I hope we all sort this out one last time I've read almost everything here, on the tape-op gearslutz and other sites about calibrating the 388. But even with 10+ hours reading and noting, and official manual in my hands I can't get right some things... Let's start with that I bought LPR35 tape which looks like its +6dB tape and 250-specs. Unit is cleaned and degaussed.
I did test repro/playback with 400hz at -10dB / 0,316V RMS) and fader set to gray area (7-8) so the meter was reading ZERO. I played it back and had results like +/- 1dB in all channels except channel one (but later on that). Some are -1, some are +1, etc. Is that OK? Some of you here suggest that it should be -3dB after playback, but why? This is my first question. I want to record loudest possible to avoid excessive noise. Background noise is unacceptable and seeing some YouTube video on recording, my 388 is MUCH noiser that exampled I heard...
2. I'm alittle bit confused about biasing 388. I;ve read a lot about it here, and it seems that tape is not needed for that process. Turns out to be super simple then - it must be a fixed value for specific type of tape, right? Just put the 12,5k signal and measure between test points and set "given" value. Does anybody know these values for different tapes - in my case, the LPR35? Here's the manual that is not helping me with it too - it says, on the 1-5-3 "connect DV voltmeter between TP01 and TP11 (TP02-TP12, TP03-TP13 etc) to obtain minimum reading on the meter". now STOP. I've tried to do it like million times and found out that counterclokwise turning bias pot = bias is constant raising... and clockwise turning bias pot = bias rising!!! So the "minimum" reading as the manual suggests is a value when bias is not near zero (not possible to do), it's just some value when it does not raise. In my case, the four points were between 0,25-0,31V. Ahh.. that manual.. not well written! Note it for your further calibration. WIll save you some time. BUT then in 1-5-4 "recording bias adjustments" it says that I should do 150mv between TPG (ground) and TP2. OKay I see that point on each channel, so 8 measurements can be made. But with the recording on, or off I get 0,00V on the test points. I have even tried to set meter to DC but no way.. still ZERO. What I'm doing wrong, is it another Tascam manual mistake? Should I play a calibration tape here (not mentioned in the manual)?
And the last thing, maybe simple but important:
3. The recording/playback. I'm a bit confused here. I put the mics on the XLRs, set all the faders to the gray area, set the trim to a nice (0 and up) values,EQ flat, arm channels 1-2, 3-4, 5-6, 7-8 + even/odd pan, arm all 8 tracks and record. Then rewind,m unarm tracks and press play. It's a lot of noise. What I'm doing wrong? I think I did one time playback that it was super loud and not noisy but I can't reall what I've done and can't repeat that again.. Should I use L/R switches somehwere or switch to RMX from MIC on each channels? What is the correct procedure?
Ufff..
Greg
I did test repro/playback with 400hz at -10dB / 0,316V RMS) and fader set to gray area (7-8) so the meter was reading ZERO. I played it back and had results like +/- 1dB in all channels except channel one (but later on that). Some are -1, some are +1, etc. Is that OK? Some of you here suggest that it should be -3dB after playback, but why? This is my first question. I want to record loudest possible to avoid excessive noise. Background noise is unacceptable and seeing some YouTube video on recording, my 388 is MUCH noiser that exampled I heard...
2. I'm alittle bit confused about biasing 388. I;ve read a lot about it here, and it seems that tape is not needed for that process. Turns out to be super simple then - it must be a fixed value for specific type of tape, right? Just put the 12,5k signal and measure between test points and set "given" value. Does anybody know these values for different tapes - in my case, the LPR35? Here's the manual that is not helping me with it too - it says, on the 1-5-3 "connect DV voltmeter between TP01 and TP11 (TP02-TP12, TP03-TP13 etc) to obtain minimum reading on the meter". now STOP. I've tried to do it like million times and found out that counterclokwise turning bias pot = bias is constant raising... and clockwise turning bias pot = bias rising!!! So the "minimum" reading as the manual suggests is a value when bias is not near zero (not possible to do), it's just some value when it does not raise. In my case, the four points were between 0,25-0,31V. Ahh.. that manual.. not well written! Note it for your further calibration. WIll save you some time. BUT then in 1-5-4 "recording bias adjustments" it says that I should do 150mv between TPG (ground) and TP2. OKay I see that point on each channel, so 8 measurements can be made. But with the recording on, or off I get 0,00V on the test points. I have even tried to set meter to DC but no way.. still ZERO. What I'm doing wrong, is it another Tascam manual mistake? Should I play a calibration tape here (not mentioned in the manual)?
And the last thing, maybe simple but important:
3. The recording/playback. I'm a bit confused here. I put the mics on the XLRs, set all the faders to the gray area, set the trim to a nice (0 and up) values,EQ flat, arm channels 1-2, 3-4, 5-6, 7-8 + even/odd pan, arm all 8 tracks and record. Then rewind,m unarm tracks and press play. It's a lot of noise. What I'm doing wrong? I think I did one time playback that it was super loud and not noisy but I can't reall what I've done and can't repeat that again.. Should I use L/R switches somehwere or switch to RMX from MIC on each channels? What is the correct procedure?
Ufff..
Greg