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I've got Dave Hunter's book, “The Guitar Amp Handbook,” and I'm thinking about building a version of his “Two Stroke” amp. I have the transformers from an Epiphone Galaxie 10 tube amp and would like some help deciding whether it is feasible to use them for this build. Like the revised version of the Two Stroke, the Galaxie 10 uses a 12ax7 pre-amp tube and a 6L6 power tube. There are, however, some differences that make me question whether the power transformer in particular will work. For reference, I've included a schematic of the Galaxie 10.
Looking at the schematic, the voltages used in the Galaxie 10 seem to be considerably higher than in the Two Stroke. Also the Galaxie 10 transformer has no 5V windings because the Galaxie 10 uses a diode rectifier.
I've done some testing of the transformer with no load and here's what I found: I get 412/412 VAC on the secondary and 7.9 VAC at the filament supply. After connecting four 1N4007 diodes as shown in the Galaxie schematic, I get 376 VDC. After connecting in a 22uf/450 volt filter capacitor after the diodes, I get over 500 VDC. Are these numbers hopelessly too high, or is there a way to bring them down to the ranges used in the Two Stroke?
The Two Stroke calls for a power transformer with ". . . secondary between 310V/310V and 330V/330V center-tapped . . ." and a "center-tapped 6.3V AC filament supply."
With respect to voltages, it says "you should be seeing from 340-360 VDC on the plates of the output tubes (pin 3), and around 300 VDC +/- on the grid (pin 4), and from 140-160 VDC on the plates of the 12AX7, (pin 1 & 6). . . "
Thanks for your help.
Looking at the schematic, the voltages used in the Galaxie 10 seem to be considerably higher than in the Two Stroke. Also the Galaxie 10 transformer has no 5V windings because the Galaxie 10 uses a diode rectifier.
I've done some testing of the transformer with no load and here's what I found: I get 412/412 VAC on the secondary and 7.9 VAC at the filament supply. After connecting four 1N4007 diodes as shown in the Galaxie schematic, I get 376 VDC. After connecting in a 22uf/450 volt filter capacitor after the diodes, I get over 500 VDC. Are these numbers hopelessly too high, or is there a way to bring them down to the ranges used in the Two Stroke?
The Two Stroke calls for a power transformer with ". . . secondary between 310V/310V and 330V/330V center-tapped . . ." and a "center-tapped 6.3V AC filament supply."
With respect to voltages, it says "you should be seeing from 340-360 VDC on the plates of the output tubes (pin 3), and around 300 VDC +/- on the grid (pin 4), and from 140-160 VDC on the plates of the 12AX7, (pin 1 & 6). . . "
Thanks for your help.
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