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Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp - Page 90

post #1336 of 9226
2/6/08 at 5:13pm
Thread Starter 
Quote:
Originally Posted by magnetiq View Post
this might sound like a silly question

but is there a particular opamp that seems to perform best in the headphone amp???
Do you mean with the stock Opamp in the DAC at the same time?
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post #1337 of 9226
2/6/08 at 5:14pm
Thread Starter 
Quote:
Originally Posted by davve View Post
that LT1364 gets so isn't it a stabilty problem? I have read that..
Do you mean hot?
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post #1338 of 9226
2/6/08 at 5:17pm
Quote:
Originally Posted by Penchum View Post
Do you mean hot?
hehe yes, but i sounds really good
the OPA2604 and my DV wasn't a good match. Overall LT1364 is better. How are the LT1361 and LT1469 in dac?
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post #1339 of 9226
2/6/08 at 5:21pm
Thread Starter 
Quote:
Originally Posted by davve View Post
hehe yes, but i sounds really good
I've ran mine for days on end and never had artifacts or drop outs from excess heat. If I was truly worried about heat, I'd get one of those stick on aluminum cooling devices, but it gets hot to a certain level and stays there. I'm pretty sure it's a non issue.
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post #1340 of 9226
2/6/08 at 5:24pm
Quote:
Originally Posted by Penchum View Post
Do you mean with the stock Opamp in the DAC at the same time?
ok how about the best combination, i'd anyone's opinion
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post #1341 of 9226
2/6/08 at 5:32pm
I'm curious on the LT1361..still impressed by the built in amp how good it sounds.
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post #1342 of 9226
2/6/08 at 5:45pm
Thread Starter 
Quote:
Originally Posted by magnetiq View Post
ok how about the best combination, i'd anyone's opinion
There are two combinations that I like. Both have great sound coming out of the DAC and the headphone amp, with HD-650s plugged in:

DAC=OPA627 X2 on adapter
AMP=LT1364 in each socket

DAC=LT1364
AMP=LT1469 in each socket

I had to consider the sound out of both the DAC and AMP, because my plans were to hook both of my Zero's to different amps, so I needed a combination for each situation. The top one is for my Zero hooked to my Vintage Pioneer SPEC equipment. The bottom one is for my 2nd Zero hooked to my Sonic Super-T Amp. Have a good one!
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post #1343 of 9226
2/6/08 at 5:48pm
Well I have more than 100 hours on my Zero and things are coming along fine.. The bass tightened up and the treble harshness was reduced..

Tried the LME49720 in the dac and greatly preferred it over the 2604.This worked quite well as dac to my P2 and Lyrix....Tried the OPA2227s in the amp and although alot better than stock there was something still missing...

Finally put the OPA627s in the dac and this thing is now singing....couldn't believe how well I like this opamp.... and with the LME 49720s in the amp section I was toe tapping to the music all night...This combo really works well for my Senn and Grados and with my ears...Very detailed yet musical..mids are very smooth, timbre is excellent, bass and treble are just right......Think I'll enjoy the music with this combo for awhile before I try the LTs....Better yet maybe I'll get a second unit to try the LTs in...I think the the OPA627s and the LME49720s are keepers...

Thanks to all who are contributing to this great thread....Your efforts are much appreciated...
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post #1344 of 9226
2/6/08 at 5:49pm
Thread Starter 
Quote:
Originally Posted by davve View Post
I'm curious on the LT1361..still impressed by the built in amp how good it sounds.
The LT1361 is actually a very nice Opamp. Considering there is just a tiny bit of difference between most of the better LT Opamps, I'd rate these three like this:
LT1364
LT1469
LT1361

Any one of these three could substitute for the other two without being displeasing. All three work well in the headphone amp, with the OPA627x2 in the DAC. Hard to go wrong with these guys, I think.
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post #1345 of 9226
2/6/08 at 6:03pm
Quote:
Originally Posted by Penchum View Post
The LT1361 is actually a very nice Opamp. Considering there is just a tiny bit of difference between most of the better LT Opamps, I'd rate these three like this:
LT1364
LT1469
LT1361

Any one of these three could substitute for the other two without being displeasing. All three work well in the headphone amp, with the OPA627x2 in the DAC. Hard to go wrong with these guys, I think.
Have you tried all three with the same dac? I think that they sound very different from each other. Maybe I need to burn them in more, or it's my headphones which somehow works different than the hd650?

