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3 way post #7 - woofer distortion measurements

Posted 15th November 2009 at 08:36 PM by relder (Rob's active 3way with transconductance chipamps build blog)

So - I setup Soundeasy to take some distortion measurements. I don't claim to be a wizard at taking these measurements and balancing the various factors (overloading the mic, etc.) so take 'em with some grains of salt but they are interesting.

Taken with a Behringer ECM8000 mic (uncalibrated) via a UB802 to a M-audio 410 PCI card.

You can pretty clearly see my noise floor. Taken in a living room with computers/fridges turned off, noisy computer in another room.

Mic was nearfield.

There's some clear differences between the plots when driven with current vs. voltage. Ignore the nasty bits around resonance for the current driven one - I clipped the soundcard input with the resonance peak.
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Old

hello, world!

Posted 15th November 2009 at 08:10 AM by davygrvy

OMG, I'm now a blogger!
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iPods 'n Things

Posted 15th November 2009 at 12:23 AM by kevinkr
Updated 15th November 2009 at 12:28 AM by kevinkr

Went to the gym this afternoon with my iPod (Classic 160GB) as usual - about 15 minutes into a torturous session on the elliptical the left channel just died. PANIC.. I had a further 45 minutes of time to reflect on the meaning of music in my life - in this case it really helps me to get through what I find to be an exceedingly tedious activity. Sonic wall paper to my life outside of my house??

Got home and quickly checked with another set of headphones and determined that my iPod was just fine.The aftermarket JVC folding headphones I purchased a couple of years ago just before this iPod apparently have an open connection somewhere. They never entirely pleased me so I am not too sad to see them go.

Have ordered a set of the folding PX100 made by Sennheiser to replace them - should be a lot better sounding than the failed JVC headphones.

It does rather make me realize just how important a role music plays in my daily life.

As an aside...
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Old

Output tubes's CCS's (bias blocks) completed.

Posted 15th November 2009 at 12:14 AM by Bas Horneman (Bas Horneman's diyAudio.com blog)

sans bypass cap.

Measure 380mV accross a 10R resistors. Therefore the CCS is set to 38mA.
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