Progress on USSA 5.1
Tested and work ok. Still working on adjustment but at first sight I should be able to tune the damping factor at least the same or even higher than the original USSA 5.0...🙂
Stability seems ok too.
Fab
Tested and work ok. Still working on adjustment but at first sight I should be able to tune the damping factor at least the same or even higher than the original USSA 5.0...🙂
Stability seems ok too.
Fab
USSA 5.1
USSA 5.1 Initial THD testing seems to show similar profile as the USSA5...🙂
But I need to test with a better PSU now...
Fab
USSA 5.1 Initial THD testing seems to show similar profile as the USSA5...🙂
But I need to test with a better PSU now...
Fab
Doh! Can't find my BD550C's. I know I bought them because I checked the order sheet. Have to see if I used them on something else?! Got the BD560s OK.
Still not all is lost because in the process of looking for them I took the time to inventory all my parts - a job that has been waiting too long - now I can just look at my spreadsheet knowing that finally it reflects what I have inside my boxes.
Still not all is lost because in the process of looking for them I took the time to inventory all my parts - a job that has been waiting too long - now I can just look at my spreadsheet knowing that finally it reflects what I have inside my boxes.
Thanks FAB for the 5.1 testing.
Building my SLB ps now, hope it can improve USSA5 even further.
Building my SLB ps now, hope it can improve USSA5 even further.
Im prepare for ordering parts
EKMH350VNN333MA63T United Chemi-Con | Mouser Greece
33000 uF
ESR:
12 mOhms
Ripple Current:
5.6 A
I should go higher about Ripple Current ?
ESMH350VNN333MA63T United Chemi-Con | Mouser Greece Non stock
Factory Lead Time:
22 Weeks
My speakers are 4Ω 300W 93db
I would like your opinion...Τhanks
EKMH350VNN333MA63T United Chemi-Con | Mouser Greece
33000 uF
ESR:
12 mOhms
Ripple Current:
5.6 A
I should go higher about Ripple Current ?
ESMH350VNN333MA63T United Chemi-Con | Mouser Greece Non stock
Factory Lead Time:
22 Weeks
My speakers are 4Ω 300W 93db
I would like your opinion...Τhanks
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Hi nikosokey
You can use the 5.6 A but I have tested with 7A ripple current. Maybe other builders have tested with lower ripple current🙄 it would work with much less ripple current but it is a matter on how good you want your psu....😉
For the first cap of the CRC you can use lower ESR and ripple current than the second cap.
Fab
You can use the 5.6 A but I have tested with 7A ripple current. Maybe other builders have tested with lower ripple current🙄 it would work with much less ripple current but it is a matter on how good you want your psu....😉
For the first cap of the CRC you can use lower ESR and ripple current than the second cap.
Fab
I would like to build 2 x monobloc SLB ps.
Still sourcing my toroidal transformers
Any suggestions on VA rating and sec voltage for above application?
RS components doesn't have 22v+22vac model.
Still sourcing my toroidal transformers
Any suggestions on VA rating and sec voltage for above application?
RS components doesn't have 22v+22vac model.
meanie,
As far as I know Antek have ready stock of 2 x 22V toroidal transformers. They will probably ship from the US which will result in some shipping/postage cost - however their transformer prices are lower vs others in most cases, so total cash outlay from your side might end up being close.
As far as I know Antek have ready stock of 2 x 22V toroidal transformers. They will probably ship from the US which will result in some shipping/postage cost - however their transformer prices are lower vs others in most cases, so total cash outlay from your side might end up being close.
Curious too to know if using the SLB makes a difference (on the good side) with the USSA5. If yes, I'm in for an SLB for sure.
I want to power ussa 5 with 15v dc. Is there anyone can tell me current value (with safety margin/peak current) for powersupply.
This is push pull class A so it can go in class AB too. So it depends on your target power in class A and the speaker load impedance.
Fab
Fab
Why do you want 15v rails? The class A output with the target rail v-range is more than enoght in small to medium size rooms with your loudspeaker efficiency.
Hi nikosokey
I had written a long response but waited too long and it expired so I lost everything😡
. With 1.25A bias current at about +/-24vdc you get in theory 25Wrms class A in 8 ohms and half of that power in class A in 4 ohms. But you get more power in class AB because of your 4 ohms (50Wrms) provided that your psu is capable of delivering it, thus maybe more 40wrms.
With 93db and 4 ohms I would use the same psu parts rating as indicated in the manual but you can reduce psu voltage and increase bias current accordingly to get same heatsink power dissipation. This way you get less max power in class AB (which you probably do not need) but more power in class A.🙂
Having said that the power in class A is more than indicated in reality because of the square law effect of the output mosfet which is increased because of the very low degeneration.
For example with +/- 20 vdc and 1.5A bias you get same heatsink dissipation as with +/-24vdc and 1.25A bias. This gives 18wrms in class A (theory) but probably 25Wrms class A because of previous explanation.
Fab
I had written a long response but waited too long and it expired so I lost everything😡
. With 1.25A bias current at about +/-24vdc you get in theory 25Wrms class A in 8 ohms and half of that power in class A in 4 ohms. But you get more power in class AB because of your 4 ohms (50Wrms) provided that your psu is capable of delivering it, thus maybe more 40wrms.
With 93db and 4 ohms I would use the same psu parts rating as indicated in the manual but you can reduce psu voltage and increase bias current accordingly to get same heatsink power dissipation. This way you get less max power in class AB (which you probably do not need) but more power in class A.🙂
Having said that the power in class A is more than indicated in reality because of the square law effect of the output mosfet which is increased because of the very low degeneration.
For example with +/- 20 vdc and 1.5A bias you get same heatsink dissipation as with +/-24vdc and 1.25A bias. This gives 18wrms in class A (theory) but probably 25Wrms class A because of previous explanation.
Fab
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