Choke loaded MOSFET in circlotron??

[Tubenstein]

Hi!
Can I have choke loaded the MOSFET in circlotron output section of this circuit? What about depletion mode MOSFET CCS loaded 2SK1058?

Amplifier End by Andrea Ciuffoli

Pros and Cons?

[ilimzn]

Mr. Ciuffoli still manages to surprise with the lack of basic electronics knowledge. 2SK1058 is NOT a depletion mode MOSFET, it's an enhancement mode LATERAL MOSFET which gives it inherent thermal stability for the usual currents it is used at.

Your question has little sense as the MOSFETs in a circlotron essentially load each other. Unless you are asking about putting a transformer coupled output.

[Ian Finch]

I think Tubenstein is trying to suggest loading a 2SK1058 with another type, i.e. a depletion mode type.
I don't know that is any better either, but it's a different meaning.

[ilimzn]

Originally Posted by Ian Finch

I think Tubenstein is trying to suggest loading a 2SK1058 with another type, i.e. a depletion mode type.
I don't know that is any better either, but it's a different meaning.

Sadly, no - he was quoting A. Ciufolli from the link, where he keeps on mentioning the K1058 is a depletion mode MOSFET and even saying it's now a new fashion to use depletion mode MOSFETs as well as other inferences that have nothing to do with the MOSFET type. Clearly no idea what he's talking about but that's nothing new
Even so, there is no sense additionally loading the halves of a circlotron output as the current passes through both halves and respective PSUs in series. Whatever you load the halves with goes in parallel with the load and when there is no signal, net DC on it is zero. So, any loading just adds a load in addition to the regular speaker load - and does not affect idle currents and voltages at all.

[pieter t]

Originally Posted by ilimzn

So, any loading just adds a load in addition to the regular speaker load - and does not affect idle currents and voltages at all.

Yes, the circlotron is actually nothing more than one possible topology of a push-pull output stage, and not basically working different from other topologies. John Broskie pointed it out clearly in his web pages (Tube CAD Journal).

[Tubenstein]

Originally Posted by Ian Finch

I think Tubenstein is trying to suggest loading a 2SK1058 with another type, i.e. a depletion mode type.
I don't know that is any better either, but it's a different meaning.

Yes, this is exactly what I meant either load the 2SK1058 by a choke or a depletion mode MOSKET CCS:

K & K Audio - Lundahl Transformers, audio DIY kits and more