ANOS Preamps tubes that "test as new"

[lv]

When a vendor says certain tubes "test as new" what does that mean?

What do these measurements mean:

59/54/32
52/52/32

Thanks

[PlinytheWelder]

Originally Posted by lv

When a vendor says certain tubes "test as new" what does that mean?

What do these measurements mean:

59/54/32
52/52/32

Thanks

They might mean something if they specify the tube tester, otherwise it's just numbers...
Maybe , it's 52 54 and the fail is 32?

[Timbre Wolf]

Originally Posted by lv

When a vendor says certain tubes "test as new" what does that mean?

What do these measurements mean:

59/54/32
52/52/32

Thanks

You'll have to confirm this with the seller, but here is how I would interpret those numbers...

The first two numbers are measurements of each of the two triodes' transconductance, and the third number ("32") would be the minimum "good" measure on the tester. Generally, the "new" test result is 1.5 times the cutoff value for good/bad (32 X 1.5 = 48). If my assumptions are correct, then those two tubes test with transconductance values that are higher than "new" values.

- Thom

[lv]

Originally Posted by Timbre Wolf

You'll have to confirm this with the seller, but here is how I would interpret those numbers...

The first two numbers are measurements of each of the two triodes' transconductance, and the third number ("32") would be the minimum "good" measure on the tester. Generally, the "new" test result is 1.5 times the cutoff value for good/bad (32 X 1.5 = 48). If my assumptions are correct, then those two tubes test with transconductance values that are higher than "new" values.

- Thom

Thanks Thom!

I've heard about matched triodes - does that have an impact on the tone? I'm going to be using these in v1 and v2 of a dumble style amp - mostly trying to fine tune my clean tones for a little more sparkle.

[Timbre Wolf]

Originally Posted by lv

Thanks Thom!

I've heard about matched triodes - does that have an impact on the tone? I'm going to be using these in v1 and v2 of a dumble style amp

Matched triodes won't make a difference in that use. Some prefer matched triodes for long-tail pair phase inverters, and some HiFi gear splits left and right channels from each triode, so it is best to use matched triodes there.

- T

[lv]

Originally Posted by Timbre Wolf

Matched triodes won't make a difference in that use. Some prefer matched triodes for long-tail pair phase inverters, and some HiFi gear splits left and right channels from each triode, so it is best to use matched triodes there.

- T

Thanks for the reply, as well as all the other tube related posts you've made that have helped me out over the years.

[Timbre Wolf]

Originally Posted by lv

Thanks for the reply, as well as all the other tube related posts you've made that have helped me out over the years.

And happy new decade to you!

- T

[lv]

btw, I asked the vendor and here was the reply (also, I've done biz with him for years, I trust him, this was more for my own edification):

The number 32 is the minimum reading for a good 12AX7 on a military
TV-7D/U tube tester.
This is the bottom number in the test results.
The two numbers above that number are the test results for the two
sections of the 12AX7.

A good 12AX7 will usually test between 50 to 60.