6L6 - 6V6 tubes.....

Tele · Post by **Tele** » 14 Feb 2001 9:25 am

Hi

I know that I could put a 6L6 tube in an amp that uses 6V6 but not the other way 'round.
My question is, does that work in any circuit?
For example, I have a Fender Reverb unit that has one 6V6 in it. If the tubes fails could I substitute it with a 6L6? Or would I cause any problems???

Andy
[This message was edited by Tele on 14 February 2001 at 09:25 AM.]

Blake Hawkins · Post by **Blake Hawkins** » 14 Feb 2001 11:04 am

Andy, The 6L6 is a much stronger tube than the 6V6.
The heaters are both rated for 6.3 volts but the 6L6 requires .9 Amp of current while the 6V6 requires only .45.
So placing a 6L6 in an amp designed for a 6V6 could cause over heating in the power transformer and a lowering of circuit voltages overall.
The 6L6 has a maximum plate voltage rating of 360 volts. However the 6L6GC is rated at 500 volts.
The 6V6 has a maximum plate voltage rating of 350 volts.
Maximum plate dissipation for a 6L6 is 19 watts. A 6L6GC can dissipate 30 watts.
The 6V6 is rated for only 14 watts.
The pin outs are the same so the tubes are plug compatable.
If you plug a 6V6 in an amp which uses 6L6GC's like a Fender Twin, you could do major damage if the 6V6 plate shorted out because of too high a voltage for it.
The output load resistance required is also different.
I am uncomfortable swapping these tubes out unless circuit changes are made to adjust for the differences.

Donny Hinson · Post by **Donny Hinson** » 14 Feb 2001 2:36 pm

I heartily concur.

Rick Johnson · Post by **Rick Johnson** » 15 Feb 2001 4:27 am

Andy
Blake was told very clearly you thats a NO NO!
There is one other choice. Try a new
old stock 6K6. Thats what they used originally.
I put one in my reissue. It might cost
20.00 vs 8.00 for a 6V6

Rick

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Rick Johnson

Blake Hawkins · Post by **Blake Hawkins** » 15 Feb 2001 10:58 am

Rick is correct about the 6K6.
The ratings are very close to the 6V6 so they can be interchanged without problems.
The difference between the two is in their construction.
Both are classed as "Power Pentodes" which means that there are 5 elements in the tube.
The 6V6 is a "Beam Power Pentode"..that is, it has a set of elements which focus the electron stream in the tube resulting in higher efficiency. So the 6V6 is rated at 14 watts plate dissipation and the 6K6 is 8.5 watts.
The original use for the 6K6 was in home radios.
The origianl use for the 6V6 was in automobile radios.
As technology has improved the tubes over the years suffixes have been added, so that the 6V6 you buy will be labeled 6V6GT or -GTA, -GTB, or -GTC.
Actually with no suffix, a metal tube is indicated but these are rarely seen and were not generally used in consumer audio equipment.
That's probably more than anybody wanted to know about this. (smile)
Blake

Bobby Lee · Post by **Bobby Lee** » 15 Feb 2001 11:03 pm

The 6L6 and 6V6 sound a lot alike, except that the 6L6 is a lot louder. I would never try swapping one for the other, though. The pins are compatible, but a circuit designed for one wouldn't drive the other very well. Damage could occur. These tubes are very different.

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<img align=right src="http://b0b.com/b0b.gif" width="64" height="64">Bobby Lee - email: quasar@b0b.com - gigs - CDs
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Gene Jones · Post by **Gene Jones** » 16 Feb 2001 11:34 am

*[This message was edited by Gene Jones on 06 May 2002 at 09:30 AM.]