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New reference headphone monitoring system Studio Headphones
Old 21st March 2010
  #1
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fradoca's Avatar
New reference headphone monitoring system

Hi,
Here's my totally balanced new reference headphone monitoring system









-Constant Current Drive
-Full Balanced Design
-DC Coupled (no capacitors on audio path)
-Absolute flat frequency and phase response
-Ultra low noise and harmonic distortion
-Very fast transient response
-Monitoring system for Mastering purposes
-24-step precision volume control
-Designed for high-ohm headphones
-Toroidal Transformer
-Vishay components
-All pure silver internal wiring

totally conceived and built by Qes Labs in Italy.
this is a reference monitoring system for mastering and for really high quality control of final masters.

It's not just a balanced headphone amp.

A deep review will follow in the next days but from the first listening
test this is the closest thing to speakers i've ever listen to.
Incredible speed response on transients and the most neutral sound i've heard.
Fantastic piece of hardware
Old 22nd March 2010
  #2
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dcollins's Avatar
 

Verified Member
Quote:
Originally Posted by fradoca View Post
Hi,
Here's my totally balanced new reference headphone monitoring system
With all that fancy technology, they forgot the 1/4" jacks.


DC
Old 22nd March 2010
  #3
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Cellotron's Avatar
 

Verified Member
Quote:
Originally Posted by dcollins View Post
With all that fancy technology, they forgot the 1/4" jacks.


DC
I was gonna say the same but figured out I was missing something.
What headphones are actually wired with dual XLR inputs?? Or are the outputs for two sets of headphones with XLR instead of TRS?? And, in the case of either option, why?

Best regards,
Steve Berson
Old 22nd March 2010
  #4
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Teddy Ray's Avatar
 

Quote:
Originally Posted by Cellotron View Post
I was gonna say the same but figured out I was missing something.
What headphones are actually wired with dual XLR inputs?? Or are the outputs for two sets of headphones with XLR instead of TRS?? And, in the case of either option, why?

Best regards,
Steve Berson
ah.balanced headphones are all the rage in the ultrafidelista trenches..

the "audiophiliac" wisdom is that getting rid of the common ground between left and right channels (single ended) would reduce cross talk and improve sound quality. read below and chuckle..
====================================================
A normal headphone cable plug has three connections on it: the tip is left; the ring is right; and the sleeve is ground. The tip connects to a wire that goes to the positive (+) lead of the left headphone driver coil; the ring connects to a wire that goes to the positive lead of the right driver. The sleeve connects to a wire that goes to both negative (-) terminals of the drive coil; this wire usually has a solder joint in the "Y" or in the earpiece where the ground wire from the plug splits into separate wires that are connected to the negative terminals of the driver coils.




Bold lines indicate common return of both left and right channels

The most important thing to note here is that as the left and right channels of the headphone amplifier drive the left and right driver coils, the return current from the drivers gets joined together and travels some distance before returning to the amp's audio ground. This common pathway has some -- possibly significant -- electrical resistance from the wire, solder joints, contact resistance at the plug/jack, and so on, which causes a common signal to appear at the negative terminal of both driver coils. This common signal (a low-level summation of the left and right channel) will generate low level cross talk and distortion in the sound heard on headphones.


Balanced headphones are just regular headphones that have been re-cabled in a special way. The normal three-conductor cable with the common ground connection is replaced with a cable that has four conductors: right positive and right negative conductors to the positive and negative connections of the right driver coil; and left positive and left negative conductors to the left driver coil. The cable is terminated in two XLR male connectors, one each for the left and right channel. A special headphone amplifier is used that has "balanced" outputs where each channel has a normal audio drive signal and a mirror image inverted drive signal. The trick here is that there is no "ground" to the headphones anymore, so there is no opportunity for the crosstalk distortion described above.


The really interesting thing though is that removing the common ground is only the beginning of the possible improvements from balanced operation. There are different ways to implement a balanced headphone amplifier, the easiest being a single-ended internal design with transformer- coupled outputs. In that case the sonic improvements come from the natural noise rejection of XLR connections (not a major factor in single-ended headphones) as well as the common ground removal. But it is possible to go further in the design and operation of balanced headphone amplifiers by using four completely separate amps for all four legs of the signal (right normal, right inverted, left normal, left inverted) as described in the graph below.



