After getting to 6 channels of ACA (2x5w, 4x8w) i had the opportunity to get a SIT-3. Now i want to try all the amps in-between.
dave
With 106db per watt speakers and subs driven from plate amplifiers the number of watts I'm using is miniscule which was my prime reason for choosing the ACA in the first place. Max recommended wattage for my speakers is 20watt. If you don't enjoy the sound from the ACA try a different source. I still believe in system synergy, perhaps the differences and mismatches between sources and amps are less obvious these days.
Not much point owning a 99% distortion free amp if you can only listen for half an hour before switching off to watch TV.
Not much point owning a 99% distortion free amp if you can only listen for half an hour before switching off to watch TV.
I would love to own a genuine XA25, but will probably have to attempt an XA25-inspired beast using a set of hockey puck output transistors. I have a suitable case already set aside, and need to pick the rail voltage and corresponding power supply to make it happen.
Meanwhile my F6 and M2x are keeping me distracted, while my Aleph J acts as my reference.
Meanwhile my F6 and M2x are keeping me distracted, while my Aleph J acts as my reference.
I have a set of speakers that i would like to bi-amp with the SIT and an XA25. For now i’ll have to use my Japanese dual mono MOSFET 150w AB amp (bias turned way up amoungst other small tweaks). Just waiting for the diyAudio Store B4-ish kit to arrive.
dave
dave
With that kind of speaker efficiency a watt is pretty intense! So much depends on the space you listen in. If you are a few feet away from that 106 db you likely never use a full watt.
Wholeheartedly agree about synergy. A DAC, turntable preamp or whatever the source may be: have to get it all working together. When you do it is hard to stop listening.
I have 4 ACA's and an active crossover on one system that drive Heil AMT's and the low end uses an 8 inch woofer from Dayton Audio. Awesome amplifier.
Wholeheartedly agree about synergy. A DAC, turntable preamp or whatever the source may be: have to get it all working together. When you do it is hard to stop listening.
I have 4 ACA's and an active crossover on one system that drive Heil AMT's and the low end uses an 8 inch woofer from Dayton Audio. Awesome amplifier.
36 volts ACA.....for 2020
36 volts ACA...will use the ON semi, FDL100N50F mosfets...
i have the boards, they are two ACA amps in one....
smps psu's doing a dual monaural amp in a single chassis...
currently looking for suitable heatsinks...
36 volts ACA...will use the ON semi, FDL100N50F mosfets...
i have the boards, they are two ACA amps in one....
smps psu's doing a dual monaural amp in a single chassis...
currently looking for suitable heatsinks...
Attachments
Chris has to be given credit for the execution of those. I did a 1st sketch and he ran from there.
These are a tribute to the copper colour we see in the Mark Audio metal coned drivers. The colour originate din the 1st CHR70 as Mark tried to match the colour of the copper phase plugs on the SDX7 (a woofer i would like to see comeback).
dave
These are a tribute to the copper colour we see in the Mark Audio metal coned drivers. The colour originate din the 1st CHR70 as Mark tried to match the colour of the copper phase plugs on the SDX7 (a woofer i would like to see comeback).
dave
Hi. I have just built a pair of monoblock ACA v1.6 that I purchased recently. I am trying to set the 12v DC Balance Adjust. The voltage between ground and Q1 pin 2 is a slow sine wave between 4v and 20v. I have connected a 5 ohm power resistor to simulate a load and no change. Do I need an input into the XLR? Should I short the input pins together? Sage advice is much appreciated. I wired the amps as permanent monoblocks with only the XLR input. I followed the wiring diagram and included the 39k ohm resistor from the left channel Out negative to the Right channel input positive. Both monoblocks exhibit the same behavior.
Hmmmm... that both the amps show the same behavior means you likely have the wrong component in the wrong spot on both amps, or your meter is suspect... do you have another meter?
The meter is a calibrated meter and I tested it with a DC supply. I’ll look for wrong components.
I would ground the inputs and try again -- just to be sure.
Can you describe your PSU?
Does it happen if you power on one channel only?