Balanced F5 question

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re: Regulator MOSFETs

I'm waffling on the regulated ps for the amplifier.
I take it is an option and not a requirement for this
project.
My concerns are a reduced power output and a
loss of voltage drive to the speakers, Seas Thors
with an impedance of 4 ohms.
 
> They are not regulators. They are multipliers.

Straightly speaking they are regulators, as they control the output to a fixed voltage (determined by the Zener diodes minus the Vgs of the pass device at bias current), irrespective of the incoming voltage. Precondition is enough voltage headroom. See Zen Version 3.

A cap multiplier is floating. The output voltage varies with the mean input voltage, even though it filters out the ripples.

The output impedance (voltage variation vs current) is the same in both vases, and equals 1/Yfs of the pass device at bias.


Patrick

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Finished Balanced F5 Channel

I finished my "Stock" Balanced F5 channel tonight. Attached is a picture before I added the 2SK170s and 2SJ74s.

I'll try it tomorrow and compare it to the Cascoded Balanced F5 sonically and electrically.
 

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I think I will try without first, but I will not be able to resist I am sure of that. I hope the lack of contact from Variac does not mean he is sick or something, it does seem very strange for no contact for that long. i'm sure someone will pick up the ball if we cant touch base with him, I do hope it does not cause delay, but most of all I hope he is well
 
> You have a simulator that plays music according to schematic?

No, but the simulator will tell me what the distortion spectrum looks like, which I can relate to sonic performance.
And to put the record straight I did write "... The rest would have to come from tests."
There is no need to quote out of context.


Patrick
 
The "regulator" has been referred to as a "cap multiplier" repeatedly throughout this thread.
30th Oct Euvl said "The regulator as in Zen3 is a cap multiplier, only using mosfet as pass devices instead of Darlington."

What has changed since then?

What is shown in ZEN 3 PSU is a Zener referenced Follower. Yes, that is a regulator.
 
> 30th Oct Euvl said "The regulator as in Zen3 is a cap multiplier, only using mosfet as pass devices instead of Darlington."
> What has changed since then?

Nothing, so straightly speaking I used the wrong technical term then, if you like.

> What is shown in ZEN 3 PSU is a Zener referenced Follower. Yes, that is a regulator.

Correct. The circuit is essentially the same as a cap multiplier, except that the Zener controls the output voltage. It is different from most conventional regulators in that it does not use a global feedback loop to control the output voltage tightly. This aspect is similar to the cap multiplier, which was what I intended to say in October.


Patrick
 
The whole concept of simulating cascoding and coming to a conclusion reminds me of an experiment I did back in my college days:

In brief, all that was known of biophysical science predicted that an experiment I was about to run would fail. I went to the Chairman of the department and argued against the experiment (waste of time, money, etc). He gave me advice which changed my life: "If we believe what everyone tells us, we mere are puppets. Run the experiment, prove or disprove the idea. Be a scientist!"

Needless to say the experiment worked, was published, and I started a company around it with the Chairman.

Nelson Pass has conveyed this idea as well - build it, listen to it, then decide. I have to say, when I started on the forum, I didn't heed this advice. Now, I try to build as much and as fast as I can. I could be wrong, but I believe Nelson knows what he's talking about.


You have a simulator that plays music according to schematic?

Sorry, couldn't resist. :D

BYW, I observed no improvement too (when using cascode in F5's input stage).
 
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