I'll say. The silly buggers are selling all their SITs. I've been buying up all the KP926's I can find. And since there's almost no Japanese stock left, they'll be the next fad. Only a 50W part but still ...
Yes, it is a 6DQ6B with a 16.8 volt 450 mA heater. They are easily fed with a 19 volt laptop power brick and three series diodes to drop about 2.1 volts.
6 volt heater versions of the higher power sweep tubes often fetch stupid-high prices and the off-voltage versions can be $3 to $20. I usually look for the higher voltage versions *first*. Even common stuff like the SN7 can be had for less than half the price if you can live with other heater voltages.
A Colleague in Rio de Janeiro makes tasty Blues Guitar amplifiers using ONLY TV Tubes.
In this one:
Max W.Fillies - YouTube
Note: mainly a Tech, barely a basic player, he´s only showing that unique "only from Tubes" halfway crunch and compression/intermodulation.
Also:
2 x EL84:
Teste Amplificador Valvulado W Fillies Magic Tubes - YouTube
VERY GOOD crunch and distortion.
ALL TV tubes (except, maybe, extra high voltage diodes and such) can be used for Audio, as long as they have basic Plate, Anode and Grid; extend that to include Pentodes which can be used as such or strapped as triodes.
Main problem? ..... you´ll have to DESIGN around them, you simply can´t straight pop them into a Fender/Marshall/Vox circuit and expect them to work with THOSE parameters.
No big deal anyway, as long as you are handy with datasheet curves, nothing further needed.
Fine for DIYers (ahem! 😉 ), and if anybody wants to get into series production, maybe he should first secure a 100-200 tube stock so as not to "switch horses in the middle of the river" if he needs more and of course justify the effort.
In this one:
Max W.Fillies - YouTube
Note: mainly a Tech, barely a basic player, he´s only showing that unique "only from Tubes" halfway crunch and compression/intermodulation.
Also:
2 x EL84:
Teste Amplificador Valvulado W Fillies Magic Tubes - YouTube
VERY GOOD crunch and distortion.
ALL TV tubes (except, maybe, extra high voltage diodes and such) can be used for Audio, as long as they have basic Plate, Anode and Grid; extend that to include Pentodes which can be used as such or strapped as triodes.
Main problem? ..... you´ll have to DESIGN around them, you simply can´t straight pop them into a Fender/Marshall/Vox circuit and expect them to work with THOSE parameters.
No big deal anyway, as long as you are handy with datasheet curves, nothing further needed.
Fine for DIYers (ahem! 😉 ), and if anybody wants to get into series production, maybe he should first secure a 100-200 tube stock so as not to "switch horses in the middle of the river" if he needs more and of course justify the effort.
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Hell, I’m barely a basic player - that’s why I wasn’t going to spend a boatload of cash on this. Only thing full price was the output transformer. All tubes were five bucks. $5 26DQ5’s, $5 12SN/SL7’s, 140 watts. I have since secured boatload of $3 TV small signal tri/Pents that I can do preamps with. Still gotta build the case and speaker cab. The extra off voltage heater windings are no big deal when you make your own power trafo out of something that came out of a 25 year old UPS. The intended speaker is prehistoric, back from when Pyle could STOMP Eminence. It’s a fantastic driver. I wish I could get a pair rebuild the old 3 ways I used to DJ with in college. Maybe with a B&C midrange. They would be fabulous with my 6x6550 hifi monoblocks.
You need to secure production quantities of the required power transistors these days before starting a run too.
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This mass of tubes, including many lifetimes of supply of old TV tubes, were just 20 bucks. There are masses of ECH and U prefix tubes, so a challenge to do anything useful with many of them.
If one is willing to experiment, tubes are still cheap. I think the value these days are in the different heater voltages - STC tubes that can substitute a KT66 with top caps and 19v heaters, on loctal bases are still 10 quid. 1619 tube, a directly heated pentode that can substitute for 2A3 in some cases, is still 10 quid.
The NOS tubes will not last indefinitely, and they don't take up that much space, or need special storage requirements, so I have collected a few.
What we need is some sort of site where we can pool our tubes, so that they can be shared amongst people with a project. If one is going to build a PP amp with something off the wall, then it is really necessary to have 12 tubes to hand so reasonably matched pairs can be selected, and a spare set is available.
If one is willing to experiment, tubes are still cheap. I think the value these days are in the different heater voltages - STC tubes that can substitute a KT66 with top caps and 19v heaters, on loctal bases are still 10 quid. 1619 tube, a directly heated pentode that can substitute for 2A3 in some cases, is still 10 quid.
The NOS tubes will not last indefinitely, and they don't take up that much space, or need special storage requirements, so I have collected a few.
What we need is some sort of site where we can pool our tubes, so that they can be shared amongst people with a project. If one is going to build a PP amp with something off the wall, then it is really necessary to have 12 tubes to hand so reasonably matched pairs can be selected, and a spare set is available.
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I fell in love with el38 tubes. Started reading about them and kept hearing how they cheap they were, 2-5 dollar range. Well, when I look for them these days they are 30-70 bucks a piece.Not only that, it's hard to find places with more than a handful in stock. I went ahead and bought my stash despite the higher prices these days since they aren't going to get any easier to find in the future.
I am glad I binged bought a load of Sylvania 6sn7 and 6sl7 about a decade ago. The prices of the 6sn7 in particular has gotten really high.
I am glad I binged bought a load of Sylvania 6sn7 and 6sl7 about a decade ago. The prices of the 6sn7 in particular has gotten really high.
EL86/6CW5 and 6GK6/EL84/6BQ5 look like they have very similar plate curves to the EL38, except they are half the Watts. EL86 uses about half the screen V.
6CW5 and 29GK6 are still $4 and $3 at Vacuumtubes.net
6CW5 and 29GK6 are still $4 and $3 at Vacuumtubes.net
Half the watts is a big difference. Even so, I might have given them a chance if I were building my own amp. The El38 tubes are for a commercial amp, they happened to work well with the existing limitations.
I used to work at an old 3M plant that produced photographic film. The film spoolers for 35mm were from italy and designed back from the 50's. anyway the portion of the machine that welded the velvet to the 35mm can was a inductive welder that was tube based. that tube globe was the size of a football and bigger round. it had cooper coils with DI water flowing through them for cooling basically forming the primary of a transformer. Anyway they were very high power triodes that ran somewhere around 2500 volts on the plate. probably could have made a heck of an audio amp with something like that.
Beautiful amp, congratulations.
PYLE made KILLER speakers, many establised makers used them, such as GK.
Fully agree on stocking before starting.
I will willingly use *any* TV tube, no matter which, as long as I have, say, 200 of each type so they last long enough to get rewards back, no use in selling half a dozen amps and then having to switch.
A friend of mine worked in a small factory making all kinds of covers and envelopes for booklets/ID cards/restaurant menus/CDs, *anything* you can make out of a couple vinyl/acetate/etc. plastic sheets, opaque or transparent.
They pressed sheets together between a shaped brass "punch" and a thick back plate in a foot operated machine, similar to a sheet metal spot welder, and at bottom of the pedal travel it switched this powerful transmitter for a couple seconds.
It used two 2 liter coke bottle sized tubes, top caps, might have been 813 or the "next larger" version.
Matches your 3M machine, included the water cooled copper tube coils.
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