RE: upgrade op-amps for the Adcom GFP 565 Preamp

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Posted by beppe61 (A) on May 17, 2015 at 03:04:15

In Reply to: RE: upgrade op-amps for the Adcom GFP 565 Preamp posted by bobwire on March 17, 2015 at 18:31:54:

Hi and i think you are very right indeed
This is a point very overlooked. The op-amps to sound clean and powerful need many and fast uF very close to them.
I have a Hegel preamp ... a P20. I see many OPA604 inside with quite big caps (i see 1000uF/63V) very close to the OPA. The sound is very clean and powerful. Not the typical hardness associated with op-amp.
For me the caps are like dampers and music like a rough path with ditches and hills.
The smaller the caps the less energy is stored and then available during music peaks.
I think that a good starting value could be 470 uF of very good quality.
But i could even use up to 2200uF ... the working voltage is usually low and so also prices for these caps.
I have here a nice heaphone amp with powerful op-amp buffers (250 mA or current available) but almost no caps close to the buffers.
I find the sound clean but hard. I am completely sure two big caps would have changed the sound for the better. I am sure of that.
A little sharpness in the details, instead, can be effectively tamed with break-in and the right cable selection (i.e. copper solid core o litz wires).
I am keeping this preamp. Even if it is op-amp based (scandal !).
I have also an old Electrocompaniet 4.5 fully discrete and more rounded and soft.
I like the transparency of the Hegel better.
Very clean line stage indeed.
So op-amps can be extremely good when rightly used.
Thanks again for confirming a sensation.
Kind regards,
bg

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Follow Ups Full Thread

Topic - upgrade op-amps for the Adcom GFP 565 Preamp - alley -kat 11:25:46 02/16/15 (13)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - aupiho 12:35:31 05/07/15 (0)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - bobwire 18:31:54 03/17/15 (1)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - beppe61 03:04:15 05/17/15 (0)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - JoeKool 14:56:05 02/21/15 (1)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - Ruinthere@sbcglobal.net 18:47:01 05/04/15 (0)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - fantja 06:15:20 02/21/15 (0)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - fantja 14:43:30 02/20/15 (0)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - Blackdog 20:39:00 02/16/15 (5)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - alley -kat 03:40:08 02/17/15 (4)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - Hornlover 09:31:42 02/17/15 (3)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - alley -kat 03:36:40 02/19/15 (2)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - jedrider 07:29:19 02/19/15 (1)

RE: upgrade op-amps for the Adcom GFP 565 Preamp - pictureguy 20:25:44 02/19/15 (0)

Follow Ups

RE: upgrade op-amps for the Adcom GFP 565 Preamp - beppe61 03:04:15 05/17/15 (0)

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