Help with mixing balanced & RCA plugs...

[Coytee]

My Peach has RCA jacks on the output.

Those will go into my EV Dx-38 active x-over which has BALANCED inputs and outputs (no RCA's on the EV)

The EV-38's (balanced) outputs will be split between two amps, one (McIntosh 2102) has balanced inputs, no problem. Other one will be solid state with RCA jacks.

Am I going to need a transformer thingy to convert to the balanced plugs? Do I need one on each side when I kick back down to RCA's for the solid state amp?

Can I just get an adapter?

Can someone do a bit of cyber-handholding and tell someone who's clueless about balanced stuff the exact layout & parts I'll need so I can patch balanced & RCA's together with minimal issues & parts?

So it's clear, the signal path is

CD player & dvd players (RCA out)

Peach (RCA in and out)

EV DX38 (balanced in and out)

McIntosh 2102 (Balanced or RCA in)

solid state (RCA in)

There's a chance I'll try the McIntosh MC-30's on the top end of the Jubilees and they have RCA in, but they also have those other plugs that I have no idea what they're for, are those balanced?

Thanks for any thoughts.

[DrWho]

You could probably solve all your problems with this unit that I just discovered today:

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=245-868

At $50 it's pretty much a no brainer too as it would be cheaper than

even the ratshack transformers. ART is a pretty respectable company

too...top of the midrange or bottom of the high end in the pro audio

world.

Send your Peach to channel one on the ART and out to the EVDX38. Then

send the output of the DX38 through channel 2 and into the solidstate

with RCA in. Run the Balanced line into the McIntosh and all your

problems are solved.

[DrWho]

And here's a little reading material if you're interested in how the interfacing works and why transformers are needed:

http://www.colomar.com/Shavano/cable_xlr_to_phone.html

[Coytee]

Thank you Doc... I'll investigate what you posted. You just paid for your invitation to the hot dog grill out []

[Coytee]

Aaaaaaaaackkkkkkkk

Got to the page to put my credit card number in... they're out of stock [:'(]

None the less, THANKS for showing it to me, I'll look around & see if I can find it elsewhere and if not, I'll do the backorder thing.

[Coytee]

Well, I did an interenet search (very small one) and didn't find it elsewhere so went ahead & backordered it. Their order page said they expected them in on the 19th so that's not so bad.

[DrWho]

Oh gosh, that's so evil - lol

Here's a few more places to try:

http://www.musiciansfriend.com/product/ART-CleanBOX-Two-Way-Stereo-Converter?sku=180613

http://www.sweetwater.com/store/detail/CleanBox/

And even better, if you go to klipschcorner.com and do an amazon search, you can purchase this unit and help fund the website:

http://www.klipschcorner.com/Shop.aspx

Type in "ART CleanBox" in the search path, and then click on the Buy

from amazon.com and you'll be taken to a page where it's $50 from 8th

street music.

[Deang]

If the runs are less than 25 feet, can't you just use properly terminated cables?

http://www.cablestogo.com/product_list.asp?cat%5Fid=2029&engine=adwords!654&keyword=%28rca+to+xlr%29

The info at the Shavano site was interesting, but does the transformer bit really apply in this situation?

[Coytee]

perhaps it'll help to know that I'd probably get a 15' line. My amp might be on side of room (relative to Peach in center) and 15' would probably deal with it.

Perhaps Mike can chime in here as if these would work just as well (?), then I'd have time to cancel my order.

As it is, I'll have to buy this box ($50) and several cables (? $$)

If these cables can work then it'll probably save me a dime or two.

[Edgar]

There's a quick and simple way to do it using just resistors, that works fine as long as "chassis ground" and "signal ground" are the same on your equipment. It's commonly called a "impedanced balanced" configuration; I've been searching the Web all morning for a diagram but haven't found anything.

Basically you always balance the lines, and you don't worry about whether the signals are balanced. ("Balancing" actually refers to impedances, not signals.)

So when you connect an unbalanced output to a balanced input, you connect source "hot" and "ground" directly to destination "+hot" and "common", respectively. You connect destination "-hot" to source "ground" THROUGH A RESISTOR EQUAL TO THE OUTPUT IMPEDANCE OF THE SOURCE, with the resistor located on the source side.

Going the other way, from a balanced source to an unbalanced destination, you connect source "+hot" and "common" to destination "hot" and "ground", respectively, but you connect source "-hot" to destination "ground" THROUGH A RESISTOR EQUAL TO THE INPUT IMPEDANCE OF THE DESTINATION, with the resistor located on the destination side.

It's a lot easier to do than it is to write about. I use this with my Merlin ISP-100 (kind of a grandaddy to the DX38).

Greg

[DrWho]

If the runs are less than 25 feet, can't you just use properly terminated cables?

That approach is often hit or miss because it usually increases the noise floor

considerably and there are possible issues with HF rolloff. Sometimes

it works, sometimes it doesn't, and for those looking for a dummy proof

solution I'm not sure if I'd recommend this route.

I've got a pair of 3 foot male RCA to male XLR's if anyone wants to give

them a try...shipping wouldn't be more than what, a dollar? If they

work you can buy them and save yourself the extra shipping and I'll

just pick up another pair next time I'm in the pro audio store. If not, just send em back.

Greg, what is the tradeoff to the resistor approach? Is it just lack of

compatibility with gear of different in/output impedances? What happens

if you use a mismatched resistor?

And one last comment. When running from unbalanced to balanced you will

need to boost the gain by 12dB. It's discussed on the second page here:

http://www.rane.com/pdf/bb22dat.pdf

Ultimately I think this is where most of the concern comes into play as

incorrect compensation will force you to run both devices hotter to

accomodate (which always means more noise).

[Edgar]

Greg, what is the tradeoff to the resistor approach? Is it just lack of

compatibility with gear of different in/output impedances? What happens

if you use a mismatched resistor?

Other than the obvious (the fact that there is an unbalanced connection, with all of its inherent disadvantages), really the only performance issue that I can think of is the fact that this configuration can pass DC, which would be blocked by a transformer or capacitor. It is sometimes difficult to determine the true input impedance of the destination, and even more difficult to determine the true output impedance of the source, but I have found that getting "close enough" works pretty well. If you're WAY off, then it becomes more susceptible to noise and hum pickup.

And one last comment. When running from unbalanced to balanced you will

need to boost the gain by 12dB.

I think that it's actually 6dB, but it's definitely there. I have not found it to be a problem; there is more than enough gain in my amps to drive them to clipping despite the loss in signal level.

Greg

[sunnysal]

if the run is short you can just convert. hosa makes nice solid rca/xlr convertors in both male and female combos.