REL subwoofer and Vitus amps

[Kinsella]

Calling all Vitus owners with REL subwoofer(s).  I am awaiting delivery of a s510 to hook up to my RI101 Mk2 integrated.  The word is that RELs are great, and in particular when connected using the high level connection.  However, Vitus strongly recommend to NOT connect a sub directly to the speaker terminals  due to the balanced nature of the amp.

 

RELs now recommended approach to connection via the high level does not involve connecting to the 'negative,' speaker cable, with the black wire connecting to chassis ground instead.

 

So, this sounds like a safe approach for my Vitus, but Vitus' response to my query has spooked me.

 

Has anyone out there experience with using the high level connection to Vitus amps?

 

Appreciate any experienced advice

Cheers and merry Christmas

 

[Keith_W]

Balanced amps like the Vitus have a + and - which both carry signal. If you connect it to a speaker, there is no problem. But if you connect it to a sub via a high level input (which has its own amp inside), the subwoofer might connect - to the ground. This will send the - of the amp to the ground. 

 

The problem is not with the Vitus. The problem is subwoofer manufacturers who think that high level inputs are a good idea. The solution is to insert a 100 Ohm resistor between the negative terminal of the sub and your amp. 

[BugPowderDust]

REL's insistence on using high level inputs is really a furphy. You are far better off using low level inputs from a preamp to a subwoofer for a wide varierty of reasons.

• Low-level outputs, such as those from a preamp or RCA subwoofer output, transmit signals at line level, which is less prone to interference and noise compared to high-level outputs.
• When using a low-level output, the subwoofer's internal amplifier processes the signal directly without needing additional conversion. High-level inputs require the subwoofer to attenuate the amplified signal back down to line level before processing it

You will never properly integrate a subwoofer with your mains unless you also consider adding something with DSP capabilities in the signal path. You will think that you can get close with manual tuning, but it will be still miles away from the results a properly integrated DSP enabled system will deliver.

[Kinsella]

  On 24/12/2024 at 4:52 AM, Keith_W said:

Balanced amps like the Vitus have a + and - which both carry signal. If you connect it to a speaker, there is no problem. But if you connect it to a sub via a high level input (which has its own amp inside), the subwoofer might connect - to the ground. This will send the - of the amp to the ground. 

 

The problem is not with the Vitus. The problem is subwoofer manufacturers who think that high level inputs are a good idea. The solution is to insert a 100 Ohm resistor between the negative terminal of the sub and your amp. 

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Thanks Keith, appreciate the feedback.  Just not sure what you mean with the resistor.  The REL high level cable has 3 wires: red and yellow both being 'hot ' and black being ground.  REL no longer recommend connecting any wire to the negative speaker terminal. They recommend red to right positive, yellow to left positive, and black to chassis ground.

Are you suggesting 100 ohm on both red and yellow.

Also, to add to the confusion, there are many other amps out there with balanced differential design.  When auditioning the REL  it was hooked up as I described to a Gryphon 333, which I believe is balanced.

Cheers Dragan

[Kinsella]

  On 24/12/2024 at 5:40 AM, BugPowderDust said:

REL's insistence on using high level inputs is really a furphy. You are far better off using low level inputs from a preamp to a subwoofer for a wide varierty of reasons.

• Low-level outputs, such as those from a preamp or RCA subwoofer output, transmit signals at line level, which is less prone to interference and noise compared to high-level outputs.
• When using a low-level output, the subwoofer's internal amplifier processes the signal directly without needing additional conversion. High-level inputs require the subwoofer to attenuate the amplified signal back down to line level before processing it

You will never properly integrate a subwoofer with your mains unless you also consider adding something with DSP capabilities in the signal path. You will think that you can get close with manual tuning, but it will be still miles away from the results a properly integrated DSP enabled system will deliver.

