Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Leevi on May 22, 2023, 09:42:28 am

Title: Weird power amp wiring
Post by: Leevi on May 22, 2023, 09:42:28 am

What is the idea of the following power amp wiring?
The cathodes and screens are connected to the OT instead of plates and the CT is grounded.
/Leevi

Title: Re: Weird power amp wiring
Post by: Williamblake on May 22, 2023, 11:57:08 am

Negative screen sag? Building a hifi amp? More impulse current? Less compression?

Title: Re: Weird power amp wiring
Post by: pdf64 on May 22, 2023, 12:58:26 pm

The OT secondary provides some resistance for bias voltage (mixed), and feedback, probably negative.
There’s a Leslie with something similar.
Also seems something weird with the rectifier common return via the OT secondary half winding.

Title: Re: Weird power amp wiring
Post by: PRR on May 22, 2023, 04:13:35 pm

The plates ARE connected to OT... through the DC supply.

It is essentially a McIntosh with the complexity moved from OT to power supplies.

Or the ElectroVoice competitor to the Mac.