You are here

Stereo to mono summing cable

Customising, building or repairing your own gear? Need help with acoustic treatment or soundproofing? Ask away…

Re: Stereo to mono summing cable

Postby Scramble » Fri Sep 08, 2017 8:48 pm

The whole point -- to me at least -- is to have it all contained in a cable, and NOT have to buy a box to do it. There's no shortage of stereo-to-mono boxes, and I have one myself. But I'd rather not have to have another box to cart around.

I was thinking of making my own cable a while ago using the Rane instructions, but although I can solder I've found that putting resistors into cables is pretty difficult for someone with my abilities -- I've done it with pseduo-balanced cables, but I don't want to do it again, it's fiddly, and slow (for me), and I don't really trust the reliability of what I produce in such cases. So I got a Radial box instead.

As for how much I'd pay, I'd go with £30-35 seeing as it will be well-made, and seeing as a stereo-to-mono converter in a box would cost at least that much, and seeing as I suggested this idea in the first place. But at that price it may not get many takers so I'd understand if SOS said No Can Do.

(I suspect a lot of people just buy cheap splitter cables from Maplin and use those, not knowing any better.)
Scramble
Frequent Poster (Level2)
Posts: 2466
Joined: Wed Sep 11, 2002 12:00 am
 

Re: Stereo to mono summing cable

Postby Folderol » Fri Sep 08, 2017 10:18 pm

You all do realise that these resistors can be miniscule don't you?

They will be dissipating negligible power, so if you go for 125mW items the resistor body is about 6mm long - if you are 'of an age' your biggest problem will be seeing them!

The trick is to put the series resistors in the L & R plugs, and the shunt in the mono plug. No plug has more than two resistors, and the ones that have two are the easiest :)

Finally, at that kind of impedance you can forget any possible cable capacitance issues - cutoff frequency in the MHz range :lol:
User avatar
Folderol
Jedi Poster
Posts: 9201
Joined: Sat Nov 15, 2008 1:00 am
Location: The Mudway Towns, UK
Yes. I am that Linux nut.
Onwards and... err... sideways!

Re: Stereo to mono summing cable

Postby ManFromGlass » Fri Sep 08, 2017 10:59 pm

I suspect I know the answer but is it worth considering providing a ready-to-solder kit? With clearer than IKEA instructions? And perhaps a magnifying glass for those of my age.
User avatar
ManFromGlass
Frequent Poster (Level2)
Posts: 2362
Joined: Sun Jul 24, 2011 12:00 am
Location: In the woods in Canada
 

Re: Stereo to mono summing cable

Postby Scramble » Fri Sep 08, 2017 11:01 pm

Folderol wrote:You all do realise that these resistors can be miniscule don't you?

That doesn't necessarily make things easier! Easier to fit in perhaps, but not easier to solder.
Scramble
Frequent Poster (Level2)
Posts: 2466
Joined: Wed Sep 11, 2002 12:00 am
 

Re: Stereo to mono summing cable

Postby bikefreeek » Tue Nov 06, 2018 8:20 pm

I know this thread/topic has been a little dormant, but I have a question for it that I hope that some of you will be able to help out with.

Is it necessary to sum going from dual mono to mono?

I'm specifically interested in the headphone out from most korg volcas, which are dual mono, to a single channel on a mixer. I've found affordable TRS 1/8" to TS 1/4" cables that would do the job, but do not have the resistors in a stereo to mono summing cable. My guess is that a stereo to mono summing cable is not needed, but I would love some assurance. Thanks!
bikefreeek
Posts: 1
Joined: Tue Nov 06, 2018 7:57 pm

Re: Stereo to mono summing cable

Postby Martin Walker » Tue Nov 06, 2018 9:18 pm

Hi bikefreeek, and welcome to the SOS Forums! 8-)

bikefreeek wrote:I know this thread/topic has been a little dormant, but I have a question for it that I hope that some of you will be able to help out with.

Is it necessary to sum going from dual mono to mono?

I'm specifically interested in the headphone out from most korg volcas, which are dual mono, to a single channel on a mixer. I've found affordable TRS 1/8" to TS 1/4" cables that would do the job, but do not have the resistors in a stereo to mono summing cable. My guess is that a stereo to mono summing cable is not needed, but I would love some assurance. Thanks!

I can hopefully reassure you that no resistors will be required. Invariably a dual mono output of this type is for headphone use, and since both L and R signals will be identical it's highly likely that they will simply be connected to exactly the same point in the circuit.

In other words, they will already be connected together, so no summing is required ;)


Martin
User avatar
Martin Walker
Moderator
Posts: 14609
Joined: Wed Jan 13, 2010 9:44 am
Location: Cornwall, UK

Re: Stereo to mono summing cable

Postby Sam Spoons » Tue Nov 06, 2018 10:35 pm

And if you decide you want to do the same with a stereo source (iPad/iPhone or WHY) Jon at Orchid Electronics made me a TRSmini to TS ¼" summing lead for less than a tenner.

http://orchid-electronics.co.uk
User avatar
Sam Spoons
Jedi Poster
Posts: 10584
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Previous

Who is online

Users browsing this forum: N i g e l