This month I am going to answer a few questions that have shown up in my in-box.

Q:
I just listened to the new Bela Fleck album and noticed it was recorded
and mixed using Pro Tools 24. I'd be very interested to know if you
used a lot of plug-ins or if you used outboard gear or both. Do you
have a list of equipment/ plug-ins used? Did you use plug-in reverbs or
did you digitally route to external dedicated reverb units? What's your
take on plug-in reverbs?

I'm interested in your opinion on these topics. If you could let me
know, I'd appreciate it. Thanks for your time and consideration!

Blair Leishman

A:
First of all, thanks for the e-mail, but I didn’t find the attached $20 bill I was expecting. On the Bela Fleck CD (which just won a Grammy, and brings Bela’s total to three!) mixing completely in Pro Tools was great. We used both outboard and plug-in reverbs. The outboard reverbs were various Lexicons connected digitally via AES connections on the 888/24 I/O boxes. When we called up a mix, we would recall the appropriate named memory in each reverb and Bingo; exactly where we were the last time that song was up. We did use plug-in reverbs on occasion. As with any reverb, we would try different reverbs on each instrument until we found the right one for the job. Sometimes we would have to switch reverbs around because the PCM-90 sounded best on the sax, but we were already using it for drums. We would then send the drums to the PCM-80 to see if that worked all right.

Bela mostly used plug-ins for compression and EQ. A lot of attention was paid to the blend of instruments during the recording process, so there was not a lot of EQ needed in the mixes. The entire recording was done absolutely flat, with some monitor reverb, but no EQ. If Bela wasn’t happy with the sound of an instrument, we would change mics, change mic position, or try another mic preamp.

Q:
Dear Roger Nichols (you will always be my Audio Hero). I was wondering if you knew a formula or conversion chart for converting tempos to milliseconds in order to dial up on the correct delay setting on an effect processor. I would appreciate any help you can give me.

Thank You
Cesar Mejia

A:
Hey, this is a smart guy! I may have to get one of those Super-Hero suits with a red cape. You can make your own chart using Excel or some other spreadsheet program, or you can easily calculate the delay time whenever you need it. The formula is:

(60/tempo)*1000= the quarter note delay in milliseconds. The rest of the note values can be figured out from there. An eighth note would be half as much. A dotted anything would be 1.5 times the delay of the un-dotted note. A triplet would be 2/3 of the delay value.

I always carry around a pocket slide rule to calculate delay times. Since I disconnect the speedometer on my rental cars, I use the slide rule to calculate my highway speed by measuring the time delay between mile markers. Maybe someone should build a metronome that reads out in miles per hour.

Q:
bonjour mr nichols.I'm a great fan of your articles in eq magazine and
i've got a lot of your favourite gear in my project studio.I've recently
bought an aes ebu card (one slot format) for my 02R in order to remain
in digital domain with external digital reverb unit. There is no problem
with the sony v 77 except that i have to buy the optional cordon,but how
coud i connect the lexicon pcm 90 and the roland r-880 that are both
spdif to this aes ebu card?
Is as simple as to connect pin2 cold with pin 1 ground? what sort of
wire should i use for the connection:coaxial 75 ohms or 110ohms wire
. thank in advance.
buy
Laurent Siboni

A:
Good work! Digital connections to all of your outboard gear are the best way to go. There are two separate issues to consider when mixing AES and S/PDIF.

The first one is the physical format difference. AES/EBU is balanced 1.5 volts, 110 Ohms, connected with XLR-3s. S/PDIF is unbalanced .5 volt, 75 Ohms, connected with RCA type pin jacks. When making a XLR to RCA adapter for audio connections, it is common practice to connect ground and pin 3 together and connect them to the ground side of the RCA. This un-balances the signal, but you still get your audio because the center-tapped audio is present on the ground lead. AES signals are not configured the same way. The ground is only a shield and carries no signal information. If you use an audio adapter cable, you will get nothing. The signal will be shorted to ground, and nothing will come out the other end. In an emergency you can make an adapter, but you must connect pin 2 and pin 3 of the XLR to the RCA connector and leave the ground on the XLR disconnected. Make sure the cable is short. For cable lengths of about three feet, it won’t matter whether you use the 110-Ohm or 75-Ohm cable, and never use audio cable for permanent connections. For the RCA to RCA wire you can use video cable like the ones used for copying between video decks.

The proper connection method is to use an adapter that includes a transformer, such as the AES3id converter made by Graham-Patten. Remember that these connection methods will only work if the software in the devices connected will allow it.

The second consideration is the data differences between AES and S/PDIF. S/PDIF is supposed to contain bits for copy protection so that you cannot copy from a second-generation DAT tape. Most professional DAT machines and outboard gear with digital interfaces ignore the copy protection bits. Sometimes the data is actually AES format, but the connector is S/PDIF. Some DAT decks, like the Panasonic 3700 series, have multiple connectors on the back for S/PDIF and AES. They will refuse to allow the wrong format into the wrong connector. There is a switch to select the desired input format. Sometimes all of the connectors are fed all of the time, and all with the same data format that is selectable in software. Such is the case with tc Electronics’ Finalizer Plus. Also, keep in mind that AES can contain 24 bit audio, but S/PDIF can only contain 20 bit audio because the extra bits are used for the copy protection and sample rate flags.

Finally, remember that the sample rates among all of the digital devices must match, or your reverb will sound like an explosion in a Rice Crispy factory.

Q:
When are you going to be done with this stinking column so I can go on to the other articles in this fine magazine?

A:
Right now!

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