Experienced one slight mechanical - not electrical - problem. When trying out parallel mode (and I am loving the sound), when tightening a jumper in the speaker jacks through-hole, one jack was not tightened down enough to the back panel and rotated. I will have to go back in and add some lock washers and probably even solder the nuts to the threads.
I do not want to think about what would happen if the jack rotated further and pulled off a bunch of wires from their terminals...
I do not want to think about what would happen if the jack rotated further and pulled off a bunch of wires from their terminals...
Thanks to everyone for previous advice and help!
Now I will try adding led vu meter kits that require 12v supply.
Where would be the optimal place to draw 24v or 12v for the vu meter circuits? Would the switched power lead be safe for 24v supply to transformer?
I do use external speaker protection unit to protect from excessive DC to the speakers and I plan to check the DC levels prior to connecting speakers.
What should I expect DC levels to be at the speaker outputs for a healthy, unmodified ACA amp?
I plan to reference the speaker level outputs at the boards for the vu meter input signals (they are designed to support speaker level input).
If I decide I want to try to "calibrate" the vu meters I will try using my scope, sending in a 1 khz signal to just below clipping amplitude and see if I can get the LEDs to match (although it was pretty easy even for my ears to detect clipping of the amps when it happened- like someone was playing a guido!).
For active cooling I just decided to sit the amps on computer laptop type cooling fan platforms. The platforms are silent to my ears, wide enough to push air through the heat sink fins with good air flow, and dirt cheap.
As always, thanks for any and all advice for this hair-brained scheme 😉
Now I will try adding led vu meter kits that require 12v supply.
Where would be the optimal place to draw 24v or 12v for the vu meter circuits? Would the switched power lead be safe for 24v supply to transformer?
I do use external speaker protection unit to protect from excessive DC to the speakers and I plan to check the DC levels prior to connecting speakers.
What should I expect DC levels to be at the speaker outputs for a healthy, unmodified ACA amp?
I plan to reference the speaker level outputs at the boards for the vu meter input signals (they are designed to support speaker level input).
If I decide I want to try to "calibrate" the vu meters I will try using my scope, sending in a 1 khz signal to just below clipping amplitude and see if I can get the LEDs to match (although it was pretty easy even for my ears to detect clipping of the amps when it happened- like someone was playing a guido!).
For active cooling I just decided to sit the amps on computer laptop type cooling fan platforms. The platforms are silent to my ears, wide enough to push air through the heat sink fins with good air flow, and dirt cheap.
As always, thanks for any and all advice for this hair-brained scheme 😉