Original Cary 300B Monos Reliability?

@leahy 

Congratulations with the Cary SET and Finale Audio speaker pairing. I use the Coincident Statement Line stage (101D tubes). You are wise to consider the upper tier quality 300b tube such as Western Electric. I'd also recommend you consider EML XLS and the Elrog 300b as well.  There are very good word of mouth reports  in regard to the Lanlai Elite 300b tubes.

Charles

@leahy For many years I ran a Cary CAD-301SE (a little-known model) with ProAc Response 2.5’s. I used the first reissue WE300B’s that came out in perhaps the 1990s--not originals, and not the new ones. I found the combination excellent. It didn’t plumb the bass (just as much the ProAc’s "fault" as the Cary’s), but with the midrange it provided it was easy to forgive.

Here’s one of the few photos I’ve found of a 301.

Charles - I found the information regarding concerns with the Carys running the 300Bs near their limits. It came from the EML web page. They suggested the XLS as a best option for Cary. Those tubes may draw more amperage, so I would check with Cary to confirm that the power supply will have no issue. Might also be a question about the base fitting into the tube cutout (a little on the lean side). I know the WE will fit and be a great tube, but I wouldn't mind paying a bit less.

Current preamp is a Croft 25 w/ phono. It's quite good without complaints, but other options might bump things up another notch.

Two-Left - thanks for taking the time to reply. I won't go wrong if I get the WE, especially based on your experience. If they last 10-15 years, it will be a great investment!

@leahy Hopefully you won't have issues with the Cary monoblocks, While I can't speak to those exact amps, I did run SLM 100 monoblocks back in the day. The Jentzen coupling caps Dennis was using at the time were known to leak, sure that's been addressed in yours. I applied diy repair here. I also had issues with bias circuit, don't recall the exact issue as I sent in for repairs.

As far as running power tubes hard, not all that unusual. Between running higher voltages in the amps and lesser quality of many new tubes, failures happen. I'd stick with the EML XLS or Western Electric 300B's in more difficult amps.

Thanks SNS. I need to look into biasing the monos.