Are there decent affordable amps with balanced inputs?

[ephemere]

I'd like get a headphone amp to connect to the balanced output of my Behringer DEQ2496. It seems like I have two options.

Option 1: Get a pro-audio piece like the Presonus HP4, Samson C-que8, Behringer Powerplay Pro-XL HA4700, or the upcoming Behringer Miniamp AMP800. These are all in the $50-100 range, which is great. But I'm concerned with sound quality, especially with low-impedence cans.

Option 2: Get an audiophile amp with balanced inputs. I'm sure this option would sound good, but I fear that it will be too expensive. For example, the cheapest balanced HeadRoom amp is $2300. I don't want to spend more than a few hundred bucks, if that.

What would you recommend for me?

 

[jpelg]

Headamp has a balanced Gilmore design-based amp for $1600:

http://www.headamp.com/home_amps/reference/index.htm

 

[ephemere]

Let's say "affordable" means less than $400. Once it gets much above that then I'd probably bypass ther cheap DAC in the DEQ2496 altogether and get something like a DAC1, MiniDAC, Stereo96, or m902. But that's more than I want to spend. I have a Presonus HP4 ($100) that I use for late-night movies, but I'm wondering if there's something better and balanced for not an insane amount of additional cash.

 

[Dusty Chalk]

The other thing you could do is get two amps, and use each one as one channel. You'd need some custom cables (balanced to double-RCA and the headphone cable would terminate in two TRS instead of two XLR jacks).

 

[l_simon_l]

The cheapest amp I've seen with balanced inputs is the swedish amp "Harmony Design EAR 90" and it's 510 eur. It has gotten some rave reviews in the swedish hifi-press. If you want to read more... here's a link: http://www.harmonydesign.se/index_english.htm

 

[ayt999]

get a pair of XLR to RCA convertors / cables. then you can use any amp with RCA inputs.

I found some for $2 each. or you can get a pair of cardas convertors for $55 a pair or so.

I assume you don't need a balanced amp for a balanced pair of headphones, or require the use of balanced cables for EMI issues....

 

[Jazper]

the main problem with balanced amps is the volume control, you need a stepped attenuator or a 4 gang potentiometer, the latter being incredibly rare. I've done some pricing and it's about 350-400 Australian JUST for the stepped attenuator. Compare this to $25ish for a blue velvet.

I (or another skilled diyer) could build you a balanced version of the ppa or the m3 without too much drama, it's just the volume control that kills the price. Another option I suppose is if your dac or playback device has a volume control, you could use that... *Shrugs*

just a thought..

 

[ayt999]

Quote:

Originally Posted by Jazper the main problem with balanced amps is the volume control, you need a stepped attenuator or a 4 gang potentiometer, the latter being incredibly rare. I've done some pricing and it's about 350-400 Australian JUST for the stepped attenuator. Compare this to $25ish for a blue velvet.

you don't need those, some people actually prefer dual stereo potentiometers for their balanced amps. of course getting stepped attenuators or a four gang pot makes channel matching a lot easier....

anyways, I think he only wants an amp with XLR inputs since that's what his source uses and isn't really looking for a fully balanced looking at the amps he mentions in Option 1.

 

[Jazper]

Quote:

Originally Posted by ayt999 you don't need those, some people actually prefer dual stereo potentiometers for their balanced amps. of course getting stepped attenuators or a four gang pot makes channel matching a lot easier.... anyways, I think he only wants an amp with XLR inputs since that's what his source uses and isn't really looking for a fully balanced looking at the amps he mentions in Option 1.

*shrugs* true.. you don't need those, but as you said.. it makes channel matching easier

 

[ephemere]

Quote:

Originally Posted by ayt999 anyways, I think he only wants an amp with XLR inputs since that's what his source uses and isn't really looking for a fully balanced looking at the amps he mentions in Option 1.

Actually I was indeed asking about balanced amps, but largely out of curiosity and exploration. I'm aware that I can use an unbalanced amp with my source with the appropriate cables, and that's almost certainly going to be the best route with this kind of budget.

One thing I don't understand about balanced headphone amps is the balanced output. How does the wiring work when the headphone's stock cable (ground/v+) is replaced with a balanced cable (ground/v-/v+)?

 

[Jazper]

Quote:

Originally Posted by ephemere Actually I was indeed asking about balanced amps, but largely out of curiosity and exploration. I'm aware that I can use an unbalanced amp with my source with the appropriate cables, and that's almost certainly going to be the best route with this kind of budget. One thing I don't understand about balanced headphone amps is the balanced output. How does the wiring work when the headphone's stock cable (ground/v+) is replaced with a balanced cable (ground/v-/v+)?

the drivers (speaker like things) in headphones have ground and v+ as you know.. so a standard cable is V+/V+/ground.. A balanced config basically just makes it V+/V-/V+/V- basically, So ground (V- here) is active on balanced configurations (it's the inverse of V+). Earth here (current return) is discarded unless i'ts used for shielding in the cable.

 

[ayt999]

oh, you were? I really didn't get that from your post.... there was the thing about the Balanced Home but everything else didn't hint at that.

a headphone wired in dual mono has two conductors going to each driver, or four separate wires total going from the amp to the headphone. with a balanced headphone amp these carry the left v- and v+ and the right v- and v+ signals. there's plenty more info if you search this site and also the web.

I think with your budget though it would be best to get a good unbalanced amp.

 

[ephemere]

Thanks, Jazper and ayt999. That makes sense. So ground is discarded, but is still provided at the output of the amp in case it's needed for shielding (or perhaps for some purpose other than to feed headphones).

I assume that, as ayt999 said, the cheap pro-audio amps I listed in "Option 1" are not really balanced internally, but only have one amp per channel.

Just curious: What's the wisdom about the benefits of a balanced design? Why would separate amps for - and + have sonic advantages over one amp? (I have a vague notion that balanced signals are common in pro equipment to avoid ground loops and so forth.)

ayt999: Yes, I think you are right that I should look for an unbalanced amp on my budget.

 

[Jazper]

Quote:

Originally Posted by ephemere Just curious: What's the wisdom about the benefits of a balanced design? Why would separate amps for - and + have sonic advantages over one amp? (I have a vague notion that balanced signals are common in pro equipment to avoid ground loops and so forth.) ayt999: Yes, I think you are right that I should look for an unbalanced amp on my budget.

To answer your question, simply, there is less distortion due to cable differences and so forth, plus you have 4x the power handling. There are probably other reasons but those are the main two I know of.

And I think that something like a ppa or an m3 would be in your budget, while they're not "balanced" per se, they do have an active ground channel offering some of the advantages of a balanced amp without the need to recable or using expensive volume controls..

 

[ephemere]

Yes, I had never heard of an active ground channel until I started perusing this site. Not sure I understand it (is it like a shared v- channel?), but I'll do some more searching around.