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RE: Adcom-- which preamps are Nelson Pass?

Posted by mcgjohn@yahoo.com on June 17, 2010 at 10:03:27:
Yes, I agree. The adcom GFP and GFA units do not use the best parts, have small power supplies and benefit greatly from any upgrades.

Many of the GFA amps used a chrome plated steel grounding buss. Don't forget that is in the signal path. replace with copper or brass buss bar stock, obtainable from sevral sources. The 555 Mk1 and Mk2 come to mind. Maybe that was done for flashy hood off display for marketing but it does nothing for sonics.

All of the GFP units need a bigger Xformer. OE units are on the order of 7 to 15 watters. Move up to a 400 watt if you want to hear what a GFP really sounds like

best