Now I ´m using a Nichicon UKA 2200uF. In this case the Nichicon UKA has a leakage current of 4uA
With 330r offset is arround 1.62Vdc (-Out and positive rail as common). With 220R arround 1Vdc. I´m not sure if I´ll continue to decrease this value since I am affecting the output frequency. I'm wrong?
How should I calculate the value of the bleeding resistor?
With 330r offset is arround 1.62Vdc (-Out and positive rail as common). With 220R arround 1Vdc. I´m not sure if I´ll continue to decrease this value since I am affecting the output frequency. I'm wrong?
How should I calculate the value of the bleeding resistor?
OK, I have finally decided to use ground as common. I´m not sure why it does not work having B + as common 
I changed bleeding resistance (300r) from B + to ground and yes, here it´s work. I have just about 20~0mVdc offset.
I think that the final layout is this:
I changed bleeding resistance (300r) from B + to ground and yes, here it´s work. I have just about 20~0mVdc offset.
I think that the final layout is this:
Attachments
Nop. Both Flukes are ok.
Second channel is working now. Same configuration (ground as common), Bias 12,6Vdc and 0Vdc offset.
Transistors are a bit hot so I need to use a box with not very large heatsinks.
I´m listening music with my headphones for test and all is correct, nice sound and total silence!! I want to try it with low capacitance and low sensibility headphones.
I'm surprised at how well the C2M1000170D works. I had already used it in other designs but I had my doubts about using it here.
I have had both channels working all night. I used my radio (Does anyone still listen to FM?) and a 10K volumen pot with my test headphones (35 Ohm): Bias is totally stable and the temperatura is about 30 ~ 35º using a small heatsink.
I need some days to test it properly but my goal was to use this amp with headphones and now I´m thinking in adding some terminals and test monitors.
The only thing that will limit me is the power of the transformer. I am using right now (T80VA 0-18v X2).
PS: Thanks to Nelson and OllBoll for the design and to Zen and PRR for the support
I have had both channels working all night. I used my radio (Does anyone still listen to FM?) and a 10K volumen pot with my test headphones (35 Ohm): Bias is totally stable and the temperatura is about 30 ~ 35º using a small heatsink.
I need some days to test it properly but my goal was to use this amp with headphones and now I´m thinking in adding some terminals and test monitors.
The only thing that will limit me is the power of the transformer. I am using right now (T80VA 0-18v X2).
PS: Thanks to Nelson and OllBoll for the design and to Zen and PRR for the support
Well, it's finally over.
My Zen V9HA:
For Papa:
It has an output for low sensitivity headphones and another for high sensitivity. In the PSU there is a total of 75,000uF for each channel. It's pretty per my goal was to keep the ripple as low as possible (3mVac).
I think the C2M1000170D is a bit noisy but it works quite well despite not having a high transimpedance. I have measured about 209mA with 35R loads (2Vrms @ 1KHz). I think it's not wrong to be a V9.
I hope you like it. Any recommendation will be welcome.
My Zen V9HA:
For Papa
:
It has an output for low sensitivity headphones and another for high sensitivity. In the PSU there is a total of 75,000uF for each channel. It's pretty per my goal was to keep the ripple as low as possible (3mVac).
I think the C2M1000170D is a bit noisy but it works quite well despite not having a high transimpedance. I have measured about 209mA with 35R loads (2Vrms @ 1KHz). I think it's not wrong to be a V9.
I hope you like it. Any recommendation will be welcome.
Last edited:
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