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Discussion Starter #1
Just wondering if anyone knows how to convert a MiniDSP 2x4HD kit into a 2x4HD balanced kit ? - A kind and knowledgeable member on the MiniDSP forums said that it is possible. I cannot find any step by step references that explain the procedure. Basically, the idea would be to replace the 6 RCA connectors with XLR connectors and wire them to be truly balanced.

Has anyone out there achieved this successfully ?
 

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Discussion Starter #2
I have some DIY instructions that explain how to achieve this but I'm not an electronics engineer.

Any electronic DIY whiz-heads here that would not mind helping ?

Essentially, what I am talking about is not some quick conversion hack, adapters or conversion cables. I am talking about upgrading or enhancing the 2x4HD to have actual and proper balanced interfaces (XLR based) in place of the existing RCA connectors.
 

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I have some DIY instructions that explain how to achieve this but I'm not an electronics engineer.

Any electronic DIY whiz-heads here that would not mind helping ?

Essentially, what I am talking about is not some quick conversion hack, adapters or conversion cables. I am talking about upgrading or enhancing the 2x4HD to have actual and proper balanced interfaces (XLR based) in place of the existing RCA connectors.
I’ve been wanting to do this for quite a long time also, still don’t know why MiniDSP haven’t just released an XLR version. If you get one built please post in this thread how!
 
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I’ve been wanting to do this for quite a long time also, still don’t know why MiniDSP haven’t just released an XLR version. If you get one built please post in this thread how!
Good to hear from you and to learn that I am not alone in this endeavour.

All we need is an electronics engineer or someone who is knowledgeable about electronics. I have a DIY paper that explains how to do it and am looking for someone who would not mind helping out.
 

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I too don't understand why MiniDsp doesn't sell this version. I would love to use MSO when my theater is finished but am not willing to lose a true balanced signal path.

Would you mind posting the DIY paper you found or a link to it?

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This is also something I'm after. I mistakenly bought the 4x10HD only to find out after the fact it's a MUCH different beast.
 

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I too don't understand why MiniDsp doesn't sell this version. I would love to use MSO when my theater is finished but am not willing to lose a true balanced signal path.

Would you mind posting the DIY paper you found or a link to it?

Sent from my SM-N975U using Tapatalk
If you only plan to use a miniDSP on your LFE channel, there's not much to lose signal integrity-wise going balanced vs unbalanced unless you have hum issues due to ground loops. There are several ways to solve that problem if it does occur, and going balance doesn't necessarily guarantee you won't have hum issues anyway.

The real reason to get the miniDSP HD is to take advantage of BEQ for movies. I don't believe the balanced versions of miniDSP are able to support BEQ.
 

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There are a few more reasons to go with the HD.

The HD has the ability to add more than 7ms of delay, works with the WI-DG, IIRC can be upgraded to use DIRAC...


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The real reason to get the miniDSP HD is to take advantage of BEQ for movies. I don't believe the balanced versions of miniDSP are able to support BEQ.
That's the frustrating part. They use the inferior unbalanced connectors with the better processor and the better balanced connectors with the inferior processor. I would like to try BEQ at some point but don't know if I will if I have to sacrifice my unbalanced connections from prepro to sub selector switch to amps. First I have to finish my room.



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You still can use BEQ with a non HD minidsp. You simply connect your laptop to your mini and manually input the PEQ settings and enjoy. The 2x4hd does make it much easier and quicker by simply loading the file using without having to connect a usb cable... by way of the wireless adapter of course:)
 

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Discussion Starter #12
Here is a quote from another paper written by Bill of Jensen Transformers, it makes a lot of sense:-

The price alone of high-end audiophile equipment might imply that designs are state-of-the-art.
Manufacturers often tout very impressive measurements of performance. But, because the
measurements are made in a laboratory setting, they reveal nothing about the noise problems
that are all too common in real-world systems. Sadly, most audiophile and virtually all consumer
audio devices still use unbalanced interfaces that are inherently extremely susceptible to powerline
noise. This seems ironic when you consider that the signal-to-noise ratio of available program
material has steadily increased over the last 50 years.
 

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You could use the high quality jensen transformers on outputs...........

The easiest way with no modifications is simply to buy Aphex 124 units, for as many xlr outputs that you need. They sell cheap and once hooked up after your dsp , will convert your signals to balanced, with zero distortion or loss of output.
 

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Discussion Starter #14
You could use the high quality jensen transformers on outputs...........

