MSB Technology: SubWoofer Isolater?? Make Any Sense?

LL21

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Dec 26, 2010
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Hi All,

This MSB piece is an attachment to the Analog Output of a Preamp that helps block 'incoming hash' from a SMPS Subwoofer that might be feeding back into the preamp. Any thoughts on this? I have no problems that I am aware of with the CJ GAT. We use one RCA output set to the amp, and there is a 2nd set of RCA outputs which goes to the Sub.

Is this MSB piece made for a setup like ours? Not particularly focused on making any changes, but was reading up on MSBs latest digital and happened to see this and was just curious to know people's thoughts.

http://www.msbtechnology.com/accessories/sub-isolator-features/

Below is from their Website:

"The Sub-woofer Conundrum

Sub-woofers need a lot of power, and they are not too sensitive to high frequency noise. So speaker makers like to match their sub-woofers up with some pretty low quality amplifiers, with switching power supplies and not much filtering. So whats the problem? The sub-woofers sound OK. The problem we found is that you have to hook that sub-woofer up to your ultra clean, ultra precision, perfect analog output from your DAC or Preamp. The presence of this noisy sub-woofer amplifier just being hooked up to your DAC creates incredibly obvious noise and thus distortion on your main amplifier and speakers. Its like serving fine wine in dirty glasses. Its just intolerable.

The Nightmare Began

It all started when we had a customer demo our volume control in a Diamond DAC, and they preferred their preamp. Well that does not happen very often and we are always puzzled when it does, for in our experience, NO preamp sounds better than NO preamp. But suddenly we saw the pattern. An external powered subwoofer was present. We dug back into other cases where a preamp was preferred and sure enough, more powered sub-woofers. So the testing began.

We hooked up an excellent speaker and external powered sub-woofer and they sounded OK but certainly not what we had hoped for. We turned off the sub-woofers and the sound came alive. Turned them on but disconnected the input. Still sounded great. Turned them on and hooked them up but turned sub level all the way down. Sounded horrible. It was not the sound of the sub that was the problem, it was the pollution caused by that nasty plate amp stuck in the back of the sub. Thus started a crazy time of desperate and incrementally more dramatic modifications to get both good bass, and completely transparent mids and highs. We finished and made music so sweet that no one who knew the speakers could believe what they were capable of.

The Solution is not an option but a necessity

The solution was a magic little box that provides a sub-woofer output that is completely ground isolated from the source and blocks noise and feedback. We have made a whole range of these devices because when you are considering a powered sub-woofer, the difference this kind of isolation makes is astonishing. So we have a configuration for every kind of system.

A Preamp Alternative

One of the roles of a preamp is to provide dual isolated outputs. But being an all purpose tool, it filters and isolates all the outputs. It blocks much of this sub feedback, but at the expense of the quality of the mains. This isolator allows a minimalistic signal path, with a single analog attenuator for volume control as the one we use in the DAC IV. So your primary AMP gets a perfect signal, and you still have an isolated sub-woofer output without having to resort to active buffers. This passive isolator is not cheap, but compared to the quality of preamp you would need to obtain this level of isolation, its a real bargain."

There are 5 Different Types of Sub Isolators. Here is the one that might (if any) pertain to the 2nd set of RCA outs of a CJ GAT?

RCA In and Out (MSB DAC IV owners with Single-Ended primary AMP and Single-ended SUB)


"This unit is for use when you have a have a dedicated RCA sub output. It acts as a line filter. It is used on the MSB DAC IV if you are currently using the RCA output for your primary amplifier, and want to use the second RCA output for your sub-woofer."
 
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bonzo75

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Interesting find, thanks
 

LL21

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asiufy

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Loyd,

You should reach out to MSB's Vince Galbo, and ask away! He's a wealth of knowledge in all things related to AC power and audio equipment, and this particular product might've actually been created out of his ideas/suggestions. He's absolutely insanely critical about AC power, and I'd say one of the reasons the MSB rooms are always among the best in shows is because he is THAT picky about it, and does everything he can to nail that part of the system.

His contacts are up on the MSB website...


cheers,
alex
 
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LL21

Well-Known Member
Dec 26, 2010
14,411
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Loyd,

You should reach out to MSB's Vince Galbo, and ask away! He's has a wealth of knowledge in all things related to AC power and audio equipment, and this particular product might've actually been created out of his ideas/suggestions. He's absolutely insanely critical about AC power, and I'd say one of the reasons the MSB rooms are always among the best in shows is because he is THAT picky about it, and does everything he can to nail that part of the system.

His contacts are up on the MSB website...


cheers,
alex

Thank you and yes, they were very responsive in the past and will ask. will come back with answers.
 

Keith_W

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Mar 31, 2012
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It would be good if he could come on WBF and explain a few things.

My subwoofers are powered by Class H (i.e. a non-switching amplifier, or a variant of the Class A/B design), so I would doubt if they inject much noise but of course I could be wrong. However, I do know that subwoofers are not the only devices that inject noise into the mains. There are also: refrigerators, wall warts (that charge your phones, etc), Ethernet Over Power (EOP), your neighbours, and so on. I can not even begin to count how many switch-mode power supplies are plugged into the mains at my home: there are 3 computers, fax machine, laser printer, monitors, TV, and countless wall warts (2 phones, 2 tablets, 2 laptops, 4 clocks, home security system and cameras, doorbell ...!!!).

I am curious why MSB think that subwoofers are the main culprit when there are so many other candidates. Is it because they inject particularly high amplitude spikes into the mains?
 

sbo6

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May 18, 2014
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Just a FYR - JL Audio Fathom subwoofers employ optical isolation on the unbalanced inputs so run out and buy a JL Audio sub ;-)
 

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