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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

Showing 3 responses by tyray

tyray
697 posts
 
Holy Holidays!

McIntosh tube tuner/preamp MX110Z (1962-1969) / KT88’s

Cayin is A88TC version 1, which has 16 ohm taps for my 16 ohm speakers.

JSE Infinite Slope Model II speakers

@elliottbnewcombjr,

I had no idea...In my ignorance of this thing audio (hifi), I always wondered why some like everything tubes? Period. Now I understand somewhat why.

Could you explain the quality of reproduction of music you get when played on your turntable through the MX110Z preamp with the Cayin is A88TC version 1 and those JSE’s?

I should have bought that Fisher 800C when I had the chance years ago.

Is there any Fisher/Mc and Cayin you can recommend me? Thanks All, for the bias education too.



tyray
697 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...


tyray
697 posts
 
@lewn,

The statement below was from a positive feedback article about the MX110Z that Elliot was gracious enough to provide us.

"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."
http://www.positive-feedback.com/Issue77/vintage_mcintosh_experience.htm

@ elliottbnewcombjr,

Talk about a labor of love and patience! You kept the same preamp and kept it working after all these years. The money you've saved and knowledge gained on that unit, from not having that dreaded disease of upgraditis...Bloody brilliant if you ask me. 

As an Architect, whose path went the way commercial interior designer. I'd love to hear some of your stories on acoustics where the materials used were passive and maybe active in a room/hall you designed with the customers acoustic wants in mind. 
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