PeeCeeBee

[Sidebyside]

Thanks again John .
Has anyone test with these fets. 2SK1530 & 2SJ201?
Thanks.

Many thank to you. I will do follow your comments

 

[PMI]

Hi PMI very good results!
Is this from version of page ?http://www.diyaudio.com/forums/solid-state/231662-peeceebee-40.html#post3490152
post#393?
Regards.
Thimios.

No, but very similar.

 

[PMI]

Hi Pete, I wish I have a scope too...
Can you try it with higher than 47pF or lower than that...
that might very interesting to know, by me at least
I use 33pF by now (was 22pF)I plan on trying lower, 22~24pFd

You have a very different board now, with two output pairs. So it is difficult to give advice when I have not tried it. My guess would be to try the 100pF.

 

[bimo]

My VSSA PCB.

 

[thimios]

peeceebee

No, but very similar.

Is this new pcb for sharing ?

 

[PMI]

Yes,

 

[thimios]

peeceebee

Yes,

Ok Sir
Waiting for this pdf!

just now i see this.http://www.diyaudio.com/forums/solid-state/244903-another-through-hole-vssa-build-thread.html
Good luck at this new travel.

 

[JOHN BALI]

Will try

So I will try my newest PeeCeeBee... http://www.diyaudio.com/forums/solid-state/231662-peeceebee-136.html#post3669805

this is the simplest one I think
I hope can made it soon, comparison is waiting

 

[JOHN BALI]

One day latter
will share the pdf when it is tested

 

[Rick G]

newest PeeCeeBee

Looking Good John. Now for the Sonic impression.

 

[thimios]

vssa

One day latter
will share the pdf when it is tested

Waiting results!

 

[PMI]

...
I hope can made it soon, comparison is waiting

Nice job! Are you building these from the original schematic in this thread?

 

[JOHN BALI]

Nice job! Are you building these from the original schematic in this thread?

Hi Pete, I'm planning build the another through hole version too
with more parts count

Yes, it is basic Shann's PeeCeeBee and only additional caps 22pF on vas
68 ohm on J162's gate, 15k offset now with series trimmer so it is so easy to zero the offset.
I will post the BoM that I use, with alternatives substitution.
Also it is nice idea to post schematic with value, I will take Shaan schematic & add the missing value & I hope he doesn't mind
(where is Shaan btw ? anyone knows?)

I have quick test them & the offset is low but not connected to speakers yet
cos I know it is all fine
(need some flux cleaning)
Tomorrow it will sing I guess now is late night here

Regards

 

[Mihkus]

One day latter
will share the pdf when it is tested

John , Id really like to give it a try!

Tell us how it sounds?

 

[DAMANHURI]

One day latter
will share the pdf when it is tested

Power is nice and I like the symmetrical arrangement.
incredible

 

[jaagut]

One day latter
will share the pdf when it is tested

hi john,

i'm going to build your second pcb iteration.
this time with premium parts too.

 

[thimios]

vssa

Hi Pete, I'm planning build the another through hole version too
with more parts count

Yes, it is basic Shann's PeeCeeBee and only additional caps 22pF on vas
68 ohm on J162's gate, 15k offset now with series trimmer so it is so easy to zero the offset.
I will post the BoM that I use, with alternatives substitution.
Also it is nice idea to post schematic with value, I will take Shaan schematic & add the missing value & I hope he doesn't mind
(where is Shaan btw ? anyone knows?)

I have quick test them & the offset is low but not connected to speakers yet
cos I know it is all fine
(need some flux cleaning)
Tomorrow it will sing I guess now is late night here

Regards

Hi John
What about first fire?
Waiting for pcb pdf!
My silicon chip 20W class A is already speaking!

 

[jaagut]

by the way, is there any speaker protect scheme recommended for this amp?

thanks.

 

[JOHN BALI]

Ok, teasted

Hi, this PeeCeeBee has been tested...
This is the schematic with value, the top & also bottom layout.
PeeCeeBee size is 80 x 60 mm
The input cap is out the board , choose your favorite.

The optimal bias for the Latfet is 160mA + 10mA for VAS + less than 3mA for input pair so if total 175mA current for one channel it is good...
Today I power it up with +/-35VDC, with only 15k resistor I got 200mA total current.
So it is about 176mA quiescent current, this make them hot...
So I try measure at 10 ohm VAS transistor shows 230mV = 23mA for the transistor & it is not good (too much current).

Then I lower the voltage at +/-32VDC & I have better feeling on this
Total current is 177mA
Bias = 161mA
VAS = 13mA
At 15k resistor is optimal at +/-32VDC (for my set up)
maybe you get another measurement.

Then I put the two 1k trimmer, now it so easy to get zero offset.
When the offset is negative turn the positive side trimmer(increase value) to make zero offset. I'm play with this, try to decrease one 1k & increase another got 99mV offset

With 16k "offset" resistor & +/-35VDC
Bias = 174mA
VAS = 18mA
So I need more than 16k if I use +/-35VDC to make it optimal.

Enough for now,
I thing somebody want to make this PeeCeeBee too...
please enjoy & let me know if it is not work on your building

About the sound it is PeeCeeBee sound , not connected to my big speakers yet
I thought my previous one sounds better, this one is good too but I feel something is missing.
I start to think the capacitor effect, I don't make a re-forming for the 2200uF caps (maybe I should try to replace them)
I try different caps here but I still have like the one I used before.
Also I add cheap input capacitor, this could be make the sound feel different.
Please take a good quality one at the input caps & don't make it direct coupled.


Regards

 

[thimios]

peeceebee

Thans john.
My next project?
Maybe but i haven't fets...