I found out about the 6LW6 in an old issue of Glass Audio. There was an amplifier design that raved about these tubes and put out nearly 100 WPC. The article is still on their web site.
http://www.audioxpress.com/reviews/media/GA399MA.pdf
I modified the design to fit parts that I had, and of course turned up the power supply voltage. I ran out of power supply before any bad behavior was noted. I was running about 800 volts on the plates, 260 on the screens, and 50 - 60 mA idle current per tube. The result 140 Watts RMS at 5 % THD at 1KHz. My OPT's were not big enough to run this power below 50Hz. They were cheap ones from Hand Wound Transformers (not bad transformers when he decided to ship them).
At the time (about 6 years ago) you could find 36LW6's on ebay for $5 each. 6LW6's went for $7 to $10 each. Even though RCA, GE and others all made this tube, it doesn't appear in any of their tube manuals. This was the last of the octal sweep tubes. I have seen at least three versions. There is one with large fins attached to the plate, these can take all of the abuse that I throw at it. The pin outs can be found on the previously mentioned link, and the data is the same as the 6LF6. The 6LW6 is rated for 40 watts dissipation in sweep tube duty, which translates to about 50 watts in audio duty. The screen grid is only rated for 275 volts, which limits the usefulness in triode (and ultralinear) mode. Never being one to pay attention to such things, I find that the tube really begins to misbehave at about 425 Volts in triode mode. In pentode mode a regulated screen supply makes this (and most sweep tubes) work well.
Being in a neighbor hood where noise is tolerated also means that you get to listen to every body else's noise too. The guy across the street works on outboard engines, there are several car guys that make a racket (including myself), as well as those motorized scooters that sound like 50 pound bumble bees. This is one of the reasons that I need 200 watts!
http://www.audioxpress.com/reviews/media/GA399MA.pdf
I modified the design to fit parts that I had, and of course turned up the power supply voltage. I ran out of power supply before any bad behavior was noted. I was running about 800 volts on the plates, 260 on the screens, and 50 - 60 mA idle current per tube. The result 140 Watts RMS at 5 % THD at 1KHz. My OPT's were not big enough to run this power below 50Hz. They were cheap ones from Hand Wound Transformers (not bad transformers when he decided to ship them).
At the time (about 6 years ago) you could find 36LW6's on ebay for $5 each. 6LW6's went for $7 to $10 each. Even though RCA, GE and others all made this tube, it doesn't appear in any of their tube manuals. This was the last of the octal sweep tubes. I have seen at least three versions. There is one with large fins attached to the plate, these can take all of the abuse that I throw at it. The pin outs can be found on the previously mentioned link, and the data is the same as the 6LF6. The 6LW6 is rated for 40 watts dissipation in sweep tube duty, which translates to about 50 watts in audio duty. The screen grid is only rated for 275 volts, which limits the usefulness in triode (and ultralinear) mode. Never being one to pay attention to such things, I find that the tube really begins to misbehave at about 425 Volts in triode mode. In pentode mode a regulated screen supply makes this (and most sweep tubes) work well.
Being in a neighbor hood where noise is tolerated also means that you get to listen to every body else's noise too. The guy across the street works on outboard engines, there are several car guys that make a racket (including myself), as well as those motorized scooters that sound like 50 pound bumble bees. This is one of the reasons that I need 200 watts!
o.m.o...That svetlana 6 pack is a waste of build time......5 stages ? No...A little perusal with a pocket calculator one can do it in 3 stages at an even lower thd.
I use 530V B+ (4x KT88's) at 2K A-A load and ECL82 strapped as triodes......triode sections used as concertina phasesplitt.
THD is below 0.5% at 180W from 400Hz to 5Khz.
Hint... crib GEC 88-50 cct, and use ECL82 as power driver.
One drawback.....driver stage will consume 50mA requiring sep B+.
richj
I use 530V B+ (4x KT88's) at 2K A-A load and ECL82 strapped as triodes......triode sections used as concertina phasesplitt.
THD is below 0.5% at 180W from 400Hz to 5Khz.
Hint... crib GEC 88-50 cct, and use ECL82 as power driver.
One drawback.....driver stage will consume 50mA requiring sep B+.
richj
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