I'm getting about a 4khz 'whine' from my turntable, a Denon DP-300F with a Shure m97xe cartridge using a AT-PEQ3 phono preamp. I do NOT hear the whine when using the integrated preamp, but the sound overall is noticeably different. (Static-y). This is noticeable with it going directly to a Schiit Valhalla 2 headphone amp or to JBL LSR-305 speakers.
The Denon does not have a ground, but the PEQ3 does. Unfortunately, Japan doesn't really believe in grounded plugs so my PEQ-3 isn't grounded anywhere. I did try moving everything to my ONE grounding post in my apartment, but that still has the same issue.
Is this likely to be something I can fix without just replacing the phono pre-amp?
How can I isolate that it's the preamp and not the turntable feeding something to the amp?
Denon DP-300F: https://usa.denon.com/us/product/hifi/turntables/dp300f
Audio Technica AT-PEQ3: http://www.audio-technica.com/cms/accessories/132f0134167a770a/index.html
Can you connect the PEQ3 earthing to TT ground through RCA ground as for an example (I use this type connection because of my TT has separate earthing but the pre-amp doesn't)?
To see if line level signal is OK just connect the TT directly to your computer inputs w/o any RIAA stage in path. Record the signal and either analyze or listen the result. If the input signal is too weak then add a digital RIAA stage in software - easiest way to go would be using equalization curve for RIAA found in Audacity but if you need some more boost for the signal just use this software - http://jiiteepee.blogspot.fi/2016/03/phonoeq-software-project.html?view=sidebar as for an example.
Any chance there is something nearby that might be picked up by the phono system, such as a fluorescent light? Grounding is generally most important for mains 60Hs, or 50Hz, and harmonics.
I will try both these things. Local power here is 100v/50hz, and the room is lit with flourescents, although those are on the ceiling and the PEQ-3.. isn't.
I'll try running the TT straight through into my scarlett 2i2 and Audition and see if I can hear anything!
I keep forgetting that I can use that 2i2 as more than a fancy mic input. >.>