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Thanks for your feedback.  Much appreciated 

 

Cheers Dragan 

[Keith_W]

  On 24/12/2024 at 10:04 AM, Kinsella said:

Thanks Keith, appreciate the feedback.  Just not sure what you mean with the resistor.  The REL high level cable has 3 wires: red and yellow both being 'hot ' and black being ground.  REL no longer recommend connecting any wire to the negative speaker terminal. They recommend red to right positive, yellow to left positive, and black to chassis ground.

Are you suggesting 100 ohm on both red and yellow.

Also, to add to the confusion, there are many other amps out there with balanced differential design.  When auditioning the REL  it was hooked up as I described to a Gryphon 333, which I believe is balanced.

Cheers Dragan

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You should check with REL. It's not Vitus' problem or anybody else's. I have no idea why REL should require 3 cables, my guess is one is from the left, another is from the right, and the third is a common ground. If you have a multimeter, you can also check the resistance between + and - on your sub. If it is at least 100 Ohm, you should be OK. 

[Kinsella]

@Keith_WThanks Keith.  I have sent a query to REL.

cheers

[JkSpinner]

  On 24/12/2024 at 10:04 AM, Kinsella said:

REL no longer recommend connecting any wire to the negative speaker terminal. They recommend red to right positive, yellow to left positive, and black to chassis ground.

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Thanks for the reminder to change mine.  I have also seen a video where you can connect both the high level inputs, and also the sub woofer out on the amp.  Not sure what this does though.

[Kinsella]

  On 24/12/2024 at 11:08 PM, JkSpinner said:

Thanks for the reminder to change mine.  I have also seen a video where you can connect both the high level inputs, and also the sub woofer out on the amp.  Not sure what this does though.

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I'm  certainly no expert, in fact a novice.  But I did see a video on YT by REL recommending to connect the LFE and either the high level or low level input.  That is for systems used for both 2 channel and theatre.  They say that the REL will then cover  a broader range than just the low frequency effects, and be set up for both music and movies.

Note they also say to not connect the high level and low level, as this can produce very high signal that can damage the unit.

[thimmy118]

My Audia Flight int amp is a balance amp. Currently, on my REL T9/X, I have the red cable connected to the ground pin of the phono input section on my amp as I do not play records anymore. I used to leave it hanging and not connected to anything but REL has since suggested that it should be grounded. It works fine - no humming or high frequency pitch. I also have a seperate AV amp and its bass output is connected to the low level connection on the REL. These two inputs are not connected at the same time though.

 

Cheers.

[Kinsella]

Thanks for that.  I think you mean black wire, rather than the red wire. The red wire is 'hot' whereas the black is ground.

 

I sent a query to REL and despite it being this time of year, they responded quickly.  They advised connection as per my description above is ok.  I have now wired it that way.  Although I think I'll go for the upgrade cable called Bassline, as it has spades and not bare wire.

[thimmy118]

Oops! Sorry my bad. Black wire it is and I have the baseline cable too and I find that it does make a difference to the quality of the output.

 

Cheers

 

Thim

 

[Unsound]

Hi Guys, 

 

A late comer to this, but I use the REL high level recommended procedure - Red to R, Yellow to L and Black to ground with my Vitus RI-101 MKII.

 

Works perfectly..

 

However on my previous amp - a PS Audio BHK 250, I had to use a resistor set up recommended by PS Audio to get it to work correctly .

 

Cheers,

 

M

[Kinsella]

Thanks for that @Unsound.  I have the black connected to the ground post in my Vitus RI 101 mk2.  When I put the amp into standby, it must disconnect the ground, as there is then a hum in the REL. Until I switch it off if course.

Same for you?

[Unsound]

No, absolutely not - just silence.

 

 

[Kinsella]

  On 15/04/2025 at 12:32 AM, Unsound said:

No, absolutely not - just silence.

 

 

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Mmmmm.....that's interesting 

[Unsound]

My wiring set up below:

 

Yellow and Red to +ve, black to GND.

 

I think you can connect Y & R either way and adjust using the phase switch.

 

Hopefully that helps

 

M