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NEW information on JH-3a - Page 144  

post #2146 of 2176

So, I have to say I'm kind of underwhelmed by the reporting, or lack thereof, re: CanJam reports on JH-3a.  As far as I can tell, only JP and Max opined,, perhaps I missed something Jude or anyone else might have written/said?

post #2147 of 2176
What you missed was pretty much universal positive response to the 3a. Most of the folks I were with are not frequent posters but are Headfi members. I'll leave it to them to decide if they want to post.

Day one the amp was fresh and day 3 it was definitely improved. One member put it against the 801 and pico slim combo and thought the 3a was better. This is now possible post change as the new unit has passive crossovers.

I'll be switching mine out as my day 3 comparisons left me liking the new version better.
post #2148 of 2176

Thanks,, I just read notes from a live blog on another audiophile website (which I'm sure everyone knows but I don't think I can name here) which stated very high impression of the system and said there would be an online video soon.

post #2149 of 2176
Jerry took us through it. It's simply awesome.
post #2150 of 2176
Quote:
Originally Posted by inthecity View Post

Thanks,, I just read notes from a live blog on another audiophile website (which I'm sure everyone knows but I don't think I can name here) which stated very high impression of the system and said there would be an online video soon.


Not sure why you can't link to the blog here?  If not, can you please PM me the link?  Thanks.

post #2151 of 2176

It's headrooms video blog i think, but the jh-3a blog it's not up yet. I could be wrong.

 

post #2152 of 2176
Thread Starter 

So, to those of you who attended RMAF 2011, did you come away with a more thorough understanding of what has happened with the jh-3a since last year?  I would assume this was the first opportunity for most of you to talk with Jerry face to face since the last Canjam.  I'm very curious to hear what Jerry's insights are on this situation. 

post #2153 of 2176

Did anyone notice on their website which has been updated already that they still show 24/192??? I thought we were down to 24/96. Do you think with all the time they had to revamp this thing that they increased the rate to what we expected in the first place?

post #2154 of 2176


 

Quote:
Originally Posted by onecolorist View Post

So, to those of you who attended RMAF 2011, did you come away with a more thorough understanding of what has happened with the jh-3a since last year?  I would assume this was the first opportunity for most of you to talk with Jerry face to face since the last Canjam.  I'm very curious to hear what Jerry's insights are on this situation. 



This is my first of two posts on the subject.  The second one will be linked here once I finished writing it, because it will take a lot of effort on my part to recapture hours worth of conversation and comparative testing he and I have conducted with the gear I've brought.  It will also outline the technical differences between the old and new design specifically how the crossover is implemented.

 

Bottom line is this:  I have returned the old amp and my shells.  The amp will be replaced and the shells modified and tuned to the new amp this week.  JHA now has 100 amps ready to go as soon as Tuesday.  Jerry will spend most of today fine tuning the DSP programming as a result of our little session and primarily listening to the new amp using the HM-801 as a source via a mini-to-mini cable (the HM-801 has no digital coax output, unfortunately).  The HM-801 had the same 24/96 FLACs I had on the iPod Touch/CLAS combo I had been using as the source to feed the old amp.

 

DSC_2388.jpgDSC_2388.jpgDSC_2387.jpg

 

Because the only shells tuned to the new amp were demo shells, I will not post any impressions here.  Not because they didn't sound good, but they are not equivalents to custom shells.  So, Jerry had offered to build the new amp, rebuild my own shells and tune them using the tweaked version of the DSP microcode he's working on today.

 

What we have discovered is that the revised analog input stage now works so well that the HM-801 24/96 analog output using its dual PCM-1704UK DACs simply outperforms the iPod Touch/CLAS combo using SPDIF out from the CLAS.  This was not the case with the old amp.  We have used only high-res material, and I have not compared it to Redbook stuff, where the iPod/CLAS combo could still perform very well.

 

The amp gain structure is now totally silent, as promised.  Battery performance has remained the same for this version, about 6+ hours of continuous playback.  It currently cannot be charged via USB wall charger while being fed via SPDIF in, but it can if analog line-input is being used.  The battery life is roughly equal of that the HM-801 is capable of with the balanced amp module, which Jerry had intently listened to using his own JH16 custom shells as a basis of comparison.  The battery life can be substantially increased with relatively modest effort for those who will want this, but Jerry has flatly declined to hold back shipping the amps out any longer, which is I think the right call considering the circumstances.  There are always things you can improve on a design and it is an iterative process, which in this case will depend on market acceptance of the current batch.

 

The other major change is that the B/M button now functions differently.  In the old amp, it has completely turned off the bass amp.  In the new one it merely drops it back to a near-linear dB level, perhaps a 3dB bump at 50Hz.  This will be useful for pro use, such as live performing artists and recording engineers, but most of us, listeners will want to leave it engaged, as before.

 

Once I receive my new amp, I will post sonic impressions.  My plan for mobile use--assuming I will be satisfied with the final outcome of the sound signature--is to revert back to my WhipMOD/Fat Boy LOD combo.  For desktop use, I will be able to use my MBP/Amarra 2.3/Cynosure/Sonicweld Diverter HR/Coax SPDIF input and play high-res up to 24/96.  This is why my CLAS and iPod Touch is now up in the F/S forum.  I'm hoping to find eventually a comparatively sized DAP with 24/96 playback, 32GB swappable storage and SPDIF output to reevaluate digital a go with the JH-3A down the road.  The HM-801 would be an option using Line-Out, but the it has a bigger chassis so it would be challenging to stack them together.

 

I will work on the second post later this afternoon and will update this one with the link.

