Hi
Yes it should sound fine. This is pretty much the same as my USSA-1 except I had used output mosfet designed for audio ( not switching ) and used current sources instead of resistors to bias input stage. For me USSA-1 sounded better than my F5.
If you want something even more breathtaking still with bjt input see the USSA-5.x amp series. The USSA-5 with its very low degeneration on mosfet provides a greater class A envelope for the same bias. Latest 5.2 version uses all easy to find parts.
USSA-5 PCB GB
USSA-5 Build with Review
Fab
Yes it should sound fine. This is pretty much the same as my USSA-1 except I had used output mosfet designed for audio ( not switching ) and used current sources instead of resistors to bias input stage. For me USSA-1 sounded better than my F5.
If you want something even more breathtaking still with bjt input see the USSA-5.x amp series. The USSA-5 with its very low degeneration on mosfet provides a greater class A envelope for the same bias. Latest 5.2 version uses all easy to find parts.
USSA-5 PCB GB
USSA-5 Build with Review
Fab
Attachments
Last edited:
> USSA-1 sounded better than my F5
Did I read correctly that your V5.2 has THD of 0.0075% at 1W 1kHz into 8R ?
And what distortion did you get from your F5 ?
If I am not wrong, the First Watt F5 has corresponding THD at 0.0013%.
And a random F5X build has H2 0.0006%, H3 0.001% at 1W 1kHz into 8R.
May be the latest trend is "higher distortion sounds better".
Cheers,
Patrick
Did I read correctly that your V5.2 has THD of 0.0075% at 1W 1kHz into 8R ?
And what distortion did you get from your F5 ?
If I am not wrong, the First Watt F5 has corresponding THD at 0.0013%.
And a random F5X build has H2 0.0006%, H3 0.001% at 1W 1kHz into 8R.
May be the latest trend is "higher distortion sounds better".
Cheers,
Patrick
Hi EUVL
I am not sure why you compare THD with appreciation of sound…..
Please don’t post in the tube amp section
I had not measured my F5 before I sold it unfortunately. I know many peoples liked its sound at an DIY show.
Appreciation of sound is personal and sorry if I have offended you…
Anyway, see my USSA-3.2B with lower distortion - if that matters - which design is jfet input such as F5 but with bjt output. It has lower THD and is not better sounding but just different sound than the USSA-5.2.
In fact USSA-5.2 was tuned to have such H2. H2 can be adjusted with P3/P4 to be as low as H3 or even lower.
My class AB designs have lower THD also and they sound different but not better.
USSA-5 PCB GB
Fab
I am not sure why you compare THD with appreciation of sound…..
Please don’t post in the tube amp section
I had not measured my F5 before I sold it unfortunately. I know many peoples liked its sound at an DIY show.
Appreciation of sound is personal and sorry if I have offended you…
Anyway, see my USSA-3.2B with lower distortion - if that matters - which design is jfet input such as F5 but with bjt output. It has lower THD and is not better sounding but just different sound than the USSA-5.2.
In fact USSA-5.2 was tuned to have such H2. H2 can be adjusted with P3/P4 to be as low as H3 or even lower.
My class AB designs have lower THD also and they sound different but not better.
USSA-5 PCB GB
Fab
Last edited: