GU29 push pull amp

[kodabmx]

I don't find they impact the sound at all. If anything they improve the performance of the amplifier because they are stiffer and easier to filter because of the high frequency. And if they were noisy, I'd see it on the scope since one of them powers the grid supply. The main reason I use them is because it's smaller, more efficient, and cheaper. Plus I can run the amp from a car battery if I want to.


As others have pointed out, you could also use a linear supply with a voltage doubler. I use one on my 36LW6 amp to get ~320V from a 62-0-62 transformer.

 

[Wavebourn]

Even before such SMPS become available for sale, I used a 220V 50 Hz inverter with removed chopping MOSFETs to power a guitar amp from 12V battery. Deadly quiet.

 

[TonyTecson]

I have noticed a lot of folks have been using SMPS systems in their projects. Do these power supplies have any impact on the sound quality when compared to core type transformers.

one thing going for the smps psu is their very good regulation, as you know,
keeping the operating points of tube stages constant helps reduce distortions...

 

[sony6060]

Looks good design to me. I like cathodyne phase inverters when the power tubes do not draw grid current. Cathodyne are considered to have a perfectly balanced waveform output.