From the testing I've done, is that they all share the tonality to an extent. LT1361 is really really clear, airy and focus on higher frequencies. LT1364 is mellower sounding, dryer midrange, softer edges and less detail. LT1469 is between those, airy and clear but not to the extent of LT1361, very detailed, just a very very slight warm coloration in the midrange, good bass texture and good amount.

Are you not experiencing this at all?

EDIT: This is with them all being in the amp.
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post #1346 of 9226
2/6/08 at 6:12pm
Thread Starter 
Quote:
Originally Posted by Henmyr View Post
Have you tried all three with the same dac? I think that they sound very different from each other. Maybe I need to burn them in more, or it's my headphones which somehow works different than the hd650?

From the testing I've done, is that they all share the tonality to an extent. LT1361 is really really clear, airy and focus on higher frequencies. LT1364 is mellower sounding, dryer midrange, softer edges and less detail. LT1469 is between those, airy and clear but not to the extent of LT1361, very detailed, just a very very slight warm coloration in the midrange, good bass texture and good amount.

Are you not experiencing this at all?

EDIT: This is with them all being in the amp.
Well, the two variable would be; What Opamp was in the DAC during that time and what headphones were used. I'm sure the HD-650s reveal a different signature than many others, so that would be a big player. However, the most variation would come from the DAC Opamp used when listening to the three in the headphone amp.
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post #1347 of 9226
2/6/08 at 6:37pm
Thread Starter 
Quote:
Originally Posted by Trapper32 View Post
Well I have more than 100 hours on my Zero and things are coming along fine.. The bass tightened up and the treble harshness was reduced..

Tried the LME49720 in the dac and greatly preferred it over the 2604.This worked quite well as dac to my P2 and Lyrix....Tried the OPA2227s in the amp and although alot better than stock there was something still missing...

Finally put the OPA627s in the dac and this thing is now singing....couldn't believe how well I like this opamp.... and with the LME 49720s in the amp section I was toe tapping to the music all night...This combo really works well for my Senn and Grados and with my ears...Very detailed yet musical..mids are very smooth, timbre is excellent, bass and treble are just right......Think I'll enjoy the music with this combo for awhile before I try the LTs....Better yet maybe I'll get a second unit to try the LTs in...I think the the OPA627s and the LME49720s are keepers...

Thanks to all who are contributing to this great thread....Your efforts are much appreciated...
Thanks Trapper, these guys have been seriously going for it, and this helps everyone, big time! Hats off to them! It is hard not to love those OPA627s.
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post #1348 of 9226
2/6/08 at 7:42pm
Quote:
Originally Posted by mp101 View Post
Hi KMEL, what power rating are the resistors? Also my power LED keeps going off, then dim, its back again now but was out for 4 days, any ideas?
The resistors are 600mW. The LED consumes up to 20mA max, the power rating should be 100mW minimum.

Check the cable between the LED board and the main board. Perhaps the connector on the main board side is loose, so wiggle it into its socket.

You can remove the connector from the main board socket: Check the connector... All 7 cables should be in their crimp contacts and the 7 crimp contacts should be locked in their socket of the connector.

You can also check the micro controller. If it is loose or not complete in its socket... push it gently.
The micro controller is next to the connector mentioned above. Thanks to davve for his picture link.
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post #1349 of 9226
2/6/08 at 7:47pm
Quote:
Originally Posted by kmel View Post
The resistors are 600mW. The LED consumes up to 20mA max, the power rating should be 100mW minimum.

Check the cable between the LED board and the main board. Perhaps the connector on the main board side is loose, so wiggle it into its socket.

You can remove the connector from the main board socket: Check the connector... All 7 cables should be in their crimp contacts and the 7 crimp contacts should be locked in their socket of the connector.

You can also check the micro controller. If it is loose or not complete in its socket... push it gently.
The micro controller is next to the connector mentioned above. Thanks to davve for his picture link.
Nice one, Thanks
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post #1350 of 9226
2/6/08 at 10:00pm
I've been doing some rolling in my Zero.
One warning I have is that in my Zero, the LT1364 is exhibiting some signs of hi- freq oscillation. When used in the DAC section, LT1364 (two different chips) ran hot and also caused the LT1469's I had installed in the Amp section to run hot. The sound was okay, a touch too bright and the audible volume was somewhat diminished. It may be an issue with my board or it may be that LT1364 is borderline unstable in the Zero. Other than the issue with LT1364's my zero is impressing me.

Just a heads up for others rolling their zeros. High performance op amps can have issues in some amps and not others of the same version - like the old Pint portable and 8697's
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