Craig's Tip: Free Analog Tape Emulator II FX Chain (with Download)

[Craig Anderton]

(Note: Anything titled “Craig’s Tip” would have appeared in the PreSonus Blog if I was still posting there, and either will be included, or has been included, in the The Huge Book of Fender Studio Pro Tips and Tricks.)

I’ve already started on version 1.1 of The Huge Book of Fender Studio Pro Tips & Tricks. This tip updates the v1.0 Tape Emulator’s distortion engine to create a harmonics profile that’s very close to a famous two-track reel-to-reel tape machine (fig. 1). The main difference is that the physical machine generated some low-level second harmonic distortion. The Tape Emulator II FX Chain’s effect is subtle, but adds analog tape’s tasty punch.

Figure 1: (Top) Harmonic spectrum of a famous two-track reel-to-reel tape machine. (Bottom) The Tape Emulator II controls have been adjusted to create an almost identical harmonic profile.

Three important characteristics provides much of tape’s distinctive sound:

• Saturation. Tape saturates. Tape’s emphasis on odd harmonics is what gives tape saturation its “punchy” sound.
• Head “bump.” This was due to a bass range peak (typically around 2 dB). The frequency varied, based on tape speed and tape machine characteristics. The head bump controls cover the range of potential sounds obtainable with 15 or 30 ips tape.
• Bias. Tape has minimal distortion over only a particular range of levels. Bias is a supersonic signal whose level pushes tape into its “sweet spot” for recording audio with the minimum amount of distortion. However, the bias setting trades off noise, high-frequency response, and distortion. Some engineers aligned their machines to underbias the tape. This increased distortion but gave more high frequencies. Other engineers overbiased the tape, for less distortion and more subdued highs. They compensated for the lack of highs with subsequent EQ.

How to Use the Macro Controls

The Macro Controls default to rational settings (fig. 2). But as usual with my FX chains, the settings can go beyond the bounds of good taste, if needed.

Figure 2: Tape Emulator II Macro Controls panel.

• Turn up Saturation for more punch and grit. -18.00 is very subtle. I rarely go above -12.00.
• Bump Freq sets the bass boost frequency caused by a recorder’s head bump. 70 Hz is typical.
• Bump Amount adjusts the bass boost’s level. 2 – 3 dB is typical.
• Turning on Bump On/Off adds a boost at the Bump Freq and enables a 48 dB low-cut filter around 23 Hz. This emulates the loss of very low frequencies due to the head bump. Depending on the program material, adding the bump may increase or decrease the apparent bass response.
• For additional flexibility, if Bump Amount is down all the way, turning on Bump On/Off doesn’t add a bump but still adds the 48 dB/octave low-cut filter.
• Turn Bias clockwise to overbias (less highs), or counterclockwise to underbias (more highs). An advantage of virtual tape emulation is that the high frequencies and saturation aren’t linked. So, the Saturation and Bias controls can be independent of each other.
• The default Hiss value is representative of tape recorders used for home recording. Turn counterclockwise to reduce the hiss. The minimum hiss level is -144 dB.
• The Hum’s default level is typical. Turn counterclockwise to reduce the hum. The minimum hum level is -144 dB.
• The 50-60 Hz hum frequency control ranges from 50.4 Hz to 59.1 Hz. These are the closest available values to 50 and 60 Hz when assigning a Macro Knob. For an exact 50 or 60 Hz, open the FX Chain, open Tone Generator 2, and type in the frequency.

Fig. 3 shows a couple of representative spectra.

​

Figure 3: (Top) Underbiased and with bass bump. (Bottom) No bass bump, and overbiased.

There’s much mythology around tape emulation, but try this FX Chain. I promise you’ll never have to clean or demagnetize it!

 

[Larry Jones]

Craig - Can this be used as "mix fx" in Studio One?

 

[lokeyfly]

Thanks Craig. I'll certainly use these macro controls from your Analog Tape Emulator II FX Chain which make for a good quick grab to start from for over/under bias, hiss, 50-60 Hz cycle hum, etc. This will help target those sometimes problematic frequencies and harmonic characterizations from two-track tape machines, AC wall outlet attenuators, and other low level second harmonic distortion sources. Your tape emulator effects chain is greatly appreciated! I can't wait to tinker with it. What is nice about having the Tape Emulator II available is that a user can nudge the various controls when they either hear some anomoly, or simply want to alter the characteristics from a targeted range where those harmonics are prevalent. Even add a little tape emulation if the sources were there to begin with. Changing bias is one I'd be excited about. I used to have to (or opt to) adjust bias based on the reel to reel tape I purchased. But being able to do so on the fly would be great for simple comparing of characteristics. Of course there are plugins that have what look to be limited set points and model differences of bias, saturation, and hiss to name a few. Only your tape emulator is right here and free of charge at that! Another "benny" of being a part of this excellent forum.

Nice touch how the bias and saturation control can be separate from each other. And you dont even have to align head azimuth!

P.S. I still wouldnt mind getting my hands on another Revox A77 MkIII. I still have those reels, and they'd be cool to digitize. Say, anyone want to buy a Teac tape de-magnetizer? It's mint!

 

[Craig Anderton]

Craig - Can this be used as "mix fx" in Studio One?

Sorry, no. It's an FX Chain, so it needs to go into the inserts, and processes only the channel in which it is inserted. But what it does would indeed make a good Mix FX!

 

[Craig Anderton]

Only your tape emulator is right here and free of charge at that! Another "benny" of being a part of this excellent forum.

Thanks! Of course, the bias isn't really adjusting "bias." What I did was research how bias affects the sound, and tried to emulate those characteristics.

Same with the bass bump, but a lot of research went into that. It's unchanged from the original Tape Emulator in the tips books for Studio One and Studio Pro. Head bump was due to a bass range peak (typically around 2 dB). The frequency varied, based on tape speed and tape machine characteristics. At 15 IPS, a typical peak is in the 40-70 Hz range. At 30 IPS, it’s in the 70-150 Hz range. However, at 30 IPS, the bass response drops off below the bump—sometimes drastically, sometimes gently. Even though 30 IPS offers better overall fidelity, many engineers preferred 15 IPS due to the bass response characteristics (and saved money by using half as much tape for the same recording time).

Of course there are plenty of tape emulation plug-ins, but I nonetheless like what this one does. There are still some tweaks I'm considering for when it appears in the v1.1 book (not happening anytime soon, maybe late Fall).

 

[lokeyfly]

Thanks! Of course, the bias isn't really adjusting "bias." What I did was research how bias affects the sound, and tried to emulate those characteristics.

Sure, bias could only be an emulation at this point. Actually, I forgot to add earlier that you must have done your homework with this. Targeting these characteristics is one thing, but seeing how changes trend is another.

Of course there are plenty of tape emulation plug-ins, but I nonetheless like what this one does. There are still some tweaks I'm considering for when it appears in the v1.1 book (not happening anytime soon, maybe late Fall).

Nice, keep us posted. It's a good start.