KVR Audio

ourafilmes · Post by **ourafilmes** » Tue Jan 11, 2022 2:54 pm

I simply love vacuum tubes.
I have them in my Hi-Fi, in guitar amps and in my studio in my microphone preamplifiers.
But... How do you know when a tube is bad?
In this video I show how I test vacuum tubes with a TV-7 - an old military tube tester.
I am testing:
a 12AX7 or ECC83
a 12AU7 or ECC82
a 12AT7 or ECC81
a 6V6GT
a 5AR4 or GZ34

Cheers from Portugal!

https://www.youtube.com/watch?v=CzuLFJTZ120

Hink · Post by **Hink** » Tue Jan 11, 2022 10:17 pm

I'm old, when I was a kid every drug store, radioshack and more had these things

The Noodlist · Post by **The Noodlist** » Tue Jan 11, 2022 10:47 pm

Thanks for the video.

Orange used to sell a simple tube tester.
https://orangeamps.com/products/accesso ... ve-tester/

Bombadil · Post by **Bombadil** » Tue Jan 18, 2022 2:41 pm

Our first tv was full analog. It's picture was very warm, with a pleasant analog distortion that manifested itself as snow. I remember my father switching out the tubes fairly regularly.

ourafilmes · Post by **ourafilmes** » Tue Jan 18, 2022 3:22 pm

Old tube TVs... Man, that was a long time ago!

BertKoor · Post by **BertKoor** » Wed Jan 19, 2022 3:49 am

So if I have some to test, can I send them to you? And after you sent them back I have to have 'em tested again because of possible transportation damage?

In my youth (1972-1977) lots of old & good working tube radios & tvs were put at the garbage, just because the owners bought transistor stuff. Me & my brother would take them apart for the parts. One of the last we scavenged that way was an early tube colour TV on its last legs. We had to put a fan at the back to keep it from overheating.

Recently I heard that dodgy contacts in the socket can be cured with spraying some WD-40 on the pins. Anyone knows whether that's true or myth?

nix808 · Post by **nix808** » Wed Jan 19, 2022 4:25 am

you could probably spray them with contact cleaner Bert?

BertKoor · Post by **BertKoor** » Wed Jan 19, 2022 2:48 pm

No, I was explicitly enquiring about WD-40, which I have laying around.
Because if you have contact cleaner you'd preferrably use that obviously.

Hink · Post by **Hink** » Mon Jan 24, 2022 4:00 pm

I used that once, wiped out all my contacts...took me weeks to get hooked up again

BertKoor · Post by **BertKoor** » Mon Jan 24, 2022 4:17 pm

Thx 4 the head-ups, so I take it using WD-40 is really really bad advice

Hink · Post by **Hink** » Mon Jan 24, 2022 4:32 pm

BertKoor wrote: ↑Mon Jan 24, 2022 4:17 pm Thx 4 the head-ups, so I take it using WD-40 is really really bad advice

I was being silly contacts as in weed contacts

Speaking of tubes, did you know that test tube babies have a womb with a view?

Bombadil · Post by **Bombadil** » Tue Jan 25, 2022 5:33 pm

whyterabbyt · Post by **whyterabbyt** » Tue Jan 25, 2022 5:44 pm

nix808 wrote: ↑Wed Jan 19, 2022 4:25 am you could probably spray them with contact cleaner Bert?

or wd-40 branded contact cleaner, for the best of both worlds.

(pedantry : wd-40 is a brand, with multiple product lines. the thing everyone calls wd-40 is actually 'wd-40 multi-use product')

Testing Tubes - how do you know when they are bad?