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Big Tube List from Landlord (part 2, full list)

N

nate86

Well-Known Member
Okay, I thought I should probably just start a new thread (moderators, forgive me if this was incorrect though). I made a large list of the tubes. I did my best to put them in 'order,' but...yea. Quantity of tubes are notated in parenthesis.

Okay tube guru's, is there anything good in here that I could make something nice with? I know, it is a long list...but any help is greatly appreciated!

(7) 1r5
1s4
(2) 1t4
(2) 1u4
(4) 1u5
1v2
1x2
1x2b
3bc5
(3) 3q4
3s4
4bc5
4cb6
4dt6
5an8
5aq5
(2) 5bq7a
5u8
5x8
(2) 6ab4
6ah6
6ag5
6ak5
(7) 6al5
6ba5
(2) 6bc5
6be6
6ar5
6at6
(3) 6au6
(2) 6ac7
6au6a
6au8
6av6
(2) 6aw8a
(2) 6aw8
(3) 6c4
6be6
(5) 6cg7
(3) 6bh6
(3) 6bj6
6bn6
(2) 6bq7a
6cg7
6a8
(2) 6as5
(3) 6aq5
(7) 6aq5a
6aq5w/6005
(2) 6cu8
6cu8a
(2) 6de6
6by6
(2) 6ba6
(3) 6c5
6cf6
6cs6
(3) 6f6
(2) 6h6
(2) 6cq8
(6) 6sn7
(5) 6j6
6sc7
6u5
6u8
6u8a
6s4a
6v3
(5) 6x4
(4) 6x8
12b4a
(3) 12ba6
(5) 12be6
12al5
(2) 12at6
(3) 12at7
12au6
12au7
12av6
(4) 12ax7
12av7
(3) 12bh7
19t8
50b5
(3) 50c5
z729/ef86


**second drawer/i am tired of trying to categorize these!****

0z4
(5) 1b3
1b3gt
1lb4
1h5
35l6gt
35y4
5a34a
5as4a
50a5
50l6gt
(3) 5u4g
(4) 5u4gb
5u4gb
(2) 5v4g
5v4
5725/6as6w
6bq6gtb/6cu6
6cu6
6ag7
6au5gt
6cd6g
6k6gt
6sk7
6sh7
6sh7gt
6sn7gtb
6bl7
(2) 6sl7gt
6au4gt
6w6gt
6w4
6x5gt
7c6
70a1
7n7
12js
12k7
12sn7gt
12sg7
12sq7
14a7
14q7
25l6gt
6xgt
(2) 6bg6g
6ax4gt

6asb
8aw8(?)
8cg7
17dq6b
17ax4gta
 
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5_4 are generally rectifiers, the 12A_7 tubes are common twin triodes, the 6/12SN7 are also fairly commonly used, and __L6 tubes are generally used as outputs in radios (the 6L6 is significantly higher power output than any of the others).
 
Lucky guy you :)
1V2 is a rectifier tube usually used in high voltage.
Most of those other tubes starting with a 1 are probably similar.
The 12A*7 tubes are basically equivalent to a 12AU7 which is a common dual triode used in preamplifiers.
6F6 would make a great power amplifier tube. Using two of them in a push pull circuit could make a nice amplifier. Since you only have 3 you could use them as two single end amplifiers for stereo amplification.
Lots of circuits out there for using a 12A*7 tube as the preamp and a 6V6/6F6 tube for the power amplifier. Using only those three tubes you could build a simple 10 watt stereo amplifier.
 
Looks like a lot of radio and some TV tubes. I recognize a bunch from AA5 sets and some AM/FM sets.
 
Thanks for the advice - this is sounding promising. Are there any other simple/good designs that may yield me a bit more then 10 watts? This will be stereo, correct? Or mono? (see, I'm a total noob)
 
You could use the 6AQ5s in push-pull and that ought to get you around 15WPC I think. Not too bad for a simple little tube amp. You've got a bunch of stuff that would work for the driver stage... 6SN7, 6SL7, 12SN7, 12AX7, 12AT7. The 12BH7s might be the best or the front end. I think McIntosh uses them in a lot of gear, and they're supposed to be good sounding tubes.

That's about the limit of my knowledge on this subject I'm afraid!

Edit: I just looked up the 6AQ5 datasheet. 10 WPC in PP. Sorry.
 
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Hmm. I think 6AQ5A's are interchangeable with 6AQ5's...which would give me a total of 11 of these babies (7 of which are the 6AQ5). Still 15wpc? :D

For some reason one of the 12BH7 Boxes had a 12AT6 in it (odd). So that leaves 2 12BH7's. How many tubes do I need for the driver stage?
 
nate86 said:
Hmm. I think 6AQ5A's are interchangeable with 6AQ5's...which would give me a total of 11 of these babies (7 of which are the 6AQ5). Still 15wpc? :D

For some reason one of the 12BH7 Boxes had a 12AT6 in it (odd). So that leaves 2 12BH7's. How many tubes do I need for the driver stage?
Click to expand...

