The Centrance HiFi M8 thread
Jun 19, 2014 at 4:43 PM Post #4,906 of 5,999
 Then, we balance the lines again right before the output jack, to minimize interference and cross-talk. And we do this in a way that best conserves the battery.

In summary, for sound quality look to CEntrance. For Marketing hype, look elsewhere. We don't have marketing people designing our products. We have engineers doing that and we make appropriate choices at every stage along the way to keep customer's needs at the top of the list.

 
  I've been away from this thread for a while, but WOW!! Imagine my surprise to find that it's not really balanced. But I would like to applaud Michael for chiming in to explain things. So, is there any real benefit to using the balanced out?

 
Hi, as you can read, Mr Goodman has already described the advantage of using the balanced ouput on the hifi m8. Now it's matter of trying how is noticeable the difference between the outputs
 
Jun 19, 2014 at 4:49 PM Post #4,907 of 5,999
Apparently you are missing the point and my initial question. I'm not asking if there's any improvement with the technology used. But the difference between the two jacks when Michael also stated that the single ended output used the same balanced impedance topology and was the same as the balanced out.
 
Jun 19, 2014 at 5:11 PM Post #4,908 of 5,999
  Apparently you are missing the point and my initial question. I'm not asking if there's any improvement with the technology used. But the difference between the two jacks when Michael also stated that the single ended output used the same balanced impedance topology and was the same as the balanced out.

I see, well I think the advantage it's for those who want to keep using their already modified headphones without swapping cables.
 
Jun 19, 2014 at 7:20 PM Post #4,909 of 5,999
I too have an M8 and really love its sound, especially when driven by the USB B input (hi res).
 
On balanced outputs, I've gotten balanced cables for two headphones in my stable that I thought would benefit from it (LCD-2, Alpha Dog).  I use those cables with the M8, although I cannot claim to hear a difference in that output vs. the unbalanced 1/4-inch output.
 
I did come across this thread from almost 9 years ago on balanced amps, which has lots of discussion from Tyll Hertsens (at a time when his post count was low, it seems) and others:
 
http://www.head-fi.org/t/140716/what-are-the-technical-advantages-of-a-balanced-headphone-amplifier/
 
I found this post particularly enlightening:
 
----------
Mick Maloney of Supratek
 
Quote:

Balanced operation
I often get asked about the advantages of balanced operation-my reply is based on the following:

Balanced/unbalanced is a conentious subject. It comes from the pro audio world where they need it to balance out the noise pickup from very long cables.
True balance involves either using balancing transfomers or turning a Single Ended cicuit (as most preamps are) into a push pull circuit with double the components, circuitry etc- this is the only way to achieve "true" balanced throughout the preamp.
There's a lot of hype about it, with a lot of so called balanced operation being psuedo balanced, which is basically having an XLR socket wired to accept a balanced signal and turning it back to unbalanced.
Personally I prefer Single Ended operation every time- there's an ease and effortlesss about it, wheras true balanced sounds more electronic to me, especially the push pull types of operation.
One area where it is useful is in helping with RF noise in the big cities- it is not an isue for me in my country town isolation, but places like NY benefit from it and in my mind the best way to use balanced is to take it off the output transformer of a preamp, which fortunately we can do with the Supratek pres- it is true and perfect balanced with the minimum of circuitry to degrade the sound.
( there's virtually no circuitry!)
One balancing point in a preamp is all that is necessary- the output transformer turns the single ended circuit into a balanced circuit with two phases and the noise common to both channels (hum, RF etc) is greatly reduced.
Going for balanced throughout is sonic overkill that does more harm than good IMO- it has been a successful marketing campaign by some companies, but it is marketed to sell amps.
 
----------
 
What this has taught me is the following (all IMO): 
 
1)  I will never recable a headphone with a permanent cord to make it balanced.  I'll only buy detachable cables for headphones to use them with balanced outputs if desired. 
2)  I will never seek a balanced connection for a portable headphone -- it simply adds bulk and offers marginal gains for that type of headphone. 
3)  Balanced amps are a "balancing act" and as such, I will never seek to buy a headphone amp just because it is balanced, "fully" or otherwise.  Of course, if an amp is great because it was designed to work in balanced mode, that is a different story as its designers made that choice.  My ears will be the judge.   
4)  Head-Fi changes a lot over enough time (I don't recognize any of the amp names, manufacturers, or even posters, except Tyll who has totally changed his job description from back then)
 
Jun 19, 2014 at 8:58 PM Post #4,910 of 5,999
  I've been away from this thread for a while, but WOW!! Imagine my surprise to find that it's not really balanced. But I would like to applaud Michael for chiming in to explain things. So, is there any real benefit to using the balanced out? If not, then I must say I'm a bit disappointed for several reasons. First, when people think of balanced, they don't necessarily  thing of "impedance" balanced. And of course not all amps claiming to be balanced are not really balanced. But at the very least they are bridged which would mean the + and - terminals are both actively driven. That's what many feel is the only benefit of running headphones balanced. So all of the discussions previously about this having a balanced amp is misleading. Although technically no one actually lied. This is what leads to my reasons of being a bit disappointed.
 
