My current system consist of a PWD MkII (Bridge II) connected to an Integrated Valve amp (KT88 power side and 6SL7 & 6SN7 on the preamp side) instead of using the preamp on the amplifier, I am using the PWD as a preamp. The sources are:
- Turntable to NWPC via HDMI to PWD.
- NAS on home network to PWD via CAT5 network cable.
About 2 months ago I decided to upgrade to the DSJr. I decided to download Huron and update the DSJr. I then went through the normal sequence of turning on the DSJr followed by the amp(acting as power amp) and there is a loud hum coming from both channel of the speakers. I thought this will go away after the burn in period. After about 3 weeks (approximately 50 hours) the hum is still there. I am using a PS Audio DecTet by the way. I have tried everything including removing all source such as NWPC, CD Player, USB(Computer) from the equation and the hum still exist. I have tried changing interconnect, power cables and even running a dedicated power line just for the HiFi system.
I even tested the DSJr with my other power amp and it still produce the humming effect on my speakers (Monitor Audio 89dB), i have also tested it with a B&W CM10 and it still the same.
I have also tried the attenuator low setting and the hum is still there but much lower and it affects the music listening experience. I then revert back to the old Torreys and i can hear a significant improvement. The hum have been reduce but still audible from my listening position about 3 meters away from the speakers. All in all i have tried 4 different combinations of amplifier and all of them produce the humming effect. The only amp the does not produce the hum is a BHK Stereo amp. By the way i have tried the cheater plug option too. The only way i can get rid of the hum is to basically use the pre amp on my integrated valve amp.
I got a few question in regards to the above issues.
- Is this a compatibility issue (between the DSJr and my Valve Amp)?
- If i was to ditch the DSJr and change to the DS Sr. will the hum go away?
Really appreciate if anyone can suggest any recommendations to eliminate the hum. Thank you.