Only N-Channel MOSFETs (NMOS); better Audio from non complements by Audio Power?

[Workhorse]

My own design

http://www.diyaudio.com/forums/attac...amp=1142507100

NVMOS thread
NVMOS amplifier

[tiefbassuebertr]

Originally posted by AndrewT
is it compulsory to read through all those links before we are allowed to post a comment or question?
Oops, just broke that rule!

That's no true. I have make the subdivisions 1) until 9) for better overview

Originally posted by KSTR
You used literal copies (cut&paste from screen), which when abreviated with "..." in between obviously give wrong URL's
Sorry for another metacomment.

Thank you for this advice. All URLs by the follow correction goes open - copies in this case I have make from the displayed address in the web address field

What means "metacomment" ?

[tiefbassuebertr]

I see for most of electronics engineer that's very hard to find for the individual versions classify and enclose since there are in some circuits transitional forms between pure "single ended" and pure "push-pull" (In contrast to "Power Follower", i. e. Gain <1 and "Power amplification" respective "common source", i. e. Gain >1 that clearly is to differentiate).
If there are pure "single ended" version, no mode in class A/B operation is possible, only pure Class-A operation
If there are pure "push pull" version, both modes, class A and class A/B are possible

A few weeks ago I had the following two threads opened with an URL collection concerning "single ended", that means only "Pure Class A" - see
URL collection of Single Ended Solid State Output Stages (overview of most circuits)
and URL Collection of Commercial Single Ended Integrated and Power Amplifier Devices (overview commercial amplifier devices)
and additional "Totem Pole" and CSPP (Single Ended related)" see
URL collection of Totem Pole and CSPP (Single Ended related) Solid State Output Stage (overview of most circuits)

Mr. Pass would filed all this kinds of circuit topologies to "Single-ended Class A systems, including SRPP and variants" because by operating in pure class A mode the measured differences by all this versions are relatively low.

My aim of this thread actually should be to make an overview about all known output stages with "only N-channel MOSFET" that not only can operated by pure Class A (i. e. also suitable is for push-pull operated in Class A/B with only 100 mA idle current through the MOSFETs). Unfortunately I forgot this to mention at the beginning.

I note by this circuit topologies, that I cannot say bei number 3), 4), 8) and 9) clearly the possibility of class A/B operation

1) driving through differential driver stages - class A/B is possible
2) driving through phase splitting transistor (Totem-Pole like Bengt Ollson, Futterman or MOSFET-DOZ) - class A/B is possible
3) driving through phase splitting driver transformers - only pure Class A ?
4) driving through current mirror phase shifter - only pure Class A ?
5) Quasi complementary output stages - class A/B is possible
6) Version orf German's company "Protovision" - class A/B is possible
7) Version of NAD integrated amp "306" - class A/B is possible
8) driving through two op amps - only pure Class A ?
9) Circlotron (lowest distortion) - only pure Class A ?

If Number 3), 4), 8) and 9) can use really only for class A, this versions must go out from this thread

when this is completely clear, I can go to the next step: Namely, to find out and investigate, which of these versions look the best suited for amplifiers repairs as to use for universal solution circuit. They would then have a cheap and good alternative for the "hard to find" MOSFET replace of many amplifiers, for which there is very expensive or no longer exists (most complementary MOSFETs). For example, there are no replacement for the famous Yamaha and Sony V-FETs and no replacement for the Hitachi lateral MOSFETs in the TO-3 outline (except only the very expensive BUZ900/901 from Semelab).

[megajocke]

Here is a fun topology which you didn't include in your list.

http://www.qscaudio.com/support/libr...es/PL6.0II.pdf

[tiefbassuebertr]

Thanks for t his advice. A photo of this power amp is to see by URL
http://www.musik-service.de/images/p...744869/i00.jpg
I would filed it by number 8 (driving through two op amps)

[megajocke]

The QSC have its output FETs in tight feedback loops with one opamp each, making them contollable current sources. Parallelling can be done with only low-resistance current sensing resistors. The intricate PUPPETMSTR (I love that name ) phase splitter balances the bridge and drives the current cells.

That Protovision circuit is quite close. If the output transistors are replaced by current cells it would be very close, though non-bridged and with a much simpler phase splitter...

[Workhorse]

Phase splitter is best for the N-Channel Mosfet Drive topology.

[Wavebourn]

Originally posted by megajocke
The QSC have its output FETs in tight feedback loops with one opamp each, making them contollable current sources. Parallelling can be done with only low-resistance current sensing resistors. The intricate PUPPETMSTR (I love that name ) phase splitter balances the bridge and drives the current cells.

That Protovision circuit is quite close. If the output transistors are replaced by current cells it would be very close, though non-bridged and with a much simpler phase splitter...

I did something similar with transformer output: I've converted such a way Altec transistor power amp to a hybrid (double triode: amplifier and concertina splitter). Opamps were driven by tubes. Sounded well on a bass guitar.

[tiefbassuebertr]

in this case also the follow thread could be of interest:
Improving the linearity of an N-ch MOSFET output stage - go to
http://www.diyaudio.com/forums/showt...68#post1902668

[RocketScientist]

And this may be of interest as well:

SemiSouth Power SiC JFETs