Whoa. When closed JP, offset jumped from 15 mV to 150mV! At 2.8mV right now, little more warming, Open JP, hopefully nothing untoward happens!
Remove JP all is good bias to 172mV, offset .3 mV. Go full bias in few moments, on to channel 2. More coffee.
Remove JP all is good bias to 172mV, offset .3 mV. Go full bias in few moments, on to channel 2. More coffee.
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same as with XA 252, checking offset with jumper open; practically you can't even influence (significantly) offset when jumper is open
when everything is in ballpark, close jumper, set DC Offset, and that's it
when everything is in ballpark, close jumper, set DC Offset, and that's it
Playing music. Left channel will only bias to 181 mV and I am out of pot turns. Other channel is at 189, I think it will go higher.
Do I need new pot on low channel? Resistor change?
Do I need new pot on low channel? Resistor change?
Guess I could have misinstalled a resistor, but both channel appear to be the same part location wise. Sounds fine, want to bias to max of 198 mV!
replace R126/226 with 1K2
or just solder 5K6 or 6K2 on top of existing (1K5) ones
how it sings?
btw. you'll not hear difference between 180mV and 198mV; that's damn Pure Square Law OS
or just solder 5K6 or 6K2 on top of existing (1K5) ones
how it sings?
btw. you'll not hear difference between 180mV and 198mV; that's damn Pure Square Law OS
I figured. There is some thing about a pot of any sort full open and isn't too much juice that interferes with best sleep, silly factor not with standing.
It sings great. Like it's brother, big open and transparent. Doesn't have that brutal dampening factor that puts a strangle hold on bass control., as XA 252.
Bass is fine, not to misunderstand. XA 252 has powerful GI Joe kungfu grip on voice coils! Not needed for most of my speaks, but X's XSD love that D.F.!!!
It sings great. Like it's brother, big open and transparent. Doesn't have that brutal dampening factor that puts a strangle hold on bass control., as XA 252.
Bass is fine, not to misunderstand. XA 252 has powerful GI Joe kungfu grip on voice coils! Not needed for most of my speaks, but X's XSD love that D.F.!!!
At 182 mV or so, amp is warm, but I think could work in a 3U 400mm deep like I used for F5m. Of course weather is still cool here.
Otherwise, another outstanding amp from Zenmod. You can hear the "family resemblance" of XA252, big open transparent sound scape, but never sharp or irritating.
I was wondering how much of that sound was from the pucks, and how much from square law OS.
The smaller mosfets sing the same song, big brother has a lot more grunt! Speaking of big brother, repaired XA 252 board getting inspected today, if all points show continuity, we will attempt firing that back up as well.
Fingers crossed!
Russellc
Otherwise, another outstanding amp from Zenmod. You can hear the "family resemblance" of XA252, big open transparent sound scape, but never sharp or irritating.
I was wondering how much of that sound was from the pucks, and how much from square law OS.
The smaller mosfets sing the same song, big brother has a lot more grunt! Speaking of big brother, repaired XA 252 board getting inspected today, if all points show continuity, we will attempt firing that back up as well.
Fingers crossed!
Russellc
just a reminder ....... Plethora of Pinjatas is predecessor of XA252
so, taking in account timeline and Papa's nomenclature, PoP is not Mini Babelfish XA252; Babelfish XA252 is, in fact Maxi Plethora of Pinjatas
Mild hickup, hooked up to XSD speaker, playing fine, then cut off. No smoke or stink.
Leds on boards off. Switched amp off, unplugged, check source, pre etc. plugged power amp back in, turns on led both lit, but a bit paranoid to proceed without asking: What was that?
Leds on boards off. Switched amp off, unplugged, check source, pre etc. plugged power amp back in, turns on led both lit, but a bit paranoid to proceed without asking: What was that?
more info
both channels?
PSU arrangement - common or PSU per channel?
do you have speaker protect?
is it common for both channels or each channel having own?
only if I have proper algorithm, I can spit some sort of answer
both channels?
PSU arrangement - common or PSU per channel?
do you have speaker protect?
is it common for both channels or each channel having own?
only if I have proper algorithm, I can spit some sort of answer
Both channels. Common ps, lone 300VA. No speaker protection. Fired up, no with music turned off, just amp idling. Offset and bias seem ok
if both channels died, and sole common thing is PSU, go figure
either cable, or IEC, or switch, or fuse, or soft start
that it happened after speaker change, sheer coincidence
either cable, or IEC, or switch, or fuse, or soft start
that it happened after speaker change, sheer coincidence
So one of those things, didn't know if there was protection circuit or no....soft start is cobbled together, but seems solid.
Odd, it turned back on fine and has been running since
Odd, it turned back on fine and has been running since