[Zaubertuba]

Quote:

Originally Posted by XXII /img/forum/go_quote.gif Find a cheap balanced source. The cheapest is probably the Lite DAC-AM (~$200). Buy a pair of Scott Endler XLR attenuators ($110 x 2) Stepped Attenuators and you have a balanced set up on the cheap. It may only work for higher impedence headphones though...

Would the balanced line-outs on the Behringer HA4700 be good candidates for this approach?

Or...come to think of it, would it be better if I just cut to the chase and tied the Attenuators up directly to the balanced outs on my 1212m?

 

[FallenAngel]

Quote:

Originally Posted by Zaubertuba /img/forum/go_quote.gif Would the balanced line-outs on the Behringer HA4700 be good candidates for this approach? Or...come to think of it, would it be better if I just cut to the chase and tied the Attenuators up directly to the balanced outs on my 1212m?

Read other page fully, this is really not recommended.

 

[Zaubertuba]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Generally there are very small DC blocking caps on the output of DACs or opamps that really like line-level signals (most opamps are good for this, such as LM4562, but they shouldn't drive low impedance loads). In the case of opamps, they simply don't sound good when asked to drive a load they aren't designed for (yes, I think LM4562 sounds pretty bad driving headphones directly). In case of DC-blocking caps, the bass will be rolled off and remember, even if -3db cutoff is around 20Hz, the phase distortion goes up 10x of that to 200Hz. In the case of the Melos SHA-Gold/Maestro driving HD600 directly - there are a pair of 10uF output caps on for the pre-amp, that means -3db is at 53Hz (already quite high but there really isn't much music recorded that hits below that anyway, seriously) but phase distortion is up to 530Hz and you can be sure that there is music in that range. It might sound "nice" because it's a great amp, but it's certainly not without distortion.

LOL--sorry somehow my brain was in neutral when I read this before. Now I get it.

Continuing along the theme of doing balanced "on the cheap," though: I was wondering if it would be plausible to utilize the multiple stages of one of the many pro headphone distribution amps out there. These amps are designed to distribute a single signal to a number of headphones, and are basically a set of discrete headphone amps in a single package.

Theoretically, you'd reverse the phase of one of the stages and utilize it for your inverted signal. I suppose on a four-channel stereo headphone amp you might even sum each channel to a mono signal, reverse the phase on two of them, and have four discrete stages for your L+, L-, R+, and R- respectively.

Maybe it wouldn't look very pretty when you were done, and maybe it wouldn't work...or maybe I'm just being silly. Just trying to think out of the box.

 

[FallenAngel]

Quote:

Originally Posted by Zaubertuba /img/forum/go_quote.gif LOL--sorry somehow my brain was in neutral when I read this before. Now I get it. Continuing along the theme of doing balanced "on the cheap," though: I was wondering if it would be plausible to utilize the multiple stages of one of the many pro headphone distribution amps out there. These amps are designed to distribute a single signal to a number of headphones, and are basically a set of discrete headphone amps in a single package. Theoretically, you'd reverse the phase of one of the stages and utilize it for your inverted signal. I suppose on a four-channel stereo headphone amp you might even sum each channel to a mono signal, reverse the phase on two of them, and have four discrete stages for your L+, L-, R+, and R- respectively. Maybe it wouldn't look very pretty when you were done, and maybe it wouldn't work...or maybe I'm just being silly. Just trying to think out of the box.

That actually sounds like a really good idea. One of those "distribution amplifiers" is simply a box with a few separate amps inside. Taking one that has 2 amps (or more) and feeding it a balanced signal would require another set of inputs or some creative wiring (I would opt for creative wiring), but it should be easily doable.

 

[Zaubertuba]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif That actually sounds like a really good idea. One of those "distribution amplifiers" is simply a box with a few separate amps inside. Taking one that has 2 amps (or more) and feeding it a balanced signal would require another set of inputs or some creative wiring (I would opt for creative wiring), but it should be easily doable.

Well, the HA4700 already has balanced inputs:

BEHRINGER: HA4700

The real interesting thing with this unit in particular is that you can mute the L or R channel, control the pan, and sum the channels in a "dual mono" mode individually for each stage. Seems to me between all this you could easily get two amps driving a pure left signal and two driving a pure right signal.

...Then, just build an adaptor that pulls the signal from the two amps for each side, simply reversing Tip and Ring on one of each of them.

Am I oversimplyfying? Surely it couldn't be that easy?

EDIT: No, wait, it's a standard unbalanced stereo output for each stage, so the Tip and Ring on the outputs would simply be summed, with sleeve as common. Hmmm....gotta be a way to make this work...

 

[LS1]

I don't know much about balanced, still need to read up on it, but I'm thinking about getting the Meier Cantate.2 Amp/DAC; says it's balanced (but maybe not true balanced?). $470. Supposed to go well with my coming Beyer 880s regardless.

Meier Audio

Can anyone shed some light on that?

 

[anadin]

Semi-balanced for what it's worth.

 

[Zaubertuba]

Well, I hit the jackpot--found this thread:

http://www.head-fi.org/forums/f6/wir...o-amps-176648/

....and the aforementioned Behringer has Aux. inputs on every channel, so I expect you could actually get this to work.

Only problem is I'm reading there's likely some QC issues with the Behringer (not surprising considering the price).

...Which leads me back to considering a DIY CMOY or other option. This is really just an opportunity for me to "play" more than anything--I'm very much a "tinkerer" at heart.

One of the reasons I'm really interested in playing with balanced setups is it seems you'd have a much better damping factor--or at least the "effect" of a much better damping factor. Is this true?

I'm looking at converting my HD 555's since I'm not out that much money if I screw up. I've read tube amps are sometimes not good candidates for low impedance phones , since they're output impedance tends to be high, and that transistor-based amps (generally) have lower output impedance and thus a higher damping factor with lower impedance headphones. Would a CMOY thus be a better candidate for a balanced setup than say, the Millet hybrid? The vast documention on the CMOY out there suggests it can even be fairly easily tweaked for low-impedance phones.

Are there other simple amp designs out there that might be better candidates? The Dynalo and Beta designs are intriguing to me but it seems silly to put that much more money into the amp than my phones.

 

[olblueyez]

Proper tube amp with the right tubes may be worth considering instead of the cheapest balanced dac and amp you can find. Bass on my Raptor with the right tubes sounded better to me than a headamp GS-X I tried. Granted my source was nicer than his but that also supports my point.

 

[Nebby]

I've been thinking of building a compact balanced CKKIII to match my compact opus dac; still in the planning stages however.