Balanced to Single ended
Dec 7, 2018 at 11:38 PM Thread Starter Post #1 of 13

Dawnrazor

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I have a source with balanced outs and am running it into an amp with balanced ins and running balanced to my m1060s mk2.

But the amp heats up the room too much. Its a Parasound halo A21 ( I am using resistors). So I need a new amp.

The amps I can afford all have single ended inputs. However could I get some of the benefits of balanced if I employed 2 amps with one driving one channel and the other driving the other? That should give me at least separate power supplies right?

Tia
 
Dec 7, 2018 at 11:47 PM Post #3 of 13
What's your budget?
the 2 amplifiers would ideally be under $100 for the pair.

I am thinking about the Dayton DTA-1 and running off batteries. But any little amp should be ok. I hooked a similar amp from Dayton and it worked find driving the m1060s from the speaker outs (using 2 rolls PM52s boxes and running balanced to the 1060s)

Thanks.
 
Dec 9, 2018 at 12:34 AM Post #4 of 13
the 2 amplifiers would ideally be under $100 for the pair.

I am thinking about the Dayton DTA-1 and running off batteries. But any little amp should be ok. I hooked a similar amp from Dayton and it worked find driving the m1060s from the speaker outs (using 2 rolls PM52s boxes and running balanced to the 1060s)

Thanks.
I might not be explaining this well. I hooked up ONE amp and it worked fine. My question is basically would I have an advantage from adding the 2nd amp. Its not balanced exactly but isnt one advantage of true balanced is that there are separate power supplies for both channels, so wouldnt that be a step up?
 
Dec 9, 2018 at 10:58 AM Post #5 of 13
The amps I can afford all have single ended inputs. However could I get some of the benefits of balanced if I employed 2 amps with one driving one channel and the other driving the other? That should give me at least separate power supplies right?

I might not be explaining this well. I hooked up ONE amp and it worked fine. My question is basically would I have an advantage from adding the 2nd amp. Its not balanced exactly but isnt one advantage of true balanced is that there are separate power supplies for both channels, so wouldnt that be a step up?

You're mixing up balanced with dual mono, the latter being possible on technically single ended connections. It just depends on the circuit. The Beta22 boards for example have to run four boards, but can run on just one power supply, or two if using dual mono. Other single ended amps even if they technically have separate L- and R- instead of shared GND aren't getting a signal running L+, L-, LGND, RND, R-, R+.

As with all things audio, doubling up the same circuit at best improves current performance on a $50 amp, since its power supply only runs one. For differences to be audible running in dual mono assumes that each weaker power supply is struggling if it has to supply current for both channels, but in the end, you'll still get the same amount of power to each driver anyway. Maybe it can improve channel separation, but that doesn't mean you can just get the same performance as a more expensive high current amp that can deliver the necessary current even with just one power supply.

Now you might think that's a cheap way to achieve that but think about all the necessary modifications. You'll have to rewire the headphones the cable terminates into two separate TRS plugs for each amp and then you lose unity gain since you now have two amps with their own preamp circuits without a single potentiometer controlling them. Unless you can DIY it you'd have to move two knobs all the time. Is that worth the hassle to you? This is not as easy to do with speakers where you can get a pair of actual mono amps that only tend to cost less than a comparable two channel amp but as for practicality they are pure power amps and your preamp will just have one control knob. Again at the very least to make this convenient you'd have to have a preamp (like coming from your DAC) and just DIY two output stage boards without preamp circuits or bypassing what is already in there.

Think of it this way. You normally drive a Tesla Model S P700, but if you're not in urban California, getting it serviced can be a problem. So now you're thinking that maybe you can put less wear on it and buy a used Mistubishi Lancer and mod it like a Tesla Evolution by mounting another regular Lancer 2.0L engine in the trunk. But since it doesn't have the Evo's AWD system, you're going to have to DIY the gear shift or the auto tranny to communicate with both engines and transmissions. By contrast getting an actual Evo would get you good enough power to pass safely on the highway, even though not exactly like the Tesla's instant torque, without going through all those modifications, unless you can do it yourself and not count the man hours as an expense by not working on something that does get you money.

