Greeting fellow members,
This is my first post, my principal interest is (for now) is comparing GM-70 amp schematic, the "contemplative state" before considering building, anyways, what do you guys think of this circuit regarding these aspects :
1 - input impedance?
2 - the use of a output transformer as an input (yes you can warn me about not to go this way, ahah)
3 - is the simplicity of the circuit worth exploring?
4 - the possibility of using a higher plate voltage
5 - the cost (of course I would look for cheaper trans than Tango)
Here is the link to the original page : http://www.ononet.jp/~micky/gm70s.html
Here are the published characteristics
Happy building and listening!
Olivier
This is my first post, my principal interest is (for now) is comparing GM-70 amp schematic, the "contemplative state" before considering building, anyways, what do you guys think of this circuit regarding these aspects :
1 - input impedance?
2 - the use of a output transformer as an input (yes you can warn me about not to go this way, ahah)
3 - is the simplicity of the circuit worth exploring?
4 - the possibility of using a higher plate voltage
5 - the cost (of course I would look for cheaper trans than Tango)
Here is the link to the original page : http://www.ononet.jp/~micky/gm70s.html
Here are the published characteristics
Happy building and listening!
Olivier
1. source impedance must be very low unless you strive for a Sakuma style effect box;
3. depends on what you expect: serious "hifi" amplifier? Not worth exploring IMO;
5. you might consider Lundahl LL9202 (6k5 primary impedance - 85mA - 57H).
When you build: take care of correct connection of the capacitors in the negative grid supply (not like in the schematic....).
3. depends on what you expect: serious "hifi" amplifier? Not worth exploring IMO;
5. you might consider Lundahl LL9202 (6k5 primary impedance - 85mA - 57H).
When you build: take care of correct connection of the capacitors in the negative grid supply (not like in the schematic....).
- Home
- Amplifiers
- Tubes / Valves
- Unusual (at least for me! lol) single-ended GM-70 amp