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USSA-5 PCB GB

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G

gary s

Member
Joined 2002
Hi fab,

I am a bit confused as to what pcb does what, in the last few posts you mention the USSA5 and USSA5.2 use the same pcb. What is the difference in the 2 versions. I assume 5.2 is the latest pcb for the mosfet drivers?

Then there is mention of the USSA 5.1 for BJT drivers - have you published info on the BJT circuit and details of which transistors you are using?

In your opinion, which version is the best - maybe a hard question to answer, but I thought I would ask anyway.

Based on your answer, I might change from mosfet drivers to the BJT one.

Regards,

Gary..
 
brianco

brianco

Member
Joined 2005
fab said:
Hi Brian
No you are not too late. Note that the USSA5 and USSA5.2 use the same pcb version.
I thought you already have USSA5 pcb?
Fab
Click to expand...


Hi Fab,

A different 'Brian':)

Yes, I have one set - but want another for a friend, hence my confirmed interest. I take it that the UK postage will be the same as for my USSAPA boards? If so I will add that same sum to my payment.
 
fab

fab

Member
Joined 2004
fabaudio.online
Paid Member
Gary
I am sorry I made a typo. Ussa5.2 should have read ussa5.1 and yes they use the same pcb.
It does not matter which version (5 or 5.1) I am curious who wants to try out version 5.1 with darlington bjt as driver instead of mosfet since I need to update the build manual for this version.. unfortunately I only have one channel mounted of USSA 5.1 so I cannot really test for sound comparison. However, v 5.1 was fully electrically tested fine. I believe that meanie and Vunce Have offered to build the version 5.1 after version 5 to compare.

I will publish the differences in parts between USSA 5 and 5.1 since it will be faster for me than to publish the updated manual (which will be eventually updated).

Fab
 
G

gary s

Member
Joined 2002
Thanks for the update Fab, can you let us know the BJT parts difference before the pcb GB is closed in case I want to change my mind, but as you mention the pcb's are physically the same, so as I understand it there are not 2 different versions of the pcb to suit either the mosfet or BJT driver amp design - is that correct?
 
Bfpca

Bfpca

Member
Joined 2007
fab said:
Hi Brian
No you are not too late. Note that the USSA5 and USSA5.2 use the same pcb version.
I thought you already have USSA5 pcb?
Fab
Click to expand...

Yes, I have the original. Just starting the planning for the heatsinks/power supply/chassis. I’m trying to use parts I have in stock for this build. I want to support your efforts and also to compare BJT vs mosfet drivers going forward.

Brian
 
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