Spare tubes? How many?


Being the anal sort of worrier that I can be, I'm thinking to buy some back up tubes. 4 KT88s, 2 12AX7s and 2 12AT7s in place now. I believe only the power tubes are really prone to fail. Welcome correction if I am wrong in that assumption. Should I buy 1, a pair or a complete Quad set of KT88s. If only one tube fails (assuming no sort of catastrophic fireworks) can you simply replace the single and re-bias? Will that make everything OK? (tubes were purchased from the Tube Store so are matched and have the matching number). Thanks for the input.
GH
128x128ghosthouse

Showing 1 response by kurt_tank

Wow!

It is great to see that I am not the only one with a sh*t load of extra tubes.

Luckily, I have a Lamm hybrid amp (M2.1), which only uses
one 6922 tube in each monoblock.
But to make up for the fact that I only need two tubes, I have the following pairs of tubes:

The stock Sovteks;
Two pairs of inexpensive new tubes;
Two pairs of medium priced NOS tubes (Orange Globes);
And, one pair of expensive NOS tubes (Pinched waist);

6 pairs of tubes which supposedly will last me a couple of thousand hours per pair.

6 pairs x 2,000 hours = 12,000 hours.

12,000 hours divided by my average of 4 hours per week (which includes an hour of warm up time) for my listening sessions = 3,000 weeks

3,000 weeks divided by 52 weeks a year = 58 years.

My conclusions from my calculations are:
One, I am not listening nearly enough!
Two, I have way too many pairs of tubes!
And Three, apparently my daughter, who will inherit my gear, is set for life too!

PS Anyone know of a cheap (and reliable!) place to buy more NOS tubes?

:-)