The gain ranges I estimated were pretty close.
I set up my computer to generate a steady tone, then from my DAC (Headamp Pico), I fed an unbalanced signal to my V3, and then SPDIF out to my PMD-661. I adjusted the signal to a specific level on the meter using the gain and the trim on the V3. Then I placed the PSP-2 between the DAC and V3 and measured the signal increase. I used the balanced outs on the PSP-2.
Mic sens "-35": gain of +28 (ie., the meter increased from -40 dB to -12)
Gain switches +6 and +12 add +6 dB and +12 dB respectively.
Mic sens "-55": gain of +48 (the meter increased from -60 to -12)
Gain switches +6 and +12 add +6 dB and +12 dB respectively.
Mic sens "-70": gain of >+60 (the meter increased from -60 to "over"; I adjusted the trim on the V3 downwards by 4 dB, and it was right around 0, so I estimate that it adds about +65 dB)
That's the best I can do with my equipment I have on hand.
So the revised gain range for the PSP-2 is:
+28 (Mic sens: "-35"; Gain "0")
+34 (Mic sens: "-35"; Gain "+6")
+40 (Mic sens: "-35"; Gain "+12")
+48 (Mic sens: "-55"; Gain "0")
+54 (Mic sens: "-55"; Gain "+6")
+60 (Mic sens: "-55"; Gain "+12")
+65 (Mic sens: "-70"; Gain "0")
+71 (Mic sens: "-70"; Gain "+6")
+77 (Mic sens: "-70"; Gain "+12")
So there probably is a pretty big margin of error and it would be nice to get an actual number for the peak value instead of estimating it by eye. I would say +/- 5 dB. I tried feeding the signal to another computer but couldn't really get the digital in or line in to work.
I was just estimating the gain range -- those values aren't an exact measurement! I just wanted to demonstrate that within the gain range that I normally operate, the PSP-2 has pretty big steps.
Tell you what -- I'll try to use a signal generator and see if I can measure the gain range.
I contend that because of the stepped gain of the PSP-2, you need to do fine level adjustment at some point after the PSP-2.
Nice work on figuring out the gain range Ted!
The PSP-2 was originally designed to work with the DAT recorders of the early nineties. Gain is set on the PSP-2 and then you use the potentiometer on the DAT deck for trim. However, I wouldn't haul around a V3 for this function unless you intended to go digital out to the recording device.