miniDSP Flex

[Megaken]

Sounds like a good solution. I've experimented with a few options in my current setup including a power strip with a master outlet that turns on the others when the preamp/streamer turns on. Also tried one of my subs as the master which has an auto wake function. Most reliable/current solution is using a 5v trigger switch in front of the power strip that is turned on by the streamer's usb port when it wakes up. I can start streaming music either from my phone or alexa, and the streamer, two monitors, and two subs all click on and start playing immediately. Could go on about this subject at length but don't want to derail this thread. Happy to continue over pm if anyone has input/questions.

What's the power strip you have?

 

[vandubi]

Thank you. Thats exactly what I was looking for.
From what I read, the Marmitek Audio Anywhere 630 might do the job. I cant find any decent reviews though.
I really wish there was some device to stream the PCM Signal via Wifi / DLNA.

As a follow-up to my earlier question: the WiiM Pro can stream digital input to other devices. So this could help to save some $ for multi room correction. Just use one Flex with pre configured filtersets for each room and stream the digital out via WiiM to each room.

 

[Igordit]

Hi guys, need some advice. Choose between balanced and unbalanced version. I plan to connect to an amplifier with only xlr inputs and to a subwoofer with rca - the main scenario. I also plan to connect the lfe from the receiver to the flex inputs - the second scenario. In both cases, adapters are needed, but where will there be fewer problems with connections? I'm leaning towards the balanced version, because the main goal is to improve the stereo.

 

[radix]

Hi guys, need some advice. Choose between balanced and unbalanced version. I plan to connect to an amplifier with only xlr inputs and to a subwoofer with rca - the main scenario. I also plan to connect the lfe from the receiver to the flex inputs - the second scenario. In both cases, adapters are needed, but where will there be fewer problems with connections? I'm leaning towards the balanced version, because the main goal is to improve the stereo.

It is a lot better to go balanced to unbalanced than the other way around. All you need is a balanced 1/4" TRS plug to RCA cable. The positive (tip) phase connects to the RCA, with the shield, and the negative (ring) is left floating. Very easy cable to make, or find an adapter for, or buy one. It should be standard item.

 

[Bjorn]

By going from balanced to unbalanced with Flex, one looses something like 15 dB of SINAD.
Edit: This is only for the input and not the output.

 

[Sokel]

By going from balanced to unbalanced with Flex, one looses something like 15 dB of SINAD.

It's the other way around:

 

[Igordit]

First I will describe my system: Hegel H390, Audiovector sr3 for stereo, Marantz 1609 with central and surround speakers (for front I use fixed rca inputs on amplifier) for cinema and Svs 2000 pro, Rel q150 for both scenarios. I want to improve my stereo system using Hegel dac loop (From manual - The function makes it possible to upgrade the digital inputs of the amplifier with an external high-end DAC. This is done by connecting the jitter reduced coaxial digital output of the amplifier to the external DAC. The output of the external DAC will need to be connected to the XLR input of the amplifier). Also I want connect two unbalanced subwoofers to balanced outputs of flex, using recommendation for cable by developers like Sokel say.
The second scenario - use both subwoofers for home theatre. I want connect my rca outputs of receiver to Flex balanced inputs for bass management then to trs to rca subs. Is it enough signal for the last one? I don’t want reconnect cable for stereo and HT every time.

 

[Sokel]

First I will describe my system: Hegel H390, Audiovector sr3 for stereo, Marantz 1609 with central and surround speakers (for front I use fixed rca inputs on amplifier) for cinema and Svs 2000 pro, Rel q150 for both scenarios. I want to improve my stereo system using Hegel dac loop (From manual - The function makes it possible to upgrade the digital inputs of the amplifier with an external high-end DAC. This is done by connecting the jitter reduced coaxial digital output of the amplifier to the external DAC. The output of the external DAC will need to be connected to the XLR input of the amplifier). Also I want connect two unbalanced subwoofers to balanced outputs of flex, using recommendation for cable by developers like Sokel say.
The second scenario - use both subwoofers for home theatre. I want connect my rca outputs of receiver to Flex balanced inputs for bass management then to trs to rca subs. Is it enough signal for the last one? I don’t want reconnect cable for stereo and HT every time.

No,this is the case (bold) described in the post above.
What's the point using low noise components if they're about to degrade so much?

(The 15db SINAD penalty is on the bench I suspect,it will be worst in real world conditions)

 

[antcollinet]

By going from balanced to unbalanced with Flex, one looses something like 15 dB of SINAD.

No, that is only on the analogue input going from unbalanced to balanced. Even than you are dropping from around a SINAD of 105 to a SINAD of 90. Not a problem for most analogue sources. Or any source come to that.

Flex Balanced connectivity: Which TRS to RCA cable should I use?

The Flex balanced is balanced in/out. If you'd like to use an unbalanced amplifier (e.g. Powered subwoofer) downstream of the Flex series, here is the recommended TRS to RCA cable to minimize detrimental effect on the audio quality. Note how...

support.minidsp.com

EDIT : Ahhhggg - what they ^ all said.

