half 6SN7 / 6CG7 7pin mini substitute?

[rafafredd]

Hi. I am looking for a 7pin miniature triode (or pentode connected as a triode) that could be a perfect substitute to half of a 6SN7.

Any clue?

 

[rafafredd]

BY THE WAY... now I see that in the circuit, both 6SN7 cathodes are wired together, so it could be one of the common cathode types, with two triodes in just one 7pin envelope, that would have curves like the 6SN7, or close, as long as Rp isn't higher.

 

[Miles Prower]

The only one that I know of that comes close is the 6C4. There aren't a whole lot of singleton triodes in the 7-pin and 9-pin mini formats. Most singletons are Octal types.

 

[Mickeystan]

rafafredd, use a 6C4 triode in your application. It is likely one of the closest triodes to 1/2 of a 6SN7.

Mickeystan

 

[rafafredd]

Thanks! I'll try the 6C4. I might have some in my collection. Have to look!

Otherwise, do you think any triode connected pentode might do the job, maybe?

 

[ruffrecords]

According to the National Valve Museum, a 6C4 is one triode of a 12AU7 which bears very little resemblance to a 6SN7 other than a similar mu.

6C4 @ The National Valve Museum

Cheers

Ian

 

[Soonerorlater]

Perhaps a seven pin version of this then


6C5 @ The National Valve Museum

 

[ruffrecords]

Perhaps a seven pin version of this then


6C5 @ The National Valve Museum

I think that is what the OP needs. The 6SN7 is essentially two 6J5s in one bottle but I do not know of a B7G version.

Cheers

Ian

 

[Tubelab_com]

Most of the 7 pin tubes have a Mu higher than 20. Look at the 6J6 or a triode wired 6AU6.

 

[ruffrecords]

Most of the 7 pin tubes have a Mu higher than 20. Look at the 6J6 or a triode wired 6AU6.

I used a triode wired 6AU6 in my first mic pre design. They are surprisingly quiet. I seem to remember the triode wired mu was around 34.

By the way, I have lots of these 6AU6 tubes I know longer need. Free to anyone for the cost of postage.

Cheers

Ian

 

[Eli Duttman]

Hi. I am looking for a 7pin miniature triode (or pentode connected as a triode) that could be a perfect substitute to half of a 6SN7.

Any clue?

Does it absolutely have to be a 7 pin mini type? Will a 9 pin mini twin triode that can be set up to use only 1 section asymmetrically in each channel do? If so, the 12BH7 is an excellent candidate for this job.

 

[JohnAtwood]

try the 12G4

Check out the 12G4. It is 7-pin and really is 1/2 of a 6SN7GT. They are not common, but I have seen a few around. See the datasheet at:
http://frank.pocnet.net/sheets/137/1/12G4.pdf

- John Atwood

 

[vanofmonks]

What about 9002?

 

[dady]

12G4 looks very close to SN7-CG7.
9002 is a different animal, little more mu, half disipation, different transconductance, different Rp. But very linear

 

[ruffrecords]

12G4 looks very close to SN7-CG7.
9002 is a different animal, little more mu, half disipation, different transconductance, different Rp. But very linear

According to the National Valve Museum it is possibly a repackaged acorn tube:

9002 @ The National Valve Museum

Cheers

Ian

 

[Tubelab_com]

possibly a repackaged acorn tube

It is a 955 in a 7 pin bottle. All of the 9000 series are repackaged acorn tubes that were used WWII aircraft electronics. I had a bunch of both styles, most of which were physically damaged so I took them apart. Same guts inside both types of tubes.

I also got to see the internals of every possible 807-1625-6L6 type variant, since I had several hundred broken tubes. All were from a collector of WWII surplus that had passed on. The warehouse was being demolished when the tubes and other stuff was found. Ever see a box full of carefully wrapped 211's and 845's.....all smashed

The 9002 is an excellent voltage amplifier triode, but due to its tiny internals the Rp is much higher than the 6SN7.

 

[dady]

Thanks my Dear Masters.

 

[dady]

Thanks my Dear Masters.

I got some 955 and compare this analogies with 9002, focusing this valves in a low distortion preamp construction.

 

[rafafredd]

By the way, I have lots of these 6AU6 tubes I know longer need. Free to anyone for the cost of postage.

Cheers

Ian

Hey Ian, I would love to have these. Can you get me a shipping quote to Brasil?

I will try these iwired as a triode in this project, but I also could have many more uses for a 6AU6, so let me know how many you have that you could send me.

That's very nice!

Now, thanks for all the inputs, guys. I have enough now to start experimenting. This is a really nice forum!

 

[ruffrecords]

Hey Ian, I would love to have these. Can you get me a shipping quote to Brasil?

I will try these iwired as a triode in this project, but I also could have many more uses for a 6AU6, so let me know how many you have that you could send me.

That's very nice!

Now, thanks for all the inputs, guys. I have enough now to start experimenting. This is a really nice forum!

I am happy to send you a dozen (12). Shipping to Brazil would be about £15.

Send me your address and I will pack some in a box for you. Send your address to my email: ianbell@ukfsn.org

Cheers

Ian