These are the circuits (triode and pentode) I tested. The component values are optimized to minimum distortion.
The results were quite similar with both 6J5B-V and 6J1B-V.
Unfortunately I do not have my memos at hand right now, so that I could say what the gain of the triode strapped circuit was.
Likely between 20...30.
The results were quite similar with both 6J5B-V and 6J1B-V.
Unfortunately I do not have my memos at hand right now, so that I could say what the gain of the triode strapped circuit was.
Likely between 20...30.
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Well, it's in german but here's a nice guitar preamp project with these little tubes:
Gitarren-Vorverstarker mit russischen Batterierohren 1SH29B - Michael Gaedtke
Gitarren-Vorverstarker mit russischen Batterierohren 1SH29B - Michael Gaedtke
Submini LV tube projects:
http://www.gtlab.net/gtlab2/filemanager/userpix/igor/low_anode_2.pdf
1P24B datasheet in English:
http://www.radiotechnika.hu/images/1P24B.pdf
bigger ideas (5 Watts P-P output):
http://tubedata.milbert.com/sheets/137/5/5639.pdf
http://tubedata.milbert.com/sheets/141/5/5902.pdf
http://www.gtlab.net/gtlab2/filemanager/userpix/igor/low_anode_2.pdf
1P24B datasheet in English:
http://www.radiotechnika.hu/images/1P24B.pdf
bigger ideas (5 Watts P-P output):
http://tubedata.milbert.com/sheets/137/5/5639.pdf
http://tubedata.milbert.com/sheets/141/5/5902.pdf
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Here's a submini tube Hiwatt amp project, using 6021s, which I believe were originally used in ICBMs. It has a "self-split" PP power stage, which has almost no benefit over regular SE. Maybe you could build a guitar amp for home use with a 5678 preamp and 6021 power stage.
I would like to look at it.....where?
I have seen self split output stages that were anywhere from "like an SE stage" to nearly perfect push pull. The good ones need a CCS in the tail which forces class A operation, and some tubes still refuse to respond to it. I found that a simple LND150 mosfet split load PI fixed all the ills of a low buck amp that formerly had a self split stage, and boosted the output power too.
"where?"
Seem to be a lot of "HiWatt" amplifiers around.
I just found this one with 6021 tubes, at
32 best hi amps images on Pinterest | Guitar amp, Audio and Guitar.
Should be called "LowWatt" I think.
Seems to mention jmyuste40 as the source. Maybe more there.
I think I would put one of those bigger (than a 6021) submini tubes in for the finals. Maybe fix up that self splitter too.
Seem to be a lot of "HiWatt" amplifiers around.
I just found this one with 6021 tubes, at
32 best hi amps images on Pinterest | Guitar amp, Audio and Guitar.
Should be called "LowWatt" I think.
Seems to mention jmyuste40 as the source. Maybe more there.
I think I would put one of those bigger (than a 6021) submini tubes in for the finals. Maybe fix up that self splitter too.
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I'm working with that tube too.
My first attempt worked like a charm, made some posts here> Battery powered Subminiature tube amp for high Z headphones
Put a small 200v to 6v PCB transformer and you have a LOFi headphone amp. With two of them in PP it is loud enough (through a celestion greenback) to annoy my wife.
But I'm using the 5672 as the power stage. They have the same filament current as the 5678.
My first attempt worked like a charm, made some posts here> Battery powered Subminiature tube amp for high Z headphones
Put a small 200v to 6v PCB transformer and you have a LOFi headphone amp. With two of them in PP it is loud enough (through a celestion greenback) to annoy my wife.
But I'm using the 5672 as the power stage. They have the same filament current as the 5678.
A sub-mini amp that can drive a speaker. I'd put an Edcor 8K OT in there if you want HiFi though.
V1a and b could be changed to 5719 or 5744 sub-minis (instead of the 6112) for less cost.
JJS.at : Electronic Projects : Class AB Subminiature Tube Guitar Amp
V1a and b could be changed to 5719 or 5744 sub-minis (instead of the 6112) for less cost.
JJS.at : Electronic Projects : Class AB Subminiature Tube Guitar Amp
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Also the Russian 6N17B-V or 6N21B for cheaper 6112 sub-mini tubes. Upgrading to an Edcor GXPP OT instead of the toroid power xfmr OT should help the Bass response.
Replace the 5902 sub-mini outputs with 6BQ5 ,6HB6 or 12HL7 (or 4x 5902 paralleled) for more slam (and Watts) and an Edcor CXPP25-8K (or 5K) OT with a bigger power supply too.
Replace the 5902 sub-mini outputs with 6BQ5 ,6HB6 or 12HL7 (or 4x 5902 paralleled) for more slam (and Watts) and an Edcor CXPP25-8K (or 5K) OT with a bigger power supply too.
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