4krow
Seasoned Member
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IMAGINE WHIRLLED PEAS
Posts: 1608
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Hard to believe, but I just got this amp back on Friday!!! There are good reasons for it, so I won't even go into it. I will say this>>> if we had any idea how crazy the amp project would be along with life issues thrown in, it wouldn't have happened. John Dee, the engineer who very graciously helped for most of the project, was able to clear hurdles that would have made me shoot the damned thing. If I am a patient man, I can't imagine what that makes him. So, here we go. In the beginning, I replaced the power capacitors with new caps due to age. The only ones that I found were almost twice the capacity and only fit with chassis modifications that you see here. Once the amp was in Johns hands, we discussed what kind of expectations that I had. I told him that a class bias would be my preference. In the end every transistor was taken out because of faulty transistors all over the . Yes, thank me for that. John decreased the number of output transistors from I think 10 per channel to just 3? Dam, I should have paid more attention. He added faster/larger caps on the board to increase rise time I suspect. just about all of the parts were replaced or upgraded. His work is better than mine, so I am glad for that. Power caps were bypassed with film caps, as all other electrolytic looked to be bypassed as well. There was So much more that was done, so basically this is a new amp. It should be noted however that the original design was made so that the power supply could easily be changed by moving a few power leads in order for the original amp to run in class A at 50 watts. John asked what class A wattage would be in the ballpark for my speakers, and i stated that 20-30 watts would be a great start. The amp can be biased up to about 50 watts, but I want to try this level first. it should also be said that I am using this amp with the DNA2 speakers that I recently made. This by a good margin the best SS design that I have used with these speakers. Since the damping factor is at 600, the bass is tight just the way I like. I do not know the rise time of this amp, but it works with the se Mark Audio drivers that I am using so well! This is one the few SS designs that gets the harmonics so much better than what I have heard from other SS designs. That means a bunch to me. Unfortunately, I cannot comment on the high frequency response of this amp, since, even though I still have fair hearing, the high frequencies are not what they used to be, period. I boost the treble by 3 db and that gives me the impression that this all sounds right. In the end I haven't heard a system this good in a very long time. Not since I sold Rachel, and was using the ZOB speakers.
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