CEntrance HiFi-M8 with Michael Goodman - Head-Fi TV - CanJam @ RMAF (2012)
Nov 25, 2012 at 12:23 AM Post #31 of 59
Quote:
No...no LOL, ROFL, or LMAO. 120 ohms is actually a 16 year old industry standard, unlike a 960 ohm fabrication. 300-600 ohm German phones w/ specific impedance curves are also quite real as well.
http://www.diyaudio.com/forums/headphone-systems/162962-maximum-allowable-headphone-amp-output-impedance-2.html#post2502688

I know it WAS an industry standard..... over 20 years and more ago.
 
The headphone output impedance should be 1/8 of the headphone you are using. 4ohms device/source/amp headphone output for the usual 32ohm headphone/iems etc......Hence my quip about 960ohm headphones, 960 being 120x8.
 
As a transportable device 1/2/10 is great, 1ohm (or even 0.5) is especially needed for multi driver IEMs and their severe fluctuations, 2ohm for the usual iems and basic headphones, 10 ohm for the larger 80ohms and above headphones.
 
Even the link you posted seems to repeat over and over how 120ohms is redundant especially for portable devices and todays portable market, it being a standard defacto measurement when people  sat at home and listened with their large headphones on their special lazyboy chair, and how low output  impedance is the sensible and scientific way to go these days.
 
even the large LCD-2 have an ohm of 50ohms, so 4ohms HPO would be about perfect for them, of course some like the HD600 have 300ohms and a HPO of 40ohm would suit them-but they arent really portable.
 
One only has to go to the iriver AK100 thread and see the vitriol given to a player these days with even only 40ohms headphone output impedance.
 
Heres a few recent players/amps and dacs and their headphone out impedances to compare where the industry standard is today
http://monoadc.blog64.fc2.com/blog-entry-99.html
 
kind regards,
 
Nov 25, 2012 at 12:49 PM Post #32 of 59
So by your logic, noone should buy the M8 because all the available impedance selections are too high anyway. Btw, your assertion that 4 ohms output-z is ideal for Audezes is completely off. So is 2 ohms for IEMs especially when many have multiple drivers w/ crossovers. The 8ohm is a made up general ratio for damping factor and is not an 'ideal' as you claim but a minimum standard as a best practice. If you could move your theoretical off-topic debate to the other site while others wait for a constructive response from CEntrance, that would be great, thx.

Thx Michael, just thought it would be something to consider since it's in development still.
 
Nov 25, 2012 at 5:58 PM Post #33 of 59
So by your logic, noone should buy the M8 because all the available impedance selections are too high anyway. ........ So is 2 ohms for IEMs especially when many have multiple drivers w/ crossovers. .
?????

No, I think the selection of output impedances are near perfect ( 1ohm and 2ohm are low) which is why i have already paid for a preorder of the hifi-m8.
I think the 1ohm option is great for multidriver iems too.

Perhaps you are confusing output power W/mW etc( and perhaps Gain) with headphone output impedance.

Hifi-M8 Specs:

Output Impedance
1, 2, 10 Ohm, selectable


Output Power
1.5W (total), drives 32...600 Ohm headphones

Max Output level*
+13.5dBV (32 Ohms load) (still verifying)
+18.6dBV (300 Ohms load) (still verifying)
+19.0dBV (600 Ohms load) (still verifying


I think you misread my post, and no i am not going to join the other site to increase their traffic nor will i continue this debate.
Best regards and bye.
 
Nov 26, 2012 at 11:12 AM Post #34 of 59
Very neat! Glad to hear there have been a number of nessicary changes made :D looks pretty interesting and I do like the different levels of Bass ans Treble since most certianly different cans needs different amping [that is ofc if you desire to color your sound, which in some case I think most of us want to ;3 [I love colorful EMD]]
 
Non the less looking forward to seeing the final product!
 
Nov 27, 2012 at 12:14 AM Post #35 of 59
Regarding the 120 Ohm output impedance:
 
We did some research at Syn Aud Con (they know everything about standards) and it was helpful to look into the history of the standard. It looks like the 120 Ohm standard was addressing a very specific need, not particular to the HiFi community. We learned that the primary reason for that standard was to accommodate parallel connection of dissimilar headphones and the use of cheaper output op amps.
 
