[Zombie_X]

Anybody have any cheap headphones they no longer want? I'll take em and slap a balanced plug on em for this test.

 

[Zaubertuba]

Quote:

Originally Posted by TheKisho /img/forum/go_quote.gif All I can think is to use the ALPs 4 channel volume control but that's a little big to cram into a portable device but it can be done, not sure how cheap that pot was last time I checked. Dual two channel controlled by motor probably isn't possible at that size. Haha I once seen a quadraphonic amplifier with dual stereo pots and gearing to control both as one, or one at a time. Could try gearing ;P It can be done. Best bet is cram the 4 channel ALPs pot in there sideways and fill the remaining space with the amp. The case limitations would be the width/height of the pot (the case can't be any thinner then that).

Wait a minute...if you're using a DAP with a volume control, then you don't even need a quad pot, just resistors of the right value on the input. A quarter of the cost of the pot (about $11) easily takes care of the single-ended-->double-ended conversion.

Think about it:

Sansa Clip....$35
Balanced (or "bridged") CMOY....$40
Balanced PortaPros...$35

A balanced setup you can easily take with you.....Priceless!

Quote:

Originally Posted by Zombie_X Anybody have any cheap headphones they no longer want? I'll take em and slap a balanced plug on em for this test

Shoot, now I might end up trying this with my HD 202's, myself.

 

[ting.mike]

Quote:

Originally Posted by TheKisho /img/forum/go_quote.gif All I can think is to use the ALPs 4 channel volume control but that's a little big to cram into a portable device but it can be done, not sure how cheap that pot was last time I checked. Dual two channel controlled by motor probably isn't possible at that size. Haha I once seen a quadraphonic amplifier with dual stereo pots and gearing to control both as one, or one at a time. Could try gearing ;P It can be done. Best bet is cram the 4 channel ALPs pot in there sideways and fill the remaining space with the amp. The case limitations would be the width/height of the pot (the case can't be any thinner then that).

Balanced CMOY is the easy part. What balanced source would you use?

 

[nc8000]

Balanced ER4-P

And a matching P to S adaptor

 

[progo]

Ooh they look staggeringly stunning! I simply prefer the looks of two 3-pin XLRs. :drool:

 

[MrGreen]

Can anyone give me a scientific reason why bass would "tighten" from changing termination type?

also regading those er4. What tips are they and how do they change the sound and how big are they compared to the triflange.

 

[progo]

Quote:

Originally Posted by MrGreen /img/forum/go_quote.gif Can anyone give me a scientific reason why bass would "tighten" from changing termination type?

It's not the plug, but the balanced amplification (and audio chain in general) that has a few benefits over single-ended gear.

 

[MrGreen]

Quote:

Originally Posted by progo /img/forum/go_quote.gif It's not the plug, but the balanced amplification (and audio chain in general) that has a few benefits over single-ended gear.

Doesnt that result in +ve and -ve voltage swings (to make double the potential difference)?
Surely a single-ended amplifier with twice the voltage swing would do something similar.

And itll remove crosstalk from RFI because the ground is not active.
But how does that "tighten" bass?

 

[progo]

Quote:

Originally Posted by MrGreen /img/forum/go_quote.gif Doesnt that result in +ve and -ve voltage swings (to make double the potential difference)? Surely a single-ended amplifier with twice the voltage swing would do something similar. And itll remove crosstalk from RFI because the ground is not active.

Plus because of the +ve and -ve voltage swings, balanced system reaches the target voltages double as quick (the slew rate).
Quote:

Originally Posted by MrGreen /img/forum/go_quote.gif But how does that "tighten" bass?

It just happens to be the side product of the immediate effects. It can be just about anything: my bet is that the balanced signal bites better to the impedance curve of the headphone. It could cause something like that.

 

[moonboy403]

OP should make a correction in your original post in which you suggested that you're pumping 1.8W into the headphone.

Your amp is capable of outputting 1.8W into 60 Ohms, but unless you max out the volume on the amp, your amp doesn't pump 1.8W into your headphone.