The easiest way with no modifications is simply to buy Aphex 124 units, for as many xlr outputs that you need. They sell cheap and once hooked up after your dsp , will convert your signals to balanced, with zero distortion or loss of output.
Thanks John, I've noticed the Apex 124B has 2 RCA input interfaces and I presume these correspond to the 2 XLR output interfaces - is that right ?

Furthermore, this device is not merely a converter, it is providing a true balanced interface ?

So one would need to 2 Aphex 124B units to benefit from 4 fully balanced outputs ?
 

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Thanks John, I've noticed the Apex 124B has 2 RCA input interfaces and I presume these correspond to the 2 XLR output interfaces - is that right ?

Furthermore, this device is not merely a converter, it is providing a true balanced interface ?

So one would need to 2 Aphex 124B units to benefit from 4 fully balanced outputs ?
That is exactly the idea.... you could get a racked pair........ many for 68 bucks a pair at the moment.... and have all 4 outputs on the mini dsp covered, with full signal down to 5hz. Personally I use one after my AVR, and then use an xlr splitter, running two balanced drive racks.

The same thing after the mini dsp will convert you to full XLR outputs........ There is also a 128 that does 8 outputs in one unit. but the quality is much better with the 124,,, plus it gives you extra level controls. The construction of these 124 is of the highest quality standards available.

One is best to pay attention to serial numbers , and get units 20000 and up.... for the most up to date pcb. I recap all mine with muse es bp bipolar caps, and put new ucc kyb capacitors in power supply , just because I can..... The only issue is one needs to use cheater plug on the aphex to avoid the ground loop....

I still got 6 spares I plan on using down the road, when expansion time comes.
 

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Discussion Starter #17
That is exactly the idea.... you could get a racked pair........ many for 68 bucks a pair at the moment.... and have all 4 outputs on the mini dsp covered, with full signal down to 5hz. Personally I use one after my AVR, and then use an xlr splitter, running two balanced drive racks.

The same thing after the mini dsp will convert you to full XLR outputs........ There is also a 128 that does 8 outputs in one unit. but the quality is much better with the 124,,, plus it gives you extra level controls. The construction of these 124 is of the highest quality standards available.

One is best to pay attention to serial numbers , and get units 20000 and up.... for the most up to date pcb. I recap all mine with muse es bp bipolar caps, and put new ucc kyb capacitors in power supply , just because I can..... The only issue is one needs to use cheater plug on the aphex to avoid the ground loop....

I still got 6 spares I plan on using down the road, when expansion time comes.
John you come across as a very knowledgeable person in terms of electronics - do you think there is a way to upgrade the 2x4HD kit (board) to a fully balanced workflow or would that be too time consuming and complex ?
 

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John you come across as a very knowledgeable person in terms of electronics - do you think there is a way to upgrade the 2x4HD kit (board) to a fully balanced workflow or would that be too time consuming and complex ?
At one time they had a balanced unit available...........

Even if you managed to just balance the in / outs , by installing XLRs somehow. ( These look pretty slim for that), you would still have a unit designed to provide consumer audio output Level signal. Personally I would not see it as worth the time, to actually mod a unit, that can be converted to a completely balanced device, buy adding some second hand Aphex 124a units.

Simply adding the 124s does the completed mod........ leaving all equipment original, for resale down the road..... with little risk in losing equipment trying to change it.....

If your device before the mini dsp is an AVR with a consumer audio signal....... Simply making the entire unit balanced, would not provide full benefits. In my books, unbalanced and balanced devices are incompatible, until the impedence mismatch is resolved first.

Depending upon what is used before and after an unbalanced device in the chain, even if the mini dsp was balanced, it would not work to its full potential being inserted between unbalanced devices. A balanced device is not simply one with 3 conductors vs 2. A balanced device operates on a completely different voltage level... and all features of the device will only work properly and to their full potential if driven, and driving,other balanced devices.

A good well shield rca cable is relatively noise free........ Note the wikipedia definiton of a balanced connection.



The term balanced comes from the method of connecting each wire to identical impedances at source and load. This means that much of the electromagnetic interference will induce an equal noise voltage in each wire. Since the amplifier at the receiving end measures the difference in voltage between the two signal lines, noise that is identical on both wires is rejected. The noise received in the second, inverted line is applied against the first, upright signal, and cancels it out when the two signals are subtracted.
 
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Thanks John for such a detailed and informative post! I will now be able to consider using the minidsp between my balanced gear because until now I totally ruled out the minidsp due to lack of balanced connections.

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Discussion Starter #20
My experience with unbalanced has not been smooth, I would rather maintain a balanced workflow. My devices have both balanced and unbalanced interfaces.
 
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