M-audio Octane design flaw

[drumvan]

I thought I would post this report due to the large number of people that ask this and other forums about which 8 channel pre-amps they should purchase.

I recently bought an M-audio Octane unit for recording drum tracks in my home studio. I use the adat lightpipe to connect to my Protools 6.4 le system. My mic setup consists of the following:

kick - Audix D6
snare and toms - SM57's
overheads - (2) Marshall MXL 2003's
hi hat - Rode NT-1A

I discovered almost immediately that when plugging my overhead condenser mics onto channels 7&8 with phantom power engaged, that a fairly loud buzzing and humming noise came up. The noise slowly faded away after about 10-15 min. I switched chords, outlets, ground scenarios etc. and it still happened after a cold start. The weird thing was that if I engaged the -20 db pad on channels 7&8 the buzz went away, even with the gain all the way up. M-audio sent me a 2nd unit to try to see if the unit was defective. Same results with the 2nd unit.

I took the Octane to a local high end recording studio to check it with other mics, cables and power supply. Same results with my mics (Marshall's & Rode) but when some Neumann U87's were used, no buzz. We started trying some other mics with different ohm ratings (ADK-A51's, Oktava mk012's, Shure KSM-141's). Bottom line, any mic less than 200 ohms caused channels 7&8 to buzz. I informed M-audio's tech support of this and they did their own testing of the Octane units at their factory with various mics. Sure enough, they have admitted to me that it is a design flaw.

So, if you have an M-audio octane or are looking to buy an Octane be careful about the condensers you use. Anything less than 200 ohms will more than likely cause you a very annoying buzz or a 15 min. warm up time for the noise to go away.

Hope this post helps someone. It cost me a lot of time, headaches and some $$ to ship one of my Octane units back to the factory. Worse yet, M-audio didn't even say thanks for finding the flaw or offer any thoughts as to if the problem would get worse over time. Go figure.

Van

 

[sixways]

I read your post on this and another forum. Thanks for the heads up. M-Audio should give you something, a cookie, a pat on the ass, a pre-amp...something.

6

 

[MadAudio]

Thanks for your post, very interesting. I use my Octane for drums, too, but I only use channels 1-5 (kick, snare, 3 toms, don't need a hi-hat mic). I'm using a pair of MXL 603s and a DMP3 for the overheads (because I had gotten the DMP3 first and already like it for overheads - if it ain't broke, don't fix it...).

I do use 7&8 on the Octane for M/S stuff, though, and haven't had any problems with it. I'm using the analog outs, though, so that may be a factor.

 

[drumvan]

octane

hey mad,

just as a test try your 603's in 7 & 8. they have a 150 ohm rating like my 2003's. power up from a cold start. engage the phantom power for 7 & 8. no -20 pad. turn up the volume or headphones and see what you hear.

i totally bypassed any outs when i was testing mine. stuck a pair of headphones right into channel 8's output. hummmmm/buzzzz.

let me know what you find out. maybe they've gotten a bad ship of electronics from somewhere lately or maybe it's always had that problem. mines about a month old.

van

 

[MadAudio]

hey mad,

just as a test try your 603's in 7 & 8. they have a 150 ohm rating like my 2003's. power up from a cold start. engage the phantom power for 7 & 8. no -20 pad. turn up the volume or headphones and see what you hear.

i totally bypassed any outs when i was testing mine. stuck a pair of headphones right into channel 8's output. hummmmm/buzzzz.

let me know what you find out. maybe they've gotten a bad ship of electronics from somewhere lately or maybe it's always had that problem. mines about a month old.

van

I was thinking of trying it anyway, so will do! I'll let you know what happens. I've had mine almost a year, BTW.

 

[punkin]

15 minutes to warm up huh? What in there could possibly take 15 minutes to warm up? Hmmmm

 

[drumvan]

i know punkin, it's strange. also mics that have lower impedance, like the rode nt-1a (100 ohms) take longer for the noise to go away (25-30 min.). the marshalls which are 150 ohms take 10-15 min. the key though is to have both channels 7&8 occupied by condensers with the phantom power on. just 1 mic won't do it alone.

the adk a51's i tested only buzzed for a couple min. the adk website does not list the impedance rating but i'm guessing it's just shy of 200. maybe 175 or so.

van

 

[kid klash]

Strange...

I've been using my Octane specifically for over a year now and I've never encountered this hum/buz problem. I use all eight channels at the same time, including the M-S encoder section of channels 7 and 8. The mics I'm using for the M-S channels are a Studio Projects B3 for the figure eight mic and a B1 for the single pattern mic. Gorgeous drum tracks every time.

 

[drumvan]

klash,

could be because the b1 & b3 is spec'd at <200 ohms. this could mean it's just slightly above the impedance that caused the buzzing in my unit. like i said, the adk a-51's buzzed for only a very short amount of time. somewhere between 150 & 200 ohms appears to be the "magic number". if the b3's would have been listed at 150 ohms i would think that maybe they got a bad batch of electronics in and you got lucky. the thing is, their tech dept. admitted that it is a design flaw issue.

hey, when the Octane warms up it sounds great. i can live with it if it doesn't get worse as the months/years go by and the warranty expires.

van

 

[drumvan]

hey mad audio,

did you try testing your marshall mics on 7 & 8? results?

van