Hi Alex
I see that you have made a new revision of the pcb (v 0.5) 🙂
What are the enhancements?
This small power amplifier is not really meant to perform that well for a subwoofer application compared to other amps since the damping factor is not very high....
Also, have in mind that the specific caps shown on the pictures are not as per the official BOM. You may get a different performance and/or sound...
Nichicon type (as indicated on the pcb ?) for Caps are usually not with very low ESR in general compared to Polymer caps...
Good luck with your build!
Thanks
Fab
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Ok, thanks for notifying. what is the minimum damping factor you have experienced satisfactorily for a subwoofer and what subwoofer design type is less affected by low damping factor?
Fab
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Again it depends on the woofer. I expect that a woofer could be designed that is happen with a current amp — damping factor <1.
dave
dave
Wow ! that is a very low damping factor value.
The ussa5 has a damping factor of about 30 to 35 for 8 ohms load (measured at 100 Hz).
What I really meant is that its main attraction is the wide and deep soundstage but in a low frequency application such a subwoofer it would not show...🙄
Fab
Any damping factor of about 20 or higher is pretty much the same once you connect a speaker with speaker wire.
dave
dave
Hi, when you get the boards? they are better than Borberly originals pcb
Best Regards
Hi Dave,
I would put that number up to somewhere in the 60 to 100 range depending on variables.
-Chris
I would put that number up to somewhere in the 60 to 100 range depending on variables.
-Chris
Dummy Load
Got fed up with my scruffy old, ad hoc, dummy load so I decided to build a more durable one. Does 4ohms ( 200W ) or 8ohms ( 400W ), with either 0.1uf, 1uf, or no capacitor in parallel. Monitor output is selectable from directly across the load or via a 10:1 attenuator.
Got fed up with my scruffy old, ad hoc, dummy load so I decided to build a more durable one. Does 4ohms ( 200W ) or 8ohms ( 400W ), with either 0.1uf, 1uf, or no capacitor in parallel. Monitor output is selectable from directly across the load or via a 10:1 attenuator.
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Yeh, a thermal cut out would be a good addition for soak testing powerful amplifiers. Thanks for the idea; simple to add so I might just do it.
