Reversing channels
Feb 26, 2006 at 11:47 PM Thread Starter Post #1 of 16

Christianbro

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I haven't posted in awhile but always enjoy reading Head-Fi. The other day something exciting happened. While listening to my HD600 by accident I put them on backwards. All of a sudden these laid back phones came alive.

I guess at my age some of the highs going into my right ear don't register. So I've been reversing from side to side by turning the phones around on my head. It works, but I think a switch on the amp before the phones would be nice. Is that possible or would it interfere with the signal?

Thanks, Dave
 
Feb 27, 2006 at 12:21 AM Post #2 of 16

Garbz

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yeah that is easy to do and won't audibly effect the signal. You need a DPDT switch (2 poles, 2 Toggles). Run the L and R into the switch's middle contacts, and the headphones from the side contacts, one of them reversed. It works the other way round too sourcing the headphones from the middle. but you get the idea.
 
Feb 27, 2006 at 1:35 AM Post #3 of 16

Christianbro

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Now that I know it can be done I think I'll try making a switch box first. I haven't done much DIY. My soldering skills could be lacking among other things. I might try running an old headphone cable into a small box with the switch and jack for starters.

I suppose the extra cable could be a problem audibly, but for now I'll be doing good just to make it work. If I don't get around to attempting this I might try to find someone to make it for me. It kinda seems like a good accessory for people with less than perfect hearing.

Thanks again, Dave
 
Feb 27, 2006 at 5:42 AM Post #5 of 16

Christianbro

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I never thought about changing the RCA's. I did change the headphone wires around at one point but wasn't sure if I was reversing the polarity or something. Anyway, I thought it would be nice to have a switch nearby I could flick around from song to song determining the best position.

It's funny some of my older Cd's have radical separation. I mean you have the guitar right, the drums left and vocals in the middle. If the cymbals are in my right ear I can hardly hear them. So, I'm thinking flick that switch and BAM, I'm in there.

I have a great system thanks to you guys (Rockhopper M3, Eastsound CDE5, and Hd600, Grado and K701 on order.
 
Feb 27, 2006 at 5:52 AM Post #6 of 16

xluben

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Why don't you make a selector box for L/R (normal), R/L (reversed) and Mono.

I'd think that Mono would be best for someone with limited hearing in one ear. That way you are getting all the info to to the good ear (and the bad ear), so you're not missing anything.
 
Feb 27, 2006 at 7:04 AM Post #7 of 16

Christianbro

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Yea, some sort of a box sounds good. Mono for some of those older recordings might not be a bad idea. But, I'd say 90% of my collection needs two channels. My hearing isn't that bad (as my wife chuckles). I just thought with the box I could experiment and get the best combo.

Thanks for the suggestion your box design sounds good. Is there a toggle switch that can do all that or do I need something else?
 
Feb 27, 2006 at 2:29 PM Post #8 of 16

xluben

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Try this:

http://www.radioshack.com/cart/index...032231.2032280

(If you're gonna pick up your stuff at Radioshack. If not just get similar parts elsewhere).

If you just want to be able to switch the channels just use one DPDT switch (you will be able to switch between normal and reversed channels).

And if you want to also be able to do mono, I'd use a seperate DPDT switch for that (to switch between stereo and mono).

Radioshack doesn't really explain what the pins do for most of their parts so you may have to look around online (or post here) to help figure out how to wire up the switches.
 
Feb 27, 2006 at 4:15 PM Post #9 of 16

Pars

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Have you ever listened to or looked into crossfeed to help balance the sounds out a bit? This in addition to the L-R reversing switch might make things sound better to you. Check on headwize in the projects section for the Jan Meier crossfeed... Pinkie (Pink Floyd on the forums) also has a nice website with full instructions.
 
Feb 27, 2006 at 9:06 PM Post #11 of 16

mikeblas

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Quote:

Originally Posted by Garbz
yeah that is easy to do and won't audibly effect the signal.


It won't? Why does using fancy wire and connectors make a difference, but inserting a mechanical switch into the signal path not change anything?
 
Feb 27, 2006 at 9:43 PM Post #12 of 16

Pars

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Quote:

Originally Posted by mikeblas
It won't? Why does using fancy wire and connectors make a difference, but inserting a mechanical switch into the signal path not change anything?


A good quality switch (silver contacts, yada yada) will be minimally intrusive, if even detectable sonically. Not everyone is committed to the second part of your sentence.
 
Feb 28, 2006 at 3:52 AM Post #13 of 16

Christianbro

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The switch box Xluben suggested sounds like something I could make, but I don't know if I would listen to Mono that much. There's just something about R/L separation.

Crossfeed sounds like a great Idea. I read a little on the Meier-Audio site and like the concept. I think I would like my amp to have a Reverse channel switch and a Crossfeed option or a separate box with both. Xluben is right this would be a little tough for me. I would definitely jam up my system somehow.

I'll email Steve at Rockhopper Audio and ask if he does Crossfeed. Later, Dave
 
Feb 28, 2006 at 5:49 AM Post #14 of 16

amb

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If you're going to implement a switch inline with your headphones, don't implement mono by shorting the two channels together. This is a bad idea and can damage some headphone amps. If you must add a mono feature there, you should also add a couple of 20Ω to 40Ω series resistors inline with each channel before the switch, but for an amp like the M³ (where its ultra-low output impedance is an important hallmark) you'll be negating that good characteristic with the resistors.
 
Feb 28, 2006 at 5:55 AM Post #15 of 16

xluben

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Quote:

Originally Posted by amb
If you're going to implement a switch inline with your headphones, don't implement mono by shorting the two channels together. This is a bad idea and can damage some headphone amps. If you must add a mono feature there, you should also add a couple of 20Ω to 40Ω series resistors inline with each channel before the switch, but for an amp like the M³ (where its ultra-low output impedance is an important hallmark) you'll be negating that good characteristic with the resistors.


Thanks, for stating that. I wasn't sure if combining two channels would cause a problem, but I'm glad you said this so no one ruins their equipment because of me.
 

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