MOTU UltraLite-mk5 Review (Audio Interface)

[Dathzo]

Hi all,

With the new Ropiee released (Linux kernel 5.15), are we god to use a Motu interface for multichannel output with Ropiee?

2022.04

• IMPROV: extend reboot schedule options
• IMPROV: restore Alarm Clock extension configuration upon update
• IMPROV: upgrade Linux kernel to 5.15
• IMPROV: switch to different NTP implementation
• IMPROV: [display] various UI improvements
• NEW: support for the Allo miniBOSS DAC HAT
• NEW: auto-update functionality

 

[mdsimon2]

Give it a try. I tried it on Moode when they updated to kernel 5.15 but had issues with network connectivity. I believe there is an underlying raspberry pi OS issue (no such issue on Ubuntu) and has something to do with how the Ultralite Mk5 is a combined Ethernet-USB device. I described my experience here -> https://www.audiosciencereview.com/...s/rpi4-camilladsp-tutorial.29656/post-1118170. Sound wise everything seemed fine which is a big improvement over older kernels.

Michael

 

[Dathzo]

Initial test: it does work. Output music is seen in the channels. I tried with headphones and works fine. Need to listen to the other channels, but in principle, seems we are good to go

 

[mccarty350]

Question for the group here. I think this was discussed earlier but the conversation was a bit over my head.

Is using unbalanced TRS to RCA in the MK5 possible or will there be issues? I know that the output voltage will be much hotter so I'll have to build in some attenuation to compensate but will this not work from a simple electrical perspective, etc. or am I going to run into real issues.

Thanks!

 

[DWPress]

@mccarty350 - Shouldn't be any problem going TRS to RCA as you intend.

 

[Nspace]

Question for the group here. I think this was discussed earlier but the conversation was a bit over my head.

Is using unbalanced TRS to RCA in the MK5 possible or will there be issues? I know that the output voltage will be much hotter so I'll have to build in some attenuation to compensate but will this not work from a simple electrical perspective, etc. or am I going to run into real issues.

Thanks!

Unbalanced TRS is really called a TS connector.

The thing with MotU Ultralite mk5 is that plugging a TS connector 'shorts' its outputs, which are designed to accept balanced three prong TRS males instead.
From the manual, "Quarter-inch line outputs are not cross-coupled. Therefore, when connecting them to an unbalanced input, use a TRS plug with the ring disconnected. Not floating the negative terminal will short it to the sleeve ground and cause distortion."

Therefore, either connect a full balanced TRS or alternatively utilize a TRS connector with its ring (2) disconnected, at cases where the plugged cables' other ends are unbalanced connectors (TS or RCAs). Never plug TS connectors to Ultralite MK5 outputs.

This has been originally discussed in this very same thread at post #201, 202, 203 and 204, where most of the above concepts were extracted from with good additional information. Particularly read the seminal RANE paper about these standards.

 

[mccarty350]

Thank you for the clarification. So basically there is no off the shelf product that has the ring disconnected it would actually require modification. It also means you can't use one piece TRS to RCA adaptors, you would have to have ones that are TRS on one end and then have a cable that terminates in an RCA so that you can get in and disconnect the ring if that makes sense. Am I understanding this properly?

 

[Nspace]

It also means you can't use one piece TRS to RCA adapters, you would have to have ones that are TRS on one end and then have a cable that terminates in an RCA so that you can get in and disconnect the ring if that makes sense. Am I understanding this properly?

Exactly.

I would suggest you don't name them "one piece TRS to RCA adapters". These properly are TS to RCA adapters.
So to avoid helping spread further confusion here and elsewhere.

 

[mccarty350]

Exactly.

I would suggest you don't name them "one piece TRS to RCA adapters". These properly are TS to RCA adapters.
So to avoid helping spread further confusion here and elsewhere.

Roger that. I found 10 packs of solder TRS connectors on amazon for a very reasonable price and I already have plenty or RCA ends and coax I used for making DIY custom length interconnects so it shouldn't be tough to fabricate my own using those materials.

I have not purchased the motu unit yet but am strongly considering it. I currently use a Behringer UMC1820 as my audio interface for fully active DIY speaker implementations (and I also was able to leverage it to eliminate my minidsp 4x10 driving a pair of Linkwitz LX521.4's) but the Behringer drivers are flukey and the line level outputs are anemic. The noise floor is also unacceptable and when switching sample rates it clicks and hitches. Resampling everything on the front end solves this but I'm not in love with the work around.

