Topic: KORG MR-1 pt.II

[tedyun]

The good news is that the CF mod almost doubles the battery life. I managed to record nearly 5 hr.

The bad news is that during the extended recording, there is a problem writing the DSD files. When recording a DFF file, the recording is subdivided into multiple files of approximately 1 GB each (approx 25 min), accompanied by a PROJ file which Audiogate uses to merge the files.

To test the runtime of the battery, I set it to record audio from my computer, and let it go till the battery ran out. On this 4+ hr recording, about half of the files were corrupted, and the PROJ file was not usable.

I repeated a long recording, this time with the unit plugged into an AC adapter, and let it go for 3 hr, which is a reasonable time for a fairly long concert. When I stopped the recording, it gave me a "Disk Error" and again, half the files were corrupted, and the PROJ file couldn't be loaded by Audiogate.

 

I suspect the problem is that the CF card doesn't write the DSD stream fast enough. The 133x Transcend card I am using is rated at 21.5MB/sec whereas the HDD and SSD write at 100 MB/sec.

So the conclusion is that as a 1-bit recorder, the CF card doesn't pass the test, so I probably won't use it in the field.

Success with the CF-mod!!

It turns out that the ZIF > CF adapter I used previously was crap! After success reported on head-fi.org, I tracked down the correct adapter and installed it. The price is about $20 on eBay, but if you are patient, you can get it from DealExtreme in Hong Kong for $6.30. It takes about 2-3 weeks:

http://www.dealextreme.com/details.dx/sku.11814

I tested it with a 133x 16 GB Transcend, and also an old PQI 2 GB card. Both worked!

Will do a battery test.

[WiFiJeff]

No sweat, just get a 650X CF card.

Oh....

[Colin Liston]

I suspect the problem is that the CF card doesn't write the DSD stream fast enough. The 133x Transcend card I am using is rated at 21.5MB/sec whereas the HDD and SSD write at 100 MB/sec.

So the conclusion is that as a 1-bit recorder, the CF card doesn't pass the test, so I probably won't use it in the field.

Bummer....but I was thinking that a CF card wouldn't be able to write fast enough.

[H₂O]

I suspect the problem is that the CF card doesn't write the DSD stream fast enough. The 133x Transcend card I am using is rated at 21.5MB/sec whereas the HDD and SSD write at 100 MB/sec.

Did you format the CF card in the MR-1 before you ran the test?  Random write performance of CF cards is usually very poor (much lower than the 21.5MB/sec quoted for sequental writes) - formating should defragment the volume and keep the writes sequental.  You can never just erase files or the volume will get fragmented.

I ran into these problems with CF fragmentation on a Sound Devices 702.  As long as a I formated the CF card at the beginning of each recording session I never had speed problems (even at 24/96Khz on a much slower card (rated at about 6.5 MB/sec write speed)).

[deadheaded]

my understanding is that cf cards cannot write the data fast enough for dsd.  that is why korg used hard drives instead.

[tedyun]

H2O --

Yep -- before each test, I cleared the CF card by formatting it within the MR-1.

I was thinking of testing whether the CF card is fast enough to reliably record at 24-bit/192Hz, 24/96, etc., or to test just how long of a recording the CF card can make. But at this point it's just out of curiosity. I bought the MR-1 to make 1-bit recordings.

Colin and deadheaded --

I kind of suspected that the CF card was too slow (guysonic brought that up in this thread), but after the success of using the CF-mod for playback (see the head-fi.org thread), my curiosity was driving me crazy to find out for myself.

At least I found out the answer. I am going to do the same tests with the SSD drive. I believe the 2.5 h recording I previously made was intact, but I don't think I tried reloading it into Audiogate. I will probably stick with the SSD, even though the battery life was not dramatically improved. Because other people have had problems with the HDD and possible write errors when moving around, the SSD will at least safeguard against that reported problem.

I suspect the problem is that the CF card doesn't write the DSD stream fast enough. The 133x Transcend card I am using is rated at 21.5MB/sec whereas the HDD and SSD write at 100 MB/sec.

Did you format the CF card in the MR-1 before you ran the test?  Random write performance of CF cards is usually very poor (much lower than the 21.5MB/sec quoted for sequental writes) - formating should defragment the volume and keep the writes sequental.  You can never just erase files or the volume will get fragmented.