First, had I  known that this wasn't really a balanced amp, I wouldn't have chopped up my very nice plusound solid core silver cable with it's nice viablue 1/8in connector in favor of a less audiophile friendly neutrick 4pin xlr. This added a ton of unnecessary bulk and weight to my jh13s. And I also wouldn't have chopped up the stock cable on my d600s, removing the iphone control etc, to make them balanced. I'm also reminded of another headfier who did major surgery on his momentums so that they could be balanced to go with his hifi m8. I can't even imagine the ones not in the diy crowd who spent serious coin to make their cans balanced. 
 
I of course wouldn't have opted for the very large and unnecessary fullsized  4pin balanced connector that's an eye sore imo. The explanation Michael gave would have been good to know in the beginning instead of misleading people into thinking the m8 was balanced.
 
But does this mean I'm putting mine up on the forsale forum? Not a chance. Remember I said a bit disappointed and not very disappointed. At the end of the day, this thing sounds incredible for a battery power device(or any device). And I think it's still a downright bargain at 699. But had I've known what I know now it would have saved me a lot of time, trouble, and a little money on supplies.

 
My exact same sentiment I enjoyed M8 even before I tried using the balanced output. I have demoed it against a Sony PHA-1 on a unbalanced output and it won me over so I bought it on the spot from a local distributor.
 
However, I was curious about using the balanced output so I bought a store-modified Beyerdynamic T1 with a detachable balanced cable. No matter what music I use to compare I really can't hear any difference between balanced and unbalanced output on M8.
 
Before I purchased my T1, I was thinking about buying a balanced cable for my JH16 or go the DIY route. I only dropped the idea when I didn't hear any difference on my T1.
 
Fortunately for me I didn't spend more on balanced cable for the rest of my in-ears and I still would get the modded T1 for convenience even if I knew M8 only has a balanced output from the start.
 
Jun 20, 2014 at 2:15 AM Post #4,911 of 5,999
  1) Our website and blog have always stated that HiFi-M8 features balanced outputs. We never claimed that it was a balanced amp. Please let me know if anywhere in our materials this is said differently.
2) Which statement by Kenny did I contradict? Could you point out what you are referring to?
 
Thanks, Michael

Perhaps some of the confusion has come from earlier posts  which stated that the M8 WAS a balanced DAC/AMP
http://www.head-fi.org/t/622939/the-centrance-hifi-m8-thread/90#post_8737974
post #96 of 4910
 
image.tiff

 
Jun 20, 2014 at 7:50 AM Post #4,913 of 5,999
Perhaps some of the confusion has come from earlier posts  which stated that the M8 WAS a balanced DAC/AMP
http://www.head-fi.org/t/622939/the-centrance-hifi-m8-thread/90#post_8737974
post #96 of 4910


Great find, thanks! If memory serves right, this is about the time (Fall 2012), still during the design phase, when we actually switched from a fully balanced path (yes, we had a version like that in the beginning) to a different circuit topology, with a single-ended, but more powerful amp and an impedance-balanced output. I still have the old PCB somewhere and can show that we did in fact test that fully-balanced version.

The reason we eventually switched was battery life. We had to make a compromise and give you both high output level AND relatively long-lasting battery. We achieved both with a design technique that was a good choice (and judging by customer satisfaction it still is a good choice today, on the sound quality level, aside from the verbal controversy.)

The reason I never got into the argument about balanced headphone cables was simple. There is a small army of devotees out there who DO hear the difference. Possibly due to RF protection offered by balanced output. May be they live in a busy metropolitan area with much cell phone interference and M8 filters that out well. Or may be because their recabled headphones offer a better balanced impedance in the send and return wires. We can only guess at the factors now, but people have written in to say that the balanced output worked for them.

Whether or not there is a huge difference is not my place to decide. I provided the feature without questioning why. If we start questioning the real delta difference between having a feature or not, let's ask if anyone has seriously benefitted from re-purchasing their music collection in full 192-kHz glory. Would it be my place to argue that the benefit there is small? Of course not! Not my business, but the business of the customer to make that call. I deliver the tools, not the taste.

Having said all of that, a sneak peak to let you know that the upcoming Mini-M8 actually does drive the balanced output with a dual amp. Not as powerfully as HiFi-M8, so we could both use the dual amps AND extend the battery life to 11 hours (Mini-M8 is designed to be used mostly with IEMs, so output power is smaller than HiFi-M8, which will continue to sell and power all big cans). So with Mini-M8 it will be truly possible to hear the difference between a balanced driver and a single-ended one. And yes, the balanced jack will have about 6dB more sound level.
 
Jun 20, 2014 at 9:03 AM Post #4,914 of 5,999
Mr. Goodman, this was a very detailed and a very honest statement.
You did a great job with the M8 concerning versatility, sound quality and battery life.
Keep on with the development of these fine portable devices.
 
Regards with respect Martin  
  
 
Jun 20, 2014 at 11:09 AM Post #4,918 of 5,999
@mgoodman
 When can we buy the mini m8, and how much would it be?


At the risk of being booted for commercial plugs... We are shooting for late summer availability and same price as the HiFi-M8, $699. Mini-M8 will have 4 inputs (USB, iPhone/iPad/iPod, just like its bigger brother, but will also add optical AND coaxial SPDIF for compatibility with many different DAPs.)

The plan is that It will also do DSD, which is what we are working on now. Because it has many additional features, it's priced the same. The drawback compared to HiFi-M8 is lower output power, but true balanced. While Mini-M8 is best for IEM use, it will still drive many low impedance headphones with plenty of oomph. As usual, we are striking a tight balance.
 

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