BHK Pre and Power on the Way - REL Subwoofer Question

Audio Components Amplifiers
21

contact duncan taylor and he can help you.

22

Exactly. If anyone needs this little bolt arrangements for their REL subs, please contact us by phone or email and weā€™ll get one to you.

23

Has anyone tried the REL kit yet? Mine just came in the mail from PS Audio and I wondered what experiences have been. Iā€™m planning to do it this weekend on my Stereo 250.

24

Hi Michael,

How did it go with your BHK250 with the REL kit? Want to hear your experience before buying a REL subwoofer. Looking forward to hear from you. thx.

25

Well, itā€™s a mixed bag.

  1. First the bad news: The grounding post didnā€™t make any difference for me - the hum in ā€œstandbyā€ mode was exactly the same whether I was using the binding post kit or floating the wire.

  2. The bass integration and subwoofer performance is much better with the REL Neutrix cable than with the low level single ended input coming off of the pre.

So, while I was hoping the binding post would work better, my solution is to turn off the REL whenever I put the BHK 250 into standby mode. A bit of a hassle but worth it for the improved performance from the REL.

Iā€™d still like any input from PS Audio.

26

Sorry about that. Iā€™ll pass this on to John Hunter. I am sorry it didnā€™t work. Let me scratch our heads with this and find a solution.

Adding the REL is exactly the right thing to do from a sonic standpoint.

27
Let me scratch our heads with this and find a solution
:)
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Paul McGowan said

Sorry about that. Iā€™ll pass this on to John Hunter. I am sorry it didnā€™t work. Let me scratch our heads with this and find a solution.

Adding the REL is exactly the right thing to do from a sonic standpoint.

Thanks. The good news is that, for me, switching off the sub isn't a big deal. So, while I want to address the issue, it isn't the end of the world either way.
29

I donā€™t run a PS Audio amp, but do run a fully balanced (MC452). I originally had the ground running to my turntable ground. After buying the DSJ, I ditched my turntable. I now run my REL in the below configuration, with no hum in the on/off position.

image

30
toddcc1 said

I donā€™t run a PS Audio amp, but do run a fully balanced (MC452). I originally had the ground running to my turntable ground. After buying the DSJ, I ditched my turntable. I now run my REL in the below configuration, with no hum in the on/off position.

Thatā€™s what weā€™re doing. The standby hum is a unique issue with the BHK/REL combination.

31
Michael said

Thatā€™s what weā€™re doing. The standby hum is a unique issue with the BHK/REL combination.

Per the REL hookup diagram originally posted, they are not the same. One straddles across the R/L outputs, one does not.

*Edit: I should also add that itā€™s not unique to BHK/REL. Itā€™s exactly what was happening with McIntosh amplifiers using their balanceed topology. Regarding the hum that was occurring in my system, I hooked both positives of the neutrik cable to only 1 positive terminal on the amplifier vs. using the right and left positive terminals on the amp, while leaving the ground afloat. No hum and the REL shakes the entire house. I would say itā€™s working to my satisfaction. The BHK monoā€™s will be here on Monday, so Iā€™ll attempt the same configuration and see how it goes.

32

toddcc1,

The connections are the same but yours looked like is going to 2 subwoofers.

33

There are two subwoofers/monoblockā€™s in the diagram, correct, I should have made a screen shot of only one side. But, the two diagrams are different, beyond there being two subwoofers in the diagram I posted. You connect both positiveā€™s (red/yellow) from the neutrik to either the right positive or left positive on the amp, while leaving it ungrounded vs. the original diagram that connects the neutrik positives (red/yellow) to both the R+ and L+ of the amplifier.

34

Though the original post was for a BHK250, I did hook up the BHK300ā€™s today and hooked the REL up. There was a hum with the floating ground. Hooked it up to the amp and it was gone. Iā€™ve been hammering the tar out of the 300, it hasnā€™t shut off and is rocking the crap out of the house.

BHK

35

I am not sure I understand the wiring in the picture. I see a yellow and red wire to the hot terminal and a black wire to the negative terminal.

Where did you connect the ground wire?

36

I hooked the ground up to the negative terminal on the amp. The inquiry leads me to believe I probably shouldnā€™t be doing it this way and possibly ground to preamp or chassis ground on the amp?

37

Thatā€™s correct. The negative speaker terminal is not ground. It is a balanced output and you donā€™t want to do that.

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Paul McGowan said

Thatā€™s correct. The negative speaker terminal is not ground. It is a balanced output and you donā€™t want to do that.


Thanks Paul. My erroneous ways have been corrected.

39
bstanwick said

From my REL S/5 manual, here is the section on connecting to the speaker outputs of a balanced amplifier using the supplied 10 meter cable. Click on the image to see it full sized.

Just to double confirm, the above is the correct connection for a single REL with a BHK power amp.

You can float the ground but the REL will hum when the BHK goes into standby.

The grounding kit supplied by either PS or REL helps this hum problem but does not eliminate it and we are thinking on a better solution.

Ultimate elimination of hum when BHK is in standby is to turn REL off.

The problem is only when BHK is in standby, and the above connection has no problem nor compromise when in normal operation.

Best regards,

Justin

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Hi Justin,

Is there a plan for a permanent fix in the future? I am a BHK user and planning to purchase a REL sub sometime this year.

Allan