Here is some general useful information about the Rio Karma that I've collected from various sources around the internet.  I hope it is helpful to someone.

Karma description from DNNA (Rio) Website

Karma Support & FAQ's

Here are the few support FAQ's posted on the DNNA website, in PDF format.

The forums at www.riovolution.com and www.riovolution.org are excellent, and reasonably active.

Some interesting tidbits I've learned from forums or on my own include:

• The firmwares before v1.68 (latest) have many bugs, such as freezing on badly encoded mp3's.  I strongly recommend upgrading to v1.68 if you haven't already.
• It appears that people who leave their Karma in their docking station all the time, even turned off, have a risk of getting swelled batteries.  Apparently the charging circuitry isn't perfect in the player, allowing a gradual overcharge (and thus the swelling) of the Li-ion battery.  The swelled battery eventually cracks the case and/or kills the HD. I personally have found that half of the players that have come in for refurbishment have swelled batteries.  Check out the forum at Riovolution for more info.
• Crazy as it sounds, many people have had success smacking their Karma when they have HD trouble.  The failure where the player stalls on the start up screen is very common, and some people have linked it to a sticking of the heads or a stalling of the platter as it tries to come up to speed.  Apparently a couple of stiff wacks during the click-click-whirr stage of the startup can do the trick.  There is a very long thread on the Riovolution forum about this.

Disassembly & Mod's

Miscellaneous Tidbits

In my search to find a source for Karma parts, I have come across a couple interesting bits of info:

• The Karma's battery pack appears to be two 840 mAh prismatic Li-ion batteries (in parallel) from Sanyo GS Soft Energy Co., Ltd.  I was able to find their website in Japan, and got a-hold of a PDF that provides all the technical specs of the cells used (I think!).  One of the used units I bought to refurbish has a different battery, made by BYD Company Ltd. in China.  I imagine this is a later battery supplier that Rio went to near the end because they were cheaper than Sanyo in Japan.  Interestingly it appears that this more recent battery has a larger capacity, something around 1800 mAh.

• I have found a number of other battery suppliers with the same capacity and physical size of cell.  One in Korea seems very good, Kokam, who apparently is very big with the RC airplane crowd.  Here is a PDF brochure and product list from Kokam.  A good local supplier of Kokam and other brands of Li-ion batteries is Batteryspace.com.  The only problem is the cells needed to replace the Karma's have to be special ordered, and special orders have minimum order quantities of 500 cells (250 packs)!  I've decided to fall back on a supply of used batteries out of the U.S.

• Most recently (spring 2007) some batteries made by a company called Cameron Sino have appeared on Ebay.  These batteries appear to be an exact match to the stock Karma battery, and I have bench tested one out and measured well over their reported 1800 mAh capacity.

• Just out of curiosity, and while investigating the nature of the batteries, I measured the current draw of the Karma.  During startup and when seeking to a song it peaks at 690-710 mA.  When playing it sits at around 100-110 mA, and when just sitting turned on not doing anything it uses around 70-80 mA.  So when Rio says the battery life is 15 hours, they are assuming an average current draw of 1680 / 15 = 112 mA.  Let's assume that after every 5 minute song the drive spins up for 2 seconds to read another song to keep the buffer full.  The power consumption per song would be (300/3600*110) + (2/3600*710) = 9.6 mAh.  This translates to 14.6 hours of continuous listening, which is pretty close to 15 since the current draw isn't pegged at 710 mA the whole 2 sec.  Thus Rio's number seems consistent with my measurements.

• Anyone who has taken their Karma apart can tell you that the standard HD is a Hitachi C4K40-20Gb (HTC424020F7AT00).  This is now an older drive that they have not made for a couple years.  Their current compact 1.8" IDE drive line, the C4K60, seems to have replaced the C4K40.  I've tried a C4K60-20Gb (HTC426020G7AT00) in a Karma, and it works fine.  I'm guessing that they've fixed the bug with the sticky heads/slow spin up, and I know from testing and published tech data that they use less power then the older models.

• For those of you interested in putting a larger drive in their Karma, make sure you buy a Hitachi brand 1.8" Travelstar drive.  All the C4K40 and C4K60 drives have exactly the same geometry, except for their thickness.  The 40 and 60 GB drives are 9.5mm thick, as opposed to the 20 and 30 GB drives which are 7mm thick.  The thicker drive means some changes to make it fit, as you can see on my Ultra Karma page.  Please note that you must get the AT (44-pin IDE) connector version of the drive, not the CE (40-pin ZIF) connector version.  Back in February '07 I found out that Hitachi no longer makes the AT version of their drives, but there are still many floating around out there, so good luck.

Last Updated:  Aug. 1, 2007

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