 

Here is the second post URL:  http://www.head-fi.org/t/576238/jh-audio-jh-3a-3-way-dsp-amplifier-crossover-design-changes#post_7828889

 

==========================================================================================================

 

Update from JHA RE: the content of this post and the preorder batch of amps.  All of the prep we had done building all of the earpieces for the 2.0 amp have to be cut open and reworked. This is time consuming and we will be completing the work as quickly as possible.  We have completed the composer file and waiting for the binary file to be emailed to us to write the 1st chips.

 

 

 


Edited by warp08 - 10/17/11 at 4:34pm
post #2155 of 2176

Yes, I was referencing headroom's video blog,,, I provided a link to a headroom post and it was removed "for a number of reasons" so I don't know (nor really care) what the mod concerns were. In any case, I was informed that headroom might be a bit biased due to JHA sponsorship, fyi. (as some people have purported and/or implied head-fi and/or head-fi users might be...) Lesson: always include your own critical assessment to any reviewer/review.

post #2156 of 2176
Quote:
Originally Posted by warp08 View Post

The battery life can be substantially increased with relatively modest effort for those who will want this, but Jerry has flatly declined to hold back shipping the amps out any longer, which is I think the right call considering the circumstances.

 

 



Hi Warp, thanks for posting all this info, things seem to be very positive with the new version so far. Wish i could be there to hear for myself, but i'm still planning to purchase shortly after the pre-orders are fulfilled.  Regarding the above quote, could you elaborate a little on the possible expansion of battery life?  Is this maybe something that buyer's of this jh3a version could either modify themselves or possible be offered as an upgrade sometime in the near future?  Personally, i'd feel a lot better if i knew i wouldn't have to purchase the 2012 or 2013 version of the 3a to get extended battery life and/or an AC power option.  Thanks

post #2157 of 2176
You can find my detailed notes and impressions on the JH3a/JH16 by clicking the link in my sig and navigating to #49.
post #2158 of 2176

Just sent back my JH3A for the new version. Now the waiting begins once more! :)

post #2159 of 2176
Quote:
Originally Posted by tcp12 View Post

Hi Warp, thanks for posting all this info, things seem to be very positive with the new version so far. Wish i could be there to hear for myself, but i'm still planning to purchase shortly after the pre-orders are fulfilled.  Regarding the above quote, could you elaborate a little on the possible expansion of battery life?  Is this maybe something that buyer's of this jh3a version could either modify themselves or possible be offered as an upgrade sometime in the near future?  Personally, i'd feel a lot better if i knew i wouldn't have to purchase the 2012 or 2013 version of the 3a to get extended battery life and/or an AC power option.  Thanks


That's cool.  I can't go into too much detail regarding the battery, since Jerry had made it clear that his #1 priority to ship out the new build to all who have been waiting for so long.  This is a sentiment I could understand, since given time and resources everything can be improved upon, but you have to baseline somewhere and get the product out the door.  Still, I got the distinct impression that the 2.0 (current) design was flexible enough where battery capacity could be increased without a lot of work and will be offered at some point as an optional upgrade for those who will need more runtime.  The design could be also relatively adapted for a desktop (AC-powered) version, however, that will be determined based on market acceptance for this version.

 

I would definitely encourage anyone who is interested in these technologies to attend Can Jam/RMAF events.  They are fun and it's great to meet and socialize with a lot of these vendors face-to-face and get to know them as well as the background behind the effort to bring to market these technologies to the market that we invest our hard-earned money.  It's not inexpensive to travel these days, but once a year it's well worth the cost as you can make a lot more informed purchase choices based on first-hand experience with these things--even if under less than optimal circumstances in a show setting--as opposed to relying on second-hand information.

post #2160 of 2176

So I am guessing that feeding the JH-3A an analog signal means that there is a conversion from A/D and then another conversion from D/A that takes place in the JH-3A. Is that correct? Also the way the CLAS is implemented there is no processing taking place inside the CLAS if that is how you want to use it. You are just pulling the data out of the ipod, not performing any processing on it and sending it on to the JH-3A. The ipod becomes a storage device and you are bypassing the dacs in the ipod and the CLAS becomes a transport mechanism for pulling the bits out of the ipod without undergoing any processing either in the ipod or in the CLAS presuming that is how you want to use the CLAS.

 

I actually had to go back and re-read both posts from warp again, the one here and the one linked as initially I thought the comment was that feeding the JH-3A an analog signal at least as it relates to hi-res files, bettered other high quality portable source/dac/amp combinations. If I can interpret what is being posted correctly, feeding the JH-3A an analog signal is besting feeding it an unprocessed digital signal and I am really struggling with that one given the added conversion from A/D and then from D/A.

 

I guess I am not getting the comparison from pervious to current JH-3A in that I thought it was generally accepted that in no case was it optimal to endure the added A/D  conversion in the JH-3A and always better to feed it a digital signal which made the CLAS a neat piece. That did make sense to me. If the aforementioned A/D and D/A conversion is taking place does that not imply that something else is also going on. Even improving the dac chips in the JH-3A would not account for this experience would it? If you improved the dac chips then the performance feeding the JH-3A a digital signal should improve as well. I can see how improving the analog section would improve performance for an analog signal but how do we account for it improving analog signal performance such that it betters digital signal performance for the same piece of equipment?

 

Is there something about this particular implementation that forces some burden onto what should be nothing more than an unprocessed data stream coming into the digital input of JH-3A that makes the added A/D conversion that occurs when feeding the analog input of the JH-3A a better compromise? If there is some burden that is added to what I am maybe incorrectly thinking is nothing more than an unprocessed digital data stream coming into the JH-3A via its digital input then I guess I get it. That would say that there is a compromise of some sort taking place in both cases and the compromise experienced via the analog input is simply more palatable. 

 

So I guess my question is for warp or for anybody with a stronger technical background than mine which means half the human race and just about everybody in this forum.

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