From: Brett Paulin Subject: Sony D8 Line In/Out Levels Date: Tue, 12 Aug 1997 18:40:15 +1000 Greetings People, I've been watching some recent messages regarding recording levels and stuff, and decided to have a tinker and see what I could find out.. I hooked up an Oscilloscope to a Sony D8 Portable to measure the input/output voltage figures and I've come up with some weird results, so I thought I'd post them and see if anyone either finds them helpful or can clear up what I'm seeing.. First of all, I wanted to know what the Input levels I could get away with on the LINE input was. The manual specifies 500mV (.5V) with a minimum of 80mV As someone pointed out recently, the more input level you can give it, the better, since the internal amplifier can run at a lower gain and results in a lower signal/noise ratio. Well, I hooked the LINE input of the D8 up to a mixer I have that has a switch that is labelled ".775v/1.5v Master Out". With the switch in the 1.5v position, and the channel sliders set so that the analog dB meters were peaking at +2 to +4, but averaging around -3 to -1, I measured input levels to the D8 at an average of 2v to 4v Peak to Peak with some peaks momentarily hitting 5v These signals looked pretty clean with no evidence of clipping, and sounded OK through a pair of headphones (yes, I know what clipping sounds and looks like) Any further and the mixer's output starts to clip, so I dont know just how high the input Ok, move the probes to the D8's output with the output switch in LINE OUT mode and the record level knob set so I'm seeing -4 to -2 on the D8's level meter, with no inidications and I'm looking at a 2v to 4v peak to peak output with some momentary 5v peaks, with no distortion or clipping evident. The manual specifies 500mv Line out ? I wind the REC LEVEL knob to max and find that the D8 will produce a momentary output of around 7v peak to peak with horrible clipping both visible on the scope and audible. winding it down, it seems that around 5v p-p is the outputs absolute maximum. Now I switch to PHONE (AVLS off) (Headphone Out), and find that with the software controlled volume set on MAX (20), I get pretty solid clipping at about 2.2v peak to peak. Turning the volume down to (15) clears it up, it starts to appear at (16), becomes audible at (17) and is pretty horrible by (18). Seems that in Headphone mode, the output is incapable of producing more than 2.2v output. This is backed up by audible as well.. the headphones are definitely louder when the switch is in LINE mode (although not adjustable of course) Just for interests sake, I tested a CD Walkman and found the line-output to be around 1.5v p-p, I'm about to head off to a friends and test a couple of CDJ-500 CD players and see what they produce. So, It seems you can stuff a lot more input signal into the LINE input than the manual specifies. and that the output level is a lot higher than specified as well. Also interesting is that the headphone mode cant produce as much output signal as the line mode can. Any comments or opinions ? --- Brett Paulin : Doofer, RevHead, Electronic Engineer & Gyrocopter Pilot "Rotorcraft pilots don't fly. They BEAT the air into submission"