Trying to get a good Headphone solution using RedBox.

I'm new to all this stuff, so bear with me!
I have a GM40 and Barefaced Cabinet 2 * 12. I practice early mornings and sometimes late at night.
Looking to utilise the GM40's natural sound through to a set of Headphones. I was thinking Redbox to either Focusrite Scarlett Solo or Presonas Audiobox iOne to good open-back studio Headphones. I have an iRig HD 2 connected to Redbox, the sound through Headphones is sh1t (getting some kind of background hum, increasing gain or volume makes the setup useless). Anyone got any words of Wisdom, don't have the knowledge to go this alone. Iv'e read up on XLR, line level etc. and am more confused than when I started. As they say, a little knowledge is a dangerous thing...

Hi Benny.

My views on this would possibly not be the same as some other members.  I'm an electronics engineer and that is where I firmly stand.  For me, (and the whole of the rest of the electronics world if not the music one), the engineering is the aspect on which predictability and reliability are based.  Mojo is just engineering that the user doesn't understand.  Mojo breeds myths!  Trying to rely on it is not the way to get to a true understanding of something nor is it the basis of any reliable solution.

Your need for a headphone output is very real.  I will say that I have never heard live guitar played through headphones which sounds convincingly live to me.  The in-head effect of the headphones always makes the playing sound kind of artificial to my ears.  But that said, whether I'm right or wrong on that point, it is a useful tool to have when you are living a normal lifestyle with other humans around you.  What you want is to have sound shaping capabilities within every component up until the headphone amp.  That should be as transparent and characterless as possible.  That is if you want your eventual sound to be controlled and shaped by the amp alone without any uncontrollable effects to deal with.  The last thing I would have thought you need is for an additional component with its own character being stamped on the sound.  So that principle should rule out any ideas of "this unit has a more sparkly top end but that one has a more solid bass".  If a headphone amp is half decent it will be flat response across the board and that isn't an expensive thing to achieve with the type of signal we are dealing with, this is not 0.001% distortion hifi!

The units you mention are money you will need to spend so the decision needs to be made with common sense applied.  If you can use the Focusrite and Presonus full capabilities then great.  They will do the job of headphone interface well if.  They will not be top of the range at this, they wouldn't hold up in a true hifi setup for example, but they will be designed to be absolutely adequate for our field. But if guitar to headphones is the only functionality you need from them then any fair quality headphone amplifier will do the job as long as it has that wrongly hated "characterless" quality.  There are some out there which are perfectly adequate at about 1/3 the price of the Scarlett Solo.  Make no mistake a "characterless" quality cannot in any way be "imposed" onto the signal the amp is acting on making it bland.  If the signal in turn is made to sound dead then the amp is by definition not characterless!  That's one way of expressing the definition of hifi and a reasonable slice of that is what you are looking for in the final stage of the headphone amp, (not the other components preceding it which actually shape the guitar signal tone of course).

But I accept you may want the other functionality that the more expensive interfaces will offer of course.  They will do the job you want.  It is a simple task.  Take the output from the Redbox, which is supposed to be a finished processed signal right down to speaker output, and boost it up without any further alteration to drive the headphones.  Your wallet will dictate your buy but there is little to ask of a unit without the discussion becoming that much loved topic of guitarists with gear, cork sniffing.  

Bordonbert,

Thank you for taking the time to write your reply. I don't require any of the added features that both of these units offer. You are correct, I'm just looking for Guitar to amp, Redbox to Headphones. Your post got me thinking - I tried the TRS cable from the RedBox straight to my Headphones, got sound in one Ear (guessing I have a TRS Cable with a Mono 1/4 Jack). I noticed that when I turn up the Volume on the Amp the volume goes up in my Ear, however the more I crack up the volume the more crackle and unwanted noise I get. I'm assuming a TRS with Stereo 1/4 Jack would sort the sound in both Ears? Would a Headphone Amp sort the Crackle and unwanted noise, should I be using TRS Mono or Stereo Cable to connect to the Headphone Amp? Again thanks for the heads-up on the Headphone Amp, I reckon you have saved me €70! Thanks!

Glad to help with the saving money aspect.  There is far too much "it's more expensive so it MUST be better" thinking in the guitar world.  I love simple and cheap solutions to our challenges and they are usually just as good as more expensive routes, often much better!

Most of the simple headphone amps you can get will be designed for standard audio use.  By that I mean the the connectors used will be intended for hifi use so will be a pair of RCA plugs or possibly a 1/4" TRS plug as they will all be stereo.  I can't find any common units which work with XLR plugs direct, at least cheaper ones such as we can use.  There is one technical aspect you should understand first.  An XLR output such as the Redbox, even in a mono setup like our amps, is actually a pair of signals rather than just one with a ground.  The two signals are out of phase with each other, one is the exact reverse of the other almost like mirror images.  A receiving circuit which is designed for this type of communication, (it's known as "balanced" or "differential"), has a pair of inputs with one expecting the +ve and the other the -ve version.  That is why the XLR connectors you see in mixing desks have three contacts, two signal lines and a ground/screen.  Once they reach the receiving circuit they are both amplified by exactly the same amount, but the -ve side is also effectively inverted back to a +ve signal and the two are combined.  The reason why this is better is simple.  If the two signals are carried in the same cable then any noise which is picked up will be the same in both lines.  When the -ve signal is inverted in the receiving circuit's input stage so is the noise so that is now a -ve version of itself.  When that is combined with the +ve version the two noise signals will now cancel out.  Balanced lines are used anywhere in electronics where good noise immunity is needed.

