F6 Amplifier

[tordnilsson]

Ooo, why so high as 25 V ? safety or ? I think Ugs is not that high.
/ Tord

 

[6L6]

Safety. If the rail sees ground through the cap, it should not leak. (Of course, other things may be broken... but the caps should be ok.)

 

[tordnilsson]

Ok, so it will work with lower values but on my own risk.
/T

 

[palstanturhin]

The "Diamonds" arrived!

Me love...

 

[buzzforb]

Please let us know your opinion on how diamond compares to Jfet buffer.

 

[Zen Mod]

it'll compare nice , especially if not overdriven

difference to JFet buffer will be more matter of taste , not quality

 

[buzzforb]

That's more nature of question. What is flavor of diamond(BJT) vs Jfet. Up to this point I tend towards Jfet, but they are becoming a sacred cow.

 

[Zen Mod]

if tweaked , THD spectra is pretty close to JFet buffer one

just don't ask how , I would have difficulties to find notes about that ..... not even thinking of remembering

spice it a little , it's easy to duplicate what my two cells achieved then .....

 

[palstanturhin]

Please let us know your opinion on how diamond compares to Jfet buffer.

You see the difference in the post 6061
http://www.diyaudio.com/forums/pass-labs/216616-f6-amplifier-607.html#post4318753

Can not comment the sound in any other way than:
It is excellent!

Will get the THDs tomorrow.

First impression however is,
folks, its pretty good now...
I could not make the F6 better than this.

 

[anilva]

I just noticed after many months of use of my F6, that it has the tendency for the output to swing little bit on offset, making my full ranger to go back in terms of cone movement and then settle back. Is it normal for F6 to behave like this, or did my power supply alter it's behavior off-late. Don't know what it is because, I did not notice before.

Thanks in advance.

My problem continues in one channel only, where the output has a big swing before settling in. Could it be a problem with C1 or C2 (1000 mfd) caps? The power supply capacitor bank is common and does not seem to be the problem as the other channel is behaving well at startup.

There is absolutely no problem in sound reproduction, gain or any other matter.

Thanks in advance.

Cheers.

 

[Zen Mod]

That's more nature of question.....

if tweaked , THD spectra is pretty close to JFet buffer one .......

aha

recollected some memory mist

more juice ( those 10K to 3k3 or even lower) and cascoded input critters

also - cascode modulation , but sadly possible only in balanced , due to needed (anti)phase

few more details , but I'm getting older and older

 

[buzzforb]

Who needs spice. I have Choky and soldering iron.

 

[labjr]

Would be nice if the diamond buffer performs as well as the JFET circuit with detail retrieval etc.

 

[Zen Mod]

something as this - not just spiced but also tried many moons ago ( while I was playing with Poor Serbian Man NEM AI-50)

I just made sim by memory , but that was it , I believe

THD spectra - 4M No, of data point samples , 7 points , Hamming , no compression

frankly , not exactly as sweet as JFet complementary buffer , but pretty decent ..... and there is iron for sweetening things

I tried CCS-es instead of 3K thingies , but my ears are not in Generg's league ...... so I didn't heard positive step in that

 

[palstanturhin]

..... and there is iron for sweetening things

Like BC550/560...

;-)

 

[nicoch58]

Who needs spice. I have Choky and soldering iron.

 

[Zen Mod]

something as this...

another crumb from memory ( seeing 1uF on recent schematic mislead me )

C was 10u and upwards ... now different , mucho .....

in fact , I put there 470uF Elna (having them around always ) but 10uF was confirmed as minimum for pleasantness

cascode output ones or not , your call

 

[buzzforb]

Use organic polymer if you can and its anywhere near signal, which I believe it is.

 

[Soundhappy]

Thanks New Record Day for First Watt F6 review video:

https://www.youtube.com/watch?v=pdw7esZBbXE

Have fun

 

[labjr]

Thanks New Record Day for First Watt F6 review video:

https://www.youtube.com/watch?v=pdw7esZBbXE

Have fun

I guess the F6 he reviewed was the newer one with IRF MOSFETs?