Cheap alternative to EF86

[Shoog]

Hi all,
I was looking for a low current small signal pentode, and in the end I found that of all the common types, the EF86 is the best for my intended purpose. The main attribute it has is low plate current and low screen current. Tubes like the 6AU6 have to high anode current.
However EF86's are rich pickings these days. Can anyone suggest an alternative which would do a similar job but cost peanuts. All obscure voltages and base types considered.

Shoog

[Wavebourn]

6J32P

[kstagger]

Check out this post I did yesterday on Audio Asylum:
http://www.audioasylum.com/audio/tub...20/202741.html

For anyone using the EF86 pentode, NOS tube prices have been rising! What to do? There are new production tubes out there - the discontinued Svetlana EF86 which has a hard brittle top end. The EH EF86 is pretty good, though it seems to lack some music 'color', reminding me of solid-state. I have to hear the latest JJ version - prices are still high on this model.

Back in 1948, Philips introduced the rimlock EF40 tube which was the precursor to the EF86. This tube was used in several pieces of Siemens theater gear and in Philips radios. What makes the EF40 different than the EF86? In this case it is just the base - the EF40 (along with several other excellent tubes - notably the ECC40) uses a B8A socket. The B8A or rimlock socket uses a nub on the side of the tube which centers the tube in the socket. Kind of neat bit of engineering and also forces good contact with the pins. The B8A rimlock socket was eventually discontinued as the majority of small tubes went to U.S. standards. Therefore B8A tube sockets are available mostly through European dealers and can also be found on Ebay. Avoid the Chinese sockets as they do not have the metal outside base to center the tubes.

*I shall make a small note that the inter-electrode capacitances are slightly different between the EF86 and EF40, but not enough to make a difference at the audio level.

Who manufactured the EF40? Sorry - no Telefunken here - just Philips (branded Mullard, Valvo, etc) from Holland and (seems to be mostly) France. Earlier versions were made in the Netherlands while perhaps production was quickly be moved to France. Later 60s production was made by Tungsram. There are also Siemens versions out there but I have yet to hear a pair and I've suspected they are actually Philips since they have the same look. I do have a single Siemens supposedly made in Germany - I would like some further confirmation on this.

Best sounding are the Holland versions followed by the Tungsram. In general the French versions seems to lack the last bit of finesse of the Holland ones - and I've found this true even for EF86s - but the French versions are still very good. Tungsrams have good slam and have excellent dynamics. All versions seem to be very low in microphonics - perhaps it is the rimlock socket holding the tube tightly.

Going prices of the EF40 make them bargains! I've paid anywhere between $2 to $8 each. Provided the socket to be replaced is hardwired, it would only take a little work to convert to use the EF40. Not many of these show up in the U.S, but Canadian and European sellers have them and would be happy if you took them off their hands.

[ray_moth]

kstagger,

That is an excellent piece of information! Thanks a lot!

[7N7]

6BR7 is a better valve than EF86 and can be bought for about £5 each on ebay. I have converted my Quad IIs to 6BR7 and they sound better.

7N7

[Gordy]

Originally posted by Shoog

However EF86's are rich pickings these days. Can anyone suggest an alternative which would do a similar job but cost peanuts.

Shoog

Right now...
http://cgi.ebay.co.uk/EF86-Electro-H...QQcmdZViewItem

UK seller

£9.99

49 available

Surely that's not expensive.


(No commercial interest, just trying to help...)

Originally posted by kstagger


...the discontinued Svetlana EF86 which has a hard brittle top end.

...oh for goodness sake...

[7N7]

Best sounding are the Holland versions followed by the Tungsram. In general the French versions seems to lack the last bit of finesse of the Holland ones - and I've found this true even for EF86s - but the French versions are still very good. Tungsrams have good slam and have excellent dynamics. All versions seem to be very low in microphonics -

This is quite amusing too. What is "slam" exactly?

7N7

[SY]

Bass Slam Defined.

[fauxpas]

Originally posted by Shoog
However EF86's are rich pickings these days. Can anyone suggest an alternative which would do a similar job but cost peanuts.

Shoog

Yeah, I did a search on ebay to find these so what is peanuts to you?

[7N7]

Originally posted by SY
Bass Slam Defined.

Well that's much better and nothing to do with EF86. And he did play with Slim Gaillard and Charlie Parker - that's good too.

7N7