The immediate benefit of such a design is that each amplifier only drives half of the coil allowing for a much better control of that coil. It also doubles the effective slew rate (the voltage an amp can swing per second) as both amplifiers are operating in opposite phase to increase the dynamic realism of the music reproduced. Such a design can get fairly difficult to implement with all discrete transistors as they require careful manual matching to ensure that both halves of the signal are amplified identically but integrated chips do remedy this in a fairly elegant and cost effective fashion, allowing entry-level balanced amps to remain quite accessible. If the theory of balanced headphones seems all rosy, there are a few hurdles you need to be aware of. They all relate to the implementation of a balanced headphone system from start to finish.
Old 22nd March 2010
  #5
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Teddy Ray's Avatar
 

Quote:
Originally Posted by Cellotron View Post
Or are the outputs for two sets of headphones with XLR instead of TRS?? And, in the case of either option, why?

Best regards,
Steve Berson
oh man.. you need to go to head-fi. you can get any can you want wired with XLRs, and the folks there encourage it..

Head-Fi: Covering Headphones, Earphones and Portable Audio - Search Results

ive even seen etymotics in ears wired with XLRs..





I have had a little more time with them and I'm hearing details in recordings I've never heard before. Some of those details I'm not so sure I wanted to hear like traffic noice from outside the recording venue and nosie from the machinery operating the organ bellows. On the other hand on a recording like Jazz at the Pawn Shop I can now often hear and comprehend the conversation going on both between the musicians and in the audience. Soundstage is probably not as big as with the GS-1000 but that is not a major concern for me. Bass is fantastic although naturally not of the quantity I get with either GS-1000 or L3000 but the quality is great except when it gets really powerfull like in Reference Recordings HDCD encoded recording of Aaron Coplands Fanfare for the common man they do break up a little with the huge bass drum and kettle drums but then so do many other phones on that track.
__________________
Old 22nd March 2010
  #6
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fradoca's Avatar
this is a monitoring system made only for balanced headphones.
On the front panel you have inputs for the left and right channel.
If you use sennheiser headphones(as i do) you can easily replace
the cable with a balanced one.
To be honest after trying a system like this i would never go back
to simple amp with trs only input.


Quote:
Originally Posted by Cellotron View Post
I was gonna say the same but figured out I was missing something.
What headphones are actually wired with dual XLR inputs?? Or are the outputs for two sets of headphones with XLR instead of TRS?? And, in the case of either option, why?

Best regards,
Steve Berson
Old 22nd March 2010
  #7
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4blades's Avatar
 

That is a top notch unit!
Tested with hd600.
Would like to hear it through the hd-800!

For me, it's the no.1 in monitoring amps.

Balanced Headphone Amplifier Amp Studio Reference for professional use - QES Labs
Old 22nd March 2010
  #8
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fradoca's Avatar
For me too.That's why i've bought it.
Because there's maximum transparency and no signal coloration.

highly recommended if you need to check your masters
through headphones or have a reference monitoring system
through headphoes.No just a balanced amp.

Quote:
Originally Posted by 4blades View Post
That is a top notch unit!
Tested with hd600.
Would like to hear it through the hd-800!

For me, it's the no.1 in monitoring amps.

Balanced Headphone Amplifier Amp Studio Reference for professional use - QES Labs
Old 22nd March 2010
  #9
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Apostolos Siopis's Avatar
 

Verified Member
It might be a silly question but why 2 sets of female XLRs?

As far as i Know, in sound applications the normal would be female XLRs for input and Male XLRs for output (the opposite of electricity plugs-although different type of connectors).
I understand a connector is still a connector, as long, as the signal passes to the next device, but there must be some reason behind your choice.
Is it because we normally use male Jacks for our headphones?

It seems that the only devices that use male connectors to receive signals are either headphones or electrical appliances (or some sort of weird fish at the bottom of the ocean)
Old 22nd March 2010
  #10
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24-96 Mastering's Avatar
Quote:
Originally Posted by fradoca View Post
It's not just a balanced headphone amp.
Why? What else does it do?

Quote:
Originally Posted by fradoca View Post
this is a monitoring system made only for balanced headphones.
By "balanced headphones", do you actually mean normal headphones with unconnected shielding (like Teddy Ray suggested)?
Old 22nd March 2010
  #11
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Franco's Avatar
 

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"-Monitoring system for Mastering purposes"

Where's the phase-flip switch, the ability to listen to the audio in mono?

What I consider my "mastering grade headphone system" is basically my Cranesong Avocet, which has a pretty excellent headphone amp and the ability to actually be a mastering-grade switcher.

The only thing I desired from it for my personal use was the ability to have 3 outputs and a passive switcher as I use 2-3 reference grade cans, but I fixed that by building my own passive switcher* (with 1/4" Neutrik jacks).

