PeeCeeBee

[shaan]

After some days listening with Olafs clever 1.0 boards i enjoy more the simple vssa.

What is the reason to add 1 Ohm resistors in V3?- i think it's written here and sorry for asking again.

Nothing fancy. The four 1R resistors act as sleek-looking jumpers! 😎

 

[brunogiovs]

Hello , I have some BD140G and BD139G, so I was trying to match then.
but the hfe is very apart like more the 100 of difference.

do you guy have any tips on how to match then?

Thanks

 

[shaan]

Hello brunogiovs.

A VAS hFE difference of up to 50 is okay. Simple hFE checking with meter will be sufficient.

If possible try to get MJE340G/350G instead of BD139G/140G.

 

[brunogiovs]

Hello brunogiovs.

A VAS hFE difference of up to 50 is okay. Simple hFE checking with meter will be sufficient.

If possible try to get MJE340G/350G instead of BD139G/140G.

thanks.. how many you guys buy to match 2 pairs?

 

[shaan]

The Onsemi-made G-suffix MJEs come in fairly consistent hFE of between 140-170. So you may go for 4 pairs and get 2 pairs with close enough gain for the purpose.

 

[brunogiovs]

The Onsemi-made G-suffix MJEs come in fairly consistent hFE of between 140-170. So you may go for 4 pairs and get 2 pairs with close enough gain for the purpose.

Thanks. and how about your experience with the BCs ( 560/550 ... )? 3x more is safe to find matched pairs?

 

[shaan]

The C-suffix ones routinely measure over 550 hFE and are very consistent. So I don't think you'll need to buy 3X. But if budget allows then I'd suggest that you get 3X, then measure and choose the best couple pair. 🙂

 

[brunogiovs]

The C-suffix ones routinely measure over 550 hFE and are very consistent. So I don't think you'll need to buy 3X. But if budget allows then I'd suggest that you get 3X, then measure and choose the best couple pair. 🙂

thanks

 

[brunogiovs]

You can use them in PeeCeeBee without any problem! 🙂

edit: PeeCeeBee doesn't have gate ESD protection zener diodes as the 1058/162 pair MOSFETs have them integrated. If you use the MOSFETs you mentioned then add 12V zeners between gate and source of each device.

Thanks I will keep in mind. I ordered v3 pcbs using the gerber files.. thanks again.

 

[masood251]

Hi Friends.

Here goes the PDFs for the new V2 layout.

Cheers and happy building!!!

🙂
shaan

Hi shan
Your pdf is invalid fomat sed valid format thanks

 

[meanman1964]

some gerber files
at post #2205

 

[shaan]

Your pdf is invalid...

Here are the Gerber files for V2 Rev2 PeeCeeBee. Minor change - some components have been corrected with more sensible values.

These have been checked with gerber-viewer.com's online viewer and seemed okay to me. If anyone finds a mistake, let me know.

Happy DIYing to all.
shaan
🙂

 

[thimios]

Hello people!

A new amplifier has been cooking for some months and a few days ago was finalized. By design it is a detour from our beloved "PeeCeeBee" design. A perfboard version is playing music and tones right now and all I can say is that electrically and sonically it is the step forward for the simple design that has been rocking for the last four years.

The new design is "marginally" complex, uses basic LED biased active CCS, all small signal transistors the easy to access BC556B/546B, emitter-follower VAS with current limit and diode-clamped soft-ish clipping with much less HF distortion than usual, uses input inclusive compensation in addition to usual Miller compensation, produces ~100V/us slew rate, lower overall THD, MUCH less low frequency distortion and MUCH higher damping factor at LF.

I have ordered a couple prototypes of the initial layout. The board would look kind of like the picture (with what Kicad calls "black" mask 😀 ). The PCB is 2 layer PTH. The full test results, schematic and layout will be uploaded in the new thread.

Hi Shaan what about the new PeeCeeBee?

 

[shaan]

Hi Shaan what about the new PeeCeeBee?

😉

 

[brunogiovs]

I haven't better way copper protection....this is a diy pcb.
BTW The first PeeCeeBee absolutely hum free! The separate inp GND connection do the job well.
I want to thank member <<coolwater>>,many of the parts on this the board is from his own donation🙂

Hello Thimios , what kind of load you had during your tests? and what rms power... or vpp?

 

[brunogiovs]

Question about V3.

Where you guys find a good 2.2k trimmer that fits well on the pcb ?

Thanks
I found this one it might fit :
T7YA222MB40 VISHAY, TRIMMER, POT, 2K2, 1TURN, THD, Newark element14 Canada

 

[thimios]

Hello Thimios , what kind of load you had during your tests? and what rms power... or vpp?

7X1R 17W Resistors in series.

 

[brunogiovs]

7X1R 17W Resistors in series.

thanks

 

[shaan]

Question about V3.

Where you guys find a good 2.2k trimmer that fits well on the pcb ?

Thanks
I found this one it might fit :
T7YA222MB40 VISHAY, TRIMMER, POT, 2K2, 1TURN, THD, Newark element14 Canada

There are extra pads added in the layout for 3296 type multi-turn trimmers. 🙂

 

[brunogiovs]

There are extra pads added in the layout for 3296 type multi-turn trimmers. 🙂

thanks