Reel to reel and DBX 150 alignment


Hi guys,

I have to transfer some reel tapes to CDs. The tapes are DBX encoded and have a series of recorded tones. Are these tones for heads alignment only, or do they have something to do with DBX adjustment, as well? Also, I'd appreciate insights on proper DBX adjustment. I have all measuring equipment and know how to use it.


Kurt Foster

Well-Known Member
Jul 2, 2002
It's impossible to tell what the original engineer did. This is why all tapes should be labled as to what the tones mean ...

Are they without DBX and for aligning the tape machine? I suspect they are.

Most likely what you have is a 100 hz tone for 60 seconds or so .. a 1 k tone and a 10 k tone.

If these tones all read back at 0 dB you are probably alright. You do need to get the calibration correct to avoid decoding errors with the DBX.

I would not adjust the levels on the machine however if you do not have a MRL calibration tape so that you can restore the settings after the transfer. Without a reference tape, you will have no way of returning the settings to what they were before the adjustment.

Try playiing the tape before you calibrate.. if things sound ok, I wouldn't mess with it. Don't fix it, if it ain't broke ..