Hello,
I have an AK4396 DAC board without the output stage. Instead I routed the + and - output from the dac chip to an capacitor coupled symmetrical Pass B1 Buffer and an balanced relais volume control. From there I go to my 10 years young beloved Aleph 5 clones and that works very well (no or in one channel very little hum). Now to my problem:
I wanted to have a balanced to unbalanced converter for my headphone amp and a subwoofer filter, but I can't get one working. I tried several schematics(simple ne5532, INA134 solutions) and all have huge hum. When I go from the output of my volume board to the input of the simple OP amp output stage from my DAC board I get a very distorting sound.
The only way to get an unbalanced signal, that is free from hum and distortion is to go to the balanced input of my NAD S300 amp and get the unbalanced signal of the tape output.
Does anybody know a good way to get an unbalanced output simulanously to my balanced output? Thanks in advance and sorry for the long text/poor english
Dirk
I have an AK4396 DAC board without the output stage. Instead I routed the + and - output from the dac chip to an capacitor coupled symmetrical Pass B1 Buffer and an balanced relais volume control. From there I go to my 10 years young beloved Aleph 5 clones and that works very well (no or in one channel very little hum). Now to my problem:
I wanted to have a balanced to unbalanced converter for my headphone amp and a subwoofer filter, but I can't get one working. I tried several schematics(simple ne5532, INA134 solutions) and all have huge hum. When I go from the output of my volume board to the input of the simple OP amp output stage from my DAC board I get a very distorting sound.
The only way to get an unbalanced signal, that is free from hum and distortion is to go to the balanced input of my NAD S300 amp and get the unbalanced signal of the tape output.
Does anybody know a good way to get an unbalanced output simulanously to my balanced output? Thanks in advance and sorry for the long text/poor english
Dirk
ZenMod, of course you're right, but I donT know wether the fotos will help.
Looks a bit like there are too much wires in ths dac, but most of the are really necessary.
First picture is the whole thing.
In the left corner there's the dac, then comes the balanced B1 Buffer with symmetric power supply and caps at the input and then the balanced relay volume control from ebay seller jimaudio. Above the volume board is a little, still unused cmoy headphone amp. The posts between the power supply boards is my star ground. I have all signal grounds here. Left under the dac is a subwoofer of course unused in the moment. I know I have to route the wires a little nicer, but I can't really think, that is the reason for the hum trough the balanced/unbalanced conversion. Moore detailed photos soon.
Looks a bit like there are too much wires in ths dac, but most of the are really necessary.
First picture is the whole thing.
In the left corner there's the dac, then comes the balanced B1 Buffer with symmetric power supply and caps at the input and then the balanced relay volume control from ebay seller jimaudio. Above the volume board is a little, still unused cmoy headphone amp. The posts between the power supply boards is my star ground. I have all signal grounds here. Left under the dac is a subwoofer of course unused in the moment. I know I have to route the wires a little nicer, but I can't really think, that is the reason for the hum trough the balanced/unbalanced conversion. Moore detailed photos soon.
Attachments
Second picture.
Balanced DAC output from chip with 0,47uF, 220Ohm and 100KOhm to ground.
Than volume control with input impedance between 10K and 1M and output impedance between 4K and 1M Ohm. From there I go straight to my Aleph 5 and that works very well, but the conversion to unbalanced is huming.
Balanced DAC output from chip with 0,47uF, 220Ohm and 100KOhm to ground.
Than volume control with input impedance between 10K and 1M and output impedance between 4K and 1M Ohm. From there I go straight to my Aleph 5 and that works very well, but the conversion to unbalanced is huming.
Attachments
Last a close up of the board arrengement.
My diverse balanced unbalanced converter boards are not in the pictures, but they are standart schematics. I tried one with ina134, one with one ne5532 and one with ne5532 and buffer, but all have the same problem: hum.
Only when I go from the output of the volume board through the 1K Ohm resistors in the output stage of the dac board (NE5532) I get no hum, but a very distorted sound.
When I install my NAD S300 amp with its balanced input and left it trough the rec out, there is no hum but the balanced unbalanced stage of the NAD is not really easy. Lot's of discrete transistors and two OP amps.
Next thing I will try is an INA134 board with + - 9V batteries, but I don't have time before weekend.
Any help ould be vary welcome, maybe I made a totally dumb error somewhere (It would be not my first one...).
My diverse balanced unbalanced converter boards are not in the pictures, but they are standart schematics. I tried one with ina134, one with one ne5532 and one with ne5532 and buffer, but all have the same problem: hum.
Only when I go from the output of the volume board through the 1K Ohm resistors in the output stage of the dac board (NE5532) I get no hum, but a very distorted sound.
When I install my NAD S300 amp with its balanced input and left it trough the rec out, there is no hum but the balanced unbalanced stage of the NAD is not really easy. Lot's of discrete transistors and two OP amps.
Next thing I will try is an INA134 board with + - 9V batteries, but I don't have time before weekend.
Any help ould be vary welcome, maybe I made a totally dumb error somewhere (It would be not my first one...).
Attachments
click on my sig , PSM LS part , and read and look on pics
maybe that will help , regarding attenuating and ground arrangement
maybe that will help , regarding attenuating and ground arrangement
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