You might as well just buy a single $100 amp that works well than two cheapo $50 amps. A single Magni3 will produce waaaaaaaaaaaaaaaaaaaay more clean power than two cheap $50 or less amps.

Or ya know...maybe just spend the $100 or more cooling the room, which, given an A/C of any kind has a wider market demographic, might be something that you can get for installment payments. I might not get a headphone amp for 0% over even 6mos down here but you might be able to find a portable A/C where the first few months can be paid off wiht the $100 you have now and then save for the rest of the payments along the way. Or just get a swamp cooler (it's basically a fan with a water reservoir that you can fill with ice water, and then it has a pump like what you find on a PC sucking the water up and at minimum has droplets of it raining across the airflow path) that you can either point at the amp or your seating position.

Downside of course is higher ambient noise but that's something you have to live with if you need to cool a room.
 
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Dec 9, 2018 at 9:25 PM Post #6 of 13
You're mixing up balanced with dual mono, the latter being possible on technically single ended connections. It just depends on the circuit. The Beta22 boards for example have to run four boards, but can run on just one power supply, or two if using dual mono. Other single ended amps even if they technically have separate L- and R- instead of shared GND aren't getting a signal running L+, L-, LGND, RND, R-, R+.

As with all things audio, doubling up the same circuit at best improves current performance on a $50 amp, since its power supply only runs one. For differences to be audible running in dual mono assumes that each weaker power supply is struggling if it has to supply current for both channels, but in the end, you'll still get the same amount of power to each driver anyway. Maybe it can improve channel separation, but that doesn't mean you can just get the same performance as a more expensive high current amp that can deliver the necessary current even with just one power supply.

Now you might think that's a cheap way to achieve that but think about all the necessary modifications. You'll have to rewire the headphones the cable terminates into two separate TRS plugs for each amp and then you lose unity gain since you now have two amps with their own preamp circuits without a single potentiometer controlling them. Unless you can DIY it you'd have to move two knobs all the time. Is that worth the hassle to you? This is not as easy to do with speakers where you can get a pair of actual mono amps that only tend to cost less than a comparable two channel amp but as for practicality they are pure power amps and your preamp will just have one control knob. Again at the very least to make this convenient you'd have to have a preamp (like coming from your DAC) and just DIY two output stage boards without preamp circuits or bypassing what is already in there.

Think of it this way. You normally drive a Tesla Model S P700, but if you're not in urban California, getting it serviced can be a problem. So now you're thinking that maybe you can put less wear on it and buy a used Mistubishi Lancer and mod it like a Tesla Evolution by mounting another regular Lancer 2.0L engine in the trunk. But since it doesn't have the Evo's AWD system, you're going to have to DIY the gear shift or the auto tranny to communicate with both engines and transmissions. By contrast getting an actual Evo would get you good enough power to pass safely on the highway, even though not exactly like the Tesla's instant torque, without going through all those modifications, unless you can do it yourself and not count the man hours as an expense by not working on something that does get you money.

You might as well just buy a single $100 amp that works well than two cheapo $50 amps. A single Magni3 will produce waaaaaaaaaaaaaaaaaaaay more clean power than two cheap $50 or less amps.

Or ya know...maybe just spend the $100 or more cooling the room, which, given an A/C of any kind has a wider market demographic, might be something that you can get for installment payments. I might not get a headphone amp for 0% over even 6mos down here but you might be able to find a portable A/C where the first few months can be paid off wiht the $100 you have now and then save for the rest of the payments along the way. Or just get a swamp cooler (it's basically a fan with a water reservoir that you can fill with ice water, and then it has a pump like what you find on a PC sucking the water up and at minimum has droplets of it raining across the airflow path) that you can either point at the amp or your seating position.

Downside of course is higher ambient noise but that's something you have to live with if you need to cool a room.
Thanks man dor taking the time to respond. Appreciate the in depth response.

