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Old 19th July 2007, 03:16 PM   #1
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Default ad845 drop in

Hello!
I have a parasound 1500 dac modified with all new capacitors and it gave a very good improvement. I also want to replace the AD845KN opamps, is it possible to put opa627's in the 845 socket? or should I make some other connections to the socket. Only pin 5 and 8 are opposite from 845/627. Thanks Teake
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Old 20th July 2007, 11:13 AM   #2
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Hi again!
I looked at the pcb lines and saw that it was oke, so I put in the 627 and got a beautiful sound, very easy, better pinpoint, it looks like if the sound is smoother, rounder and got more air between the instruments, voices are clearer and more refined, you can actualy hear the breathing more. The 845 was more shouting and unforgiving, to much for my ears (51 years) but that does not mean that the 627 got less detail, no its so quiet that it looks like there is less, but there is not. So now I got an other question. Do I still have to decouple the opa627 with 100nf and put an extra buffer on the v+/- of 220uf's, and will that improve the sound also? I hope someone can give me an answer. Thanks Teake
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Old 5th August 2007, 03:11 PM   #3
arupg is offline arupg  Latvia
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Hello intense-tavda:

Interesting post, at least for me since I was contemplating AD opamps for my Audio Alchemy dac-in-the-box Dac. Please read my post
Which Opamp Do U suggest ??

The BB OPA2107 I'm told is quite similar to the much more expensive OPA627 + also need 2pcs + Browndog adap for the fit into my dac.

How is your soundstage size compared with the earlier AD?

Inputs will be appreciated.
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Old 5th August 2007, 10:23 PM   #4
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Hi ARUPG!

The AD845 gave a wider soundstage and the opa627 gave a deeper soundstage and was more precise with placing the voice and instruments. The voice came with the 627's more on the foreground and sounded more pinpoint. With the Ad845 it sounded if there was more around the voices. grtz Teake
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Old 6th August 2007, 06:42 AM   #5
arupg is offline arupg  Latvia
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Hi!

Thanks for the explanation. Couple of queries:

1. Is the width you got with 845 similar to what you are getting with 627?

2. I understand 627 shows more depth with layering wherein main voice is in the foreground and other background voices instrument off-foreground and into the background like layers. I presume this is how it should be.

3. How is the tonality from Top-to-Bottom all the way between the 2 chips?

4. Do you feel at any moment the 627 slows down the "pace & rhythm" of the music? I ask this as BB chips are termed to be laid-back.

5. What sort of decoupling/bypassing do you have in your circuit where you are using the 627s now?

Thanks & Rgds

ARUP
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Old 7th August 2007, 02:26 PM   #6
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Hi!
The 845 is more shouting, unforgiving, and it sounds if there is some more distortion at the higher frequenties. It does have a little wider soundstage, but on the other hand the 627 is more precise. You got right about the layering, there is more dept on the 627 in stage layering, you can actualy hear the band playing on different points, just as it should be. Like I wrote before: It looks like there is less with the 627, but there is not, its easyer to listen to, it has more rest! You don't get tired listening to the 627. The 845 you will! GRTZ Teake
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Old 7th August 2007, 02:30 PM   #7
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And ARUP I don't have any bypassing, that was my question at first. Should I do it? And what's the point of leaving it, the sound is allready very good! But as I am a person to get evrything out of something, maybe I wil in the future.
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Old 7th August 2007, 02:37 PM   #8
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Its in the parasound DAC 1500, there are a couple of opamps. What the tonality between the two opamps is; opa627 cleaner, preciser, a little bit warmer, the 845 more shouting more direct, sometimes more a chaos.
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Old 7th August 2007, 08:20 PM   #9
arupg is offline arupg  Latvia
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Thank you very much for the elaborate explanations. I can clearly see the benefits of the 627 and hence the asking high price seems to be justified.

Decision taken - will go for it. 2 x 627 on a browndog adapter.

Thanks once again!!
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Old 7th August 2007, 10:26 PM   #10
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Mojo ARUP, Teake
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