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REL subs with Rowland Amplifiers

I'm having issues connecting my REL Carbon limited subwoofer to my Jeff Rowland 625 S2 amplifier via the high-level input. I connected my sub according to REL's instructions...yellow lead to positive on one channel, red lead to positive on the other channel, and floating the black wire(ground). I get minimum output when connected according to the instructions. When I use the low level input, the output is sufficient and the sub sounds great. Per my conversation with Jeff Rowland I need to ground the black wire by loosening a screw on the amplifier and connecting the black wire, but if it isn't properly grounded I may damage my amplifier. Is there anyone that owns a REL with Jeff Rowland 625 S2 amplifier or other balanced differential amplifier? If so, how do you connect your REL via the high-level input. Is there an easier way to ground the wire than unscrewing the screw on my amplifier. I just don't want to unscrew the screw and prefer another method of grounding the sub.   
ricred1

Showing 4 responses by lalitk

lalitk's avatar
lalitk
5,055 posts
 
@ricred1,

Here is an article from REL that talks about proper grounding to class D amps,

https://relsupport.zendesk.com/hc/en-us/articles/115004486607-Class-D-Amp-Connection-Methods

I ran into similar situation recently where I could not connect REL’s to my custom 300B amps. Since they were custom made, I was able to sent back the amps to have outputs properly wired for ground reference. The manufacturer also sending me a pair of speaker to line level converters as a back up. I am expecting everything later this week.

PM me on Saturday if you would like to try the speaker to line level converters and I will be happy to send them over.
lalitk's avatar
lalitk
5,055 posts
 
Richard,

I am quite surprised that REL unable to help or provide amicable solution. They were extremely helpful when I contacted them about high level connectivity with my ARC amp.

Let me PM you my contact at REL. 
lalitk's avatar
lalitk
5,055 posts
 
Hi Al,

Now that makes perfect sense 😊

I also experimented (skeptics at first) with non-grounded power cords for all of my components except preamp to eliminate any ground loop or hum issues. The results were shockingly good, my system is dead quite now...the interconnects from preamp provides static dissipation through the secondary ground connection & neutral thus eliminating any ground loop caused by interconnection of electrical equipments having multiple paths to the ground.
lalitk's avatar
lalitk
5,055 posts
 
“Over the years I’ve seen a number of members here mention that they connect the black wire of a REL sub to the negative output terminal of a fully balanced amp, and the results seem good. To that I say they should count their blessings :-)”

@almarg,

Not sure what do mean when you say ‘count their blessings’...is it a cautionary smiley at the end?

I own dual mono SET amps and after consulting with REL and amp manufacturer, I also connected red/yellow wire to positive output and black wire to negative output of the terminal. Like Daveyf, I am also using dual subs. The Input Impedance of each mono is 100 kOhm.

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