Guys,
on the audio interface from steinberg, the UR44, there are 6 channel ins:

Channel 1 and 2 -->Mic/Hi-Z
channel 3-4-5-6--> Mic/Line

They call the channels 1 and 2 'Mic / instrument'
My simple question: knowing those 2 channels, 1 and 2, can accept both a mic signal, or a guitar... or a bass,

I was wondering, could those 'instrument' channels also accept line signals?
Also, stupid question, are there any instrument--> line adapters ?

Too bad steinberg didn't use those first 2 channels as mic/Inst/Line inputs, just like they did on some of their other interfaces, instead of only Mic/Inst....
...yeah, with 6 line channels, on a 350 € interface, people would think twice, before dropping 800€ on the UR824

 

For inputs "1 & 2', if you plug a TRS-line level, or an XLR-line level signal, you'll wind up with an impedance mismatch. You can use a DI box to convert Instrument to Mic level. If you're plugging in a Hi-Z instrument like a guitar or bass, then make sure that your DI has at least a 1 megaohm input to plug your instrument into.

You could try a RADIAL JDI which could convert your signal from XLR-LINE to XLR-MIC.

 

In that Audio interface, instruments chanel can be used for line signal.

 

Thanks for your reply.
I checked your radial jdi, thinking 'if it's a little 20 bucks adapter, i will get 2' ..... wow, it's almost the price of the audio interface. But it must do much more than dimly converting signals...

I wonder if some special audio driver exists, so we could use several audio interfaces at once (a few interfaces allow some kind of daisy chaining, up to 3 devices, but must be natively built for that purpose)

There are apps for virtual cables, virtual midi ports, etc etc...it shouldn't be that hard, to create a windows driver capable of sending/receiving data from 2, 3 or even 5+ audio interfaces at once.
It smells like an 'industry' limitation, so users can't just buy 3 interfaces for a total of 600 bucks, and have the same ins/outs as a 3'000 $/€ interface.
Any dev that would code such app would quickly be in trouble.

 

I think RME can have multiple interfaces connected. But seeing that ASIO drivers are quite specific to each device it would he hard to create a perfect ASIO driver for all interfaces at once (asio4all is an example of how this isn't reliable in all situations). So you could say that it is individual manufacturer's responsibility to decide if they wanna do it.

Supposedly it's not easy to code - something about usb being unreliable here, google it for more information. Maybe they indeed maybe want to keep people from combining cheaper interfaces. Who knows - but it's interesting that RME is known as they only company with perfect drivers so there might be some truth that it's not easy to create and they have their own secret sauce.

 

Yes, such a thing exists and is called a preamp. Traditionally you'd step instrument level down to mic level with a DI box and then use a mic preamp, but lots of preamps these days include combo XLR/TS jacks that let you skip the DI box part

There's no problem with having too high of an impedance at your inputs. High impedance (Hi-Z) inputs mean you don't need a lot of current, which passive devices (guitar pickups) can't deliver and thus suffer a high frequency rolloff. Instrument inputs are actually easier to drive, line is more challenging. The only issue I could see with instrument level inputs is you'll probably get lots of gain so watch your levels. With some audio interfaces you can even get clipping with the gain at zero when using a line-level signal.

TL;DR: Hi-Z/instrument input is a feature, not a problem, line levels work with it

Pretty much all audio interfaces with instrument inputs use JFET-input opamps these days. TL072 ($0.35 in one-off quantity, likely a lot cheaper in high volume) has its input impedance rated for a typical value of 10^12 Ω, that is 1 TΩ or 1,000,000 MΩ. TL072 is the low noise variant, there's also TL062 (low power) and TL082 (wide bandwidth). All are rated for 10^12 Ω. There's no need for a separate DI with such a high input impedance. TL082 is found in cheap Behringer ADAT preamps (ADA8000, ADA8200), so you can imagine some higher-end interfaces use even better spec parts. For passive DIs the issue stands.

No, that's not what a DI box is for. The purpose of JDI is to convert instrument level unbalanced TS jack to mic level balanced XLR, also providing a passthrough via unbalanced TS jack. There aren't even two XLR sockets on it, so you would have to get creative with adapters to use it that way. Line level is higher than instrument level. So you might end up with not enough attenuation and get clipping, possibly even in the DI itself since it wasn't designed to handle line level.

Well, functionally that's it. It's basically just a transformer in a metal box. The quality and price of said transformer influences the price. In some cases, you'll hear it influence the sound.

