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TUBE BIAS, socket to me!

BIAS: (I'm starting from zero understanding) 

I have never measured/adjusted bias in the 3 tube amps, 3 tube receivers, and 2 tube preamps I have acquired over 47 years. I just switched my current Cayin from 6550's to KT88's. Adjust bias? Adjusters inside, scary electrocution warnings. I could pay someone else to do it, i.e. Steve at VAS 1 hr away in NJ, soooo, 

What really counts? (personally I don't care about either heat or life, but would like to understand)

Heat?
Life?
Output stays Matched when adjusted?
Acoustic Performance?
_________?

Over the years, fronts off, bottoms off, I hose em down with contact cleaner/lubricant, compressed air, all controls and switchers, any adjusters, swish full spin back and forth. Kill any spiders, look for, replace the rare burnt resistor. 
Then leave any adjusters (whatever they are) in the middle position, button it back up.

Two tube testers, my big hickock always agrees with small portable one, test strength, shorts, matched strength old and newly purchased. Large collection of NOS, used. Often used test essentially same strength as new ones.

When they go, it's usually a short.
elliottbnewcombjr
tyray
655 posts
 
Now this knocked my socks off...
Like me, after living with the MX110Z for a while, you may wonder why all modern preamplifiers don’t include FM tuners and equalization controls—they’re great fun! Also, tell me, is there anything even remotely comparable to the vacuum tubed McIntosh MX110Z currently available today at any price? No, which is a pity.
From the link provided by @ elliottbnewcombjr

A tube tuner/preamp with equalization controls?! Such blasphemy! I can’t tell you how many times I’ve read here on Agon that tone control is a bad thing! Hah!
’It degrades the signal/sound. The pots go bad. You don’t need tone control if you system has good resolution ect.’ Oh and don't get me started on having a FM tuner.

Am I missing something here? Sounds like a revelation to me...


elliottbnewcombjr OP
5,529 posts
 
I’m not using my tone controls, but I like having them, you never know. Actually my Chase Remote Line Control has remote treble and bass, again, I don’t use them. I use the remote balance occasionally, would hate to be without it.

Don’t forget the advantages of the McIntosh Mode switch, balance control, and optional Loudness, which if understood/used properly can maintain involvement at low levels, for me primarily keeping jazz bassists heard.

My Chase unit has automatic ’loudness’, again, it’s volume has to be properly coordinated with the preamp and amp to avoid misuse.

the platitudes: no separates; no tone controls; are mostly platitudes IMO.
wolf_garcia
6,711 posts
 
I'm biased toward tubes, both preamp and amp (and guitar amps of course) although my power amp is cathode biased needing no adjustment (single ended class A Pentode). I actually enjoyed biasing my previous tube power amp, even with the occasional mildly burnt finger.
oldhvymec
5,101 posts
 
OP, there is one thing for sure. You know it's done, BETTER than most because you did it.  That has always been my position..

Saying that, I have backed off a bit on the self imposed brain surgery (s).
YES practice makes perfect.. Any volunteers? I'm getting close, not seeing double anymore, or less..:-)

Happy Happy...

Regards
elliottbnewcombjr OP
5,529 posts
 
oldhvymec

It's hard to adjust bias with vision problems they tell me.
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