Phono cable not caps to le with preamp?

A VERY loud hum is possibly due to a more major ground fault than the hum that typically results from failure to ground the TT or tonearm, in my experience. If the usual suspects don't work at all, I would look at either the cables (maybe the solder joint between the cable itself and the grounded barrel on one of the RCA connectors came loose) or the new phono stage itself.  Crack open the chassis and have a look at the solder joints to the outputs.  But one huge question: Is the hum in both channels or in one channel?  If in both channels, then my hypothesis loses some credibility.

@lewm it’s a buzz. Like overdriven guitar sort of. I put the old phono back in (Andover SpinStage) and it’s dead silent again.

ill play with it tonight and see what I can glean from it. I’m in touch with the importer as well.

edit: forgot to mention the phono stage is plugged into an isolation transformer.

@ghdprentice ​​@lewm

got home and swapped cords again. I get sound from both outputs. Playing with the ground alters the tone of the buzz a little bit that’s it.

old phono preamp back in and quiet as a tomb.

seems like sloppiness here but I know nothing about soldering (see my system pics for the guts of the new phono)

EDIT: funny enough I just realized the ground from the TT was never connected to the Andover. And yet it’s still dead black quiet. 

Sounds like maybe a defective phonostage. 🙁

My phono pre gives these instruction and has these grounding switches as part of its circuit.

Improper grounding of an outboard phono sections can often result in excessive hum. Since the grounding on every sytem is different, it is impossible to provide a uniform grounding strategy that will work for every system. Be assured that with correct grounding almost all audible hum can be eliminated. If you are experiencing some hum, try the following:

1. Be sure to have the phono pre plugged into the same outlet or power strip as your preamplifier.

2. Connect the turntable ground to the ground lug on the rear of the Phon Pre

3. You may need to connect a ground wire from the Phono pre to your preamplifier.

4. Try different combinations of the internal grounding switches g1-g4 under the Phono Pre access panel
    

   

   Grounding switches g1 through g4:

   The four small grounding switches g1, g2, g3, g4 will most often be set in the forward position as shown in the preceding photographs. If you are experiencing excessive hum you can try moving them in the various possible configurations g1, g3 forward g2, g4 to the rear, etc.. Some cartridges that share internal grounding between channels may require that one channel be grounded while the other is not (e.g. g1, g2 forward and g3, g4 to the rear).

   

Some or all of the above should eliminate most hum. If this fails to cure the hum, call customer service for further advice.
If not GoChurchGo trying Thoughts & Prayers may work