It exists. In OS X it's built into the system and called an aggregate device. In Windows you'll need to use ASIO4All.

It's not really a 'industry limitation', you just need lots of knowledge about how Windows works and how to write drivers. Might also be an issue with Windows not letting you mess too much with modifying the drivers. After all, virus programs could do the same. So it might be not worth the time to learn all the hardcore driver programming stuff, when you'd have to tell your users to enter debug modes, disable security settings etc.

Also, as far as adding I/O goes... ADAT is not really adding I/O since you need a chip in the interface itself to grab the ADAT signal and decode it. For more flexible I/O options you should probably be looking at AoIP - Dante and digital snakes. That way you just plug one more box with 16 inputs into your router. There's an ASIO driver that lets you route any of the signals around, and have 32 or 64 (would have to check) inputs at once in your DAW

 

I meant to reference the JDI duplex. It converts XLR LINE to XLR MIC, as well as HI-Z to XLR MIC

When mixing, I sure as hell will not output a line signal from my DA converter through my outboard gear back into a HI-Z input, and I would not plug a passive guitar into a LINE input @ ~2-10kΩ. Passive guitar gets no less than a 1 MΩ input over here - JDV, RNDI, REDDI, or JDI DUPLEX (with an active buffer before the input.) If the source isn't captured correctly then what's the point? my $0.02

 

Last edited: Apr 10, 2019

There's no problem with that. The tone doesn't suffer in anyway, line level means the output of your gear is powerful and can sustain anything you plug it to, even line. It can work with instrument/hi-z inputs very easily so no problem there. You will need to just turn down the gain on your instrument input very low.

Yeah, that's very valid of course. Though I wouldn't be surprised if the inputs went straight to a opamp-based preamp (since there's still gain on the line inputs usually, just less of it), so you might get hi-z anyway, just with less gain.

 

A user said an instrument socket can accept a 'line' signal. Fine.
But the problem is, will the line signal be too 'hot' for the hardware, and create a lot of artefacts, distortion, etc etc ?
Because steinberg have interfaces with mic/inst/line sockets, others like mic/line, and others like mic/inst.

IF steinberg really wanted users to be able to connect a line signal on a LABELED #mic/inst# socket, without any problems, maybe they would have labeled the socket as 'mic/inst/line...?
So, if they didn't do it. .. maybe we are not supposed to do it, simply. .. maybe the line signal is just too hot, and the mic/inst socket don't have the capacity to digest that hot turd of a signal. ..?

I remember when, by mistake, i would try to connect the phones cinch (red & white) connectors from my 1210mk2 to a 'line' socket on the mixing desk, , the sound, or signal, would be too weak.

Another rant, but,
Couldn't the industry just make some standards, and have one socket for many cables and signals, symmetrical or not, trs this, trs that. .. i mean, one socket, where the device , mic, etc, will be auto detected, and its done. Phone signal ? Amplify it. Need 48v ? Enable 48v.

 

Too hot is not a problem if you have output volume in whatever source you connect to the input. Just start with the volume at zero and slowly turn it up. If it's still too loud, you'll need something to turn that volume even lower. A pad switch (-20dB) in your interface, or a pad in the form of an adapter that you plug between the source and the interface, or a DIY homemade cable that lowers the volume by 20dB should help.

Because a turntable is not a line-level output. You need a phono preamp to get line level. Think about it. The little needle cannot deliver a powerful signal like eg. a synthesizer would produce. It's more like a microphone, you'd have to first boost it up.

The thing is, audio is simple. It's not like USB where there's communication between the devices. USB is a bit like:

"Hey PC, you there?"
"Yes, I'm here. Who are you?"
"I just came here, I'm a mouse"
"Okay mouse, what kind of mouse are you?"
"I'm a Logitech mouse"
"Okay Logitech mouse, you are now free to talk to me"

Audio is way simpler. There is just the signal and nothing else. You can't really detect if 48v is required. XLR is just XLR. What if it's a tube microphone that has a separate power supply? Or a ribbon that would get destroyed by 48v? The closest we got is XLR/TRS combo jacks with a line/instrument switch.

 

cheap interfaces usually don't support line-level signal on instruments inputs, seek for manual online of the interface and read there for actual information

 

There isn't anything to "support". If they set up the gain knob so you can get it low enough to not clip, it's "supported". That's it. If you're still clipping, you'd need to turn down the output volume on wherever the line-level signal comes from, or use a pad/padded cable. There's no issues of impedance, the only thing to care of is level.

 

Always read the manual