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Projects => General Questions => Topic started by: mcasemo on April 06, 2015, 12:58:09 AM

Title: Tubes, need help
Post by: mcasemo on April 06, 2015, 12:58:09 AM
A good friends father passed away a while back, he was an electronics guy, tv circuits and such early on, raytheon control systems, apollo mission controls guy.  did not get to meet him.  he has been clearing out his house and gave me the second batch of tubes he found.

Can anyone identify if these are worth keeping for projects?  I have a separate box of unboxed tubes that i need to pull and identify.

i'll list these out if you can't see them

(http://lh6.googleusercontent.com/-lk1j8IYDxn8/VSHZCliblDI/AAAAAAAAtHM/crv6g19sUQY/w1109-h832-no/IMG_3071.JPG)
Title: Re: Tubes, need help
Post by: jimilee on April 06, 2015, 01:05:21 AM
Now when you say identify, the boxes are marked with what they are. What are you looking for?


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Title: Re: Tubes, need help
Post by: mcasemo on April 06, 2015, 01:44:09 AM
haha, "identify" if they are useful for guitar projects.  or if anyone here is interested in them.  I'm going to start googling, but figured i'd check here for any guitar usefulness. 

the first round of tubes he sold at a garage sale (or gave away), the guy who bought them was so excited, later my friend was like i should have let you see them first.  I was just glad he did not throw them out and they got picked up for use by someone.  Just want to see if these are useful.

Title: Re: Tubes, need help
Post by: davent on April 06, 2015, 02:05:59 AM
I have two amps and building a third that use 6aq5's for power tubes. One of those uses a 6u8 for the preamp.

I think i've seen a few early schematics using the 6au6 for a preamp tube.

6CA7 similar to an el34.

12au7, 12at7 also useful.

Those are the ones i recognize off hand.
dave
Title: Re: Tubes, need help
Post by: mcasemo on April 06, 2015, 02:18:09 AM
thanks dave!
Title: Re: Tubes, need help
Post by: GrindCustoms on April 06, 2015, 03:19:18 AM
The 6BZ7, worth to thinker around.

http://www.classiccmp.org/rtellason/tubedata/6BZ7.pdf
Title: Re: Tubes, need help
Post by: davent on April 06, 2015, 03:43:42 AM
Now there's a box i can see 6E... if it's a 6eu7, that's a 12ax7 equivalent, parameters the same but different pinout, have a socket for one on my 5F2a amp, equivalent but maybe quieter?
Title: Re: Tubes, need help
Post by: GrindCustoms on April 06, 2015, 03:48:22 AM
Quote from: davent on April 06, 2015, 03:43:42 AM
Now there's a box i can see 6E... if it's a 6eu7, that's a 12ax7 equivalent, parameters the same but different pinout, have a socket for one on my 5F2a amp, equivalent but maybe quieter?

Yeah, i also have some 6EU7, anti-microphonic of the 12AX7.

To OP, a simple trick to sort tubes is by their first and last number, the first number will say the maximum heater voltage, so 6.3V and 12V is what you might want to look for as it's what we find in most amplifier. Usually the tubes model number finishing by 7 will be the 9 pin packaging that we are used to see in preamps.
Title: Re: Tubes, need help
Post by: mcasemo on April 06, 2015, 04:24:09 AM
thanks guys, i'm going to list them out and post.  i can't do anything with them, so aside from holding a few back for a possible amp or tube pedal, would like to get them in the hands of folks who want to mess with them.  they may be all useless, but if you see something you want, let me know.
Title: Re: Tubes, need help
Post by: lincolnic on April 06, 2015, 05:13:00 AM
Quote from: GrindCustoms on April 06, 2015, 03:48:22 AM
Yeah, i also have some 6EU7, anti-microphonic of the 12AX7.

To OP, a simple trick to sort tubes is by their first and last number, the first number will say the maximum heater voltage, so 6.3V and 12V is what you might want to look for as it's what we find in most amplifier. Usually the tubes model number finishing by 7 will be the 9 pin packaging that we are used to see in preamps.

I can't believe nobody's ever pointed that out to me before.

(http://i2.kym-cdn.com/entries/icons/original/000/014/033/knowing.jpg)
Title: Re: Tubes, need help
Post by: juansolo on April 06, 2015, 08:10:24 AM
Certainly some useful stuff for amps in there too.
Title: Re: Tubes, need help
Post by: micromegas on April 06, 2015, 08:21:20 AM
I think you also have a Sylvania 6v6GT on the right lower corner of the box
Title: Re: Tubes, need help
Post by: mcasemo on April 09, 2015, 12:13:47 AM
Thanks to everyone for looking through these.  I've discovered i know nothing about tubes, but interested to learn now.  These are all common TV/Radio kinda tubes, but should give me some fun making some single tube starved plate stuff, or maybe experimenting with the step up voltage projects using MAX1771.  Some are useful for tremolo reverb stuff i think.

But what i seem to have multiples of will make silvertone 1430? / sears 5XL type low watt amps using 12au6, 35w4, 50c5 tubes, the "all american five" radio amps.  So thinking I'm going to try to fit one in a small enclosure (octo box!) and use the MAX1771 and forgo the straight from 110AC non isolated widow maker thing.

cheers,
mark