming both are driving easy loads, far from max current)?

cheers
peter
Nice post, peter. Regarding BUF634 in DIP-8 and BUF634T in TO220-5, I did not have chance to compare them. My choice was the BUF634T from the simple reason - in my buffer application I use the coax. cable terminated at both ends by 50 Ohms, i.e. 100 Ohms load for the buffer. This, especially terminating resistor (R12 in the Audio Buffer schematics) has brought dramatical improvement of the whole soundstage. Any hint of grain or harsh is over.

Pavel
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
AD8610, OPA134, OPA627, BUF634 SMD headphone amp peranders Headphone Systems 75 18th March 2013 09:01 AM
Anyone interested in PCB's for OPA627/BUF634 based headphone amp? Maxhawk Headphone Systems 39 21st February 2013 06:32 AM
Mini Portable Headphone Amplifier, with Discrete Diamond Buffers cetoole Headphone Systems 3 30th May 2006 06:32 AM
YardBird OPA627/637 BUF634 preamp/headphone amp Russ White Headphone Systems 4 23rd November 2005 01:53 AM


New To Site? Need Help?

All times are GMT. The time now is 08:53 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2