Well, in push-pull you need multiples of 2 per channel. So you'd be one short of doing a stereo parallel push-pull amp using four tubes per side (8 total). Parallel Push Pull (PPP) would get you 20 WPC. Note my edited post that 2 6AQ5s give only 10 watts, not 15.

You'd be surprised how loud 10 watts can be with the right speakers. I grew up with inefficient AR-4x speakers running off a Dyanco SCA-35 that is barely 17 WPC and it was PLENTY loud enough in a decent sized bedroom for a teenaged boy who liked rock and roll.

The driver stage design is beyond my capabilities, but usually there's only one tube per channel though they are usually dual packaged tubes, in other words they are like two tubes in one glass envelope. The 12A_7 series, the 6SN7, 6SL7, etc all fit this bill, as does the 12BH7 I think. Some driver designs use three sections per channel, which can be accomplished with three tubes total per stereo amp. In that kind of setup it is possible I believe to have two tubes of one type and one tube of a different type.

Your'e going to need much more capable help on this than I'm able to provide.
 
Okay good to know- opened up the 6CG7'S and they are the right value, albeit definitely used and kind of cruddy and DEFINITELY need to be tested. (boo)

6SN7'S Look barely used and have tested as good. 12AT7's look alright. 12AX7's look okay- 1 is labelled Sonotone 12ax7a, made in usa...odd...darn...not a telefunken
 
Jon- any help is a learning experience for me! Thanks for contributing. So it sounds like I could pick up another 6AQ5 (or dig around in this box some more) and I'd have more than enough power...
 
Nice.
RE: the two 6F6 method which would yield about 10 watts- I have 2 cunningham tubes which look like they were never used that would be perfect for this.

Opinions as to whether I should try 12 6AQ5's, or 2/4 6F6's? Would either method differ noticeably in sound quality? Would one method be cheaper to build?
 
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Frankly there doesn't seem to be a lot of love for parallel push-pull amps around here. I don't know why. Certainly it's a more complicated build, more parts, more wiring, a beefier power supply, and bigger output transformers. I don't know if there is a sonic detriment to PPP that doesn't exist with PP. There are some uber-expensive, high-end, high power PPP tube amps out there.

I think there may be some merit to a "walk before you run" approach here.
 
Heh, okay. Whatever is easier = better for me = less chance of me blowing something up. So it sounds like PP is the way to go...
 
nate86 said:
Heh, okay. Whatever is easier = better for me = less chance of me blowing something up. So it sounds like PP is the way to go...
Click to expand...

I'm telling you... don't place too much stock in what I say. I've started planning a much simpler tube build but I've not ever done one from scratch. I'm not the guy you should be looking to for solid advice, there's people on AK who are light years more knowledgable and experienced than me. Probably best to start a new thread in DIY and hope that some of the really good guys chime in.
 
Ah no worries, thanks Jon.

I am hoping there is an easy DIY setup/project somewhere online that might suit my needs. I think you are right though; the DIY forum is probably best for this
 
Email me for a schematic for the V-M 1448 output stage - uses a 12AX7 and two 6AQ5s. tbavis(at)rochester(dot)rr(dot)com
 
Or, if you wanted a higher-power amp- the Magnavox AMP142 schematic would work. It actually IS PPP output. As long as you kept within the voltage limits of the 6AQ5, they're functionally identical to the 6V6, used in the '142. Set up your power supply for about 265V B+... that would work fine. A power transformer of about 255-0-255 would work fine, with a 5U4 rectifier (as original to the '142).

If you wanted to do a power supply on the cheap, you could use a 120v, 2 amp isolation transformer (output will be about 115VAC) with a solid-state (diode) voltage doubler for B+, and a 6v, 10 amp transformer for the heaters. I'd be inclined to use a 1H, 400ma choke, for a stereo amp (both channels on one chassis. If you could find a power transformer from an old solid-state amp or receiver that would give around 55-0-55 volts, that would work fine... wire the secondaries in series (110v) and use a voltage doubler...

A 25 watt output transformer, anywhere from 3.8K-5.5K primary impedance, would work fine with this design... such as this: http://www.edcorusa.com/products/422-cxpp25-ms-4k.aspx

You have all the tubes you need for stereo- 8- 6AQ5s, 2- 12AX7s and 2- 5U4 rectifiers.

Should wind up with 18-20 watts, per channel...

Regards,
Gordon.
 
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Gordon- thanks so much for the help. I like this idea. Hey, more power sounds good.

Is there any way we could put a list of parts together that I would need to order for this? When I try to search for this stuff on digikey, mouser, etc., I get all kinds of types of stuff that I'm not 100% sure about (e.g., things like, what kind of choke? how many ohms? etc...). For instance, parts needed...

-1H, 400ma choke
25 watt output transformer like so http://www.edcorusa.com/products/422-cxpp25-ms-4k.aspx
 
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