I ran into these problems with CF fragmentation on a Sound Devices 702.  As long as a I formated the CF card at the beginning of each recording session I never had speed problems (even at 24/96Khz on a much slower card (rated at about 6.5 MB/sec write speed)).

my understanding is that cf cards cannot write the data fast enough for dsd.  that is why korg used hard drives instead.

[Colin Liston]

Thanks for testing.  Keep up the good work!

[RTD]

hmmm, wouldn´t have a Sandisk Extreme 4 enough speed to handle DSD steams? I mean it promises more than 40 MB/s...

[tedyun]

I think these new fast cards use UDMA technology, which I have no idea what that means, but you need devices that are UDMA compatible in order to achieve those read/write speeds, and I'm not sure if these ZIF > CF adapters handle that.

I do have a 4 GB 300x UDMA Lexar card (http://store.lexar.com/?productid=CF4GB-300-381) that I can try, but it is a bit small to do the extended test. I think it will only record under 2 hr. I'll try it and if the files are corrupted, it will mean that these fast cards won't work for whatever reason. If everything goes fine, that will open the possibility that these fast cards could work, but I will have to get my hands on a 8 or even 16 GB CF.

Edit: My adapter apparently supports UDMA. It is the same one as in this pic:

http://cgi.ebay.com/Compact-Flash-CF-To-Toshiba-CE-1-8-ZIF-Adapter_W0QQitemZ220468721260QQcmdZViewItemQQptZAU_Components?hash=item3354f5b66c&_trksid=p4999.c0.m14

I'll test it out now and report back (in < 2 h!) 

hmmm, wouldn´t have a Sandisk Extreme 4 enough speed to handle DSD steams? I mean it promises more than 40 MB/s...

[H₂O]

I would think modern CF cards would be fast enough, but you never know.

I know 1bit 2.8Mhz DSD file sizes are about 2.4GB per hour where as 24/96 files are about 2GB per hour and a 24/192 is about 4GB per hour.  I would think a CF card that runs over 10MBps would be more than enough to handle DSD streams. 

I would think a 1bit 2.8Mhz DSD 2 channel DSD stream would be around 0.68 MBps (or about 3Mbps)
 
Right as you say maybe the bottle neck is elsewhere.

[tedyun]

My 300x UDMA card doesn't work. I recorded 1.5 h, and it had the same problem.

At this point, it could be the adapter, or it can just be that CF cards aren't compatible. I agree with H2O that it should be fast enough, so I'm not a techie to figure out what else could be going on.

Just from doing all these tests, my failed attempts, ie., the RunCore SSD and the CF-mod shared the common feature that they have slower write speeds than the Mtron SSD or Hitachi drive. I guess the other common feature is that they are cheap parts sourced in Asia too, so I'm not sure what kind of standards they are adhering to, or what kind of QC is going on.

I would think modern CF cards would be fast enough, but you never know.

I know 1bit 2.8Mhz DSD file sizes are about 2.4GB per hour where as 24/96 files are about 2GB per hour and a 24/192 is about 4GB per hour.  I would think a CF card that runs over 10MBps would be more than enough to handle DSD streams. 

I would think a 1bit 2.8Mhz DSD 2 channel DSD stream would be around 0.68 MBps (or about 3Mbps)
 
Right as you say maybe the bottle neck is elsewhere.

[RTD]

hmmm...Thanks for the info. I would like to get rid of the "noisy"drive. 

[RTD]

Dunno if someone has mentioned: firmware 1.6 is available. 

http://www.korg.co.uk/products/digital_recording/mr/dr_mr1.asp

[H₂O]

Has anyone tried the following SSD in the MR-1?


http://www.kingspec.com/solid-state-disk-products/ssd-18zif-mlcs.htm

http://www.memoryc.com/storage/solidstatedisk/32gbkingspeczif40pin.html

Looking at the wattage it looks like it may pull slightly more power then the HDD currently installed.


They are starting to get cheap enough to look at as a viable replacement for the stock HDD.

[Colin Liston]

Dunno if someone has mentioned: firmware 1.6 is available. 

http://www.korg.co.uk/products/digital_recording/mr/dr_mr1.asp

Updated Audiogate software too.  Includes FLAC support