6SN7 equivalent?

[Alf]

The circuit 6SN7 Another valve to consider, with a B9A base is the 6BQ7. Not very expensive (yet!)

[peter_sol]

Although it is not stated there, you will need to use high impedance headphones.

[bikerhifinut]

Originally Posted by Skywave

Really? O.K. - it was just a thought! Perhaps it's just me, but I can't see what is so special about an ECC32 or a 6SN7 to command such high prices.

6SN7 shouldn,t be so expensive as they are still in production from various sources. Unless its a certain sort of "NOS" made from magic vacuum back when vacuum was proper (joke).
ECC32 is a long defunct valve and thus its the rarity value that pushes the price up. Really only for those restorers who "must have the authentic valve" and I feel best left to genuine restorers who have a difficult enough time finding the parts to keep old kit looking and working well.
I think the OP has enough info now to make an informed choice.
A.

[G8HQP Dave]

I believe that measurements show that the 6SN7 (and 6CG7 etc.) has lower distortion than ECC82, when used in a similar circuit. This partly explains why it is popular with audio people. Being octal makes it popular too, as some wish to display their system rather than simply listen to it. It may or may not be true than modern 6SN7 are as linear as NOS examples, but there is a general problem that modern valves don't seem to last as long as NOS. Take this, then add a generous sprinking of fashion, and you get the market for NOS 6SN7.

[Des Miles]

Hi CS.
I have several NOS 6SN7GT valves still in their original boxes. Two makes, RCA and Heintz & Kaufman. Cant see myself ever using them so you are welcome to two of them. If interested PM me your details and I will post two to you. May take 2 weeks or so to get to you as I am in Port Elizabeth, South Africa.

[Marconi_MPT4]

As others have said, the 6SN7/6SL7 and ECC anything have reached cult status and originals fetch '££ excellent' due to ever increasing audiophile demand.

Looking at the alternatives, it is possible to use quite a few in this circuit as it is not at all critical. In the past EBC33/6Q7 single triode, with diodes strapped to cathode, have worked exceedingly well in regenerative leaky grid circuits. Choose a valve with less than 2.5mA/V slope and adjustable HT for smooth reaction performance.

One possibility is to use a PCL83 TV triode-pentode as the triode section characteristic is very similar to a 6SN7. Currently it is fairly cheap, (won't be now ) and the pentode can be strapped for triode operation with bias circuit adjusted to allow for headphones. Note, if using magnetic headphones make sure these are connected with correct polarity due to DC current flow.

Rich

but I can't see what is so special about an ECC32 or a 6SN7 to command such high prices

You can't because there isn't anything special, just a silly fad.

[Radio Wrangler]

I rather suspect that the firms still making valves just stuff the structures of an ECC82 onto the pinch of an octal envelope and print 6SN7 or ECC32 on the outside. Why have the tooling for different working bits when the end product is electrically similar?

David

[barretter]

If that were true it would be another reason for the high price of vintage 6SN7s. However the Russian ones don't look like that and they are available quite cheaply on eBay.

[chriswood1900]

I picked up 4 - 6SN7 made by Sovetek on Ebay for £6 each, they all tested good and work fine. I'm just pointing out they are available at sensible money.
Chris

[Radio Wrangler]

I may have a real American 6SN7 in my junk box, and I don't have anything which uses them. A hang over from jukebox fixing many years ago.

David

[daviddeakin]

Originally Posted by k_yller

6SN7 = 6Н8С (6n8s in Russian)

+1. Very cheap and just as good.

[bikerhifinut]

Thats a good bit of info
A.

[Diabolical Artificer]

I can also vouch for the Russian 6H8C off ebay, I bought 20 I think, everyone tested good. Did'nt take long to get here - can provide seller's name by PM. Have used them in a few repairs of Advance sig gen's, no trouble.

The mutual characteristics arn't 100% the same as a 6SN7, but near as dammit.

Andy.

[Mike. Watterson]

Characteristics can be +/- 20% and still a manufacturing pass. Part of the reason for some military variations which are simply the standard part selected on test.

[Radio Wrangler]

I'll have a look in the attic this evening.

David

[Radio Wrangler]

The attic came up trumps. I found a Brimar 6SN7 and a Taylor 45D tester to try it on!
It seems OK. Both sides run about 7mA at the rated grid voltage.

As it's for a radio and not to create wondrous fast bass and soundstageing, you can have it, if you want it, for the cost of postage.

David