NO!!! it isn't safer

Posted by Russ57 (A) on April 10, 2007 at 10:19:02

In Reply to: to finish my thought posted by Mark Tinordi on April 10, 2007 at 09:03:42:

Forgive me if I, in any way, gave you the impression that it was okay to plug any old tube into any socket in which it would fit. That is not the case at all!

When I mentioned picking up a lot on ebay I was talking about a lot of assorted 12au7's.

With regards to the 6cg7 swap....go to tdsl and look up the 12au7. Down at the bottom of the page pick the link for Dave Crittle's site (retrovox). Read the second paragraph on the first page of the tube data sheet. It states the 12au7 is very similar to the 6sn7. The 6cg7/6fq7 is a 6sn7 in a nine pin mini bottle. The only difference in pinout/wiring is your 12au7 has pins 4&5 tied together and one heater wire there and the other heater wire on pin 9. To convert remove the jumper between pin 4&5 and attach the hetater wire on pin 9 to the vacant pin, either 4 or 5. Repeat, the heter wires for the 6cg7 are pins 4&5. But be forewarned the 6cg7 needs twice the heater current and I don't know if the foreplay 2 has the ability to handle it. The foreplay 1 didn't but the foreplay 3 does.

Also, if you check the bottlehead forum you will see the 6cg7 conversion is quite popular. I have heard it and can vouch for it being an upgrade.

In time you will learn how to look at data sheets and determine if another tube could be suitable. And of course there are places that list subs. In general it is best to ask the company that makes your gear and not to blindly trust others....including me:) Info on the web isn't always to be trusted and even tube data sheets have errors!

Russ

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Follow Ups Full Thread

Topic - How do you find substitutes for rolling? (that are unlike the tubes they're replacing) - Mark Tinordi 09:01:03 04/10/07 (13)

Re: How do you find substitutes for rolling? (that are unlike the tubes they're replacing) - SETdude 01:19:52 04/11/07 (0)

You can't do this without an EDUCATION - grhughes 14:17:12 04/10/07 (0)

I would not sub a tube unless I was .... - PureAudio 09:44:29 04/10/07 (3)

Reminds me of what a friend of mine did. - nightdoggy 16:31:51 04/10/07 (2)

Wow, I feel like less of a moron now... - Mark Tinordi 20:40:34 04/10/07 (1)

Re: Wow, I feel like less of a moron now... - gortnipper 22:20:03 04/10/07 (0)

to finish my thought - Mark Tinordi 09:03:42 04/10/07 (6)

NO!!! it isn't safer - Russ57 10:19:02 04/10/07 (4)

Yeah, that was kind of a stupid question, wasn't it? - Mark Tinordi 12:40:32 04/10/07 (3)

Where do you live? - Russ57 16:18:00 04/10/07 (0)

Some of my favorite 'basic' 12au7 types are ..... - PureAudio 12:54:38 04/10/07 (0)

Tube substitution lists - Ron Oehlert 12:42:59 04/10/07 (0)

Re: to finish my thought - Tre' 09:53:20 04/10/07 (0)

Follow Ups

NO!!! it isn't safer - Russ57 10:19:02 04/10/07 (4)

Yeah, that was kind of a stupid question, wasn't it? - Mark Tinordi 12:40:32 04/10/07 (3)

Where do you live? - Russ57 16:18:00 04/10/07 (0)

Some of my favorite 'basic' 12au7 types are ..... - PureAudio 12:54:38 04/10/07 (0)

Tube substitution lists - Ron Oehlert 12:42:59 04/10/07 (0)

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