Re-tubing a McIntosh power amp

Thing is tho, by your intent you will in fact be tube rolling!
Are you looking to replace a whole set of signal and OPT’s or a combination of same?
If you are considering replacing valves ( Mainly the KT’s) that you feel.  may be a little tired my first inclination would be Mac factory tested and approved via a Mac dealer.

 

not rolling but upgraded from stock, oh baby what a quest.

stock tubes from whom, OEM tubes or you bought used? I imagine OEM's put what they believe is best, then people replace/roll. The difference to the OEM of 'stock' tube cost is insignificant to the cost of the amp.

You will get into the issue of Bias, I started a thread about that 1-1/2 yrs ago, after ton's of advice, then Covid, all kinda other new stuff all over the house, did nothing about bias.

https://forum.audiogon.com/discussions/tube-bias-socket-to-me?highlight=bias%2Bsocket%2Bto%2Bme

Since 1973 I have messed with these power tubes: EL37's; EL34's, 6L6; 7581, 5881; 6550, KT88. weak, shorts, got hold of some money, .... a variety of amps and reasons.

Most recent, my Cayin A88T came with used 6550's. I like having spares, got some b'day $, bought some new KT88's. I loved the 6550's, I love the KT88's more. Convinced myself with my own expectation bias?

Source: Brent Jesse, http://www.audiotubes.com/

It currently has the standard McIntosh branded tubes in it. I have just read that they have a pretty high failure rate and there are much better tubes out there for that amp. I want to replace with the same types of tubes (KT 88, 12 AX7A, etc) but switch to a different brand. 

Golden Lyon KT88s. 4-6000 hours

12AX7, 12AZ7, very close. Golden Lyons, Tellies, RCAs (if you can afford and find them) or if you want a sharper edgy valve, PSVANE
all over 5000 up to 7-8000 hours.

They last a LONG time in a new Mac for sure. I have a GG with 15000 hours, I did lose an original power valve within the first 1000 hours.. It was a made in China valve. It said Mcintosh on the side.. LOL it was probably a JJ.
I have Solvex in there now, wonderful valve for the money.

I paid about 75-80 per quad in bulk. 15% failure, no kidding out of the box or within 50 hours.. After they were burned in (and didn't BLOW up).. Just like any other valve.. 5-10000 hours

A quad of Solvex is 125-175.00 close

Regards

Andy at Vintage tube can help you and rather than fireworks Crap shoot he will get you great tubes, graded and matched… for your amp