|
|
Post by creolian on Aug 2, 2017 16:22:19 GMT
Hello all, I recently re tubed my pre amp pedal and am looking to replace valves in a couple old Ampegs. Recently a Friend who's father was a ham operator and electronic hobbyist gave me a box of old tubes including some 12ax7 and Ecc83 along with some power tubes in nice old RCA boxes. Considering the corner store no longer has a tube tester I've got no way than other than visual inspection to know what condition they are in. I put a couple in the Vtwin pedal and it sounded pretty weak before i shut it down quickly. Ultimately I bought a couple new ones and much to my relief I didn't damage or destroy the pedal, Found a tiny crack around one of the pins... Any ideas on how to test old tubes without a tube tester and not using vintage amps as guinea pigs? The nearest tube tester I have found is in Birmingham Al ( 5 hr drive). I've got what is becoming a collection of old And newer tubes and am afraid to use them. Does anyone test by mail ? What do you do with em ? Baffled on the Bayou  TIA, Jeff |
|
|
|
Post by Pickers Ditch on Aug 2, 2017 17:13:51 GMT
|
|
|
|
Post by Michael Messer on Aug 2, 2017 17:21:55 GMT
Well spotted PD!
It is not a cheap tool at $499 USD, but it does look very good.
I WANT one!
Shine On
Michael
|
|
|
|
Post by Stevie on Aug 2, 2017 17:43:17 GMT
It's a lot cheaper than an old AVO valve tester!
e&oe...
|
|
|
|
Post by Pickers Ditch on Aug 2, 2017 17:44:37 GMT
A friend of mine has one and it paid for itself after him having gone through a box of NOS valves and floggin'em on eBay. It's good bit of kit and saves a lot hassle now that our local valve wizard has retired. BTW Creolian, they are called VALVES not tubes. |
|
|
|
Post by creolian on Aug 2, 2017 20:48:39 GMT
LoL In New Oyunz, our version of the English language is such that we cannot say the word 'valve' without injuring our mowfs. |
|
|
|
Post by Pickers Ditch on Aug 2, 2017 21:28:10 GMT
Yup, I nearly got a sore mahf in Canal Street when I asked for a poor boy instead of a po' boy.  Fortunately the bars head honcho came to my rescue realising I was British. That was a great holiday though! |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Aug 2, 2017 21:44:33 GMT
Aluminum,meer(what you look in when you're shaving),missle,trunk,fender--I could go on.When oh when will you Americans learn to speak the Queen's English.
|
|
|
|
Post by creolian on Aug 2, 2017 21:50:03 GMT
Aluminum,meer(what you look in when you're shaving),missle,trunk,fender--I could go on.When oh when will you Americans learn to speak the Queen's English. I can relate! Us New Oryenians cannot understand americans either.  |
|
|
|
Post by Michael Messer on Aug 2, 2017 22:09:36 GMT
  Shine On Michael |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Aug 2, 2017 22:16:18 GMT
You really cannot damage an amplifier by installing and testing a Preamp, oscillator, or phase inverter tube. It will give you a realistic, loaded, reliable test, especially in terms of microphonics. Power and rectifier tube testing in the amp is more risky, since a shorted power tube can draw excessive current.
|
|
|
|
Post by mitchfit on Aug 3, 2017 0:13:18 GMT
another aspect to consider...
here a TV7DU in good condition that has been gone through and recently
calibrated pricing starts costs around 700-1,000 dollars. they can pay
for themselves if you want to buy untested valves and show their results
on ebay.
but really that only tells if it is electrically and mechanically sound.
some amp builders i know feel putting it in the circuit and applying some
ear time is the only true test.
could be cheaper to buy from a reputable source instead of getting a
tester unless you plan to resell, or build up a stash for yourself
on the cheap. this would be a sure fire investment strategy as the
supply has already reached near critical mass.
if you feel you gotta have one, contact me. i have a TV7DU that needs
to be gone through and calibrated. the cost of doing so runs 1-200
dollars.
if you do enough research that you feel you can trust the tech.
to me better to buy untested [as per fredcapo-preamp] valves and test
them in the amp/pedal if the commercial option doesn't appeal.
mitchfit
even texicans know "tube" means TV...
:^)
|
|
|
|
Post by creolian on Aug 3, 2017 0:43:42 GMT
Thanks for the info all. I'm one of those pack rats that never throws out anything that might be of use and along with a lot of other junk I have accumulated a couple dozen tubevalves of my own as well as the donation. 40 or so years worth. I'm not looking at buying a tester... Yet ! Not a cost effective expenditure for my needs. Seems like this comes up so seldom I'll probably just keep getting new ones if needed. Maybe a yard sale on flea bay for the old stuff... One day. I'm curious, Do Texicans prefer Tube Televisions for their soft analog distortion ? J |
|
|
|
Post by pete1951 on Aug 3, 2017 7:59:17 GMT
You really cannot damage an amplifier by installing and testing a Preamp, oscillator, or phase inverter tube. It will give you a realistic, loaded, reliable test, especially in terms of microphonics. Power and rectifier tube testing in the amp is more risky, since a shorted power tube can draw excessive current. Good advice, For preamp valves of the 12ax7/ecc83 types I use a Champ amp. As it has only one preamp tube. Any noise shows up and you can compare the sound with other tubes. A valve tester give useful numbers, but I want to know what it sounds like! (I am also too mean to get a valve tester) I do have a few valves that could do with testing!  |
|
|
|
Post by mitchfit on Aug 3, 2017 23:08:35 GMT
creolian asked:
...I'm curious, Do Texicans prefer Tube Televisions for their soft analog distortion ?...
oh , my. just minutes after i posted that it occurred to me that my TV screen now is LED.
hopelessly analog in a digital world!
guilty as charged your honesty,
mitchfit
:^)
|
|