I was reading about the questyle dac and how getting 2 of them would give a true balance experience as there would also be a dual mono config. Then it hit me that I have a 2nd parasound amp in storage and could grab that. But if one is heating up the room 2 would be out of the question. So I started thinking of smaller class d amps.

You are riight about the logistics but I am not using headphone amplifiers. I am using the speaker taps and running bannanas to 1/4 into two Rolls PM 52 boxes that have resistors and are designed to hook up phones to amplifiers. Then 1/4” to 2.5mm to the M1060s. Two Rolls boxes are used so the grounds are isolated and the headphones are balanced. Amp is balanced (but not dual mono) and source is balanced.

All affordable amps are single ended. And so while not balanced I could get dual mono. I was wondering if it would be worthwhile over just a single amp

Fwiw I have the Vali-2 and while good, the little dayton d120 run off the speaker outputs is way better to my ears.
 
Dec 10, 2018 at 2:16 AM Post #7 of 13
I was reading about the questyle dac and how getting 2 of them would give a true balance experience as there would also be a dual mono config. Then it hit me that I have a 2nd parasound amp in storage and could grab that. But if one is heating up the room 2 would be out of the question. So I started thinking of smaller class d amps.

You are riight about the logistics but I am not using headphone amplifiers. I am using the speaker taps and running bannanas to 1/4 into two Rolls PM 52 boxes that have resistors and are designed to hook up phones to amplifiers. Then 1/4” to 2.5mm to the M1060s. Two Rolls boxes are used so the grounds are isolated and the headphones are balanced. Amp is balanced (but not dual mono) and source is balanced.

All affordable amps are single ended. And so while not balanced I could get dual mono. I was wondering if it would be worthwhile over just a single amp

If you won't have any problem with having two separate volume controls then maybe it's worth a shot. But really I'd probably just put that $100 towards an A/C than an amp, even a portable one so you don't really need to hire somebody to mount one on a window. Just cut up ply wood to cover the entire window frame (depending on your window design, cut a hole for the A/C exhaust, and then line the rest of the plywood with some kind of acoustic material to minimize noise outside getting in through that now open window.
 
Dec 13, 2018 at 4:29 PM Post #8 of 13
If you won't have any problem with having two separate volume controls then maybe it's worth a shot. But really I'd probably just put that $100 towards an A/C than an amp, even a portable one so you don't really need to hire somebody to mount one on a window. Just cut up ply wood to cover the entire window frame (depending on your window design, cut a hole for the A/C exhaust, and then line the rest of the plywood with some kind of acoustic material to minimize noise outside getting in through that now open window.
Thanks man. Its a long story but I have ac. Though its not as strong in this wing of the house which is perfect as I like it hotter than the rest of the house.

Anyhow I bought 2 of the dayton T-amps. will see how it goes
 
Dec 18, 2018 at 11:30 PM Post #9 of 13
T-amps were a bust. I could get them to play but just no volume. Guess they like 4 ohms.
 
Dec 19, 2018 at 7:52 PM Post #11 of 13
Not really...unlike really good A/B or even Class A amps only the high THD Class D's made for subwoofers would double their output at 4ohms.
The ratings are 15w @ 4 ohms. So i am guessing my 50 ohm cans and the resistors in the rolls box lower the output too much.

So thats what I was alluding to not that they double into 4 ohms
 
Dec 19, 2018 at 7:53 PM Post #12 of 13
Took a new tack and am ordering two of the behringer p1s. Should give me dual mono balanced with battery power.
 
Dec 19, 2018 at 10:39 PM Post #13 of 13
The ratings are 15w @ 4 ohms. So i am guessing my 50 ohm cans and the resistors in the rolls box lower the output too much.

So thats what I was alluding to not that they double into 4 ohms

These generally won't double the power going from 8ohms to 4ohms but the output also trails off more sharply than 4ohms to 8ohms as you go up above 8ohms.

AFAIK this is one reason why Class D isn't a thing for headphones yet apart from a few integrated DAC-HP driver chips, and even Sony calls them something else.
 

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