Are these tubes any good?

[ballooneater]

Just got back from my local ReUse center, where I stumbled upon some old "electron tubes".  I bought 10 of them, but am not sure if they have any value.



Is it worth buying more of them?

[earthtonesaudio]

Check here:
http://www.tubedata.org/

And see what kind of tubes are in that box.  I would say buy stuff that you recognize as being used for guitar (12ax7, EL34, etc.), other than that, triodes and pentodes are probably your best bet.

[ballooneater]

Thanks for the site, I'll be spending a lot of time there tonight.  I'll probably just end up buying the whole box, it'll only be around $8.

Any good circuits that use tubes other than the traditional 12AX7?  I don't recall ever seeing any pentodes or triodes in schematics before.

[Zben3129]

Yes you do 

12ax7 is a (dual) triode, and el84 is a pentode 

Sure there are plenty of things that use other tubes. Rick (frequencycentral) has made a metric crapload of great circuits with assorted tubes. I have also messed around with assorted tubes in amps and on the breadboard as effects before. Just because a tube isn't commonly used doesn't mean its bad. Every tube was manufactured for a reason.

However, for effects, as said triodes and pentodes will be best. Stay away from rectifiers, diodes, etc. Also, try to look for tubes that have 15 or less as the prefix (that use that style of branding).

Zach

[Renegadrian]

Hi there...Unfortunately people like Rick, myself and you are on a undiscovered territory, still there are some that say "what, tube stompboxes at low voltage?" as you have said the worst thing in life...
There is almost nothing on the net on the use of unconventional tubes in guitar fx...
I believe that a lot of good circuits are only there for us to just being discovered on trial and error on breadboards...
So let our breadboards be our daily bread!!!  (uh, had to write this...eheheh)

Let me suggest you another good site for tube reference...
http://www.nj7p.org/Tube4.php?index=1

Welcome on the tube train... jump aboard!!!


BTW ...$8 for all those tubes?! Man, you're lucky!!!

[ballooneater]

Thanks for your input, Zben3129 and Renegadrian.

I'll go buy the tubes tomorrow and check out some of FrequencyCentral's designs.

One small problem that I've noticed is that tubes don't exactly fit on breadboards....Any solution to this other than temporary wirewrapping?

[Renegadrian]

You could have "flying" wires attached to the tube socket or you could build something like this...
I've seen this one on the bay, but $11 is too much, you can just build it away with some perf...

[DougH]

Those tubes are terrible. Ship them to me and I will dispose of them properly for you.

[ballooneater]

DougH-

I'd send a few of them over your way if you pay shipping.

[MikeH]

Dude are you in Ann Arbor?  I think I was looking at that same box of tubes a couple weeks ago...

[frequencycentral]

Rick (frequencycentral) has made a metric crapload of great circuits with assorted tubes.

Hahaha! - thanks Zach

Hi there...Unfortunately people like Rick, myself and you are on a undiscovered territory...................I believe that a lot of good circuits are only there for us to just being discovered on trial and error on breadboards.

Yes - just because you haven't seen a circuit doesnt mean you cant use a tube, Its just down to a bit of research and experimenting. There's loads that can be done with tubes, boost, overdrive, tremolo, panning, vibrato, filtering, compression and probably loads more. It's worth checking out the heater voltage and current requirement of any tube you buy. I've learned a $h!tload about tubes this year - I never used one before April '08. Adriano is right, we are just at the start of what can be done with them.

If you want to experiment with some 'unknown' tubes, there are a bunch of people here who will point you in the right direction and give design tips and advice.

This is my breadboard mounting device for 12**7, I just solderered some jumpers from my breadboard jumper kit to a 9 pin tube socket, it just plugs straight into the breadboard. Works a treat! But I do prefer submini tubes - they just slot right into th breadboard like any other component.

[ballooneater]

MikeH- Yep, I've been an Ann Arborite for my whole life.  I saw the box on previous trips, but had no idea what the tubes were for until I started making pedals.

frequencycentral- thanks for the idea, I'll try that.

[frequencycentral]

Just looking up a few of those tubes at random on the site Adriano suggested, they seem to be mostly television tubes - I don't know if thats a good or bad thing - definately 'undiscovered country' though. Some of them have unusual heater voltages and high current draw. Though $8 for the whole box, there might be some gems - and you'll have fun finding out! The dual triode/pentode in one package seems sexy.

[ballooneater]

In your circuit drawings, frequencycentral, you have the tube symbol appearing differently than in the datasheets I found online.  Would you mind explaining which part is what?

For example, you had:

in one of your schematics, whereas on the datasheet it appears as:



I do realize that the one in my datasheet is a double pentode, so I can ignore half of it, right?

[frequencycentral]

5672 tube:

1 - plate
2 - grid 2
3 - grid 3 / heater +ve
4 - grid 1
5 - heater -ve

Those 5672 tubes are known as 'directly heated' ie grid 3 is internally connected to the heater +ve.

On the tube pinout you posted grid 3 is pin 4 and 7. Not sure how you would connect these, I guess they want a lowish +ve voltage. I've only experimented with directly heated pentodes (so far!).

Here's the 5672 data sheet to compare: http://frank.pocnet.net/sheets/127/5/5672.pdf

[petemoore]

  I don't know if 12ay3 is anything like a dual triode [12ay7 for instance], and easy to find an application for...
  Tubes are relatively cheap compared to the rest of the building of something around tubes.
  A list of the tube types and count of each type, then look at data sheets [schematic helps if available].
  Many of these are probably TV tubes, RF amplifiers and such, tuner tubes.

[Zben3129]

12ay3 is a single diode. Are there any uses for these at low voltages that anyone knows about?

Zach

[ballooneater]

In case you guys want to look more into this, I have a list of all the tubes and their basic type.

Format: Name_#Type1#Type2
Key: P=pentode, T=triode, D=Diode

For example 6AG11_2D2T would be a dual-diode, dual-triode 6AG11 tube

10AL11_2P
10EW7_2T
11AR11_2P
11BQ11_2P
12AL11_2P
12AX4GTB_D
13GF7_2T
13V10_2P
14B6_T
15BD11A_2TP
15BD11_2TP
15KY8A_T
17AB10_P
17AY3A_D
17BS3_D
17DM4_D
19AU4GTA_D
24JZ8_TP
6AG11_2D2T
6AY11_2D2T
6B10_2D2T
6BA11_T2P
6BE3_D
6BF11_2P
6BH11_2TP
6BN11_2P
6BV11_2P
6BX7GT_2T
6DE4_D
6FJ7_2T
6FM7_2T
6M11_2TP
6T10_2P
6W4GT_P
8AR11_2P
8B10_2D2T
8CB11_2P

The datasheets can be found at http://www.mediafire.com/?sharekey=e90660f29537b438d2db6fb9a8902bda.  It's a 10MB .zip file.


Can't thank you guys enough for your help.

[frequencycentral]

12ay3 is a single diode. Are there any uses for these at low voltages that anyone knows about?

Zach

Clipping maybe? You could use a pentode as a boost and two diode tubes for an all tube Distortion+. Maybe?

[Renegadrian]

That 13GF7 seems interesting...Maybe it'd work good even at 12v?! Valvecaster?! Who knows...
http://www.nj7p.org/Tube4.php?tube=13GF7

The 12AL11 could be nice to try...space charge pentode! 12.6v to power it...yum!