Bottlehead Forum
Bottlehead Kits => BeePre => Topic started by: blackharp on March 07, 2023, 08:47:29 AM
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Just finished the Beepre 2 and ordered the Kaiju.
I was trying to find an easy way to add another RCA output for a powered REL subwoofer I use with my Altecs. I have tried y splitters and for whatever reason, they do not work. Is there an easy way to add RCA outs, without the XLR mod? I've read doing the XLR mod could change the sound in some systems so I am hesitant...
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What do you mean that Y splitters don't work?
You can plug in an XLR to RCA adapter in the BP2 without any issues, and that's a very convenient way to get a second set of outputs.
Any solution I can think of is electrically equivalent to using a Y splitter though...
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I mean they don't work. For whatever reason, the subwoofer doesn't work with them. It produces a loud hum without any music or sound. The McIntosh preamp I used previously had a separate RCA out for the subwoofer and it worked. I have also used that weird box RCA converter for car speakers with ground/ +/ - negative wires connected directly to the power amp out, and that works, but I don't really like wires and box dangling off the side of the amp, and something about it seemed wrong.
I'm not sure why the Y splitters I have tried don't work with that sub. I remember them not working with a M&K sub, too. They are bother powered, so I think that has something to do with it.
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You might just want to plan on using the speaker level connections, as a splitter on a line output is 100% standard across the industry and there isn't really any reason for the REL to not play nicely with that.
On the other hand, there are some issues with subwoofers using three wire power cords and ground loops, so that may also be worth looking at.
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Like Paul said, if your sub has speaker level inputs it is a simple solution. I run a length of CAT5 or 6 cable - a twisted pair for each wide-band speaker and a pair for both sub-amps powering the LF drivers. My 0.02 /YMMV
Karl
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It doesn't. RCA only.
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Image attached.
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With the two prong power cord, I would not anticipate noise issues with a BeePre.
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Lots of people use Y-splitters to send signals to their subs, including me. In the 43 years I've been an audiophile, I've never heard of a Y-splitter not working with a sub. Since both REL and M&K are popular, well-known, quality brands I am sure there's no problem with your subs. I would say that either your splitter is defective in some way, or there was something wrong with how you connected the sub to the splitter. A 50/60 Hz ground loop hum is probably what you heard. Are you sure the connections at both the splitter and at the subs were secure and pushed in all the way? If not, that would cause the 50/60 Hz hum.
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With the two prong power cord, I would not anticipate noise issues with a BeePre.
It actually terminates into the wall outlet as a 3 prong cord.
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There are only two metal prongs in the IEC power inlet on the subwoofer plate amp, so the third prong just isn't used.
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Lots of people use Y-splitters to send signals to their subs, including me. In the 43 years I've been an audiophile, I've never heard of a Y-splitter not working with a sub. Since both REL and M&K are popular, well-known, quality brands I am sure there's no problem with your subs. I would say that either your splitter is defective in some way, or there was something wrong with how you connected the sub to the splitter. A 50/60 Hz ground loop hum is probably what you heard. Are you sure the connections at both the splitter and at the subs were secure and pushed in all the way? If not, that would cause the 50/60 Hz hum.
I'll be more clear. It worked with the M&K, but not very well. Loud hum, but it has speaker level inputs, so that was easy. With the REL, I have tried a few different splitters with the BeePre and a Harman Kardon Citation IV preamp, which does not have a second RCA out. I assume in your 43 years, you did not own the specific REL model HT1003 MK1 subwoofer and Citation IV model preamp? The splitters or hardware were not defective. Yes, I am sure the connections were secure. I ended up using a speaker level RCA adapter which has 6 extra wires and a big plastic box, and that works, but doesn't seem clean and I do not want a plastic box hanging off the side of the amp. I am currently using a Citation II as a power amp, and the box is behind the amp in an enclosed cabinet, but with the Kaiju, I will be exposing that and finishing it nicely, so the exposed, hanging car audio jig is a poor solution for an all around expensive system.
The REL is UK made I believe which is probably the first issue.
I was asking if it were easily possible to add a second set of RCA outputs to the BeePre instead of doing the whole DC conversion with balanced outputs (which I can connect XLR to RCA cables I assume) because I have read the sound can change significantly and I would like to use the preamp stock for a while while breaking it in before deciding if I want to change anything.
Thank you for your time.
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There are only two metal prongs in the IEC power inlet on the subwoofer plate amp, so the third prong just isn't used.
Interesting...
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Interesting. I had a look at the manual online and it has a picture of this configuration with RCA cables from the preamp output to the sub low level input jacks. The output RCA jacks are for daisy chaining another sub so be sure you are connecting to the input jacks.
I agree with Paul that a splitter should work fine but to rule it out you could connect the preamp output to the RCA low level inputs of the sub. Turn up the crossover point and play some music. It won’t sound great but if you hear music without a hum the connection is working. If that works add the splitter at a the preamp but keep the only cable going to the sub. The other side of the splitter is empty. If that makes music that side of the splitter is good. Then move the cable to the other side of the splitter and test. Now you know both sides of the splitter are good and the sub is playing without hum.
Now add the amp connections on the empty sides of the splitter and see what happens…
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Blackharp, my Marantz CD player has the same two prong power inlet but was supplied with the standard three prong cord. Maybe the companies anticipated the hum issues Paul is referring to.
Karl
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Resolved. Strange thing, the splitters didn't work with the Citation II and BeePre2, but I recently finished the Kaiju and works fine. Very Interesting.