The Opamp thread

[leeperry]

Quote:

Originally Posted by ecclesand /img/forum/go_quote.gif When I had all 3 HDAMs, I too preferred the Sun V2. It was well suited to metal and progressive rock.

did you like Moon? its RMAA measurements are as lousy as can get, and it sounds like a cheap car stereo to me...Kingwa thinks mine was faulty

I'm completely stunned by the 2*LT1364+Earth, it's eye popping

I've ordered a whole bunch of Earth and Sun V2...can't wait to try them on the Claro Halo soundcard

 

[ecclesand]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif did you like Moon? its RMAA measurements are as lousy as can get, and it sounds like a cheap car stereo to me...Kingwa thinks mine was faulty I'm completely stunned by the 2*LT1364+Earth, it's eye popping I've ordered a whole bunch of Earth and Sun V2...can't wait to try them on the Claro Halo soundcard

Out of the three, I liked Moon the least. I would like to try them in some circuits other than the Compass which was mediocre at best. I might pick up a couple of single channel HDAMs and try them in my modded Lite Dac-AH.

 

[ROBSCIX]

Quote:

Originally Posted by K3cT /img/forum/go_quote.gif Anymore Sun V2 to Earth comparison? The Sun is too bright for me now, considering selling it if it stays this way.

I like the Sun V.2 also but prefer the Earth for I/V.

 

[crapback]

I'm thinking about swapping out the evox bypass caps for some k40y9 pio's to see if that changes the sound characteristics of the hdams. I like the dynamics of the sunv2, but it is too bright for my tastes, both in my zero and in my compass. I don't really like the moon in my compass, but in my zero it sounds pretty good in the dac. I'm trying that out for a while to give it a chance, cause I already know I love the earth in there.

 

[ROBSCIX]

A few said they like the discrete better without the caps.

I find the Earth is really good for I/V but the Sun may give a signature that some may find bright..depend alot on the circuit and what your using for cans/speaker etc.

 

[leeperry]

Quote:

Originally Posted by crapback /img/forum/go_quote.gif I already know I love the earth in there.

yeah, Earth is cool stuff! I've tried it w/ the OPA827 as final buffer...but I'm currently listening to 2*Earth alone w/o a final buffer, vocals are not in front like on the LT1364 anymore...it's more natural, the LT1364 was obviously pushing them upfront at the first row, they are seamlessly mixed within the SS now.



it seems that the more Earth you stack, the better the SQ....can't wait to put 4 of them on the Claro Halo(w/ 5cm extension leads): http://www.bukowc.com/Galerija/Avtom...aroHaloXT6.JPG

PS: it's funny how loudness material was totally unbearable on IC's, but is now totally OK on the Earth...sound is still brickwalled to death but the SS is not one big clipped mess anymore, there's still some life

 

[LuciferX]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif it seems that the more Earth you stack, the better the SQ....can't wait to put 4 of them on the Claro Halo(w/ 5cm extension leads): http://www.bukowc.com/Galerija/Avtom...aroHaloXT6.JPG

Let me know your test results! You have buy it a Claro Halo? If you have some time, Can you test how different is the sound with 4 default opamps vs 4 x 2132 and 2 x default + 2 x 2132?

 

[leeperry]

yeah, a friend of mine wants a good multichannel soundcard...and he wants a whole bunch of discrete op-amps too, now that he's heard them on my HD2

well, I can already tell that it'll end up with 2*Earth and 2*LT1364..or possibly 4*LT1363

LT136x is the shznit for vocals(it makes movies "holographic") and Earth allows it to blossom...Earth w/o LT1364 is natural and boring, and LT1364 w/o Earth is not refined enough to my taste

whatever U8/U10 or U9/U11 still remains to be decided...

BTW, can you run a few tests for me please? I've explained it here: http://www.head-fi.org/forums/f46/ht...1/index13.html

and it's better that we discuss there, as this is the right thread

 

[leeperry]

BTW, replacing 2*LT1364+OPA2132P by 2*LT1364+1*Earth opened the SS in a pretty tremendous way...even wider than the OPA827, it just sounds miles better!

but I've just tried 2*Earth+1*LT1364 and it's terrible

SS is narrow/bloated, all the Earth details have gone down the drain...only the killer vocals are back. I will replace it by 2*LT1363 and 2*LT1028 tommorow, but anyway yeah...dual op-amps are evil cross-talk wise

 

[ROBSCIX]

Quote:

Originally Posted by crapback /img/forum/go_quote.gif I'm thinking about swapping out the evox bypass caps for some k40y9 pio's to see if that changes the sound characteristics of the hdams. I like the dynamics of the sunv2, but it is too bright for my tastes, both in my zero and in my compass. I don't really like the moon in my compass, but in my zero it sounds pretty good in the dac. I'm trying that out for a while to give it a chance, cause I already know I love the earth in there.

Have you tried any caps mods yet on these units or just considering it?
I mentioned before that I heard a few guys say they prefer these units without the caps.

 

[crapback]

I haven't had a chance to try any yet. Maybe tomorrow night when I get back home, if I can get motivated. If not I'll try it tuesday. Being a truck driver makes this hobby a little difficult to keep up with sometimes.

 

[ROBSCIX]

Quote:

Originally Posted by crapback /img/forum/go_quote.gif I haven't had a chance to try any yet. Maybe tomorrow night when I get back home, if I can get motivated. If not I'll try it tuesday. Being a truck driver makes this hobby a little difficult to keep up with sometimes.

OK, I see. Post you results when you get time to test.
I have considered trying new ones myself o possible trying the units without caps on them at all.

 

[leeperry]

BTW, I might try the LT1028ACN8 on these : Single-to-dual Op-AMP Adapter - DIP version (p/n 021001)

and this: http://images17.newegg.com/is/image/...04-S01?$S640W$

if the caps are too high, I will had an additional dip8 socket between the card and the adapter to rise it a bit....LT1363CS8 and LT1028ACN8 will be my last tries at IC's I think

 

[ROBSCIX]

Quote:

Originally Posted by diditmyself /img/forum/go_quote.gif You should use Ohm's law. R=U/I. A couple of mA is enough. Eg if the supply is +/- 10 V and you want 2 mA: R=10/0.002 => R=5k. I guess the recommended 2k2 or 3k3 is fine too. Consider using constant current sources instead, like a JFET with appropriate source resistor. Look at how it's done in PIMETA, PPA or M3. You don't need cascoded JFETs.

I have new adapters coming and a large selection of resitors, time to get into some new testing. Some I have spoke with about this topic said that experimenting with values may give the best results. I have been considering a constant current source for this application. As I said I am just getting into biasing to class A with opamps. Do you use any opamps that are biased?

 

[diditmyself]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif Do you use any opamps that are biased?

I stopped class A biasing of opamps after I did some blind tests. All testing was with constant current sources. I couldn't hear any improvement. In fact I heard no difference at all. Before that I experimented with restistors, and at that time I thought I could hear the difference, and it was to the better. Now I think that it might have been placebo. Those tests were with the opamps in front of diamond buffers, a very light load, 100's of kOhm.

I've tried 15 mA class A biasing of AD8397, driving high impedance phones, and I could hear no difference in blind tests.

Maybe I didn't give it enough time. Flipping back and forth with a switch isn't the same as long time listening. All my discrete amps are class A. I think I'm sure that they sound less fatiguing in the long run at higher bias.