MS16 Calabration

  • Thread starter Thread starter ron-e-g
  • Start date Start date
Just wondering..Why the manual doesn't mention the fact that DBX should be switched off. Or maybe I missed it somewhere else. I will admit, I haven't read it cover to cover. But I am pretty sure I covered the main areas. another thing, I've noticed Track 16 seems to have to be in a certain state, before some adjustments can be made. I'm thinking it has something to do with that track being reserved for time code. That too is not covered by the manual.

Lastly, Does the recorder have to be in the "Record Ready" state at anytime (like the manual says) to do these adj.?

I've already erased 3-4 seconds of cal. tape!:facepalm:
 
ron-e-g said:
Lastly, Does the recorder have to be in the "Record Ready" state at anytime (like the manual says) to do these adj.?

I've already erased 3-4 seconds of cal. tape!:facepalm:
Click to expand...

oh, no. NEVER put the recorder in REC mode with a calibration tape loaded. Also make sure all of the buttons for the track are NOT in rec ready mode.
 
Yea, That's good. I thought that was just asking for trouble. And I got it...you practically have to lay down in front of the recorder to do these adj. and that's not the best way to try and use the transport buttons. Of course I should have been using the AQ-65 because I have it. But not everyone does.

Just read section 4-13 (DBX) of the manual. Explains a lot! seems I should not even set the input levels with DBX engaged.
 
Started checking the input levels @1kHz w/dbx off. The meters (both RMS and recorder) bounce around a lot. But hover at the -10 RMS and 0db on the recorder.

Is this normal?
 
turn off DBX and do everything from scratch at this point. even input levels. given all the different setups and changes it is impossible to know exactly what you did with or without DBX. So turn it off and start the whole calibration from the beginning. It should be stable and not hover. If they are hovering, something else is going on, maybe unstable connections or something.
 
Maybe crappy generator. maybe crappy RMS meter, Maybe crappy MRL tape. Maybe crappy recorder! And yes maybe crappy connections!:D Sorry, a lot of firsts and unknowns here. But, if you'll be patient with me here? I am so grateful for your help.

I'm using the same connections as before. But can't rule that out. I will switch dbx back on for the input check and see if that is the source.

Ron
 
no issues Ron, we are happy to help. So i suggest the following:

0. Use the jumpers in the back and remove the DBX from the equation completely
1. Connect the generator direct to the RMS meter and check if it is stable or not, if not then it is the generator
2. If it is, then connect it directly to the recorder input and the generator to the recorder output. Put the recorder on input mode

If #2 is good, connect the DBX again (in OFF) mode and compare results
 
Thanks for the suggestions fgonza2. I don't know where the problem was. I moved the generator and RMS meter and plugged them both into a different power supply. I also used two separate RCA's rather than the two connected 1white/1red type cable. the problem went away. So hurray! generator good..RMS good.

I re-calibrated the recorder. Everything great in SYNC and REPRO @ 1kHz and 10kHz.
Everything great in SYNC @ 10kHz. REPRO All is great (exception)

Trk 1 -2 on VU -12 on RMS
Trk 10 -1.5 on VU -11.5 on RMS
Trk 16 -3 on VU -12 on RMS

So I'd say much better.
 
ron-e-g said:
Thanks for the suggestions fgonza2. I don't know where the problem was. I moved the generator and RMS meter and plugged them both into a different power supply. I also used two separate RCA's rather than the two connected 1white/1red type cable. the problem went away. So hurray! generator good..RMS good.

I re-calibrated the recorder. Everything great in SYNC and REPRO @ 1kHz and 10kHz.
Everything great in SYNC @ 10kHz. REPRO All is great (exception)

Trk 1 -2 on VU -12 on RMS
Trk 10 -1.5 on VU -11.5 on RMS
Trk 16 -3 on VU -12 on RMS

So I'd say much better.
Click to expand...

that's good. so for those cases, even with the EQ adjustment, you can't get to 0db ?. the range is +/- 2db so it is not too bad. Check azimuth now. in both sync and repro modes. Remember to the scope part and the ellipse... we discussed that one like 50 posts ago or so.
 
fgonza2 said:
0. Make sure to calibrate playback levels first with the calibration tape (both repro and sync head)

1. Put them in GND mode

2. Use the position knob (vertical) to make sure the ground is at zero. Not trigger, dont change anything in there.

3. Ok to not disconnect if you use the GND mode.

4. Do this for both channels

5. Yes .1 on the dial

6. After this go to XY mode

7. Yes, change in the test tape from 1khz to 10khz

8. As suggested by jpmorris, you can use the generator first and connect it to inputs 2 and 15, then put it in input monitor mode, and you should see a perfect 45 degree line (make sure the generator output is at 0.3V rms), so you can make sure the setup is correct. If it is not 45 then your levels are off somewhere either on the generator or in the input circuitry calibration. (post picture)

9. After that switch to repro mode and you will see the ellipse (with the 1khz tone it will be nicer) look at it with 10Khz and 16khz tones on the tape, post pictures.

10. Repeat with sync head

I can see the pictures now :) let us know how it goes. Did you setup levels already ? how did you measured it ?
Click to expand...

So you can see where MY head is at I'll ask you to please explain your earlier post.

0. I understand
1. Whats Them?
2. I think I understand
3. disconnect what?
4. You saying do 0-3 for both channels?
5. I understand
6. Was I supposedly in some other mode than XY already?
7. Make checks in both 1kHz and 10kHz?
8. Connect generator output with Y cable to channels 2&15 while outputs of recorder go to scope? (Making sure generator is outputting -10 or 0.3V rms) So no cal. tape involved here.
9. After what? you saying, I should do the #8 in sync mode first then check repro ( or do it visa versa)?
10. I understand
11.N/A
 
I went over this thread again. I used the suggestions you made fgonza2. With the following results. It's all making sense to me now!

View attachment 79089View attachment 79090View attachment 79091

At this point I should be able to disconnect the generator from the recorder inputs and load the MRL tape? Then check azimuth at both 1kHz and 10kHz for both REPRO and SYNC?

How far north do you live in CA?
 
yes, looks good. You may also want to change the scope scale to 0.5 or 0.2 instead of "1" , so you get a better view. You are right after you confirm with the generator directly and see the perfect 45 degree line, it is time to load the MRL and capture it with 1k and 10k tones. Post pictures, change the scale as mentioned before, so you get a "bigger" picture in the scope. I am in the sacramento area.
 
you need azimuth adjustment on both. SYNC is worse. the scale is good now, as you can see a better picture.

This is a little tricky, be patient do one head first and report progress. Start with SYNC which is the worst case. Do it with the 10Khz tone. If you fix 10Khz, the 1Khz will be good if you fix 10Khz.
 
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