The Canadian Guitar Forum banner

1 - 14 of 14 Posts

·
Premium Member
Joined
·
4,280 Posts
Discussion Starter #1
I run my guitar signal through the Presonus AudioBox iOne and then output into two guitar amps. To me, the sound is great but I know the output from the iOne is balanced TRS.

Someone said I should be using an adaptor to take the balanced signal out of the iOne and convert it to unbalanced. Why?

iOne.png
 

·
Premium Member
Joined
·
3,178 Posts
Why they suggested that is becasue people thnk that the in and outs have to be matched perfectly for things to be right. This is not always the case.

Most electronically (vs transformer) balanced outputs in modern prosumer type gear will be servo balanced meaning that they sense whether the cable is shorting ring to sleeve on the other end and so that's not an issue (check yer manual).

In your specific case there is a further issue which is output level of the Presonus. With a balanced out, I would expect it to be pro line level, which will be a bit hot to put it mildly, for a guitar amp input. It will work fine but you will find that you are having to turn down either/both the output on the Presonous or the input gain on the amp, somewhat significantly. This can be fine, and if what you hear is good, carry on.

What you could do is try using a 'reamp' type box. Most of these will do a few things: pad the signal or provide a volume control, as well as simulate the reactivity of a pickup so that the amp 'responds' as it would plugging a guitar straight in. Others will also isolate the signal (with a transformer). Easy enough to DIY. If you google there are plenty of DIY projects well documented out there; you can build one for very cheap. A commercial one (by anyone who makes DIs, eg Radial) will cost you $100+/-.
 
  • Like
Reactions: greco

·
Premium Member
Joined
·
4,280 Posts
Discussion Starter #4
To Greco, yes, I did read that whole thing and learned quite a bit but nothing that really helped me as I'm not experiencing any issues.

To GG, yes, the signal seems to be a bit hotter than the one that was coming out of the GT-100 if the position of the volume knobs on both devices have similar ranges. Without touching the volumes on the amps (from where they were before) I'm at 1/4 volume on the iOne whereas the GT-100 was a little less than half to get the same sound level as before. I'll investigate the re-amping options you mentioned but it will be a low priority as I think everything sounds just fine. I just didn't want to damage any equipment or get less than optimal performance out of my gear.
 

·
Premium Member
Joined
·
4,280 Posts
Discussion Starter #5
Ok, so I did some quick checking on passive reamp boxes and they seem pretty neat. You can buy kits for about $50.00 that you can build yourself. They all take XLR as inputs though.
 

·
Premium Member
Joined
·
3,178 Posts
Anything XLR can be replaced or adapted to TRS (use TRS to XLR cable to plug the Presonous outputs into the box, or just build the box with TRS jacks instead).

Unless the kit has a brand name transformer in it, that's a bit expensive; you can do waaaaaay cheaper, but it can be a pain to source all the parts if you're not into building things as a hobby.
 

·
Premium Member
Joined
·
4,280 Posts
Discussion Starter #7
Anything XLR can be replaced or adapted to TRS (use TRS to XLR cable to plug the Presonous outputs into the box, or just build the box with TRS jacks instead).

Unless the kit has a brand name transformer in it, that's a bit expensive; you can do waaaaaay cheaper, but it can be a pain to source all the parts if you're not into building things as a hobby.
Yes, the one I was looking at used a made-in-USA transformer. I know I could prob gather all the parts for about $15.00.
 

·
Premium Member
Joined
·
4,280 Posts
Discussion Starter #8
Anything XLR can be replaced or adapted to TRS (use TRS to XLR cable to plug the Presonous outputs into the box, or just build the box with TRS jacks instead).

Unless the kit has a brand name transformer in it, that's a bit expensive; you can do waaaaaay cheaper, but it can be a pain to source all the parts if you're not into building things as a hobby.
Would it matter if the TRS to XLRis stereo or mono?
 

·
Premium Member
Joined
·
3,178 Posts
Yes. But to be clear the cable itself is not mono or stereo; the cable is just a cable. It is what you plug it in to (e.g. a stereo output or a mono balanced output) that is the relevant thing. If you are plugging in to a single amp, there's not point going stereo, just use the Left output only from your Presonous and don't use any 'stereo' effects because they won't work properly anyway. If you do run stereo signal (20 2 amps) then you need 2 reamp boxes (or a stereo reamp box) - the XLR input on the reamp bix will be expecting a mono balanced signal. Sending a stereo signal to the box may screw up the differential input.
 

·
Premium Member
Joined
·
4,280 Posts
Discussion Starter #10
Yes. But to be clear the cable itself is not mono or stereo; the cable is just a cable. It is what you plug it in to (e.g. a stereo output or a mono balanced output) that is the relevant thing. If you are plugging in to a single amp, there's not point going stereo, just use the Left output only from your Presonous and don't use any 'stereo' effects because they won't work properly anyway. If you do run stereo signal (20 2 amps) then you need 2 reamp boxes (or a stereo reamp box) - the XLR input on the reamp bix will be expecting a mono balanced signal. Sending a stereo signal to the box may screw up the differential input.
Would the cable not be TRRS if stereo? Right now, I have the iOne Left going to one amp and the Right going to another. My iPad's FX software is set to stereo output with a mono input (guitar). I know I'd have to build/buy two kits, one for each output. Not sure the stereo effect is worth it. I can just ABY the amps together using my Radial anyway. If I do go this route, I wanted to make sure I bought the right type of XLR to TRS cable. They're pretty cheap anyway.
 

·
Premium Member
Joined
·
3,178 Posts
Nope. T = Left, R = Right and S = common ground for an unbalanced stereo connection. For balanced stereo on one jack you'd need 2 more conductors (no such 1/4" jack exists) not just 1 and the grounds to not have to be seperate. Think standard headphone jack (the second R on your phone headset/output jack is for the input mic, vs the stereo output; they all share the common ground on the S).
 

·
Premium Member
Joined
·
4,280 Posts
Discussion Starter #12
Nope. T- Left, R - R and S - common ground (unbalanced). For balanced stereo on one jack you'd need 2 more conductors not just 1 and the grounds to not have to be seperate. Think headphone jack (the second R on your phone is for the mic, vs the stereo output).
Ah OK then. So it doesn't matter which cable I buy. Makes things easier as they all seem to be called stereo. Thanks for all your assistance btw, you are a fountain of knowledge and I'm just catching the edge of the spray :)
 
1 - 14 of 14 Posts
Top