Code:

Redbox     Cable              Amp Input
Output   Adds Noise      Inverts -ve and sums
+Sig -> +Sig +Noise -> (kept as is) +Sig +Noise
-Sig -> -Sig +Noise -> ( inverted ) +Sig -Noise

Added together in input stage:  (+Sig +Noise) + (+Sig -Noise) = 2x +Sig    Noise cancels out.


I think you could assume that you will have two inputs to the headphone amp, a left and a right, and I haven't seen any common simple units which have a stereo/mono switch.  Here is one which does but it is a second hand unit.  It's cheap and it will certainly do the job, it would be my sort of choice, but you may prefer to look for something new.  Amp with XLR Inputs and Mono/Stereo Switch  Here is another of the more easily available new ones.  RCA Inputs only and No Mono/Stereo Switch  This one has only the basic stereo RCA inputs and no mono but we can get round that with cables.  Anything in that sort of ballpark which has the simple functionality we need will do.  Decent hifi quality is good enough for us in the guitar world.  Why worry about distortion of around 0.05% when we are trying to introduce distortion of around 5-10%?  The tiny contribution is absolutely inaudible.

You can get a custom style XLR -> RCA cable.  These do exist but they usually only go to a single RCA plug which would be fine if you have a mono/stereo switch of course. You could add a simple RCA splitter or Y-adapter to that to give left and right signals and you are done.  Make sure to get a 2male-1female so the female fits onto the end of the XLR/RCA cable and "copies" the signal onto both of the male plugs.  If you aren't sure about any of this then just have a think and a look around then get back to us with any ideas for units to buy and we can advise.

Does this all make sense?

Bordonbert,

Over and above the call of duty (yes it all makes sense)! I'm living in Ireland, so going to pull the trigger on the second hand unit you suggested. My understanding from your post, unless I'm mistaken is that I can use a XLR cable from the Redbox straight into one of the Ports on the back of the used Ebay Amp. I could then use the second port on the back of the Headphone Amp and connect it to a an iPad with XLR Cable to play backing tracks? The Backing-track feature is not important, not sure I have a use for it - I use a looper. Again I really appreciate the effort that you went to, to help me out. Thanks!!

Kudos for the idea of the backing track, that never occurred to me.  Yes that would actually work but bear in mind that without a Mono/Stereo switch you will get a very separated sound setup then.  The guitar would be exclusively in one ear and the backing track would be exclusively in the other.  That will sound a bit weird and unnatural but it is perfectly workable.  If that doesn't work for you another option could be to go a step up and consider a small domestic mixer with headphone output built in. Of course the Mono/Stereo switch sorts that problem out.

Have a look at this unit, it is pretty much what I would have considered Mixer with Headphone output  An advantage here is that you have two separate inputs, each with XLR and 1/4" jack in the same socket which is an advantage from the Redbox point of view.  You can cable direct in, mix your signals, balance their levels, then output to headphones all from the same unit.

If that seems to be useful have a look on ebay as there are many units like this on there.  This one has a US plug attached and they send you an adapter with the unit.  I don't like that approach but it may be fine for your situation.

Again, thank you! The Seller with the XLR offering on Ebay, will not ship to Ireland. You have given me an idea of what I'm looking for... I have mulled over the the Mixer, think I'll keep it simple and go with the simple Headphone option you suggested. When you add in more tech, it detracts from playing - practice and the fun of learning new techniques. As you said in one of your earlier posts, headphones and Guitar are not natural - I'll continue to blow the Doors off when my Wife goes out! Your concise explanations above have really helped me understand the basics of my needs and you have saved me Money to boot! Thankyou.

Excellent news. Glad you got something which you can use. Let us know when you get things up and running, it can always help someone else looking for the same thing.

Happy strumming!

On the back of Bordonbert's help, I pulled the trigger on one of these.
Amazon Prime - £20 ($27).

Donner EM2 in-Ear Monitor Amplifier Analog Headphone Amplifier Stereo Headphone Earphone Amp Volume Control Audio Booster with 2 XLR and TRS Input 3.5mm Output Jack.

https://www.amazon.co.uk/gp/product/B08D8Y8J2H/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Looks like it will allow me to go GM40 Redbox - EM2 (XLR) & use my iPad headphone jack - EM2(TRS) to play backing tracks/Guitar technique Video's. Hopefully, I'll be able to mix the two signals and get a decent sound through my Headphones.

I'm not sure if I'll need a Mono 1/8 - 1/4 or Stereo equivalent TRS Cable. Unit should arrive in a couple of days, so I'll update the post and let you know how it works out!

I’ve tried all the tricks and shorts cuts with headphones on the GM as I have similar needs for headphone use at times. In the end I spent more money trying to save money than if I had just took the right approach the first time around which was Redbox into a inexpensive 4ch mixer. Love the results since doing it and very happy with the headphone tones I can get. The best benefit was not having to actually use the headphones when I normally would have needed to. By that I mean with the mixer and a couple of 6” studio monitors on the outputs I can drive the amp as hard as I want into the mixer and then just crack the volume on the mixer getting killer sound out of the studio monitors without any higher volume levels than the sound of the guitar playing acoustic. Point being you should consider a mixer to get the most out of your gear and when you do actually use headphones the EQ features you have on the mixer help to have a lot. If I remember my mixer new was around $100 usd so second hand you could find something decent for less

Irocdave12,

Thanks for the suggestion... The Kit turned up and have it doing exactly what I want for now. If it decides to kick the bucket, I'll look at something more durable. My main concern with cheap stuff is fire (I don't leave this thing plugged in when I'm not using it)! The Headphone Tone is good/loud enough for me, I'd say your setup lets you dial it in and get better sound. I'm also trying to keep my Rig simple (Amp, Cabinet, Headphone amplifier, Tuner, Looper). I know I'm doomed if I start down the Pedal path :-)!