All Hitachi Lateral Fet amplifier for DIY described by Paul Kemble

[Jay]

Originally Posted by gaborbela

Hard to believe so little interest on these amp circuit

That's because you cannot build an amp. If you can, you may also have little interest on the amp.

Some might have discarded the idea simply from looking at the VAS.

Some might have discarded the idea after doing some simulation.

Some might have discarded the amp after building and listening to it.

If you want to listen to all fet amp, go to Lineup thread or Fetzilla.

[gaborbela]

Originally Posted by Jay

That's because you cannot build an amp. If you can, you may also have little interest on the amp.

Please don't write these (I ask kindly) I built or tested over 100 amplifier some with my own mod , PC boars design etc.
If I had little interest on the amp I do not start these thread!

Some might have discarded the idea simply from looking at the VAS.

What is wrong with the WAS? Let s fix it, that is why DIY..

Some might have discarded the idea after doing some simulation.

Simulation and reality is two different think. Not to write about the sound!

Some might have discarded the amp after building and listening to it.

If I build a amp and sound bad at least I would warn other DIY-ers NOT TO BIULD sound bad, not working etc.
I assume you to, or not?
Please do not take it personal criticism, I have nothing against you..
All my respect to all fellow DIY-ers.
Why I like these circuit? Not very often see on the forum all (lateral) fet schematic!
One think I would like to ask, if you think these or that is wrong in the circuit please let us know why and how would you fix it!
It would be much more positive than just these no good or that
Some advise would be more constructive than criticism even if that sound positive...

Greetings and thank you for all of you for the comment!

Gabor

[donpetru]

@gaborbela, and other users here, I notice that you ignored my remark in a previous post. What you want to do or has done design from Naim, I began to conceive through 2003.

To figure out what is wrong with amplifier diagram posted by you and made ​​from designer to Naim, I recommend viewing below attached project designed by me. DP400 is a project I started when I was in college and during this topic, I thought I outline a final revision. Initials project name is my name.

And please, do not ask me about PCB.

[gaborbela]

Originally Posted by donpetru

@gaborbela, and other users here, I notice that you ignored my remark in a previous post.
What you want to do or has done design from Naim, I began to conceive through 2003.

And please, do not ask me about PCB.

No I do not ignore no body's remark just it would be nice to be constructive like these post of yours!

To figure out what is wrong with amplifier diagram posted by you and made ​​from designer to Naim, I recommend viewing below attached project designed by me. DP400 is a project I started when I was in college and during this topic, I thought I outline a final revision. Initials project name is my name.

Very nice design in did! To sad (to me only) not based on lateral fet. I did read many time Hex fet need high bias to sound good. Has to be biased in Class A..

I didn't tested so these based on another people opinion.


Greetings

[Zen Mod]

in original schmtc lower current mirror (in VAS) is biiiig question mark

[Jay]

Originally Posted by gaborbela

Why I like these circuit? Not very often see on the forum all (lateral) fet schematic!

Some advise would be more constructive than criticism even if that sound positive...

Hehe... You asked why there is little interest. I just tried to give an accurate answer

My advise was to try the Fetzilla thread, for all FET amplifier.

Gabor, think about the truth or logic behind this:

Lateral fets are very expensive. You don't want to put it (two pairs per channel!?) in mediocre circuit.

[wahab]

The input cascode can use bipolars for the upper pair , cheaper and
performing as good if not better than the fets.

Keep the input fets , they can be replaced by recent ones.

There s no advantage on a all fet VAS , using bipolars would certainly
provide better perfs as well as getting rid of problematic availability.

The output stage , well , i wont say nothing about it , i m myself using
those very same laterals, although with a different topology.

[gaborbela]

Hello Jay

I would like to keep these as a high power amplifier, that is the reason for 2pair power mosfet.
Yes I did follow for a while the Fetzilla amplifier great design but how I stated I want higher power amplifier (I have 40-0-40VAC) transformer 700VA.
Yes lateral fets are expensive but sound great in a well designed circuit. It worth that extra cost.
We want to build great amps from cheap devices, I do not say not possible but to me worth that extra cost. I already have them. Renesans produce them $7/device I think that still affordable...

Welcome Zen Mod.

Welcome Wahab
I agree with you 100%! All do 2SK214/2SJ77 and similar fet still available and very good device
I will come up wit a new front end and WAS I hope I get help not negative or discouraging comment.
To exchange the was to bipolar probably I will need help there..
I will try may be we can go forward with these project.

Guys I want to learn, I do not think someone can say he didn't leaned nothing on the forum from other people.

Greetings Gabor

[gaborbela]

Hello wahab

Is these acceptable for front end??

Greetings

[Zen Mod]

may I give you (small ) advice ?

just google for Marantz MA24

(Jaccolina is da Man ; I just adore him , but don't tell him that)