I am a loyal consumer of PS Audio Products drawn in by the video vignettes and other offerings.
With recent retirement I redirected funds to complete my “forever “system. Folly of course given the PGM releases. Bragging rights aside I have a common problem but still seek best advise regarding solution. After scanning the available resources I have yet to find a safe solution I find sensical.
My System:
Aspen FR 30
REL Carbon Fiber Subs x 2 (hi level connect to amps)
BHK 600 monos
BHK Pre
Stellar Phono pre
Rose HIFI 150B
Sony ES CD Modwright
B&O Beogram 8002 turntable
P15 x2 one for each amp
P4 x1 power to components
The P15’s each receive power from a dedicated 20 amp breaker (2 separate circuits)
The P4 also has a dedicated 20 amp circuit.
So you put it all together only to have a hum noticeable when no media playing.
Without going into my embarrassing trouble shooting this is consistent with ground loop as evidenced by it being resolved by using AC ground cheaters on both amps when plugged into their respective P15’s. “Cheating”the pre alone does not resolve not does cheating the other components. I did not try the two prong on the P15.
So now I have an unsafe situation with ungrounded amops performing as one would like.
So what is the solution>. The suggested Hum X (70-100 USD) is what PMG suggests as a solution but I have a hard time believing a device rated at 6 amps is good with a unit that has 15 amp fuses. Not sure the draw BHK amps have as I must have missed it in the manual.Plus it looks silly running a 7 gauge power cable to terminate into a small device.
My thought would be to ground the amps separately. Basically use the cheaters and ground the chassis either using a cheater that allows a separate ground (so using the ground of the plug but redirecting the ground wire to a seperate ground post just for the dedicated lines) or use a chassis found from a suggested location. My subs use the ground post and although REL tells me the ground can serve doubles duty I’m not sure I like the esthetic.
My thought was to chassis ground. Not sure using one of the grounding box solution would add anything kin this situation as the goal is creating a safety groung. Separating the components and assigning the same gound seems to make sense but I can be my worst enemy sometimes.
As you know, ground loops occur when multiple devices in an audio system are connected to different ground potentials.
Here you are powering each amp on a different circuit. This is the problem. You need to eliminate the difference in ground potentials between these circuits.
I had this problem (similar system) and the source of it was the Rels. I know because the ground loop only occurred after adding the Rels (no other changes). One thing that affects this in general is whether the Rels are connected via the high level amp outputs or the line level preamp out; mine is from the preamp. I initially powered each Rel from the P20s feeding BHK 600s and then plugged the Rels into the same outlets feeding the P20s, both resulted in hum.
My solution was simple but may not work in your case. I hope it is useful as a data point as you experiment. I have a dedicated building with it’s own main service panel which feeds a subpanel in the listening room for the system only. There are 5 or 6 dedicated lines from the subpanel, one for sources/pre, another for a bass amp and two more for the P20/BHK’s. All of this is grounded back to the main panel per code. (Sorry for the long explanation but it’s relevant.)
What worked for me was to plug the Rels into room outlets from the main panel which bypass the subpanel. What I learned was that I did not understand grounding as well as I thought.
It seems grounding issues with subs are not infrequent. I don’t know why this is the case. I will say that my system is somewhat complicated (three amps, two active crossovers) and I have changed many components over the years with no hum problems. So I point the finger at the subs, something in their design (at least some of them).
Well this turned out more long winded than I anticipated. At any rate I hope this helps a little and good luck solving the hum issue.
I think the generally accepted answer is “it depends” on the amplifier, the cleanliness of the electrical power present coming in, personal preference, etc. The usual suspects.
I’m not sure that’s the issue as the ground for the entire electrical is common. All the grounds run to the circuit box and are fastened to the same bus which in turn is connected to the same ground rod.
My thinking is certainly simplistic but all grounds on a panel and sub panel have a common termination usually the rod poiunded into the ground creating a common path of least resistance in circumstances of a system short. This gives the current a place to go rather than electrocuting someone.
Yes, the hum from a ground loop is from differentials in resistance generated by different gear and the particulars of their construction but that can happen without regard to individual circuit(s).
That said, the hum was still there prior to cheaters being used and everything into the same circuit.
Practically speaking given the specs of the system components and their draw and based on other systems having dedicated circuits is not that uncommon. The current draw with the powerplants and BHK 600 is substantial. If everything was on the same circuit its predictable fuse would be blow in serveral circumstances. PS Audio uses P20’s for each 600 in demos and when I was buying another P15 were dubious it was big enough for the amps.
I might be full of it but those are the thoughts Ive had as I seek solutions.
I have spent way too much for a system I will never appreciate (old ears) just for the dopamine rush of having the best. Battling these issues is intellectually stimulating but frustrating when I think back to the days of a Hammon Kayden 330c and AST speakers. No hum. I thought I’d be bullet proof with the powerplants, then the new circuits then ….
True but the problem predated the REL installation. The problem persisted with or without the REL plugged in or connected. More importantly the hum is gone with cheaters between the amps and powerplants. My concern and question is grounding the amps safely so there is not an electrical hazard.
Have you taken a meter and measured the voltage potential between the two amps?
There can be a problematic voltage potential among pieces of kit in both a dedicated circuit and in multiple circuits. This can be the case even when all of the circuits share a common ground
