I thought I would post this report due to the large number of people that ask this and other forums about which 8 channel preamps 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 Pro Tools 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-endrecording 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