Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ernest on March 05, 2012, 06:35:21 pm

Title: box of used tubes_Next Project
Post by: ernest on March 05, 2012, 06:35:21 pm

I got a box of old tubes. I wanted to list some as I go through them.  Looking for some advice if any of these would be usable to audio amplifier applications.  I think lots are for TV but I did find 3 big light bulb type 5U4 tubes that will for sure be in a project....found a good 6v6 in there as well just not sure about most of these.

In my search for anything close to the #s 12ax7, 12au7, 12ay7, I was only able to find the following

TUBE    QTY

12BE6 - 3

12AV6 - 2

12BA6 - 4

12HL7

12CA5

I'll post some power tubes I found later and some more of these 9 pin tubes....

Title: Re: box of used tubes_Next Project
Post by: kagliostro on March 05, 2012, 06:58:34 pm

12av6 is something like 1/2 12ax7 (+ there are two diode .... that you can ignore)

read also here

http://www.el34world.com/Forum/index.php?topic=11590.0 (http://www.el34world.com/Forum/index.php?topic=11590.0)

Kagliostro

Title: Re: box of used tubes_Next Project
Post by: RicharD on March 05, 2012, 08:06:00 pm

http://www.mif.pg.gda.pl/homepages/frank/vs.html (http://www.mif.pg.gda.pl/homepages/frank/vs.html)

Title: Re: box of used tubes_Next Project
Post by: DummyLoad on March 05, 2012, 09:48:37 pm

12BE6 - no, not easily.

12AV6 - yes - it's 1/2 12AX7 with 2 diodes - ignore the diodes. 12V version of 6AV6

12BA6 - remote cut-off - no, unless you're building a compressor.

12HL7 - video amp - yes, but likely more trouble than it's worth since you'd likely need a separate PS for the screens - a very high-slope tube. gm is 21K. very easily input overloaded.

12CA5 - yes, was designed for audio output stages in systems with low B+ supplies - 5W diss. should make 4-5W or so dependably in push-pull.

--DL

Title: Re: box of used tubes_Next Project
Post by: ernest on March 05, 2012, 10:15:17 pm

looks like this guy is making something out of 12HL7 (http://amps.abraxasaudio.net/g-se.html).  looks cool

man, not seeing many of these listed out of what you guys posted in the other thread.   looks like the three 5U4 and one 6v6 cost me 60 bucks.  better make something of what I got.

Title: Re: box of used tubes_Next Project
Post by: DummyLoad on March 06, 2012, 12:58:50 am

hit the local HAM shows. usually the larger ones still have a few tube sellers.

--DL