Another USSA-5 Build and Review

[bvtrinh]

Just like ggetzoff, I had read sparse reviews about the USSA-5 here and there but from what I read, piqued my interest. I contacted Fab to see about purchasing a pair of boards but was saddened when he informed me he did not have any boards for sale. Instead, he kindly offered to give me a pair of boards with only one condition: I build and provide a review of the amp. I have been occupied by other things and have not kept to the timeline I agreed to. That changed after I saw ggetzoff’s post which reminded me to stop being lazy and complete the amp. I just need to complete the power supply in order to test the amp modules per instructions. Then I need to finish the chassis, get it powder coated, finally assembly and review!

Here the boards have been assembled for a few months now. I also have it on the heatsinks.

 

[e_fortier]

Looking forward for your review.

I had the chance to deal w Fab on many occasions and he’s a very generous and kind person.

Good luck w your amp.

 

[poseidonsvoice]

Hi!

Looking good! Love the heatsink color!

What are the diameters of the test point holes on these pcb’s? 0.040 inches or 0.062 inches?

Thanks,
Anand.

 

[fab]

Hi
Thanks for interest and post

You seem to have nice and big heatsinks which makes it perfect to increase bias furthermore and especially if you have 4 ohms speakers to increase class A power. Or you can also slightly increase PSU voltage to get a little more power in class AB.

From your pictures I seem to notice a possible mistake for P2 and P4 which value seem to reversed. P2 should be 10k (103) and P4 should be 1K (102).

Remember that if you follow the manual and test each mounted section (CCS, input stage, medium stage, output stage) one at a time you normally get a working amp board at end of test procedure. Step-by-step testing makes it easier I believe.

Looking forward to seeing the final assembly (internal and outside).

Good luck
Fab

 

[zman01]

Nice to see another USSA 5 build underway. And the color of the heat-sinks should make for a pretty distinct looking chassis.

Good luck with the build and keep the updates coming.

 

[bvtrinh]

Hi!

Looking good! Love the heatsink color!

What are the diameters of the test point holes on these pcb’s? 0.040 inches or 0.062 inches?

Thanks,
Anand.

Hello and thank you! I’m not sure how big the holes are. The pins I soldered on wobbled in the hole prior to soldering. Perhaps Fab or someone can chime in.

Bao

 

[bvtrinh]

Hi


From your pictures I seem to notice a possible mistake for P2 and P4 which value seem to reversed. P2 should be 10k (103) and P4 should be 1K (102).


Looking forward to seeing the final assembly (internal and outside).

Good luck
Fab

Hello Fab,

They are definitely reversed! Thank you for the catch! I’m at the point in the manual where I start adjusting the current sources and am glad you noticed that before I proceeded.

I probably will run higher bias and see how it sounds!

Bao

 

[Project16]

Hi!

Looking good! Love the heatsink color!

What are the diameters of the test point holes on these pcb’s? 0.040 inches or 0.062 inches?

Thanks,
Anand.

The test point holes are of diameter 0.040 inches.

 

[pinnocchio]

Those are nice big heatsinks! You should be able to go for 1.3A

Congrats on your build!!

Do

 

[Hicoco]

Hello and thank you! I’m not sure how big the holes are. The pins I soldered on wobbled in the hole prior to soldering. Perhaps Fab or someone can chime in.

Bao

Hi bvtrinh, nice and congrats could you share the test point type or post a link were you find it,
Thanks
FR

 

[bvtrinh]

Hello and thank you! I believe I purchased it here: Lot of 20 SAMTEC TS-109-G-C HEADER SIP VERT 9 PIN SOLDER FORK TERM .1C GOLD | eBay