Re-amping Analysis

A big question I've always had when re-amping my guitars is "Would a re-amp box improve the quality of my recordings?". This video aims to answers this question, and provides more info on the practice of re-amping.

Setup

Using two setups, we will record the re-amp of two guitar signals into Cubase. One clean, and one distorted.

Here is setup #1, going directly out of the MBOX monitor out into the input of the vox amplifire.

Here is setup #2, going out of the MBOX monitor out into the input of the Radial re-amp box then back out into the input of the Vox amplifire.

Using a multimeter both setups were calibrated to deliver the same voltage into the amplifire's input. All applicable cables used to connect the equipment were checked against each other for quality and consistency.

Testing

After recording the re-amped guitar signal of each setup we put on cans of sardines and had a listen. Audibly, there was no difference between the two setups for the re-amped clean signal. The distorted re-amp exhibited a slight amount of attenuation in the treble frequencies, still barely noticeable.

Clean Signal Frequency Graph

Distorted Signal Frequency Graph

However, when we re-amped a section of audio where the guitar wasn't playing anything using the overdriven channel, the setup that included the re-amp box in the signal chain had a significantly cleaner sound.

Additional Testing

Our final test involved re-amping sine waves doubling in harmonics from 125Hz, up to 16,000Hz, white noise, and then silence. We placed the settings on the vox amplifire to their default positions and used the clean channel for this test. The two setups exhibited the same levels up until 4kHz, where the level of the setup using the re-amp box began to drop. From 4kHz to 8kHz, this drop in level was 0.4dB.

From 4kHz to 16kHz, the drop in level was a rather large 1.6dB, a difference that was audible in the high frequency content of the white noise. We did not notice any difference in the re-amped silence between the two setups.

Summary

To summarize the tests, here are the main differences we noticed between the two setups. - The setup using the re-amp box fed the guitar amplifire a cleaner signal, this was only apparent when using the overdrive channel and when the guitar wasn't playing anything.

- The re-amp box has high frequency filtering.

- The setup using the re-amp box introduced ground hum into the signal chain, something that wasn't an issue in setup #1 when using the direct output of the MBOX into the guitar amplifire.

Conclusion

So, do you need a re-amp box? In our particular setup, no. However... this isn't to say that you don't need a re-amp box in your setup. A re-amp box is designed to fix the following four issues:

1. Ground hum via ground lift switch.

2. Gain staging via trim knob.

3. Impedance mismatching.

4. RF noise & interference. Since we had none of these issues in the first place when only using the MBOX, we had no reason to add the re-amp box into our signal chain. But if you're experiencing ground hum, interference, or need gain control prior to entering the amplifire, then a good quality re-amp box will likely be beneficial in your setup. So as you can see its usage is situational. Do whatever sounds good. Goodluck and happy re-amping!