I've read up a lot on what goes on in Head-Fi:

*EDIT: Since these cats are only giving you one pair of XLR outs, I can build you a passive switcher; we can use gold Neutrik XLRs or any XLR jacks you want, I still have some 18awg solid SPC (silver plated copper) and plenty of Cardas Quadeutectic solder. I'd charge you, I dunno, $1,000 since that would put it in the "esoteric high end" ballpark if you want!
Old 22nd March 2010
  #12
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fradoca's Avatar
well,
i was looking for a balanced reference Stereo monitoring system through headphones and the hpba-2 meet my needs.I have worked many years with different cans and headphobe amps.
This is by far the most neutral and transparent i've ever tried.Nothing more nothing less.What you listen is what you get.I use it to check my masters before the final deliver to the customer
I don't pretend to put in the ballpark of audiophiles gear but i consider it a professional device.Befor buying this i've tested a SPL Phonitor and
a Lake People G100.The Qes labs hpba-2 is best i've tried.Really neutral and transparent.That's the reason it has been conceived and built.
I just want to say that if you are looking for a professional stereo balanced
monitoring system through headphones this could be your choice.

cheers
Old 23rd March 2010
  #13
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bewareofdogs's Avatar
 

I've had a test through this unit some time ago.
My can was a recabled Beyer DT-770, not the best for mastering purposes.
Anyway, when hooked through the hpba-2 from QES Labs, the improvement was obvious.

As already stated in some previous post, I think that along with the new HD-800 you can really get your headphone reference system.

A true solid performer.
Old 23rd March 2010
  #14
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fradoca's Avatar
here's a little review of it:
the stereo image is really excellent.You can clearly hear where all the
instruments are placed in the mix.The transients are really really fast.
Much faster than my previous amp the Lake pople g100.
You have much better definition on the bass and on the drum kick.
I can really say i'm starting to feel the limits of my hd600.
The sound is clear,trasparent and neutral.I've tested the hpba-2 with some of my reference recordings.
The one i've used most is the dvd audio version of "The Nightfly" by Donald Fagen.
The dvd audio has a pcm 24 bit 48 khz stereo track.
Since it came out i've used as my main reference recording to test equipment.
Well i can hear everthing about that recording.Plenty of dynamics and definition.
The frequency response is really really balanced.All i want to say is that after trying this amp
i don't feel the need to go back to a normal system without balanced connection.
It really monitors the source you're listen to.And i've tried
many cans and many amps in last 5 years.

This is clearly the winner.
I'm not in any way payed or associated with Qes Labs.
I had the opportunity to try it and i've decided to buy it according to my specifications.
I'm just a really happy owner of a fantastic piece of gear.

If you have the chance try it and make up your own mind.
Don't judge things before trying them in your studio with your gear.

My search for a reference stereo balanced headphone system had ended.

Highly recommended.

cheers.
Old 23rd March 2010
  #15
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macc's Avatar
 

Verified Member
Very pleased for you Francesco! I know it has been a long road heh

Hope to hear it one day...
Old 23rd March 2010
  #16
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Jerry Tubb's Avatar
 

Verified Member
Quote:
Originally Posted by fradoca View Post
The one i've used most is the dvd audio version of "The Nightfly" by Donald Fagen.
The dvd audio has a pcm 24 bit 48 khz stereo track.
I can see you have good taste in music, one of my favorites as well.

I also have the original vinyl from 1982, some of Roger Nichols finest work.

JT
Old 23rd March 2010
  #17
Gear Maniac
 
bewareofdogs's Avatar
 

Hey, I think the nightfly IS widely used as a reference recording.
Worldwide.
The DVD :
The Nightfly (DVD Audio): Donald Fagen: Amazon.ca: Music
thumbsupthumbsupthumbsup
Old 23rd March 2010
  #18
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fradoca's Avatar
Thanks Mr Tubb,
i really love that record and the dvd version is amazing.
Listened to it so many many times that i really know all the nuances
and the sound of almost every instrument playing.
You really need a high end monitoring system to get the full picture.
The only one system that gives me the entire picture through
headphones is the HPBA-2.Really in love with this piece of gear

Quote:
Originally Posted by Jerry Tubb View Post
I can see you have good taste in music, one of my favorites as well.

I also have the original vinyl from 1982, some of Roger Nichols finest work.

JT
Old 27th March 2010
  #19
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Teddy Ray's Avatar
 

Quote:
Originally Posted by bewareofdogs View Post
I've had a test through this unit some time ago.
My can was a recabled Beyer DT-770, not the best for mastering purposes.
Anyway, when hooked through the hpba-2 from QES Labs, the improvement was obvious.

As already stated in some previous post, I think that along with the new HD-800 you can really get your headphone reference system.

