Tube-Town Forum
Technik => Tube-Talk => Thema gestartet von: JesseJJ am 13.01.2021 22:55
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Hello,
Im dreaming up a project to make a micro tube amp in a large pedal enclosure using a v pump. 12v wall adaper wich can power the tubes in series and use that for the high voltage as well. I was thinking about a simple 12ax7 preamp with two simple gain stages and and a 12au7 as power amp in either push pull or parallel. Small hamond A output transformer.
The big question however is: Can the V pumps 15ma output be enough?
Anyone willing to jump in and help me?
Kind regards,
Jesse
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Assuming 1.5mA per 12ax7 triode you will have about 6mA for each 12au7 output triode.
This is not much current, but will work somehow. At least you have to set the bias correctly, to not load the Vpump more than allowed.
The bigger problem will be the PSU noise generated by swithing in Vpump.
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Hi,
Otherwise I could recommend to build a small Amp using the small Print transformer from the shop. You will also get low current but it will work for a single 12AU7 triode. Using a common 12ax7 and a 12dw7 (ecc832) you get a nice small amp. As output transformer, the reverb transformer with 22k is a nice option. But all together that will hardly fit in a pedal ::)
Actually the V Pump May manage to get that running as well. Problem is the need of an output transformer.
If the format of a big pedal is a must, the concept of the "tomato blaster" (check in the shop) may be your best bet.
Cheers,
Laurent
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(...)
The bigger problem will be the PSU noise generated by swithing in Vpump.
Well, it should be easy to keep the switchung frequency above 20kHz, isn't it?