Recording - November 2009 - 26

Fig: 3b Fig: 3a simulated speaker software in your DAW do the rest, while monitoring at sane levels. ~ Proper impedance matching: Tone depends greatly on the interaction between a given guitar’s pickups and the input impedance of a given amp head; with HGRM, you’re still feeding your guitar into your amp, not into the generic “Hi-Z” input of a recording interface, which can affect your tone. (Digidesign has just announced the Eleven Rack, which has an auto-adjusting input impedance, but I haven’t tried this interface yet.) ~ The use of real tubes: There’s still nothing quite like real tubes, and you preserve CPU power since emulating the tube’s action (creating complex harmonics, etc.) tends to be most CPU-intensive. ~ Use all of your favorite analog/digital pedals, rack gear, etc.: No need to try and “emulate” what you know and love in the real world. Use the FX Send/Return loop between preamp and power amp of your head, especially for compressors and for time-based effects (delay, chorus, flange, and even reverb). ~ Use your amp’s reverb: If your amp has a spring reverb, you can actually use it and track a good ‘ol’ fashioned analog wet signal (don’t forget to bring a towel), saving you tons of resources on your CPU by not using a hungry, hungry reverb plugin! But unless you’re certain about how much reverb the final take will have, I suggest that you track with a dry signal, especially if you are stacking or layering multiple parts; it can start to sound messy after a while, and there’s no going back. ~ Lower CPU usage = better “feel”: Another advantage of going easy on your CPU is the reduced latency, the time it takes for the notes you play to appear in the monitors or headphones. Adjust the buffer settings of your DAW and research what’s involved, then experiment. One example: In Pro Tools you’ll find the H/W Buffer Size option in the Setup > Playback Engine menu. If you select Low Latency Monitoring (under the Options menu), any plug-ins on the record-enabled track will be bypassed, and you cannot change a send’s mute state or an insert’s or plug-in’s bypass state while its track is in lowlatency monitor mode. So you must work with the buffer settings to achieve low latency while tracking in Pro Tools LE. Your own DAW’s and computer’s mileage may vary. Power-Soak Option To make HGRM work with amps that only have speaker outputs you need a device like the THD Hot Plate (www.thdelectronics.com; see Figures 1 and 2) I mentioned before; you plug the speaker cable from the Speaker Outs of the tube amp into the Hot Plate’s input labeled Input From Amp (see Figure 1). This type of power attenuator, sometimes called a power soak after the original device invented by Tom Scholz, is a hardware device used (in laymen’s terms) to “trick” the amplifier into acting as if the volume knob is set higher than it actually is. So it demands more power from the tubes, which allows you to reap the benefits of Fig: 3c ~ Recording Out: Some amps include a /4" output that’s been optimized to interface with a console, PA or recording device. This is a great option to try with HGRM. And best of all, you don’t necessarily need to run out and buy a power attenuator to interface it with your computer. Still, to avoid serious damage—before you disconnect the speaker(s), be sure that the amp head can function without the load that speakers or a dummy-load power attenuator provide. Consider yourself warned! ~ DI Out: Supplies an “unfiltered” preamp signal. This signal, being “direct”, may have bypassed your amp head’s toneshaping circuitry; still, you might find interesting sounds if you interface this with your DAW and use both amp and cabinet emulation. HGRM—the advantages ~ Noise preemption: You crank the amp head as needed for tone and let theRECORDING NOVEMBER 2009 Fig: 4a Fig: 4b

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Recording - November 2009

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