BHK Pre and Power on the Way - REL Subwoofer Question


If you have hum when you hook up the sub, feel free to reach out to us, and we’ll send you a REL grounding kit for free.


Thanks, I’ll let you know.


Kit didn’t work for me.


Would the phono ground on my Marantz 7007 receiver work? I also have the sub connected to the RCA out of this receiver. Just got the amp and it sounds great. Before I try to hook this up I’d like some feedback. If this doesn’t work, then I’ll try PS Audio’s replacement screw.


Do you mean you have it hooked up to the receiver as well as the BHK. If not and you are going to run it line level off the receivers pre-outs you don’t need to connect it to the BHK. If you are going to hook it up just to the BHK then yes remove the RCA’s from the Marantz and if you have a hum with the BHK and the REL the normal method then use the phono ground on the Marantz.


Yes, both are connected right now with the floating wire. Only when I turn off the amp do I get the hum. So I thought of the receiver as a ground. I don’t have a preamp involved. Just the DSD Sr. and the BHK.

I had the 700M hooked up this way with no problems. Different senerio with class D Amps.

I’ll try this set up tomorrow. Also thought of using the Marantz IR outputs to turn the BHK on and off as a zone2 device.


If you are not using the receiver to control the BHK then take the RCA’s from the REL out and then just hook the REL’s speaker level red and yellow to the BHK and the ground wire to the phono ground of the Marantz.


Months ago I connected the REL network (resistors) and PSA GND lug; hooked it up the proper way and zero hum. Placed the BHH250 in standby and zero hum, dead quite. Months go by and this morning I walk over to the back of the component rack hooking up my Giga FOIL filter and hear the tiniest of hum from the right REL S3/SHO sub, barely auditable and the left sub a lot less. Now I’m puzzled; thought I solved that hum. Well back to REL video and went out and got RCA stereo pair. I hooked them to the BHK250 input RCA connection (I’m using XLR) and the REL LFE RCA connector; turned potentiometer CCW. BOOYA, problem solved. Not a peep, zero hum! You could not hear the tiny bit of hum from my chair; however, the right sub had just enough when I got behind it in the corner to be annoying. Of course there is no way I’m going to stand for that; especially since I keep the REL sub amps on all the time. Even if I can’t hear it from my seat. So one step forward with the amazing Giga FOIL filter, one step back and then solved… what a day… :slight_smile:


Hey Cadri, what does this mean? “turned potentiometer CCW.”

Just curious, my subs buzz as well when the amp is off, but I haven’t really set about solving the issue as I power them off with the power plant by turning off their zone in my programmed “off” activity on my harmony remote.


Counter clock wise


Ha, thanks so much!


Sorry, engineer term… :+1:
I thought I had it taken care of, then heard a very, very faint hum. Also, I turned the BHK250 to standby to make sure and no hum. Yeah, I removed all that clap trap crap and put heat shrink on the REL black spade ( Baseline Blue)… then wire tied it to red/yell wire to get it out of the way. Such an easy solution.


I keep every piece of equipment on especially if it is a non tube amp and REL amp is not tube. At night I place the BHK Amp & Preamp in standby and the rest stay on. Tubes warm up very fast, the rest need a lot of time to stabilize. So, it was very important to solve this initially and also this morning.


Siri can’t keep up with you. She defined CCW as channel command wave. Thought you would get a kick out of her engineering knowledge.


Or centre channel weighed


I would leave my amp on all the time if I could it is just too much though. It draws ~500W no matter what. On the other hand it has worked great as a heater if I leave the door shut on my office! Nice and cozy!


Yeah, context is so important. The word potentiometer and CCW in the same sentence… as a hardware design engineer, just forgot about the general audiance. My apologies…


No apologies necessary, I always appreciate your comments.

I thought counter clock wise was the most logical use of that acronym. My Siri inquire was out of curiosity. Her definition surprised me and she offered no alternatives; this will strain our on going relationship :slight_smile:


So, thought I got rid of the hum, tested the solution by turning the amp to standby and no hum w/ REL amp on. OK, solution realized as I drank my port with a grin like I fixed it. Those pesky gremlins… never sleep… :sneezing_face:. Then I turned my amp to standby late last evening and hum. Crap. Went to bed thinking of a solution. This morning I started getting ready to remove my amp feet and replace w/ Isoacoustic isolation pucks and the thought occurred. Why not go sub auto standby. Stop the input like Roon or the DMP wait 30min and when REL amp goes to standby (white LED to lower amber, can be seen easy from the opposite end of music room), turn the amp to standby. It worked like a champ. No hum. In addition, no hum when I turn the amp on and also when the REL amp turns on. So, this seems to be a good comprimise for me. The only difference is that the REL amp is in standby all night. I will operate it like this for a month and then decide if that is good. If not, then I need to figure out REL amp on sounding hum w/ amp in standby.


Yeah, I tried some things last night that I could think of, but no luck on my end, I am pretty happy with the power plant shutting them off (mine don’t have standby (T9i)). The only issue I ever have is that I need to remember to turn on that zone if I only listen to music instead of turning everything on, like the OPPO etc. Of course the easy thing would be to create another activity, which would take like 5 minutes but it’s so much easier to bitch about it!