 

[Atanasi]

Roger that. I found 10 packs of solder TRS connectors on amazon for a very reasonable price and I already have plenty or RCA ends and coax I used for making DIY custom length interconnects so it shouldn't be tough to fabricate my own using those materials.

If you want to use ready-made parts:

TRS-2xRCA cables are readily available. The white side connects to the positive pole, and the other pole is left floating. Female RCAs are preferred, so that the connectors are not touched by accident.

 

[differenceclouds]

So.... in order to get the least distorted signal when using unbalanced equipment (nearly 100% of professional outboard gear, let's be honest), I need to buy 10 of these, and leave the red side of each unused? That is uhh.... not ideal. I'm grumbling

If you want to use ready-made parts:

 

[MCH]

You might also use this?

Post in thread 'miniDSP Flex' https://audiosciencereview.com/forum/index.php?threads/minidsp-flex.28660/post-1172004

 

[differenceclouds]

What about something like putting some particularly resilient tape over the portion of a normal TS connector where the ring of a TRS connector would be? That would get the job done right?

 

[Trell]

What about something like putting some particularly resilient tape over the portion of a normal TS connector where the ring of a TRS connector would be? That would get the job done right?

I would not risk having any tape or glue stuck in the jack, especially as good connectors/adapters are cheap.

 

[differenceclouds]

I just tried it with heat shrink tubing, and it doesn't really work. The tubing would have to be flush with the rest of the sleeve to fit properly. Almost felt smart!

 

[mccarty350]

This is amusing coming back to see this thread and all of my racing thoughts voiced by others. I literally thought the same about wrapping the ring in either tape or silicon based crazy glue in a layer that would stop conduction, etc. etc. but then thought about how any of it coming off in the jack housing would really damage some nice and not incredibly cheap equipment. At the end of the day here's a dirt cheap option and Atanasi's suggestion was just brilliant about using the dual female RCA to TRS premise.

Monoprice 1/4in (6.35mm) TRS Stereo Plug to 2x RCA Jack Splitter Adapter, Gold Plated - Monoprice.com

6.35mm (1/4 Inch) Stereo Plug (Male) to 2 RCA Jack (Female) Splitter Adaptor - Gold Plated Warning: This product may contain a chemical known to the State of California to cause

www.monoprice.com

At a whopping $0.49 a piece you can buy 10 of them to have a few spares in case one is bad and then use a toner/continuity test to find out which one of the RCA's maps to the ring and then you can take a sharpie and mark it and use the other for your connection. I'm not a believer in boutique cabling so I have no shame in using something cheap as long as it works. The only question is whether or not these wider dual RCA fixed position connectors will fit on the back of the motu stacked one atop the other or not. But given that the position is fixed it eliminates the chances of anything touching or shorting out.

 

[Nspace]

EDIT: I read more carefully and it is an Stereo TRS to RCA...

Monoprice 1/4in (6.35mm) TRS Stereo Plug to 2x RCA Jack Splitter Adapter, Gold Plated - Monoprice.com

6.35mm (1/4 Inch) Stereo Plug (Male) to 2 RCA Jack (Female) Splitter Adaptor - Gold Plated Warning: This product may contain a chemical known to the State of California to cause

www.monoprice.com

 

[MCH]

EDIT: I read more carefully and it is an Stereo TRS to RCA...

Monoprice 1/4in (6.35mm) TRS Stereo Plug to 2x RCA Jack Splitter Adapter, Gold Plated - Monoprice.com

6.35mm (1/4 Inch) Stereo Plug (Male) to 2 RCA Jack (Female) Splitter Adaptor - Gold Plated Warning: This product may contain a chemical known to the State of California to cause

www.monoprice.com

Still valid, just use the L RCA and leave the other not connected.

 

[Nspace]

Still valid, just use the L RCA and leave the other not connected.

Yes, stereo TRS to stereo RCAs would probably be internally connected like this:

When you get them, could you check this and confirm? Thanks

 

[mccarty350]

So basically a valid $5 solution if you ignore shipping/tax and have any time of electrical tester to check continuity.