Topic: New Preamp Woes (and questions).

[javertim]

So, I just purchased an SP-PREAMP-11 (http://www.soundprofessionals.com/cgi-bin/gold/item/SP-PREAMP-11) and have been trying it out with my Edirol R-09HR.  So far, I have been much less than impressed with my purchase.  To my ears, the SP-PREAMP-11 seems to produce more noise than the R-09HR's mic-in preamp. ... I started by recording a straight tone with the preamp connected to the line-in, with the gain set at "low" (22gb).  With the recording level at about 55, my levels were just hitting the -20dB mark. ... So, then I tried my old SP battery box connected to mic-in, and at a recording level of 45, everything was hitting the same mark (right at -20dB).  I then Normalized both files to 50% just so that I could hear the noise levels a little better, and the preamp/line-in combination seemed to produce more noise. ... Am I testing this correctly?

Also, when I use the Preamp, is the "low" (22gb) gain setting actually increasing the self-noise of my mics (SP-CMC-8s)? ... And is it better to use a preamp > line in than it is to go battery-box > mic in and then adjust the recording levels?  I've heard that adjusting the "gain" of the signal by adjusting the recording levels is a poor way to control the signal. ... Is that correct?

Thanks!

[guysonic]

I've done similar tests with equivalent input gain for both deck mic input and line+external preamp gain set at equivalent -35dB reference input gives 0dB VU full scale reading with both conditions having 1000 ohm dummy load input resister.

And yes, the line input+external preamp sounds to the ears a bit noisier, but the character of the noise is quite different. 

See spectrum graph below showing far less low frequency noise, higher mid-band noise, and far less high frequency (spike noise) with using LINE input+preamp.



More graphs and 09HR deck technical info at: www.sonicstudios.com/r09hrrev.htm

[carpa]

Just to understand...
If the line in with external pre sounds noisier, why not use just an external phantom power and go mic-in, if it is better?
Maybe "noisier" doesn't mean "worse", and there might be some other considerations  on the good side.

[digifish_music]

So, I just purchased an SP-PREAMP-11 (http://www.soundprofessionals.com/cgi-bin/gold/item/SP-PREAMP-11) and have been trying it out with my Edirol R-09HR.  So far, I have been much less than impressed with my purchase.  To my ears, the SP-PREAMP-11 seems to produce more noise than the R-09HR's mic-in preamp. ... I started by recording a straight tone with the preamp connected to the line-in, with the gain set at "low" (22gb).  With the recording level at about 55, my levels were just hitting the -20dB mark. ... So, then I tried my old SP battery box connected to mic-in, and at a recording level of 45, everything was hitting the same mark (right at -20dB).  I then Normalized both files to 50% just so that I could hear the noise levels a little better, and the preamp/line-in combination seemed to produce more noise. ... Am I testing this correctly?

Also, when I use the Preamp, is the "low" (22gb) gain setting actually increasing the self-noise of my mics (SP-CMC-8s)? ... And is it better to use a preamp > line in than it is to go battery-box > mic in and then adjust the recording levels?  I've heard that adjusting the "gain" of the signal by adjusting the recording levels is a poor way to control the signal. ... Is that correct?

Thanks!

You may be interested in this...

http://www.digifishmusic.com/public/articles/edirol_mic_preamps.htm

About the noise, the question is, I suppose, how audible is the hiss under normal playback conditions of typical recorded sounds. Looking at Guysonics graph the  PA-3SX looks technically good...that is if it's the same as the SP-PREAMP-11?

digifish