If I disconnect the subs and the cheater plug remains between the P 15 and the BHK 600 the hum remains absent. If I put the cheater on the subs and leave the cheater off the amps the home is present. If I unplugged the subs and disconnect the wires going to the amps so that there’s no contact or connection whatsoever with the subs to the system and the amps are not cheated the buzzes present. If you put the cheaters back on the amps, the buzz is gone so I really don’t think it’s the subs that are contributing. Plus as I said, the buzz was there before I installed the subs.
I am sorry. I missed the detail the hum preceded the subs. Maybe you should measure the different outlets, as Elk suggested.
Not a problem I appreciate everyone’s thoughtful input. Right now I’m leaning to chassis ground the snow as a safety measure. Just need to determine the best location to attach the wires
We have a couple of people on the forum who are very knowledgeable. I hope they are available to chime in soon.
While I cannot help with the hum issue, I can congratulate you on a wonderful system!
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Just thought of something. Check if power cables are touching interconnect cables, and if so, try to keep them apart.
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The chassis ground would be a good safety option. I’ve dealt with ground loops, specially when involving double insulated equipment, and they can be maddening.
I am assuming you are using XLR interconnections (at least between preamp and amps). If so, I remember reading that the ground wire on the XLR already doubles as chassis ground, being connected to the upstream and downstream equipment chassis in the XLR plugs.
So, should you a have a live wire failure on you amp (downstream), the current should be transmitted to the preamp chassis (upstream), and from there to your safety ground, tripping the breaker.
in fact, I remember people exaggerating this, and suggesting leaving only one equipment connected to the safety ground by the mains wire, and all other relying on the XLR ground wire.
You may want to explore this option, and people here that know the topology of the BHK series can confirm if this scheme is safe (in fact, you can even test for this, checking for electrical continuity between the amp and preamp chassis while using the cheater plug in the amp).
if it works, you can later get a couple of PSAudio power cords, that will let you remove the ground pin, so you won’t have to use the cheater plug.
Best of luck.
Can I jump in here? First off, congrats on a beautiful system. Wow. Nicely done.
And, let me assure you that the BHKs without their ground pin connected are completely safe, so no worries there. However, let’s see if we can’t narrow this bugger down.
I am a little suspicious of what I am reading and want to make sure of what you are saying. What I am “hearing” is that with no inputs connected to the BHKs (very important, the input cables are disconnected), and the BHK outputs connected only to the Aspen FR30s, there is hum to be heard through the Aspens. Is that correct? And, if you cheat the BHKs power cables the hum goes away. Please verify and actually make the experiment once again.
If this is true, can you cheat just one of the BHKs and not the other and report back your findings?
Sorry you’re having to go through this mishigas.
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you probably mean ‘connect’
Update: I stand corrected. Cheat referring here to a cheater plug. Sorry.
Nope. I meant “cheat” as in cheater plug. Sorry to be unclear.
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I believe he means cheat as in using a cheater plug.
Hah! Beat Elk bu half a second.
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As you can imagine I have gone through lots of permutations seeking resolution. In the process I over thought everything and thought I had a more complex issue. In fact it seems it may be a bread and butter problem.
Summary:
My cabling has been swapped a few times, nothing crossing or touching. Have custom cables made with Cardas or Mogami wire and Neutrik connectors. all XLR unless RCA only option.
The hum comes from both speakers
The volume of the hum is static (not effected by preamp volume level)
The hum is present:
All interconnects removed from amps, only amp connected to FR30’s via 4.2 anti cables (I have tried a few other speaker wires as well) amps plugged into P15. There is a hum.
Also if amps plugged into their dedicated circuits (separate) with P15’s between there is a hum.
If both amps plugged into their dedicated same circuit without powerplants there is a hum.
Using a cheater plug between outlet and p15 hum present.
Direct from a source like the Rose HIFI 150B into the amps bypassing the pre the hum remains if the cheaters are not in place between power and the amps.
Silence—->
Cheater plug into P15 and amp plugged in the hum is gone on that side. Cheater plug between both amps and their respective P15—silence.
Cheater between amp and directly into outlet—silence.
I have tried different permutations with the pre as well. Normally the pre is powered through a P4 but adding a cheater to the pre and using any of the 4 outlets available the hum is not affected.
My biggest concern at this point is safety from an electrical perspective and whether or not I need to establish a safe ground path to protect the gear and the animal that operates it.
One other observation is when I go analogue (Thorens 147 restored TT Beogram 8002 TT through an ancient creek phono preamp or the Stellar phono pre). Before the effective cheater was placed between power and amps there was feedback\hum that shook (really shook) the passive drivers in the FR30’s. That has resolved at least at the volumes I listen.
These trials are tedious mostly because patience is required powering up and down.
I’m thinking of developing a checklist flow sheet to make sure something isn’t missed. Then again I am an over thinker.
Many thanks
John
I may have missed it or do not understand this sentence, but what happens if you plug the amps diectly into the wall without the P15s and into the same circuit? ( Nothing else plugged in and no interconnects.)
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That sentence is as you describe. Both amps, same 20 amp circuit, no powerplants, only wire connections are speaker wires. No interconnevts. Hum present
Does the hum go away if in this same configuration you put a cheater plug on one of the amps?
I did not try or at least don’t recall. I do know cheaters on both amps regardless of power supply works.
So I am searching to be sure to address a potential safety issue as well as protecting the gear as best possible.
I would also be curious if @paul had an opinion on the 6a rated Hum X in this situation given the potential draw from the amps.
It’s still frustrating having to troubleshoot given the everything being so high end. Most of all seeing that cheater at the end of 7 gauge braided cord looks silly. I might just cut off the ground pin on the heavy duty power cord which would functionally make it a very expensive cheater. esthetics matter. Form follows function and all.
i really appreciate the sense of community and input so far. Has a bit of a family vibe.
Don’t do that.
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Ground loops can be incredibly frustrating and just as difficult to resolve.
There has got to be a way to solve your issue.
More people will login Monday, hopefully with good ideas.
Maybe it would be a good idea to hire an electrician to check the wiring from your house inlet including ground rod to the outlets.
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