1. Is your tape machine properly aligned/calibrated?
2. Is all of your other equipment calibrated so the "0" on the meters means the same thing?
3. Dbx is the last thing to be set. Use Ikhz @ 0vu. Level should remain within 1db when nr is switched in or out.
4. You defeat the purpose of the dbx by recording past "0." It can no longer operate properly. If you back down so that average is in the -3 range and peaks don't exceed +1, you will be much better off.
5. Your video shows a line level source (cassette deck) going through an nr unit (is it the right type for that tape?) going into a preamp (not needed at all) going to a bunch of other signal processing gear as well as the M-30. It is no wonder the end result is noisy. It's not the gear, it's the operator causing most, if not all of the problems you cite.
1. No, not yet. I keep waiting for a friend of mine to get his act together so we can calibrate our decks. I'm tired of waiting. I might just bite the bullet and buy a MRL tape for myself to keep.
2. That is what I will be working on tonight.
3. I'm going to figure this out. I have the manuals for 150x units.
4. I may be misunderstanding something here, because what you say contradicts my interpretation of
the dbx 150x manual. To quote the section titled "Compensating for an Encoded Signal":
The hotter you record (or transmit) a dbx-encoded signal, the better the overall dynamic range and Signal-to-Noise will be. This holds true until you hit tape saturation, at which point the playback quality will deteriorate.
After a signal has been encoded, peaks are 50% lower. You are safe recording at least 50% hotter. If you have peak-reading meters on your deck, set the record levels on the machine so that the signal never exceeds the tape's headroom and tape saturation problems will be avoided.
This is the reason why I was recording up to +3: I interpreted the paragraphs above as saying that I should do this. However, if you skip to the middle of the next paragraph in the manual, you will find this:
(Since many tape meters stop at +3, and have different 0 levels, and since meter time constants vary so much, we can't even suggest a [level] number.)
So, I wasn't really sure what to do, and I've clearly done myself a disservice by not first calibrating the NR units once I dropped them into the signal flow. I'll address this at the end of my "tune-up", as you have suggested/advised.
5. The cassette was recorded on my Marantz PMD-430 using its built-in dbx type II noise reduction. The noise reduction unit shown in the video is a dbx NX-40 Type II noise reduction unit. I used the preamp to boost the signal into the mixer and then through a compressor, in order to "compress up" the signal. It seems like doing it this way works better than using the output gain on the compressor. The preamp on my compressor (dbx 166xl) seems noisy to me. And, in the video, the dbx EQ was not in the signal chain. The signal flow was:
Cassette -> dbx NX-40 -> preamp -> M-30 (on XLR ins) -> Buss effects-send to compressor -> buss effects-return on M-30 -> dbx 150x -> Tascam 34b
There's a lot of steps in the chain. Perhaps a better way to achieve the result I want would be this:
Cassette -> dbx NX-40 -> preamp -> compressor -> m-30 -> dbx 150x -> Tascam 34b
- - -
Either way, it's quite clear that I need to pull everything apart, rethink my strategy, and calibrate everything along the signal chain. I've noticed a couple of other issues coming up and it's either because I'm doing something wrong or that my equipment isn't setup correctly. It's likely both, possibly more of the former.
This has been a real educational experience for me, which is *exactly* what I was hoping for. My recording setup has grown to a point where I really need to mind signal flow and minimize the number of "links" in the chain.
I'm considering getting a patch bay, too. I need to stay on top of "what's-plugged-in-to-what", and it's getting pretty difficult. It's also a real pain to scoot everything around to make dis/connections. You can probably see in the video that I don't have very much space to work with. It's also time to get a bigger desk
