Balanced output to unbalanced Input, to Float pin 3 or short pin 3 to Grd?

[CoolCat]

I had to come back to this thread due to my having buzzing and horrific sound issues on this ISA430 to the Line 6 UX8 unbalanced Line In.
Tried the Pin 1 to 3 and the float 3 and it was still distorting and buzzing a lot. I wondered why is this so hit and miss and it works then it doesn't and its noisy or anemically thin?

Feeling like a dull tool...I just realized (read online) this UX8 interface is not just a cheaper Unbalanced Line In....its a cheaper -10 signal Line Input Unbalanced designed for -10 consumer stuff and drum machines and keyboards. ...not +4 outboard preamps etc...

It gets financially expensive this "technical rabbit hole".
To buy a Pro ISO Radial is too expensive for 8 channels...for a $100 interface from 2009. No go...

To buy a new interface that workins in +4 and has Balanced LINE IN is pretty expensive.

To just use the Outboard Preamp into Interface Mic Preamp XLR balanced is FREE. (and last I looked I wasn't making any money on this gear. lol)

so appreciated all the inputs and help before, but apologize because I left out it was a "unbalanced Line In but also -10 consumer, line in, 10k impedance.
and the ISA430 has +4 only with transformer out balanced....

Doubt anyone is interested in a Line 6 UX8 interface but the Balanced to Unbalanced discussion was informative!

 

[LazerBeakShiek]

It outputs -10. Not the end of the world really.

+4 is where it is at.

A Focusrite6i6 USB gen2 interface is about $50.
a Presonus MP-20 microphone preamplifier, Discrete, has Jensen transformers. Mono output bus and stereo output busing. About $100 on reverb.
I rarely lose money when I sell my gear. Keep your shit clean. Keep it nice.

 

[ecc83]

CoolCat, +4dBu down to neg ten is, near as Behringer is to swearing, a 12dB loss. Very close is the series combination of 8k2 and 2k7, -10dBV across the 2k7. That gives a load on the source of 10.9k not going to bother anything remotely decent. Those resistor values do not take into account source resistance nor input resistance but should be near enough. If the signal is a bit low, swap 2k7 for 3k3, if high swap 8k2 for 9k1 or 10k. A box of dinky Metal Film resistors is peanuts from Zon.

A transformer output should be on XLR 2 and 3 (tip and ring for jack) I doubt it will have a centre tapped ground to pin 1. You may or may not need to connect pin one (jack sleeve) to the destination ground depending on whether or not you get a ground hum.

Jusfort! Balanced -10dBV inputs are as rare as rocking horse dropping but should you need one, split the 8k2 into 2X 3k9 "either side" of the 2k7 and take the signal again across the 2k7. Rin drops a bit to 10.5k, still nay bother.
Dave.

 

[CoolCat]

the Focusrite 6i6 allows software switching to +4 or -10....wish this had that.

what's weird is I swear it was working for this, but it was really buzzing and thin/distorting sounding.
the old Aphex 207 here... allows unbalanced Output with a -10 or +4 switch, nice little feature for consumer-gearheads.
none of my other preamps do that. UX8 Line 6 state the units have good headroom of 18.5? whatever that means.

rocking horse droppings? lol

 

[Steenamaroo]

I had to come back to this thread due to my having buzzing and horrific sound issues on this ISA430 to the Line 6 UX8 unbalanced Line In.

Might be stating the obvious here but if you're using an unbalanced connection between preamp and interface, you're at the mercy of whatever noise is in the environment so are you
1: Using the shortest cable possible
and
2: Keeping your cable away from obvious sources of noise, like transformers, power supplies, etc?

UX8 interface is not just a cheaper Unbalanced Line In....its a cheaper -10 signal Line Input Unbalanced

Unbalanced inputs generally are.
It's not a guarantee but a reasonable expectation.

Not seeing why running both devices from the same power socket and using your shortest TRS patch cables shouldn't be fine.
If your patch cables run by a big ass transformer or something, you might need to do some rearranging.

 

[ecc83]

"UX8 Line 6 state the units have good headroom of 18.5? whatever that means."
Headroom is usually referring to an input and means how many dBs over the Operating Level the device can handle before distortion sets in. Sometimes (but rarely!) they will state the distortion level at the dB level, e.g. "+20dBu at 0.1%THD" For comparison, these days you would expects distortion to be lower than 0.01% at all levels below that.

But! These specifications are nightmare for the non-technical. First we have two (at least) op levels, +4dBu about 1.2V rms* and -10dBV 0.316 V rms. Now, is that headroom figure stated ref "dBu" that is referred to 0.775V rms or is it reffed one volt? Matters coz the first is 6.5V and the latter 8.4! Manufacturers are bloody terrible at giving good, rational specifications. Often a frequency response of a mic is given as a bare "50Hz to 16kHz" is that ref 1kHz and how many dBs up or down at the extremes?

This did not matter or happen so much 50 years ago. The studio and hi fi magazines (when the latter were run by engineers and not beardy tweaks!) would review perhaps 3 or 4 items per issue and woe betide any firm who failed to supply a properly written specification! They would be castigated by the experts and the firms knew that would lose them sales. Today the market is flooded with kit and there is no time nor enough technicians to sort the buggers out.

*rms? Don't sweat it, it is the "normal" way to specify an alternating voltage and the suffix is rarely shown.


Dave.