 

[antcollinet]

What's the point using low noise components if they're about to degrade so much?

But degrading from very very inaudible to just very inaudible. And this on a LFE channel. I don't think this is going to be an issue.

 

[Sokel]

But degrading from very very inaudible to just very inaudible. And this on a LFE channel. I don't think this is going to be an issue.

As long as the device is safe and no noise heard,agree 100%.
It's the company's warning that worries me.

 

[antcollinet]

As long as the device is safe and no noise heard,agree 100%.
It's the company's warning that worries me.

It is an odd way of putting it for sure.

I've always taken it as a sign of the importance of good measurements ASR is managing to drive into the industry. Companies bought into it like MiniDSP don't want their reputation for good measurements tarnished, so are making the warning of degraded performance very prominent.

I can't see any mechanism whatsoever that would result in any sort of "safety**" issue. Certainly what they are warning of (a 15dB loss of SINAD) has absolutely zero safety implications. I've been using unbalanced to balanced on the input to my flex since day 1 (for turntable) and have seen no problems, audible or otherwise.

(** I assume by safe, you are meaning safe for the equipment - obviously there are not going to be any personal safety issues here)

 

[Igordit]

Thanks all for answers. Antcollinet, as I understood you use recommended cable by developer for inputs and outputs of your flex balanced and its safe. What about quality of minidsp cables? I have master who can do hi quality cables for the same price.

 

[antcollinet]

Thanks all for answers. Antcollinet, as I understood you use recommended cable by developer for inputs and outputs of your flex balanced and its safe. What about quality of minidsp cables? I have master who can do hi quality cables for the same price.

For the input I use standard RCA to TS (no ring) cables. This is fine, since on the input connecting the cold terminal to sleeve (ground) is not only safe, it is needed. The cable suggested by MiniDSP should not be used on the input, since it leaves the cold terminal floating and able to pick up noise.

On the output I've made up my own cables, by cutting the RCA off the end of a standard interconnect and soldering on a TRS in place. This means I don't follow the exact wiring suggested by MiniDSP (in mine, the shield is connected at both ends and is used for the analogue return). It works fine. MiniDSPs reccomendation would give some better immunity to ground loops - but I seem not to suffer from that in my current installation.

Regarding source of cables - go with whatever is most convenient.

 

[Sokel]

(** I assume by safe, you are meaning safe for the equipment - obviously there are not going to be any personal safety issues here)

If it was about personal safety (apart that if something expose the full output and blow ears) it would be a different conversation

 

[antcollinet]

If it was about personal safety (apart that if something expose the full output and blow ears) it would be a different conversation

In my just posted reply to @Igordit I've just noticed something. In the warning they state:

We've noticed a performance drop (15dB SINAD drop) when using such adaptor for INPUTS of the FLEX

The adapter they are talking about is the one they've specified for outputs - but it leaves the cold terminal unconnected and uses a signal wire for the ground return. I wonder if that could be a source of the loss of SINAD when using it for an input.

Two problems - the low impedance shield is not used for the analogue return - which means the impact of a ground loop is worsened, and secondly the cold input terminal is left floating and able to pick up any interference.


I have a feeling they've just used a poor method of connection for the RCA to balanced conversion. Certainly using a thin signal wire for ground rather than shield on an unbalanced connection is really bad.

 

[Sokel]

In my just posted reply to @Igordit I've just noticed something. In the warning they state:



The adapter they are talking about is the one they've specified for outputs - but it leaves the cold terminal unconnected. I wonder if that could be a source of the loss of SINAD when using it for an input.

Two problems - the low impedance shield is not used for the analogue return - which means the impact of a ground loop is worsened, and secondly the cold input terminal is left floating and able to pick up any interference.

That would be nice to know when I measured it (and returned it) but I guess makes sense to think about it this way.

 

[Igordit]

Is my amplifier can be volume master when it connect from flex trs outputs to fixed balanced inputs? Because when I connect my receiver to amplifier using fixed rca inputs, I can control volume of receiver from amplifier - like back connection.

 

[radix]

Is my amplifier can be volume master when it connect from flex trs outputs to fixed balanced inputs? Because when I connect my receiver to amplifier using fixed rca inputs, I can control volume of receiver from amplifier - like back connection.

If the Helel volume control is applied AFTER the digital out loop, then this will not work with the subs coming off the Flex. They would see full volume. You would have to use the Flex volume control. If the Hegel volume is applied BEFROE the digital out loop, then this would work with the subs.

If the volume is AFTER the digital out loop, you would need to put the subs on the VARIABLE OUT from the Hegel. The Flex would still equalize them, but it would not be able to independently do time correction or cross over the mains and sub.

 

[Igordit]

But now I use hegel like front amplifier in my 5.1 HT. And when I control volume from hegel, my receiver marantz 1609 also change volume in center and back speakers including sub. I can see in it in receiver screen. It’s synchronise through rca, like back connection.