anyone done mods to amp, pre,or cd?

One of my buddies just modified a power amp of his with fast recovery diodes in place of the bridge. He said that the difference was staggering. The noise floor dropped, sound was much more liquid and transparent. It was so noticeable that he was now able to hear how flawed some of his other components were. He then went on to do about a half dozen other amps and preamps, all with similar results.

I've got to figure out which diodes i want to go with and get busy. My only concern is that many state that this mod causes a thinning or leaning of low frequencies. Supposedly, different brands and types of diodes work better on specific types of gear i.e. Schottky's on digital, brand x on tubes, brand y on SS, etc...

I also have to wonder if the people complaining of this phenomena were using diodes that were rated for a sufficient amount of current. After all, bass peaks can draw HUGE amounts of momentary current. Using a diode that was not rated for enough current in the bridge would have the same effect as a voltage sag. On an extended duration passages you would end up with weak and soggy bass that lacked both impact and staying power.

I know that Bob Crump has quite a bit of experience in this area. Bear from Bear Labs probably has some good points to add to this conversation also. Hopefully, these guys will chime in and share their knowledge. Sean
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PS... good thread and thanks for bringing it up : )

I have ordered some Jensen paper in oil caps for my LS7. Got them through the Welbourne labs site. Been also thinking about upgrading the pwr cord but instead of a iec plug just ordering a cord with the ends bare and hardwire in place. Then again maybe a iec is the way to go. This way I can try different cords and make a decision. So many mods-so little time.

you should talk to john hillig at: http://www.musicaldesign.com/
he's very knollegable and can defenately help you.

I was going to suggest John Hillig, but you beat me to it. He's been in the mod business since the l970s and knows what he's doing.