Thursday, September 22, 2016

The Differential Power Amplifier - Part 1

Hi!

After the successful completion of fully differential line stage and phono stage, here comes the matching set of mono power amps.




I have often been asked why I have no push pull amps in my line up. Finally someone commissioned a set of push pull mono blocks, so no more excuse!




Like the matching line and phono stages they will be fully differential throughout. Nut just a PP output stage but also a differential input stage. Of course they can also be used with single ended preamps. Phase splifting is done via input transformers.




Output tubes will be a pair Elrog 300Bs per channel, driven by a pair 10Y. Alternatively 801A can be used as well. These should be good for a solid 15W per channel. Operation will be pure Class A.




Construction has just begun, so not much more to show than the top plates with the tubes at this  point.




The power supply will be using my favourite rectifiers, 4 6AX4 in full wave bridge configuration. Choke input filtered and with oil caps. Filaments will be purely DC fed as in my other DHT amplifiers.




Once the concept is proven with this first set of amps, an all silver ultimate version will follow to complete the series with the ultimate phono and line stage.




Stay tuned for updates on this project!

Best regards

Thomas

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