Questions & Answers

Can the 2 1/4" inputs on the front of the Quantum 2 be used for line level signals?

0 votes
asked Feb 15, 2018 in Thunderbolt - Quantum by markszymanski (520 points)
Hello, it appears that the front 2 inputs can only be used for mic or inst., no line level on the Quantum 2. Is this the case? Only the 2 inputs on the back accept line level? Thanks

5 Answers

–2 votes
answered Feb 21, 2018 by philangus (10,130 points)
Yes. I suggest you watch one of the many available reviews on YouTube for example.
0 votes
answered Feb 21, 2018 by markszymanski (520 points)

@philangus thanks, but your answer isn't helpful at all. I've read and watched many reviews. The PreSonus website says this:

The Quantum 2 offers two combo mic/instrument inputs and two combo mic/line inputs, each with a digitally-controlled XMAX preamp and individual +48V phantom power.

So, they make it sound as if it's only setup for DI impedance. Obviously you can stick a 1/4" cable in there and record, but there will be an impedance miss match if it's not able to accept line level signals.

Further more, the manual says:

Microphone inputs. Your Quantum-series interface is equipped with 8/4 digitally controlled PreSonus XMAX microphone preamplifiers for use with all types of microphones. The XMAX design provides a Class A input buffer, followed by a dual-servo gain stage. This arrangement results in ultra-low noise and wide gain control, allowing you to boost signals without increasing noise. The ¼-inch front panel inputs on Quantum can be either line or instrument. By default, they are set to line. These inputs are not switching on the Quantum 2.

So, again, it's reading as if they are not. I've heard a few people say they are, but would like a concrete "YES" from presonus. Thanks

0 votes
answered Feb 21, 2018 by philangus (10,130 points)
My apologies, I didn't notice the 2 on the end of Quantum, so I was basing on my own knowledge with the Quantum (not Quantum 2). The Quantum states it can be switched between + 4db and -10 db. I would be surprised if the 2 does not have the same functionality but I can't say for sure.
0 votes
answered Feb 21, 2018 by markszymanski (520 points)
No worries! I thought maybe I'd get an answer here from presonus, I normally don't use these forums so wasn't sure. I'm really used to support from companies like Universal Audio, Motu, Focusrite etc where it's easy to make a call or drop an email. I literally just went through a loop on the presonus site submit a question. It's a huge turn off for me...
0 votes
answered Feb 22, 2018 by philangus (10,130 points)
edited Feb 22, 2018 by philangus

Extract from the Quantum manual which includes both models:

When a ¼-inch TRS cable is connected to the inputs of your Quantum-series interface, you will be provided with an input sensitivity toggle switch. By default, the input sensitivity is set to +4 dBu. Most professional line-level devices output at this level. Consumer line level is usually -10 dBV. For these lower output devices, switch the input sensitivity to -10 dBV to match your device.

Power User Tip (Quantum users): By default, inputs 1 and 2 are set to line, inputs 3-8 default to mic when nothing is connected

So the first paragraph seems to be referring to the series so both models and the line in bold is referring to the inputs of the Quantum. My guess is (and it is only a guess) the Quantum 2 is the same so should probably read as follows, however, the manual is not clear!

Power User Tip (Quantum 2 users): By default, inputs 1 and 2 are set to line, inputs 3-4 default to mic when nothing is connected