Original Cary 300B Monos Reliability?


Anyone have long-term experience with the original Cary 300B monos (with the single 6SL7 tube)? I'm looking for feedback regarding reliability. I've read that the engineering choices made in the design should have the amps failing on a regular basis, along with eating tubes. 

Outside of a few DIY complaint/discussions, I haven't really seen this brought up as an issue.

I'm not concerned about the sound qualities or speaker compatibility as I have heard the combination before. Just looking to see if any of you have experiences to share regarding technical issues. I realize that these amps are now 28 years old, but they are point to point with basic parts. If the chosen values have worked for years, replacing defective caps/resistors should be straightforward.

Thanks for sharing!

128x128leahy

Agree with @russ69 , these are very straightforward well designed amplifiers that have successfully withstood the test of time. One of the primary assets of SET is their simpler circuit and relatively low part count. The Cary 300b SET would not have its establhed longevity/reliability  it they were built cheaply or poorly implemented.

Charles

Thanks all, for offering your feedback. I understand schematics, but I'm not good at all with the math for circuit design. The discussion centered around too much capacitance after the rectifier, and they also thought the 300B was run quite hard. Many who chimed in "knew" that Cary had made dubious circuit decisions through the years. I was just looking for any real-world issues with former owners of the first iteration of the monos.

Charles, I was hoping you would check in. You weighed in on my Cary/ProAc questions a little while back. I have an Audible Illusions M3B lined up to borrow when I get the Carys, so I'll be duplicating a system I heard so many years ago. 

I really like my CJ CAV45 S2, but I still want a little more of the reach out and touch them midrange that I recall from the Carys. I'm closing in on a deal for a nice original pair with the additional 14 capacitor bank - just have to work out shipping for three boxes $$$. I also acquired a pair of Response 2 speakers, so I'm ready to get this going!

Will let you know when things come together.

@leahy

I really like my CJ CAV45 S2, but I still want a little more of the reach out and touch them midrange that I recall from the Carys. 

I do not doubt  that  your CJ CAV 45 amplifier is serving you very well.  However the "reach out and touch " tactile quaility you're seeking is in my experience a true strength of good quality output SET amplification. 

As good as my  previous push pull amplifiers were, my Coincident Frankenstein 300b SET just took this characteristic to an upper level.  I'm curious to see how this plays out in your audio system given the inevitable variables and the Spector of component/system synergy. 

Charles 

Update: somewhat disappointed with the Cary monos/ProAc R2 combo, BUT, my 16 ohm single driver speakers (Finale Audio: Vivace Mini) are an excellent match. I'm missing a little bit of the mid-bass weight from my JBL L112 along with ultimate volume. For most daily listening, these Cary's are just what I was looking for. 

I am looking to max out the 6SL7 and 300B tube options. I'm thinking new WE 300B ($1,500!!!) and some nice NOS 6SL7 tubes. Any thoughts on these options would be appreciated.

Charles, what's your preamp with the Coincidents?