N
N Cook
2x 200W mixer amp
I have the schematics for this amp but anyone familiar with them ?
Problem in protection (falsely triggering occassionally), both amps dropping
out.
Of course I have not been able to induce activation.
2 separate power amps otherwise apparently the same , both carying output DC
protect and overheat protect output relay drive ccts. But only one normally
open thermal switch going to one amp only so apparently dropping out that
relay only with no apparent interconnect to the other amp.
When it was up together I did not think to try shorting the thermal switch
but I assume it would drop out both relays and both amp outputs.
Anyone know how they interconnect. Also what I assume to be o/p fault DC
protect uses 2 470uF back to back electrolytics off the output sense line.
I never like to see this form of "non polarised" high C cap , is that just
me or anyone else find it iffy, questionable or perfectly valid design-wise.
?
More likely a problem with the thermal sw or 12V supply to both protection
cct and the fan , rather than a fan problem as it did occur once at sound
check and once at switch on. The fan does stop when this happens so unlikely
a send/return bypass sw problem, the monitor outputs still continue to work
so not a mains failure problem.
There is also a thin low current , signal level earth wire from the ps that
has come adrift loose in the case , broken at some pcb solder point
presumably, somewhere indeterminate from the schema, anyone happen to know
where?
Yet again bits of hardware, 2 bolts that hold the heatsink to chassis loose
and wandering around inside the case, but probably just incidental to the
main problem.
I have the schematics for this amp but anyone familiar with them ?
Problem in protection (falsely triggering occassionally), both amps dropping
out.
Of course I have not been able to induce activation.
2 separate power amps otherwise apparently the same , both carying output DC
protect and overheat protect output relay drive ccts. But only one normally
open thermal switch going to one amp only so apparently dropping out that
relay only with no apparent interconnect to the other amp.
When it was up together I did not think to try shorting the thermal switch
but I assume it would drop out both relays and both amp outputs.
Anyone know how they interconnect. Also what I assume to be o/p fault DC
protect uses 2 470uF back to back electrolytics off the output sense line.
I never like to see this form of "non polarised" high C cap , is that just
me or anyone else find it iffy, questionable or perfectly valid design-wise.
?
More likely a problem with the thermal sw or 12V supply to both protection
cct and the fan , rather than a fan problem as it did occur once at sound
check and once at switch on. The fan does stop when this happens so unlikely
a send/return bypass sw problem, the monitor outputs still continue to work
so not a mains failure problem.
There is also a thin low current , signal level earth wire from the ps that
has come adrift loose in the case , broken at some pcb solder point
presumably, somewhere indeterminate from the schema, anyone happen to know
where?
Yet again bits of hardware, 2 bolts that hold the heatsink to chassis loose
and wandering around inside the case, but probably just incidental to the
main problem.