A true solid performer.
the HD800s are not all that. Ive lived with them for a while. Id say "reference for artificial "etched" hifi sound"
Old 27th March 2010
  #20
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Silvertone's Avatar
I just got to use, listen and master with the Stax headphone system while I was down at Chris Muths place... wow, never heard headphones sound like that! Of course for 2800.00 plus another 900.00 for the pre-amp they better sound that good.

They are the first pair of headphones that I ever heard that I think I could use to master with. Very impressive... now if I win the lottery, they're mine!
Old 27th March 2010
  #21
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fradoca's Avatar
Stax headphones have their own cable and external amplifier.
HPBA-2 is a reference system for dynamic headphones not
for electrostatic ones like the Stax.I had many telephone calls
with Val at Qes Labs.He really fulfilled all my requests like the pure
silver internal wiring and the toroidal transformer.But the most
important thing is that before making any purchase i had the chance to test the amp for 5 hours with my own gear
and my own headphones.Coming from the use of a SPL Phonitor and a Lake people G100
it has been easy for me to immediatly recognise the differences and where those amp were lacking.
I think i know pretty well the sound of my hd 600 and now with this new
reference amp i really have a true monitoring system.
Regarding the hd 800 i can say that those cans are an hungry animal.
The need a lot of power to be properly driven especially if you want proper
sound response on bass frequencies.Also you get improvements replacing
the stock cable with a much better one.There is plenty of choice.
Apart from that the hd 800 are among the most neutral headphones i've heard.
I'll be never tired of reccomending you an amp like this one if you want
a balanced reference system with no sound coloration.
Old 7th April 2010
  #22
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ThetaAlpha970's Avatar
 

What was "lacking" in the Phonitor now that you have your Qes?
Old 8th April 2010
  #23
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fradoca's Avatar
the hpba-2 has much much better instrument separation and speed
on transients because of the constant current drive.

more info here:

Balanced Headphone Amplifier Amp Studio Reference for professional use - QES Labs

Also the frequency response is more neutral than phonitor.



Quote:
Originally Posted by ThetaAlpha970 View Post
What was "lacking" in the Phonitor now that you have your Qes?
Old 22nd October 2010
  #24
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Wharfrat's Avatar
 

Comparing QES Labs Amps to Violelectric Amps

As quite some time has passed since you last posted on the QES Labs HPBA-2 headphone amp's virtues, I hope this is not totally too late to ask several questions.

Compared to the Lake People G100, do you feel there is more in the QES amp to power higher SPLs for most reference quality balanced headphones (i.e, Tesla, HD800, Ultrasone Edition 9) without distortion or other sonic anomalies?

Reason for asking this is because I have a hereditary severe hearing loss, but have learned to augument what remaining hearing I have with tactile "information". Attending some headphone meets has taught me that there are some amps that can sound really great at higher than normal SPLs, but for me that means hitting the vol pot up to 2 o'clock position (most folks are happy at 9-11). A headphone amp designer (see ALO Audio Amphora at www.aloaudio.com) offered to do a gain increase internally so I would have higher SPLs at my disposal. Then I discovered online that the Lake People Violelectric HPA v181 amp/preamp has adjustable gain settings up to 20dB.

I am wondering how the current drive capacity of the QES gear would serve the same purpose. Any comments?

stikestikestike

Wharfrat
Old 23rd October 2010
  #25
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fradoca's Avatar
if you contact Valerio at Qes Labs he will be able to offer a plenty list
of custom options.This amp can go really loud and can offer a wide dynamic range.I'm a really satisfied customer
and i would never go back to a traditional kind of amp.Let me tell you: just drop him a line:

http://www.qeslabs.com/e_index.asp
Old 23rd October 2010
  #26
Quote:
Ultra low noise and harmonic distortion
how much?? where are specifications
Old 24th October 2010
  #27
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fradoca's Avatar
for all the info please write to Valerio at this address :

http://www.qeslabs.com/e_index.asp


thanks
Old 26th October 2010
  #28
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4blades's Avatar
 

Quote:
Originally Posted by fradoca View Post
I'm a really satisfied customer
and i would never go back to a traditional kind of amp.Let me tell you: just drop him a line:

http://www.qeslabs.com/e_index.asp
Hi,
I was wondering if you had the chance to test it with the hd-800.
Thank you.
Old 26th October 2010
  #29
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fradoca's Avatar
not yet.
but i think it would the definitve combination.
The best headphone with the best amp!
About the replacement cable i think you've plenty of choice.

i hope to find a second hand hd800 and make some evaluations soon


heh
Old 21st June 2011
  #30
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chet.d's Avatar
 

Just stumbled in this thread as I search for a HP amp solution for the Audeze LCD-2's.

I will contact Val, but if anyone has any further thoughts on this potential pairing for mix referencing please do chime in...
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