See this post for an Alpha 4R version with lower bias.
- 4R compatible: 1.94A bias + FB shunt resistor of 1.8K
- ground lift for the input signal
- FB divider 50R-50R to double the damping factor, gives a DF of around 50 on 4R speakers, DF 4R = 1/2 DF 8R
Regards,
Danny
- 4R compatible: 1.94A bias + FB shunt resistor of 1.8K
- ground lift for the input signal
- FB divider 50R-50R to double the damping factor, gives a DF of around 50 on 4R speakers, DF 4R = 1/2 DF 8R
Regards,
Danny
There are murmurings of an Alpha BB with built in Smooth Like Buttah (SLB) power supply - the ABBB (Alpha Big Boy with Buttah). Im sure it will be fantastic.
Wicked!
Dayton MPT 10uF/250V audio grade cap on C1021
Excellent choice, no need for a bypass on this.
ABBB, the new Masterpiece of JPS64 is starting to take shape...
Is there a dedicated thread for the ABBB?
The render looks awesome, JP always does such great job at layout.
Great! I have some left over from passive crossover builds. That guy barely fits as is!
Danny, I found a post where you called out R111 as the FB shunt. There are so many post it's kind of hard to take it all in. A book about this project could be easily written from this forum!
Danny, I found a post where you called out R111 as the FB shunt. There are so many post it's kind of hard to take it all in. A book about this project could be easily written from this forum!
Is there a dedicated thread for the ABBB?
The render looks awesome, JP always does such great job at layout.
No, not yet maybe when we get a bit further along. We asked JP to pause work while Jhofland is figuring out an on-board SSR relay protect and startup delay circuit. We want this to be a true "single board amp". To paraphrase Ron Popeil: "Connect it, and forget it!."
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Thanks for the info danny_66! To clarify about the FB shunt resistor, that is R111 on the modified 4R schematic?
Yep, that's it (original 820r, 1k8 for 4R) or the R6 in this schematic,
pay attention to R17 0.33, R10 0.15, R13 885 they set the bias at 1.94A
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