And if I put an elyt on the regulator output the hum stopp completely...
Is it any harm in doping so?
Completely silent...
Is it any harm in doping so?
Completely silent...
I don't think so - Rod might be along shortly, but I don't think you can do that. Essentially you are putting a cap across the filament resistor. I think it points though to the heaters being the problem.
Are you using one 5V SMPS for both regulators? If you have 2 SMPS, then could you swap these around and see does the problem move with the SMPS?
Are you using one 5V SMPS for both regulators? If you have 2 SMPS, then could you swap these around and see does the problem move with the SMPS?
Swap the R.C. regulator outputs: the now "humless" R.C output connect to "humming" channel. It' only swapping two wires.
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I am not sure what the circuit for your preamp is now.
It would help us, to help you, if you could make a pencil sketch of the circuit you have made, and take a photo.
Please mark the voltages on the schematic, and all the resistor and capacitor values.
It would help us, to help you, if you could make a pencil sketch of the circuit you have made, and take a photo.
Please mark the voltages on the schematic, and all the resistor and capacitor values.
This is one channel,the other one is the same..theres hum in one channel.But now i soldered a (What I had on hand) 2200uF elyt on the filament regulator out put, then it became dead silent.
With 4V output, the input voltage needs to be 8V, and more is ok. Do you have any other transformers with higher voltage?
If you don't have any transformers, you can connect as normal cathode bias (auto bias) and add a bypass capacitor.
If you don't have any transformers, you can connect as normal cathode bias (auto bias) and add a bypass capacitor.
No I dont have any suitable transformer,so I am going back to cathode bias.
Thanks for the help all.
Thanks for the help all.
Ive been thinking,if I connect the 2 6v Windings in seriel so that i get one 12v Windings.
And if I parallel the 2 rectifiers on the AC side.
Will that work?
And if I parallel the 2 rectifiers on the AC side.
Will that work?
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12V winding will give ca. 16V DC . That is too high.
With your 6.8V DC you can run cathode bias.
It will work perfectly.
I think it is best to try it. You can try filament bias, if you like the preamp.
The Raw DC for L and R channels must be independent, and not connected to ground!
With your 6.8V DC you can run cathode bias.
It will work perfectly.
I think it is best to try it. You can try filament bias, if you like the preamp.
The Raw DC for L and R channels must be independent, and not connected to ground!
If I wanna try induktor load instead of the gyrators,is this the one I should use??
www.hammfg.com/part/156C
It is 150H 8mA.
www.hammfg.com/part/156C
It is 150H 8mA.
3A5 plate resistance is 8k3.
If you paralleled two halves (twice the current!), the 150H is almost enough.
The HF bandwidth would be decreasing, due to the anode choke parasitic capacitance.