I have only used it with my Sennheiser HD 650 also. I have not tried the line out (Pre out) yet. 🙂
Regards
Bambos
Regards
Bambos
Hi, would be thankful for help. I have no sound on one channel. I hooked up the ACP plus with a laptop charger at 19vdc. The working channel measure 9,5 vdc but non working channel measure 16,5 at dc1 and the heatsinks are cold. Could it be faulty q5 or q6?
Thanks in advance
Thanks in advance
It could be a bias problem. What is the voltage drop across R15? It should be about 4.5V.
Also where did you obtain the parts from? Was it a diyAudio kit?
Also where did you obtain the parts from? Was it a diyAudio kit?
Thanks, I measure 0.06 on the faulty side and 4.7 on the working side so there is a difference there. I have used spareparts and not the diyAudio kit. Is it the Jfet q3 that might be the problem?
Always include unit of measurement.
I assume the measurements are Volts. 0.06V is not good.
In the faulty side what is the value of R4 and what is the voltage drop across it?
I assume the measurements are Volts. 0.06V is not good.
In the faulty side what is the value of R4 and what is the voltage drop across it?
Is R4 125 Ohm?
Regardless of the value, it needs to be lower to suit the J113 that you have. The J113 is working as a constant current source and its source resistor, R4, needs to be adjusted so that (voltage drop across R4)/(value of R4) = 0.010A
Regardless of the value, it needs to be lower to suit the J113 that you have. The J113 is working as a constant current source and its source resistor, R4, needs to be adjusted so that (voltage drop across R4)/(value of R4) = 0.010A
Yes I use 125 Ohm but I will try with a lower value. I start around 55 Ohm. Many thanks for your effort. Cheers
Hopefully that will fix it. I am wondering about the 0.06V across R15 as that seems very low for 0.57V/125R=0.0046A (4.6mA) of current flowing. Q1 may be questionable too.
You're welcome. A happy ending. 
You can fine tune the R4 value for each channel if you want each channel to meet the design specification of 10mA of current from the J113 CCS.
You can fine tune the R4 value for each channel if you want each channel to meet the design specification of 10mA of current from the J113 CCS.
Cheers! That is a very good thing to know for future tweaking!You're welcome. A happy ending.
You can fine tune the R4 value for each channel if you want each channel to meet the design specification of 10mA of current from the J113 CCS.
Will the ACP drive small 8ohm bookshelf loudspeakers (Sony SS-5GX)? I already have the PCB but have put-off spending on the parts. I don't really need the Adcom 545II that used to power my grand system - now gone. Nor do wish to spend on a smaller but still bulky power amp.
I rarely have my passive volume control (Schiit SYS) as high as nine O-clock using the Adcom amp. And that is as 'loud' as I dare lest I annoy my downstairs neighbor again. 🙂
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Another ACP+ Is alive in Hammond case. LED is muttering “almost there…”
1V in, 5.8VPP out. Driving F4 nicely.
PSU is 24V.
thd 0.08-0.12% RCA out
9.8mA through R4 (47R)
Sounds wonderful with 32ohm headphones.
1V in, 5.8VPP out. Driving F4 nicely.
PSU is 24V.
thd 0.08-0.12% RCA out
9.8mA through R4 (47R)
Sounds wonderful with 32ohm headphones.
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