6LW6 operating points

[AmpKiller66]

Hello, I recently got a pair of Sylvania 6LW6 off of Ebay. I have heard that it is possible to obtain 140+W from these tubes at around 700 plate volts. However, I have been unable to find more info on this claim, such as necessary load impedence, screen voltage, bias voltage, bias current, etc. I have also been unable to find suitable plate curves to determine these points myself. Can any of you provide any information on these operating points? Thanks in advance.
Matthew
P.S. This is for a guitar amp, so low distortion is definately not a requirement.

[Bandersnatch]

hey-Hey!!!,
Treat them like a 6LF6. Properties are similar and you'll be close.
cheers,
Douglas

[AmpKiller66]

Thanks for the reply, but I looked into it and there really isn't much data on the 6LF6 either, at least not configured in pentode mode. All I can find are audio specs for screen drive, unless the two modes are somewhat similar in characteristics?

[tubelab.com]

I am one of the people who have obtained 140 watts from a pair of 6LW6's. I did this at least 10 years ago and don't have the original information any more. I used a 6600 ohm OPT, but may have put the 8 ohm load on the 16 ohm tap, for a 3300 ohm load. Drive was conventional control grid drive, and it was a guitar amp. B+ was obtained from a bridge rectifier on a 600 volt industrial control transformer. The exact screen voltage remains unknown, but was probably in the 300 volt range.

More recently I have operated a pair in screen drive mode at 550 volts of B+ with a 2500 ohm load. Power output was in the 150 watt range. At least one other forum member has done this also.

There are several different versions of 6LW6's. All can handle 40 to 50 watts of dissipation with ease, but some versions can do far better. The best are the GE's that have two large heat radiating fins welded to the plate. They also have fins on the inside surface of the plate. My current cathode follower experiments using 6LW6's are using Sylvanias which can operate at 75 watts easilly and don't red plate until 90 watts.

[AmpKiller66]

Thank you for your help. I will experiment with both of these setups.

[Brett]

Originally posted by tubelab.com
I am one of the people who have obtained 140 watts from a pair of 6LW6's. I did this at least 10 years ago and don't have the original information any more. I used a 6600 ohm OPT, but may have put the 8 ohm load on the 16 ohm tap, for a 3300 ohm load. Drive was conventional control grid drive, and it was a guitar amp. B+ was obtained from a bridge rectifier on a 600 volt industrial control transformer. The exact screen voltage remains unknown, but was probably in the 300 volt range.

More recently I have operated a pair in screen drive mode at 550 volts of B+ with a 2500 ohm load. Power output was in the 150 watt range. At least one other forum member has done this also.

There are several different versions of 6LW6's. All can handle 40 to 50 watts of dissipation with ease, but some versions can do far better. The best are the GE's that have two large heat radiating fins welded to the plate. They also have fins on the inside surface of the plate. My current cathode follower experiments using 6LW6's are using Sylvanias which can operate at 75 watts easilly and don't red plate until 90 watts.

Thanks. I think I have some of these in storage and if 150W is obtainable, may make a good bass guitar amp with the right iron.
Edit: and 2 or 3 pairs in PPP.

[AmpKiller66]

More recently I have operated a pair in screen drive mode at 550 volts of B+ with a 2500 ohm load. Power output was in the 150 watt range.

What were the bias and drive requirements?