Audio fidelity was never a concern, rather overall cheapness of solution was the priority. You can actually drive longer cable lines with high output impedance. You can also use cheaper op amps without fear of blowing them out. However the damping factor will invariably suffer. I can see how this may be useful in large distributed environments, such as studio headphone feeds or conference room listening setups.
 
For HiFi use however, the higher output impedance is probably less ideal. In general, you want the amplifier to have the best possible damping factor, which is achieved by lowering the output impedance. This helps fight off any impedance non-linearity in the inductive load (headphones in this case). Raising the output impedance does not make the frequency response any more linear. While it may be a better match for a couple of high-impedance headphone models, it will be less ideal for the majority of headphones, which feature low impedance (such as most IEMs and those models that came out in the iPod era).
 
In the result of this research we are concluding that higher output impedance will not make the sound quality any higher. If you happen to own those (rare) headphones that require higher output impedance, and are planning to get a HiFi-M8, please let us know and we will adjust one of the impedance switch positions for 120 OHm to meet your need. We don't mind making custom mods like that and in the result you will have a unique unit.
 
Knowing that most of our customers will use IEMs, we will keep the main model at lower output impedances, for a better match with those, more popular headphones.

Thank you for the opportunity to learn about a new standard.
 
Michael
 
Nov 27, 2012 at 9:43 AM Post #36 of 59
Watched the video, a confusing product, but as Europe as a market is not even mentioned I guess we will miss out again.

Dear USA, Europe still exists BTW
 
Nov 27, 2012 at 9:32 PM Post #37 of 59
Finally I get a size comparison... It's a bit chubbier than I thought it would be, though it sounds like they've stuffed all that space with some good filling!
 
Edit: Post 100!
 
Nov 28, 2012 at 12:48 AM Post #38 of 59
Brilliant response Michael, you nailed it perfectly and thank you for considering such requests.  For my particular needs I'll be pre-ordering the M8 w/ an impedance selection of 1/10/120 then.   
 
Many thanx! 
 
Since we are on the subject, I presume '1' is the lowest possible value w/ this architecture?  Obviously even less is better for say a multi BA/xover w/ 12-16 ohms impedance as even the O2 w/ 1 ohm has shown some linearity issues w/ such IEM compared to other amps.  If the actual value is really <1 but just uses '1' for the sake of simple language, then disregard the question entirely.
 
Thanks again.  You're the man Michael! 
 
Nov 28, 2012 at 1:15 AM Post #39 of 59
> Dear USA, Europe still exists BTW
Yes, I was born in Europe, so I know :)
 
We are actually in the process of setting up serious distribution in the EU, so all is not lost.
I sent you a PM. Please ask any questions you may have here or by PM. We love Europe!
 
Nov 28, 2012 at 1:17 AM Post #40 of 59
Just in case you guys missed it, there is a separate HiFi-M8 thread, currently almost 50 pages long!
 
http://www.head-fi.org/t/622939/the-centrance-hifi-m8-thread
 
And please don't forget to visit our daily blog, where we talk about bringing the product to life:
 
http://centrance.com/products/new/blog/
 
Michael
 
Nov 30, 2012 at 3:46 PM Post #41 of 59
Quote:
Just in case you guys missed it, there is a separate HiFi-M8 thread, currently almost 50 pages long!
 
http://www.head-fi.org/t/622939/the-centrance-hifi-m8-thread
 
And please don't forget to visit our daily blog, where we talk about bringing the product to life:
 
http://centrance.com/products/new/blog/
 
Michael

While the M8 is a little thick but still very portable, do you guys plan to keep the same form factor in the final product?
 
Jan 9, 2013 at 2:13 PM Post #43 of 59
Quote:
> Dear USA, Europe still exists BTW
Yes, I was born in Europe, so I know :)
 
We are actually in the process of setting up serious distribution in the EU, so all is not lost.
I sent you a PM. Please ask any questions you may have here or by PM. We love Europe!

 
Excellent! May I be the first to suggest the UK to reach out to the rest of Europe 
very_evil_smiley.gif

 
Seriously, seasoned head-fiers may be crazy enough to import, but not having to pay import charges and international shipping is always nice to minimise the wallet hurt and may even swing a purchasing decision
 

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