[HiGHFLYiN9]

If you guys ran into my threads I hated the AD8610 in my PPA, it was just too bright and fatiguing, also not very kind to older recordings. I couldn't even listen past three on the blue velvet and even then, after a half hour it was painful. When I rolled to the OPA627/637 combo it was sooooooooooo much more enjoyable to listen to, I could listen well into five all day long without fatigue. I would never even dream of going back.

 

[SteeleBlayde]

Frankly, I dont like the AD8610 much either. You sould like a candidate for the LT1122. Sounds even better than the OPA's.

 

[iamdone]

Where can I get the LT1122 opamp?

 

[xtreme4099]

http://www.linear-tech.com/prod/data...?datasheet=242

you want to get the dip version ...

 

[Sean H]

Wow, I have similar company. I kind of thought I was nearly the only one who found the 8610's bright. Of course that was in the XP-7 but I thought I might give the bugger a try again as it's a whole different amp. But sounds like their character continues in PPA's as well. I just remember going from the 8610's to AD797's (supposedly similar to OPA's) in that amp and going ahhhhhh........

SteeleBlayde- How would you describe the sound of the LT1122's in comparison to the OPA's? And the AD8065? Similar to xtreme4099's impression being a smoother/darker 8610? I'm interested in Mark's 744 idea too.

 

[SteeleBlayde]

The OPA's have always sounded somewhat dry and flat to me. Some say they sound really smooth, but I havent really noticed that. The LT on the other hand does sound smooth! It definitely minimised the harshness coming from my MS-Pros. It also sounds quite lush and full-bodied. Not to the extent of tubes, but its got the same idea. Its not overly warm either, which is good. The 8065 on the other hand is just a tad warmer and while it doesnt sound as lush and smooth as the LT1122, I feel its more of the "rock" op-amp because it has really great attack without the grating sound of the 8610. It works really well if you've already got a smooth sounding headphone, since it helps to add some liveliness without making you wince.

Thats my observations though; some of the folks I've been listening with love the 8610 and I just shake my head and ignore them.

Edit: This is all with the AD8610 in the ground channel, since I've been told this op-amp is supposed to be particularly stable.

 

[iamdone]

Quote:

Originally posted by xtreme4099 http://www.linear-tech.com/prod/data...?datasheet=242 you want to get the dip version ...

What's the exact part number? And I should leave the current ad8610 is the ground, right?

Thanks for all the help.

 

[Sovkiller]

Mine is on the way to mark, my buffers are waiting there, tunned just for the CD3K, but I have a quick question SeanH, as you may know we both love the little Perreaux, one thing that let me always thinking was the soundstage that this little amps has, the PPA is good but I was always anxious of squeezing it a little bit more, to make that difference with the Perreaux even bigger, with the current configuration I have, the soundstage is not the parameter that make me keep it, as I know that it could be better, do you notice if by any chance the new buffers contribute to improve the soundstage of the PPA in any grade....????.

 

[Sean H]

Hi Al- It's been a while! I definitely hear a more layered soundstage and depth of space with the discrete buffers on board. It's not a transformation but notable. I liken it the feeling that you are a bit more immersed into the music, it's a litte closer and the feeling of air and space is a bit more discernable and more clear. You'll like the buffers! Looking forward to your impressions.

Are you going to have OPA627's across the board now since the 637 is technically not compatible with the buffers? That's what I have. You could experiment here. If you are seeking a bit more air and such you could try the 8610's. Or the 8065's are said to be close to them but with not quite the ruthless high end. Just a thought.

 

[Sovkiller]

Well according o the last tests made by Phil the 637 is compatible with the boards also, he tested about 12 samples and all of them work perfect, technically maybe they were excluded, but in the practice they work, of course in case of any problem I will go for 627, I will post my impressions and even some pics here after I got it, if you don't mind, voodoochile will take them, I modded the case a little bit, and made a nice front panel, lets see, hope in a few days, OTOH, also Phil personally biased and tweaked the buffers particularly for the CD3K, so it will be another point in favor, as he owns a pair.....I'm like a kid now, waiting for the new toy....LOL....

 

[Voodoochile]

My buffers were missing two of the five bypass caps, which may well have been why it would not start properly.

If I fired up the PPA without cans attached, then plugged in the cans, no problem. If the cans were already plugged in and I powered up, then the 637s would not settle.

I did not try it after installing the caps that were missing, as I found this out on the shipping date at the 19th hour. Once I added the other two caps, the amp starts fine in any state of connection. That may well have held true with the OPA637s.

Al- I would certainly try it before I swap out your op-amps, no worries there. Depending on the bias of the buffer, you may even prefer the 627s now over the 637s, as the buffer does offer an (even) cleaner, more detailed high end as Sean pointed out. Not overkill, but the difference is there. Maybe you could discuss with your partner in ex-Perreaux goodness about it also. Granted you guys have radically different taste in cans... yet similar taste in amps.

 

[ITZBITZ]

Quote:

Originally posted by Voodoochile My buffers were missing two of the five bypass caps, which may well have been why it would not start properly.

I'm concerned about the cap situation. My diamond buffer came with three Nichicon Muse Green caps on it, 47uF I think, electros, one seemingly adjacent to each channel of the triad. From what you are saying, this isn't right and it should have five caps on it? What's the deal? Is my board not configured right? Is there a datasheet on this thing from Larry. I'm almost afraid to plug it in at this point...

 

[Sean H]

EDIT. Sorry.

 

[Voodoochile]

Quote:

Originally posted by ITZBITZ I'm concerned about the cap situation. My diamond buffer came with three Nichicon Muse Green caps on it, 47uF I think, electros, one seemingly adjacent to each channel of the triad. From what you are saying, this isn't right and it should have five caps on it? What's the deal? Is my board not configured right? Is there a datasheet on this thing from Larry. I'm almost afraid to plug it in at this point...

No no... I'm not saying it's right or wrong. Mine came with three film caps, and I had some trouble with the 637 chips, which was anticipated. No trouble with the 627s, which was also anticipated.

I was told I could (and should) add the other two caps. But this is all in the realm of box film caps. I have no idea about the NP electro caps. That said, the one I have for Al does indeed have all five of the green NP electros, not three. You should discuss this wil Larry or Phil directly, not in this thread. We are drifting pretty far off topic.

 

[guzzler]

itzbitz... i've got the same buffer as you:

DO NOT PLUG IT IN, until you've checked those caps

those caps are only 16V Muses and will *pop* if you've got a power supply over that. I emailed Phil and he said it was a mistake during building that resulted in that. I'm going to try and get some 10uF BG N-types for their replacement, but it's a little annoying after shelling out £64 for it all

g