F6 Amplifier

[Rush]

SIT

Could the F6 be built with these devises: 2SK82 and 2SJ28 ?
I bought a pair of each a while back and need a project for them.

Rush

 

[Zen Mod]

probably too much complicated , at least comparing to intended SS ones

difference is that your's are depletion mode devices , needing negative voltage on gate (ref. source) for proper biasing , while SS SJEP are enhanced mode devices , needing positive voltage on gates (ref. source) for proper biasing

meaning - for SS , all you need is few resitors , pots and caps

for your's - you need at least one additional PSU rail , more negative than main -PSU

 

[nicoch58]

Laguna Seca !!

Yess

 

[buzzforb]

Could the F6 be built with these devises: 2SK82 and 2SJ28 ?
I bought a pair of each a while back and need a project for them.

Rush

Ill get to it eventually with R085. As ZM has suggested, we dont know whats going on with bias and any tricks Nelson might be pulling. All smoke and mirrors for now.

 

[Zen Mod]

if you mean on depletion R085 - it's not worth complication , if you ask me

sometime is needed to draw a line in overcomplication

(sez a guy who is Babelfishing Papa's simple amps in something much less simple )

 

[Antoinel]

If I remember correctly, it was Florida. It was the title song to the movie Midnight Cowboy.

Right on!.

 

[tiefbassuebertr]

I have taken up the challenge to try fill in parts of the F6 design before Nelson releases his complete design and specs.
I agree that SPICE doesn't know much about transformers, but at this point I cannot get decent distortion results (less than .01% at 1 watt) even with an "ideal" transformer.

Then you will be disappointed in the F6, as I am not even trying for lower than
0.1% at 1 watt.

For me not the measured results is the benchmark (particularly regarded the value of low order THD), but the perception sonic results by listening tests at various loads (i. e. various loudspeakers).

More Ideas:
The first both topologies about
http://www.ant-audio.co.uk/Theory/N-channel D-MOSFET output stage with improved linearity.pdf
shows a NMOS Power gain output PP stage (common source) and Current gain output PP stage (source follower).
Is this also possible with a passive solution (i. e. by use of a driver transformer, as intended here) ??

 

[Antoinel]

For me not the measured results is the benchmark (particularly regarded the value of low order THD), but the perception sonic results by listening tests at various loads (i. e. various loudspeakers).

More Ideas:
The first both topologies about
http://www.ant-audio.co.uk/Theory/N-channel D-MOSFET output stage with improved linearity.pdf
shows a NMOS Power gain output PP stage (common source) and Current gain output PP stage (source follower).
Is this also possible with a passive solution (i. e. by use of a driver transformer, as intended here) ??

The first two schematics are interesting. The second one describes a linear transconductance amp; noting the general interest in this type of amp.

 

[flocchini]

Please guide me to find the schematic [bolded]. Thank you.

http://www.diyaudio.com/forums/pass-labs/97540-f4-power-amplifier-303.html#post2136036

http://www.diyaudio.com/forums/pass-labs/97540-f4-power-amplifier-340.html

and following

the links above are to different pages in the F4 thread

 

[lhquam]

Then you will be disappointed in the F6, as I am not even trying for lower than
0.1% at 1 watt.

Hmmm. Another misdirection? I think it can do a lot better, depending on the xformer.

 

[Nelson Pass]

Life will be a lot easier if you stop thinking I would deliberately mislead you.

Easier for me....

 

[lhquam]

Life will be a lot easier if you stop thinking I would deliberately mislead you.

Easier for me....

Ok, I will be (partially) silenced until I do better than .1% will the real thing.

 

[Zen Mod]

you can always build Halcro

 

[Antoinel]

http://www.diyaudio.com/forums/pass-labs/97540-f4-power-amplifier-303.html#post2136036

http://www.diyaudio.com/forums/pass-labs/97540-f4-power-amplifier-340.html

and following

the links above are to different pages in the F4 thread

Thank you flocchini. The threads are rich with valuable information.

 

[buzzforb]

You mean you dont have a Halcro, then "your audio system is suffering". Did you know they use industrial grade components? And their lab people where coats. None of this jeans and tshirt stuff. It gives the amplifiers a very clean and precise sound. Take that Nelson.

 

[Variac]

Laguna Seca !!

I think you could stay at my brother's house out Carmel Valley!
Around this time of year he suddenly has a lot of friends!, but he also has a big spread..

 

[jacco vermeulen]

None of this jeans and tshirt stuff.

ZM in a white coat and using less than alien old parts ?
I'm thinking data.

 

[Lazybutt]

Would any of these line matching from James Transformer do the trick ?

·sºô頁1

Looks like JS-251N would be fine , no?

 

[Rush]

Would any of these line matching from James Transformer do the trick ?

·sºô頁1

Looks like JS-251N would be fine , no?

Looks like JS-252N, you need 2 separate secondary windings.

Rush

 

[Zen Mod]

Would any of these line matching from James Transformer do the trick ?

·sºô頁1

Looks like JS-251N would be fine , no?

according to data , yes ;

but!! only if CT means that you can wire them as needed : 150 // 150 : 150 +150 (where + means independent )

will they be better that Jensens .......... just direct comparison can tell