TOPIC:

My Lepai amp will automatically switch between 3.5mm and RCA based on new input. It would be nice if the 2x4 HD could switch between RCA/Toslink/USB based on input, so I don't have to manually switch it. This would be great for Echo Input integration.

That's a good idea. I've built a remote control free setup in my living room and to achieve this, I'm using a passive stereo mixer Rolls mx42.
Both the audio from the music source, video source and Bluetooth source are always on, mixed together and sent to the amplifier.
While using a passive mixer doesn't add any noise, it definitely limits the maximum line volume by many dB.

It would be so nice of the MiniDSP (2x4 HD in my case) had the ability to mix multiple inputs OR had auto input switch feature as suggested in the post above!

Note that the MiniDSP 4x10 HAS the ability to mix one analog and one digital input on it's routing tab : (page 21)
www.minidsp.com/images/documents/miniDSP...%20User%20Manual.pdf

supermattt wrote:

It would be so nice of the MiniDSP (2x4 HD in my case) had the ability to mix multiple inputs OR had auto input switch feature as suggested in the post above!

Yes!!! Yes!!! Yes!!!

I control what is playing by, ... wait for it... , by controlling what is playing.

I often want sources such as Alexa or my PC to be able to barge in. Having to go flip the source selector, say "Alexa, what is the weather today", and then go flip the source selector back to my Squeezebox is a real pain. Instead, I just pause the Squeezebox, ask Alexa my question, and the resume playing the Squeezebox.

Because of that, I use an Ashly LX-308B as the preamp for my home office configuration so that all sources are always on (and I can level the volume across each source). I would have bought the SHD in a fast minute if it had the option of mixing (instead of switching) input from the network port, a digital channel, the USB channel (if separate circuitry from digital), and the audio channel.

Hi,
Yes, this should not just be a feature request or suggestion, but a "speaker-damage-prevention" request!

Scenario: the minidsp has two sources:
1. TOSLINK input is usually a 0dB signal without volume control. (from a TV)
2. Analog Input which comes from a Rotel pre-amp (selecting between CD, vinyl, iPhone, etc....)
--> The minidsp outputs are connected to the Rotel power amp (no volume control).

To match the input volumes of the two minidsp sources, the preamp must be max volume - which is a non-normal situation for most applications. The master volume of the minidsp must be reduced (by remote) for a TOSLINK source. For a pre-amp source, the pre-amp volume control can also be reduced.

Now listen to a pre-amp source, and the user mistakenly controls the minidsp master volume control to 0dB instead of lifting the pre-amp volume dial (preamp is at say 1/4 volume, and minidsp vol is max). If someone presses "SOURCE" (to TOSLINK) on the minisdp remote, then the speakers receive a 0dB (max volume hit).

This is dangerous!! (I am very lucky not to have damaged my speakers when this occurred).

Please, minidsp, give the user an option to couple the input selector dropdown box with the config.

Many thanks,
Trevor

Anybody know if there exists a purely digital mixer, which can accept multiple digital inputs and mix it in a single digital output? 

This is something a computer could do fairly well (windows or linux) . Even a raspberry pi would work well. Just have to find the right usb digital input interfaces

I was thinking the same, but couldn't find any Raspberry Pi projects which could do this. 

I think I will go for an automatic spdif input selector instead, such as this one www.tindie.com/products/beni_skate/autom...calrca-audio-switch/

Morten14 wrote:

I was thinking the same, but couldn't find any Raspberry Pi projects which could do this. 

I think I will go for an automatic spdif input selector instead, such as this one www.tindie.com/products/beni_skate/autom...calrca-audio-switch/

Good find, this device looks awesome!

Whilst these external mixer ideas are nice, it does not solve the miniDSP issue of switching between SPDIF and analog inputs (on the miniDSP) and the different dB gains incurred.
I think this needs to be in a minDSP firmware update that the input selector is included/saved in the config setting. Then one can switch configs instead of switching inputs, where the difference between config 1& 2 is just the input gain and input selector.
Alternatively, the miniDSP firmware should normalise the SPDIF and 2V/4V inputs to the same dB gain...
 
The workaround to this firmware exclusion are the suggestions here about external digital mixing.
Cheers,
Trev