The Centrance HiFi M8 thread - Page 10

I was under the impression that this is more of a transportable device rather than portable/pocketable device. 

Edit: Holy crap!!! I didn't know it was this size!!!

OK, OK. Battery life, over powering monsters it is then. Either way it should be able to drive full size cans like Sennheiser HD600/HD650 quite well.

Indeed. This could be the benchmark portable DAC/AMP that suits many different kinds of users.

Survey for output, battery level of the CEntrance HiFi M8

Yours truly will have some work to do to satisfy both camps. Please bear with us, this means a slight delay, but I'm not giving up on an optimized solution. Not with this kind of support!

At this point I don't have the need for either high gain or long battery life so I'm trying to take a step back and look at the design itself. With the balanced outputs it's a product that is not only targeting the portable crowd but the high-end crowd as well, in my view it would be a shame to see the design hamstrung for those users. In my opinion the M8 not only needs to have a low gain option that allows IEM's to be driven in a manner where they have a good amount of useable volume control and no noise but also so the higher gain model will drive the likes of the LCD-2, HE-500, etc. effectively. A balancing act indeed.

Michael, I don't think this question got answered. If you're using easy to drive, sensitive IEM's in low gain mode will the battery life be longer than a harder to drive headphone in high gain?

New CEntrance blog update.

Briefly, from the survey he gathered that more people treasure the battery life due to the realisation of the portability. He's working hard with his team to seek better battery life from the 'power' config.

Quote:

Originally Posted by eron 

Looks great! http://www.bhphotovideo.com/c/product/544607-REG/Grado_MINI_ADAPTOR_Mini_Adapter_Cable_1_4.html

I absolutely HATE those long Grado and Sennheiser 1/8" to 1/4" adapters - they are just too big to carry around and I do feel that the crappy cable inside will degrade the sound, unlike those tiny solid 1/4" to 1/8" adapters.  I'll take a 1/4" jack over an 1/8" jack every time, and just use the smaller adapter with no extra cable between the plug and jack.

Michael, I just tuned into this thread, and I'm only halfway through reading it, but I did go to your questionnaire about output jacks and put in my vote.   I also think the dual 3-pin XLR would be worse since we've moved away from that over the past 3 years.

I recommended either (a) 4-pin XLR + 1/4" jack, or (b) RSA jack + 1/4" jack, or (c) mini 4-pin XLR jack + 1/4".  In my case I have an RSA to 4-pin adapter, to use full size phones with my SR-71b.  Unfortunately all my balanced IEM use the RSA plug.  

I also have Moon Audio convertible cables for my LCD-2 and HE-500, where they have a mini 4-pin XLR plug that connects to an adapter for single ended amps, another for RSA amps, and another full size balanced amps.  This way I can use my LCD-2 and HE-500 on the DACmini, SR-71b, or Eddie Current ZDT amp.  The problem with an amp using only the mini 4-pin XLR is that most people would need you to include an adapter that steps it up to a full size 4-pin XLR jack.  For instance, my HD800 cable has the large 4-pin XLR and I'd need another adapter or cable to connect those to a mini XLR.

I'll go back and finish reading the thread now.  Looking forward to seeing you at RMAF!

Quote:

Originally Posted by eron 

New Centrance Blog post, and back panel pic:

http://centrance.com/products/new/blog/2012/09/25/back-panel-controls/

 

 

Saying it will be compatible with iPad, means it will be compatible with the old 30pin connector. Then it will be odd if the M8 isn't compatible with the new iPhone 5, or other new devices with Lightning connectors. Reading up on the CLAS's blog reveals that the Lightning connector works fine with it. So I'm assuming that they will all work the same in extracting data, thus Apple supplied usb dock connector cables will work for all respective iOS devices.

 

So my question is:

 

Will USB-->'iOS devices' cables be provided? Especially shorter ones for the iPhone.

My lightning cable and iPhone 5 also works fine with the Nuforce iDo digital dock, and I suspect the HP-P1 and the HiFI-M8 would also work with it.

Quote:

Originally Posted by mgoodman 

Q: I would be extremely interested in a true line out option on this letting me send the signal to my home amp and using the internal amp for my portable.

A: We are struggling with this one. Turning the volume pot "off" is effectively what you are asking about. We don't think that this would be possible. However, the XLR outputs will feature low noise and distortion, so they should be perfectly fine for driving the home setup. The XLR outputs, even though designed to drive headphones, are as good driving line-level signal. The only issue is you may need to position the volume pot in the middle. We will have more info on that soon.

