Panasonic SE-405 CD-4 Demodulator Calibration Instructions
The Panasonic SE-405 CD-4 demodulator came "pre-calibrated" for the ceramic (or semi-conductor) phono cartridge that was originally included with it (the EPC-450C-II). This cartridge, although not the best, is still very much adequate. Even if you are still using this cartridge, I strongly recommend calibrating your demodulator yourself to ensure you are getting the best performance possible.
Before you attempt to calibrate your demodulator, please make sure that your turntable is set up properly. I won't go into too much detail, but here is a quick checklist:
q Verify that your phono cartridge is indeed CD-4 compliant. This includes a Shibata or line-contact type stylus and an upper frequency response of at LEAST 40 kHz (50 kHz or more is strongly recommended.)
q Turntable is grounded properly.
q Turntable is as level as possible (use a bubble level to make sure.)
q Phono cables are connected properly to the SE-405 (make sure the right/left channels are not reversed!)
q Phono cartridge wires are connected properly to the tonearm – it is very important that the four tonearm wires are connected to the correct corresponding connectors on the phono cartridge!
q Set the cartridge selector button on the back of the SE-405 to correspond with the type of phono cartridge you are using (SC for semi-conductor or MM for moving magnet.)
q Phono cartridge is properly aligned. Here is a link to a free alignment protractor:
http://web.archive.org/web/20041209085301/http://www.enjoythemusic.com/protract.htm. THIS STEP IS EXTREMELY CRITICAL!
q Stylus pressure set to upper-end of stylus/cartridge manufacturers recommendations (e.g. if manufacturer recommends 1.0 to 2.0 grams of stylus force, go with 1.7 or thereabouts – do not exceed 2.0 even if recommendations allow for it!)
q Anti-skate is set properly – this is very important for CD-4 records! Ideally, you should set anti-skating with a test record that has a special blank "band" for this purpose. If such a record is not available, set anti-skating to be equal to stylus pressure. Note: linear tracking turntables do not have an anti-skating feature.
q Verify that the four channel outputs on the SE-405 are connected to the proper inputs on your pre-amp(s) and/or amplifier(s).
q Make sure you have a CD-4 test record containing a Separation or CD-4 Adjustment Tone track and (optionally) a channel identification track.
Okay, after you have completed the above checklist, you are ready to calibrate your SE-405 for optimum performance! On the underside of your SE-405, towards the front, you should see four small holes giving you access to the calibration controls (you will need a small regular screwdriver to access them.) If your unit has never been manually calibrated before, these holes will be covered with a sticker warning you not to muck with them! If this is the case, carefully cut out the holes with a sharp knife.
Two of the controls are marked "Carrier Level" and two are marked "Separation". These are each separated for both the right and left channels.
Set both Carrier Level controls to their maximum positions (fully clockwise.) Set both Separation controls to their minimum positions (fully counterclockwise.) Set the Function switch on the front panel of the SE-405 to "Four Channel Auto".
Position the SE-405 in such a way that you can access and adjust these controls "real time" while a record is playing. This usually means allowing the SE-405 to overhang its resting surface a bit. If it is not placed on a high enough shelf, you may find it difficult to get "under" the unit!
At this point, you should power on all your equipment in preparation to play your CD-4 test record. Some test records have separate left/right “Separation” tracks and some have a single track for both channels called “CD-4 Adjustment Tone.” In either case, you should mute the two front channels of your quadraphonic system so that only the rear channels can be heard. If your test record has a combined CD-4 Adjustment Tone track, you will also need to mute either the left or right rear channel.
Play the Separation or CD-4 Adjustment Tone track of your CD-4 test record for either the left or right channel. As the record plays, turn the separation control for the corresponding channel back and forth. You should notice that the volume of the tone is minimized at some point between the minimum and maximum positions of the control. If this is not the case (i.e. the volume is minimized at either extreme end of the control position) then something is not right and you should go back to the turntable setup checklist and re-evaluate all steps.
You may need to play the adjustment track a few times until you find the spot within the separation control's range that produces the LOWEST volume for that channel. When you have found this position, leave it there!
You will now need to perform this same task for the other channel using its separation control. Play the corresponding track on the test record or mute the other rear channel as necessary. When you have found the position for that channel that produces the lowest volume, leave it!
At this point both separation controls are set for maximum separation. We are now ready to adjust the carrier levels for maximum performance. For this purpose, any CD-4 record will do. You do not necessarily need the test record for this purpose. I actually prefer to use a "standard" CD-4 LP record, as it will help adjust the carrier level for a "real use" scenario (as opposed to a test record which is usually a 7" 45 rpm disk made of thin vinyl and does not represent the type of disk that you will normally be playing.)
After you have selected a record for carrier level adjustment, mute all four channels of your quadraphonic system (or simply turn off the amplifier(s).) Set the SE-405 function switch to the "Four Channel Auxiliary" position. Set the two carrier level adjustment controls on the underside of the SE-405 to their minimum positions (fully counterclockwise.)
Now, go ahead and play the CD-4 record you selected (make sure your turntable is set for the proper speed if you just switched from a 7" to a 12" record!) As the record plays, SLOWLY turn the LEFT carrier level adjustment control clockwise until the carrier light comes on. Stop turning the adjustment EXACTLY when the light comes on. You may want to turn the control back and forth a few times until you get the feel for when the exact moment the lighting occurs.
At this point you need to switch the SE-405 function switch back to "Four Channel Auto." Continue playing the CD-4 record and SLOWLY turn the RIGHT carrier level adjustment control clockwise in the same manner prescribed above.
Congratulations, you have just calibrated your SE-405 for optimum performance! Now you can turn your amplifier(s) back on. To verify your handiwork, retrieve your CD-4 test record and play the channel identification band (most CD-4 test records have one.) After you are satisfied that each channel is properly identified, you can start enjoying your CD-4 records!
