gentlemen: i own an alpha dac and delta transport. i too notice a bit of extra treble emphasis. i will give some ideas of how to deal with it but i also owned a sigma dac and heard the sigma 2.
i did not like the sigma because it was a bit lean. it is possible that the alpha has more treble energy than the sigma, but neither are smooth sounding and pleasant to listen to.
now for the solutions: line cords, interconnects, anti resonant devices and tubes.
lets start with tubes. my favorite 12 volt tube is a ge 5751 black plate. i use it in my other cd player, the audionote cd2.
next choice would be a 5814, perhaps raytheon red label or ge black plate. yes a 5814 is like a 12au7. you can use 12ax7, 12ay7, 12at7 and 12au7 with that dac. i have already tried a ge 5814. what i have in right now is an older (vintage unknown) tesla 12ax7. next i try to find cable which is slightly subtractive in the upper mids/lower treble. i like dcca for that purpose. finally line cord. this is tricky. i'm using sunny cable technology line cords on the dac and transport.
uh oh, i forgot the digital cable. i can't say too much here other than to recommend eoither the original illuminati single ended cable or the original ps audio x stream digital cable. i have no suggestions for xlr cable.
anti resonant devices which are soft help too--sound boosters, furniture foam or sorbethane will work well under dac and transport.
it is also possible that a transport other than the delta may be a help to offset the aforemntioned character of the dac.
i'm not done yet. i thought of one more tweak. use ers on the transport and on top of the power supply of the dac.
contact still points. they come in about 8 by 11 inch sheets for appropximately 22.00 .
i hope this helps.
after following all of my own suggestions i have ameliorated the problem to some degree, but i still prefer my audionote cd2.
i did not like the sigma because it was a bit lean. it is possible that the alpha has more treble energy than the sigma, but neither are smooth sounding and pleasant to listen to.
now for the solutions: line cords, interconnects, anti resonant devices and tubes.
lets start with tubes. my favorite 12 volt tube is a ge 5751 black plate. i use it in my other cd player, the audionote cd2.
next choice would be a 5814, perhaps raytheon red label or ge black plate. yes a 5814 is like a 12au7. you can use 12ax7, 12ay7, 12at7 and 12au7 with that dac. i have already tried a ge 5814. what i have in right now is an older (vintage unknown) tesla 12ax7. next i try to find cable which is slightly subtractive in the upper mids/lower treble. i like dcca for that purpose. finally line cord. this is tricky. i'm using sunny cable technology line cords on the dac and transport.
uh oh, i forgot the digital cable. i can't say too much here other than to recommend eoither the original illuminati single ended cable or the original ps audio x stream digital cable. i have no suggestions for xlr cable.
anti resonant devices which are soft help too--sound boosters, furniture foam or sorbethane will work well under dac and transport.
it is also possible that a transport other than the delta may be a help to offset the aforemntioned character of the dac.
i'm not done yet. i thought of one more tweak. use ers on the transport and on top of the power supply of the dac.
contact still points. they come in about 8 by 11 inch sheets for appropximately 22.00 .
i hope this helps.
after following all of my own suggestions i have ameliorated the problem to some degree, but i still prefer my audionote cd2.