As you stated, with low distortion and noise it could be used as a pre-amp.  I've done that with the DACport and other good DAC/amps, and there's no reason why this device couldn't work as a pre-amp too.  Interestingly, my old Apogee mini-DAC could drive balanced headphones like HD-600 via the XLR pre-amp outputs using a simple XLR gender adapter, but it was designed as a pre-amp line-level output.  

Quote:

Originally Posted by mgoodman 

Guys, we need some help. It may be time to pull together another one of them surveys...

 

We have a choice with HiFi-M8:

- About 5 hours of battery life and output performance that’s equal to DACmini (pretty much any headphones, incl. over-the-ear)

- About 8 hours of battery life and output performance that’s equal to DACport (most headphones, certainly all IEMs)

How many people really need to drive the tough-to-drive HiFi Man cans? We are going to be fine with most IEMs regardless...

Thanks for your help, in advance!

Here is the blog post explaining this in more detail:

http://centrance.com/products/new/blog/2012/10/03/output-level-dilemma/

If the device can charge while plugged into a PC USB for the DAC to function, then less battery life is acceptable at about 5-6 hours.  I assume the battery is only needed for playing with an iDevice while mobile.  At the bedside if it can charge from wall power while using an iDevice that would be best.  If it will run out of juice in 5 hours no matter what it's plugged into, and can't be charged while it's used, then I'd maybe vote for 8 hours with less power.  I'm pretty happy with something like this if it will run forever while plugged into power, and having battery for 5 hours is just icing on the cake. 

Regardless, to drive full size balanced headphones like LCD-2 and HE-500 you want as much power as you can get, and DACmini levels are more desirable than DACport levels of power.  I completed eron's survey on this too.

Okay, one last thing before bed - I think many people would be agreeable to an extra 2-3mm in height for a bigger battery with longer life in the high power setup.  

Also, it seems to me that you either make it (1) a smallish portable balanced DAC/amp with good battery life, less power, and use the RSA jack to keep size down, or (2) since you are using full size jacks for full size headphones then you may as well optimize for power rather than size, and give it less battery life but indefinite run-time while connected to external power (wall power or additional battery pack).  It can then be used as a desktop replacement, transportable, or portable.  The length and width could be dictated by the size of the iPhone 4S, 5, or new iPod touch, for stacking the iDevice on top of it; while height or thickness could be defined based on the battery size needed to get 8 hours or more of life.

True. If we are expected to use the full-size XLR jacks for our full-size balanced headphones, the power should definitely be there. Version 2 (more battery life, smaller balanced jack, single-ended jack) can be a bit less powerful, probably. Of course, why not both? :)

With regards to the battery life vs. power debate, if creating the most powerful portable DAC/amp is really your mission statement, you should remain true to your vision.  However, not being able to drive orthos with a portable rig is essentially no different than not being able to drive electrostatic phones.  Big deal.  You'll never be able to drive them all.

 There are plenty of guys left with their Grados, their AKGs, their Beyerdynamics.  In fact I dare say most if not all of the planar magnetic headphone owners own one or more alternatives as well to choose from.  Comprehensive headphone comparisons are mostly for industry or forum review benefit, anyway, not real life recreational scenarios.

As a baseline design reference, battery life should at least be able to last the duration of a transatlantic flight.  I think that criterion is applicable for most of us these days.

Hi Larry, good to hear from you!

Q: (a) 4-pin XLR + 1/4" jack

A: Yes, that's what we are going to offer. Not at RMAF, but shortly afterwards.

Q:  I'm pretty happy with something like this if it will run forever while plugged into power, and having battery for 5 hours is just icing on the cake. 

A: Yes, it will work forever when plugged in, and retain XX hours of charge when not plugged in. We are still collecting data on that.

Q: It can then be used as a desktop replacement, transportable, or portable.  

A: Yes, that's we are leaning. A multi-functional device. We weren't thinking this way initially, but this here community lead us down that path. The draw back is that's extra work and now I'm living totally without sleep... Thanks, community! (LOL)

Q from jJacal01: As a baseline design reference, battery life should at least be able to last the duration of a transatlantic flight.

A: I wish they brought back the Concorde! :) But seriously, I totally hear you on this one.

This week is shot due to RMAF preparations, so design changes will occur sporadically. We are still holding to our goal to ship before XMAS. Did that with DACport. Did that with DACmini. HiFi-M8 is probably double the complexity though...

Michael

Quote:

Originally Posted by mgoodman 

 

This week is shot due to RMAF preparations, so design changes will occur sporadically. We are still holding to our goal to ship before XMAS. Did that with DACport. Did that with DACmini. HiFi-M8 is probably double the complexity though...

 

Michael

What headphones will you be bringing to RMAF this year, for demoing your gear?