I am glad there is someone else here who likes to have at least a bit of space around hand-assembled components. (It was starting to feel a bit drafty... 😀)Link to Daman's layout added.
Who's next?
I've been thinking about tweaking my layout so the board can use the double-die higher power devices from Exicon or Profusion. Not the complementary pair Alfets like LC, just the 3-terminal packages with two dies inside.
How is your new layout going?
Yeah a space-y peeceebee is very good to assemble and mod. 🙂
You are most welcome!
The dual SK/SJ? Not complete yet. I'll get back to the editor next week. A bit busy with the current boards. I think I'll print a few pieces of the dual FET thing too. Seems good for my soon-to-be-born 2ohm sub with +/-28VDC.
shaan
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I can not explain right now, because I'm using improvised part, I will explain when all the parts are in upgrate. while this is what I hear pretty clear and solid bass sound and I love the soft power is symmetrical.
Added pictures of finished boards from Pete, Jason, Dobrivoje, John and Daman.
Thanks again for your contribution. You guys rock.
Thanks again for your contribution. You guys rock.
Have anyone modify the output stage to drive headphone with +-15V power supply, maybe class A? Soon, i will try Peeceebee with and without CCS. I design PCB that can use both version.
Hi bimo!
Welcome to the thread.
There is not too much to modify at the output stage.
For +/-15V you need to do the following:
1: Decrease the current-source resistors to get a VAS bias of around 20mA.
2: Insert another 4148 diode in series with the existing ones in the output bias node to get ~1A of FET current.
BTW, I think even a bias of 200mA will be enough Class-A for headphones.
All the best.
p.s.- Please post CCS related stuffs in the original VSSA thread. Thanks.
Hi Bimo,
+-15v
I used 4.7k instead of 15k.
I used 22omhs instead of 10 omhs
100/4.3k feedback resistor
Result? Sounds great. The bass is solid and I loved it.🙂🙂 You must try it.🙂
Regards,
Boyet
The new double FET layout will have the VAS bjts aligned so that they can be mounted to the main heatsink along with the FETs. Also a variation is being designed for VAS bjts with separate small heatsinks or one plate type heatsink for two trannies with two pads to short the hs to both the upper and lower ground track. There will be a loop in the ground node, but outside the input/feedback network.
I am thinking of a separate connection for input and feedback ground, a faston tab near the inputs, which will be connected to the star ground with a separate wire presenting a clean reference to the input and feedback signal(s). Of course there will be provision to install a ground lift resistor, which can be replaced with a jumper if not necessary.
Please comment.
I am thinking of a separate connection for input and feedback ground, a faston tab near the inputs, which will be connected to the star ground with a separate wire presenting a clean reference to the input and feedback signal(s). Of course there will be provision to install a ground lift resistor, which can be replaced with a jumper if not necessary.
Please comment.
Thanks for the comment naf.
Here are some more details:
Board dimensions: 5" x 2.5" (127mm x 63.5mm)
Hole/Pad distances for components as follow,
PS decouple caps: 0.4" (10.1mm) and 0.3" (7.6mm) for electro and 0.2" (5mm) for film types.
Zobel cap: 0.2"
Input cap: multiple from 0.2" upto 1" (25.4mm)
RF filter cap: 0.2"
Compensation caps: 0.2"
Feedback caps: 0.2" and 0.3"
VAS supply decouple caps: 0.3"
Resistors: all 0.4" (10.1mm) except zobel resistor which will be 2W vertical-mount and have pads 0.2" apart.
Diodes: 0.3" for 1N4007s and 0.2" for 1N4148s.
Here are some more details:
Board dimensions: 5" x 2.5" (127mm x 63.5mm)
Hole/Pad distances for components as follow,
PS decouple caps: 0.4" (10.1mm) and 0.3" (7.6mm) for electro and 0.2" (5mm) for film types.
Zobel cap: 0.2"
Input cap: multiple from 0.2" upto 1" (25.4mm)
RF filter cap: 0.2"
Compensation caps: 0.2"
Feedback caps: 0.2" and 0.3"
VAS supply decouple caps: 0.3"
Resistors: all 0.4" (10.1mm) except zobel resistor which will be 2W vertical-mount and have pads 0.2" apart.
Diodes: 0.3" for 1N4007s and 0.2" for 1N4148s.
Shaan , according the issue on 10ohm smoked resistor after dioda on vssa thread... would you mind if make multihole incase someone want to install at leat 1/2 or 1 watt resistor (i do it in my last peeceebee build by installing 1/2 Watt)