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USSA-5 PCB GB

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#481
Hi manniraj
That voltage should be reduced by maybe 1vdc or more depending on your transfo when under load (with bias of >1A) . +/-27vdc should be OK. Just ensure your heatsink is big enough to handle the resulting added heat to dissipate. If you are using nominal 8 ohms speakers you can reduce a bit the output bias and you will still stay in class A even at max power listening level.

Looking forward to seeing your progress 🙂
Fab
 
Last edited:
#482
fab said:
Hi manniraj
That voltage should be reduced by maybe 1vdc or more depending on your transfo when under load (with bias of >1A) . +/-27vdc should be OK. Just ensure your heatsink is big enough to handle the resulting added heat to dissipate. If you are using nominal 8 ohms speakers you can reduce a bit the output bias and you will still stay in class A even at max power listening level.

Looking forward to seeing your progress 🙂
Fab
Click to expand...

Thanks Fab, yes I think under load it should reduce another 1v or so. I have a 300/150/85 sized heat sinks and I have used the same heat sink for Aleph J as well 🙂 Should be more than enough for this amp build.

Yes I have 8 ohm speakers (Audio Nirvana super plus 8" drivers build) full rangers.
 
#483
fab said:
Yes ECX is single die and ECW is double die Lateral Mosfet. If you look at respective datasheet parameters like ID, yfs, Ciss , Coss and package size talk by itself.
Double die has a big advantage over using 2 single die packages in parallel because you can expect the best possible parameters matching between the 2 internal transistors 😉
In the USSA5 the main advantage is the transconductance of the output that is doubled which can increase furthermore the open loop gain thus at the same time increases the damping factor to the required target value.
The only drawback is the max power handling capability because of smaller area to dissipate heat for double die compared to 2 independent packages🙄

Fab
Click to expand...


Okay! I'll just get ecw and bias them 400ma upwards. I like it a little rough.

I'm burning in the fssa power supply and later pre burn in the front end. Save heaps of electricity cost.
 
#484
New Group buy starting

Hi
After a few inquiries I decided to start a new group buy.
The pcb price will vary based on the order quantity.
As usual, high quality pcb:
2 Oz copper trace
2mm thickness
Gold immersion

The colour (black, blue, green, yellow, white, red) of pcb will be based on the selected one by majority.

Shipping via international airmail and no tracking (unless specifically requested). Usual price varies between 9 to 15$ (Depending on destination) for a pair of pcb

List:
# Name Qty Colour Country State (Only required for USA)
———————————————————————————————————
1


——————————————————-

I also have several preamplifier USSPA pcb available from last ordered batch. This is a stereo pcb at 10$ USD plus shipping.

Thanks
Fab
 
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#491
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 PCB -ANY- UK 1pc of 1pair ?
5. myl any color 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB yellow? HK
 
#492
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 PCB -ANY- UK 1pc of 1pair ?
5. myl any color 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB yellow? HK
8. TomTest - 2 PCB - black - Germany
 
#493
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 PCB -ANY- UK
5. myl any color 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB Any Color HK
8. TomTest - 2 PCB - black - Germany
 
#494
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 STEREO PCB -ANY colour - UK
5. myl any color 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB Any Color HK
8. TomTest - 2 PCB - black - Germany
 
#495
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 STEREO PCB -ANY colour - UK
5. myl any color 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB Any Color HK
8. TomTest - 2 PCB - black - Germany
9. Roundtoit - 4 PCB - red - USA
 
#496
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 STEREO PCB -ANY colour - UK
5. myl any color 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB Any Color HK
8. TomTest - 2 PCB - black - Germany
9. Roundtoit - 4 PCB - red - USA
10. drpro - 2-pcb - any color - USA
 
#497
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 STEREO PCB -ANY colour - UK
5. myl Red 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB Any Color HK
8. TomTest - 2 PCB - black - Germany
9. Roundtoit - 4 PCB - red - USA
10. drpro - 2-pcb - any color - USA
 
#498
Guys,
Due to too many unfinished projects I'd be willing to let go the black PCB's I bought last year.
Also there are 2SJ313Y and 2SK2013Y transistors, 8 of each in matched quartets.
Drop me a PM when interested, preferably from someone close wrt shipping cost.
 
#500
1. hifiramr - 4 pcb - Green - India
2. Pinnocchio - 2 pcb - black - Canada
3. kbhuvi 2 PCB Red - India
4. Brianco 1 STEREO PCB -ANY colour - UK
5. myl Red 4 pcb hk
6. nanakos 2 PCB any color GREECE
7. Arthur 4 PCB Any Color HK
8. TomTest - 2 PCB - black - Germany
9. Roundtoit - 4 PCB - red - USA
10. drpro - 2-pcb - any color - USA
11. mituisho - 4 pcb - black - Hong Kong
 
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