Please take 1 look at the schematic. It's in the first post. 😉
Thank you.
Edit: in your service: Here, the schema->
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O yeaa... my second channel singing 🙂
Input tr sa970/sc2240
Input bias 13.9 mA
Dc offset 3.5mV
Final bias 100 mA
Congrats naf.
Remove that 470ohm parallel to the diodes and you'll get ~170mA. 🙂
Yes. Removing it will set the bias to that with the two diodes, i.e. about 170mA.
happy listening
shaan
Interesting idea to mount them on top of each other, only that you would have to instal proper U-shape Al profile in between them, to ensure adequate heat dissipation (1 W) for TO-126 BJTs. 😎
Hi borys.
For multilayered layout and different schematic than the one posted in the first post, please use the VSSA thread.
Thank you.
shaan
Hi Shaan,
VSSA PeeCeeBee now is singing beautifully. Sound absolutely great. Vocal are very clear and detailed. Sound quality better than my Denon 1908 avr.
I used 2sa970 and 2sc2240. I don't have BC transistor.
Power supply +-35V from scrap component
DC offset 0.0volt. I parallel 10k and 47k to 1000uf capacitor in V+ side. It is ok shaan to put it there? Please comment. You can see to Tester.
Bias? I don't know how to check.
I put resistor in PCB bottom. I don't have a drill. Only capacitor and transistor in the top.
Thank you very much LC and shaan your great amp.
Edit: How can I upload the image?
Thank you.
Boyet
VSSA PeeCeeBee now is singing beautifully. Sound absolutely great. Vocal are very clear and detailed. Sound quality better than my Denon 1908 avr.
I used 2sa970 and 2sc2240. I don't have BC transistor.
Power supply +-35V from scrap component
DC offset 0.0volt. I parallel 10k and 47k to 1000uf capacitor in V+ side. It is ok shaan to put it there? Please comment. You can see to Tester.
Bias? I don't know how to check.
I put resistor in PCB bottom. I don't have a drill. Only capacitor and transistor in the top.
Thank you very much LC and shaan your great amp.
Edit: How can I upload the image?
Thank you.
Boyet
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Hi boyet!
That's great news! enjoy...
Yes it's okay.
Connect the power supply with a 1ohm/1w resistor in series, in both + and - rails. Set the multimeter to mV and place the probes around one of the 1ohm resistors. Turn on the amplifier. The reading you see in the meter is the total bias. 🙂
Your pleasure our pleasure.
Click "go advanced" below, in the reply page click on "manage attachments", a small window with a lot of "browse" buttons will show up, click one of those buttons, select the file you want to upload and click open(do the same for more than one file, in the other blank "browse" buttons), click "upload", wait for it to upload, close the small window when the uploaded filename is shown in the main window. That's it.
happy diying & happy listening
shaan
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BRAVO!!! 
edit: boyet, that's possibly the roughest VSSA job I have seen so far, but you deserve applause for successfully making it sing, and also to beat your Denon!
Congrats!
shaan
edit: boyet, that's possibly the roughest VSSA job I have seen so far, but you deserve applause for successfully making it sing, and also to beat your Denon!
Congrats!
shaan
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Decided to try the Spark free layout software, and this is how far I got with my layout. I am basically using the circuit layout posted by Shaan as a guide.
The board is about 100x65 mm, which is intentional, so has plenty of room.
Added a couple pots since I have room for them (easily left off if not needed later). Some component sizes and capacitor pin spacing still need checking.
Not sure how much room to allow for heatsinks. Layout shows drivers mounted on a single wide and narrow heatsink.
Comments welcome.
The board is about 100x65 mm, which is intentional, so has plenty of room.
Added a couple pots since I have room for them (easily left off if not needed later). Some component sizes and capacitor pin spacing still need checking.
Not sure how much room to allow for heatsinks. Layout shows drivers mounted on a single wide and narrow heatsink.
Comments welcome.
Attachments
Hi PMI.
Cool layout! And seems error free to me. Parts placement is good too. Just a little more thickness for the ground track will be good.
Cool layout! And seems error free to me. Parts placement is good too. Just a little more thickness for the ground track will be good.
Thanks. I have room to make it wider. Maybe go to 4 mm. Nice job on the original layout, can appreciate it better now since I actually followed all of it, LOL.Hi PMI.
Cool layout! And seems error free to me. Parts placement is good too. Just a little more thickness for the ground track will be good.
Any suggestions on the heatsink? Do you think thermal coupling the drivers will make any difference here?
BRAVO!!!
edit: boyet, that's possibly the roughest VSSA job I have seen so far, but you deserve applause for successfully making it sing, and also to beat your Denon!
Congrats!
shaan
Sorry shaan, I'm beginner in using toner transfer method. Yes it beats my Denon!
I set my Denon in Direct mode and set up my vssa with same speaker. vssa is very clean compare to Denon.
I only use 2 4700uf in power supply. Shaan, is there improvement if i used recommended power supply?
Thanks,
Boyet