Anyone know how to tell if a Vacuum Tube is good?

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Mack45

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Fender Hot Rod Deluxe amps use the 12AX7s, 4 of them. So if you know anyone who has one they could plug them in and see if they work. I have one AND a tube tester but Quapaw is a couple of hours away from Tulsa. You could also list them on ebay, lots of that kind of stuff there.
 

kd5rjz

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Thanks for the suggestions guys (especially you noober... that would work great if I had whatever device these work in :saywhat: ).

I never thought to go take them down to a music store. Now that I think about it, I know there are a couple of electronics parts stores in town too, I could just take them down there and maybe they'd buy them too if they work? I'd be happy just to get some lunch money from it rather than throw them out. I just don't want to waste too much time dealing with it, but I have this built-in fear of throwing away potentially good parts.

I have a tube tester in my office at work. If you need to test them, hit me up during the week.
 

xnavychief

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I happen to build amps around those very things(link below)....

Current production 12ax7 style twin triodes are available from many vendors but New Old Stock USA's are still what the gear heads want and pay dearly for. The problem is that unless you have flawless packaging with the original dividers it's hard to sell them as such. Most testers you'll find locally are of the emmission, short, parametrical variety which will tell you that the tube is functional, but a mutual conductance or dynamic conductance tester is the only way to validate true matching in a tube that has two separate three element tubes in it(twin triode) as they do.

If they are the standard green label long plate variety of sylvania that are so plentiful and test good you are looking at at easy $20 - $25 ea on ebay.

6AQ5's are the lower plate voltage/less dissipating predecessor of the more common 6Bq5 / el84 (used in vox ac15, 30's and all or Brad paisly DrZ rigs clones etc.) Not that many people build around them anymmore but very popular with early Gibson collectors. Worth about $30 a pair if authentic NOS.

Hope that helps.
 

HMFIC

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I have a tube tester in my office at work. If you need to test them, hit me up during the week.

Cool Mike, I might just do that if I can get a few minutes to run over that way this week. Thanks. :)


I happen to build amps around those very things(link below)....

Current production 12ax7 style twin triodes are available from many vendors but New Old Stock USA's are still what the gear heads want and pay dearly for. The problem is that unless you have flawless packaging with the original dividers it's hard to sell them as such. Most testers you'll find locally are of the emmission, short, parametrical variety which will tell you that the tube is functional, but a mutual conductance or dynamic conductance tester is the only way to validate true matching in a tube that has two separate three element tubes in it(twin triode) as they do.

If they are the standard green label long plate variety of sylvania that are so plentiful and test good you are looking at at easy $20 - $25 ea on ebay.

6AQ5's are the lower plate voltage/less dissipating predecessor of the more common 6Bq5 / el84 (used in vox ac15, 30's and all or Brad paisly DrZ rigs clones etc.) Not that many people build around them anymmore but very popular with early Gibson collectors. Worth about $30 a pair if authentic NOS.

Hope that helps.

Well I guess I should have just gone straight to the authority lol. I don't know how I forgot you build tube amps seeing as how I drooled all over your webpage. Thanks for the info, that's encouraging to know that they might actually be worth a lil bit of money. I'm hoping these are good ones. I'll take some photos later today and post them so you see exactly what they are. I'm thinking they're pretty old though... probably from around the 60s
 

10Seconds

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I love tube amps, such a more beautiful sound. Many have no Idea what they are missing. Glad you didnt just pitch them, someone will appreciate it.
 

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