low power bedroom amp

[JoeAlders]

This is my take on a low powered amp. Going to be reconfiguring my old DC7 amp to look like this over the next few weeks. Good for 7W and maybe a bit more. I would say that the tail of the input LTP will need a little negative supply, with it not been ideal.


Shoog

Shoog, are you willing to upload the .asc file?

 

[Shoog]

Here it is.
The power supply is designed round an old Sony receiver power transformer with a centre tap 45-0-45 winding into a voltage doubler/tripler which gives 240V for the drivers and 150V for the outputs The OT will be toroidal power transformers, the input transformer are from OEP who make cheap but decent audio transformers. The Diodes are just to get the sim working and can be any 400V rectifier. The chokes are florescent light ballasts.

 

[JoeAlders]

Here it is.
The power supply is designed round an old Sony receiver power transformer with a centre tap 45-0-45 winding into a voltage doubler/tripler which gives 240V for the drivers and 150V for the outputs The OT will be toroidal power transformers, the input transformer are from OEP who make cheap but decent audio transformers. The Diodes are just to get the sim working and can be any 400V rectifier. The chokes are florescent light ballasts.

Thank you very much Shoog!! Much appreciated.
Joe.

 

[Shoog]

I have also modelled it with ECC88 drivers which gives more power output, up to around 12watts. Still the ECC88 is a weaker driver than the 5687 so in reality it may just not perform as well. I have done quite a bit of research and really it boils down to those two drivers or adding an additional gainstage to the front end. Adding an ECC88 LTP at the front into a 5687 driver LTP would give significantly to much gain - but would allow gNFB which should bring down overall distortion significantly. Zero negative feedback and less than 7Watts is more than adequate for me so I am thinking of sticking with the 5687.

Shoog