 

[nc8000]

Quote:

Originally Posted by MrGreen /img/forum/go_quote.gif Can anyone give me a scientific reason why bass would "tighten" from changing termination type? also regading those er4. What tips are they and how do they change the sound and how big are they compared to the triflange.

The tips are Shure black olives with the spacer mod (although you can't see the spacers in this picture). Can't compare sound to the triflange as they to me are so painfull and uncomfortable that I have never been able to use them.

Another benefit I realised when going balanced is that with no shared ground I have gotten rid of some low level hum/noise and that in it self then improves the percived bottom end of the sound.

 

[ting.mike]

Quote:

Originally Posted by Zaubertuba /img/forum/go_quote.gif Wait a minute...if you're using a DAP with a volume control, then you don't even need a quad pot, just resistors of the right value on the input. A quarter of the cost of the pot (about $11) easily takes care of the single-ended-->double-ended conversion. Think about it: Sansa Clip....$35 Balanced (or "bridged") CMOY....$40 Balanced PortaPros...$35 A balanced setup you can easily take with you.....Priceless!

Zaubertuba,
how does a resistor takes care of the single ended to double ended conversion?

 

[Zaubertuba]

Quote:

Originally Posted by ting.mike /img/forum/go_quote.gif Zaubertuba, how does a resistor takes care of the single ended to double ended conversion?

No...that's not what I meant. I was talking about two different things:

If I remember correctly, you have to have some resistance at the input in lieu of a volume pot on a CMoy. That's what the resistor would be for.

As far as conversion, there's any number of opamp-based solutions that take a small number of components to implement. The TI DRV134/135 series looks like it would be pretty easy and inexpensive to implement. Not as "purist" as transformers, but we're talking entry-level/portable here, and an opamp solution is a lot cheaper and could go on the same board as the amp.

I'd go into the benefit on purely the amp/headphone side of things, but progo beat me to it.

I will say we're not making this stuff up--as I said before, I had noticeable improvement doing this with an a47.

Speaking of which, at barely more than a third more parts, the a47 is a good candidate for this. Just keep in mind battery life is probably going to drop pretty quickly for a balanced CMoy, and even faster on an a47.

Sorry for the confusion!

 

[TheKisho]

Quote:

Originally Posted by Zaubertuba /img/forum/go_quote.gif Wait a minute...if you're using a DAP with a volume control, then you don't even need a quad pot, just resistors of the right value on the input. A quarter of the cost of the pot (about $11) easily takes care of the single-ended-->double-ended conversion.

Um I'm unfamiliar with a DAP (Digital Audio Processing? Digital Audio Potentiometer?). I'd probably still build the portable amp with a quad pot just for the heck of it, if I made one.



Quote:

Originally Posted by ting.mike /img/forum/go_quote.gif Balanced CMOY is the easy part. What balanced source would you use?

You don't have to use a Balanced source. You could always make a unbalanced to balanced converter with some Op Amps. If you want to go balanced all the way, you could always make a balanced DAC while your at it.

 

[Zaubertuba]

Quote:

Originally Posted by TheKisho /img/forum/go_quote.gif Um I'm unfamiliar with a DAP (Digital Audio Processing? Digital Audio Potentiometer?). I'd probably still build the portable amp with a quad pot just for the heck of it, if I made one.

Digital Audio Player (this is your Ipod, Sansa Fuze, etc...). Most have a built in volume control so a pot on the amp is actually a bit redundant (it is a bit safer, though).

Quote:

You don't have to use a Balanced source. You could always make a unbalanced to balanced converter with some Op Amps. If you want to go balanced all the way, you could always make a balanced DAC while your at it.

Balanced-out DAC would definitely be the "high-end-portable" way to go. Unfortunately few DAP's have digital out, and the digital-out docks that are out there are tabletop models for the iPod.

I'd still like to try and see if you could get the pinouts to build a digital out dock for the Sansa Fuze, but it's not likely.