Using solid state rectifiers on Cary SLI80 Amplifier

I appreciate the comments and expressed concerns much of which have been part of my own thinking. And i realize that in the opinion of Cary staff they thought the voicing would would be a generalized most appropriate sound for the end users. The fact that they decided on solid state rectification, though, must be based on some reason of sonic improvement. In any case, it ultimately must result, good or bad, in change which can only be good or bad in the opinion of each individual. Most in this hobby seem, or at least claim, to  believe that listening tastes are so individual, no single component or combination of pieces can be the most appropriate for everyone. As much as I appreciate the Cary I’m not convinced that it fits me perfectly so if there is some way to achieve that goal it makes sense to me to find it. To the extent that I understand it, changing to ss rectifiers will not result in anything more than faster response and not an increase in sustained power increases to the various internal components, trying the ss rectifier seems like a relatively safe experiment. To avoid the initial surge, use of the Variac that I discussed earlier should accommodate that concern. I’m not an expert in any sense of the word so much of this argument is based on assumptions. That being said, I invite any comments that may keep me from doing something likely to be regretted. 

Until this discussion I’d never heard the term “super rectifier” and I’ve been in this hobby off and on since 1959. My previous thinking about rectifiers has been that, because their function is not in the signal stream, their influence on sound personality/quality would be minimal and should be the last priority in pursuit of circuitry modifications to influence sound. Experimenting with biasing levels, though, has changed my mind. Although I’ve never considered myself to have the ability to discern subtle changes, adjustment of the Cary bias amperage from 75 to 90mA was significant even to me and I thought I’d found  a nice compromise between the Cary and several of my favorite ss amps. When Cary reps advised against the biasing increase or the substitution with ss rectifiers it was for reasons of shortened tube life, not degradation of sound quality. Anyway, I have a couple of ss rectifiers that I bought to replace the 5U4’s (as an experiment) but I’m a little afraid to try them based on warnings expressed here. I’m willing to accept some degree of shortened tube life associated with heavier biasing but my concerns about ss rectifiers damaging other components resulting in the need for expensive and time consuming repairs are what my worries are about. 

Atmasphere not atmosphere. Damned spelling correction feature. 

Atmosphere, over the years I’ve learned much from your posts and I appreciate this response which I think I mostly understand. Anyway, because I’ve already bought them I’m going to try the ss rectifiers simply out of curiosity. I have one question, though; for those ss diodes that are designed to mimic tubes, if part of that feature is to more slowly ramp up the application of power, will that not also affect these diodes’ reaction speed overall and negate the reason for their substitution in the first place? Im probably overthinking this and a bit over my head technically but this all started when I went back to using the relatively low sensitivity Martin Logan CLS2 speakers and was looking for a bit more dynamics still keeping the Cary in the system. 

Ok, before considering any circuitry mods to accommodate rectification considerations, I wanted to know whether exchanging the tubes for ss would be worth pursuing in the first place. I plugged in the YJR Yellow Jackets, reset the bias to Cary’s 75mA recommendation and started listening.
The sound across all frequencies seemed tighter and with increased dynamics but the biggest improvement seems to be in timbre, especially listening to solo guitar music. Overall, the sound across the board just sounded more crisp (less tubelike?) similar to my favorite ss amp, the Ayre V3 which is very musical like the Cary but with a seemingly tighter overall presentation. So now I have some idea about the sound but I still have important decisions to make primarily regarding which setup I prefer listening to and whether I want to invest what’d be necessary to assure amplifier reliability. 

Hoping not to run this into the ground I have a little more to say. The observations I reported in the last post remain correct to the extent that I’m meaningfully able to get the points across.  It’s obvious that everything is tighter and attack, especially for percussive sounds is quite noticeably sharper. The bottom line, though, after listening to many different pieces of music, other changes accompanying what sounded like improvements in clarity started surfacing. Upper mid and higher frequencies have become more sharp to shrill which doesn’t appeal to me. Some may prefer this sound, especially those experiencing upper frequency age related hearing loss (I’m one of those people but now wearing hearing aids). For me, those changes that I like are are not enough to trump the more laid back sound that I’ve become habituated to so, for the time being at least, I’ll stick to stock sound of the SLI80. Thanks to each of you who helped me get to this point. 

Yes, jss, during the same conversation with Cary I asked about the ss diodes as a substitute for the 5U4’s. The response was similar to the bias question; they recommended against it for reasons of potential reliability and longevity compromise. Atmasphere, I agree that abandoning an idea simply because of one or several of its outcomes didn’t go completely as desired  can be a mistake. Also, even though I hadn’t thought of a noise factor, it’s possible that substantially  increased noise could result in my having written it off as strident. Also, although hearing aids have vastly improved my listening enjoyment, they can also play tricks with certain frequencies. Anyway, before I give up on the idea I will look into the HEXFRED suggestion although a bit more involved than a simple plugin.