 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
In Reply to: Re: assemblage DAC 3.0 opamp upgrade posted by highendman on May 04, 2003 at 11:43:32:
thanks very much, I just put OPA134 back on (originally I used 8 OPA627) and it sounds warmer though less detail. With all 627 it just sounds too crisp on high. So I wounder 825 could give a warm and detail sound.
Follow Ups:
Cleaning up the power supply or putting bypass caps on the power pins of the opamp may soften up the highs as well as give you better resolution.I can't really make a call about the highs of the 627 vs the AD825s because I use them in different applications (and everything seems to sound warm and detailed for me these days -- too much so).
Some have said the AD8620/10s are the most sophisticated on the top end (smoother than the AD825s). Your +/- can't be more than about +/-13v though.
8 OPA627s -- that's a lot of money in opamps.
Evertime I have inserted OPA627s I have removed them later in favour of the AD825s. Far too bright and 'incisive'.
It seems a few people have found the 627s bright. I have never had this problem with the 637s, but then I'm not the best person to critique this point as my highs are a touch soft right now. As always, it depends on your circuit application and your system. In another case, someone found the bass of the Mapleshade Ribbon interconnects a bit lean, but I did not have this problem. Upon futher investigation, I found that swapping my Highwire or Magnan ICs for the Mapleshades produced and even stronger fuller bass for me. It never would have occured to me that the Mapleshades were lean because my amp/speakers are a bit plump in the midbass and the Mapleshades compensated perfectly.I can offer a different perspective on the 637BPs used in a linestage application, however. I use them with 3 or 4 coats of clear nail polish all the way around the chip and run it biased with about 1.2mA from the negative supply. I also use bypass caps on the power pins. All and all the circuit gives them a great chance to have as little brightness and glare as possible. The sound I'm getting is surprisingly good to me -- extended but wonderfully smooth and sophisticated, great great soundstaging -- super wide, deep and open, outstanding tonality, excellent bass and dynamics. Amazingly, these chips are throwing a mid-hall perspective for me with a very deep stage, but will still put some images in front of the speakers on certain material. The deep soundstage and tonality reminds me of the ARC solid state power amps I listened to in the early and mid 90s. I like every aspect to the sound, except one, which may be a killer for me -- the midrange is slightly recessed. I listen to a lot of vocals and prefer a prominent midrange. In fact, I'm going to put a post inquiring about obtaining a prominent midrange.
I received 2 OPA 627APs yesterday and am going to pop them in place and give them a preliminary listen. Some have found them to be sonically identicle to the 637s. I'll be listening to the difference between the chips, the nail polish and break in (at first). Let me take a quick listen... be back in a few hours...
After 2 hours of warm up:
The 627APs sound similar but not as smooth at present. The midrange is a touch more apparent as well (could be from the edge) and it doesn't seem to have quite the tonal vibrancy and differentiation of the 637s. This is all most likely primarily due to not being broken in. The nail polish adds a bit to the cleanness, resolution and smoothness of the 637s. Of course the opamps could sound slightly different as well. Perhaps I'll take off the 4 layers of clear nail polish... I'll have a better idea in a week.
Are they normal Ad825 or the LC audio modified AD825? Does the LC audio modified 825 has advantage over normal 825?
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
