Hi,
I am looking for thoughts on how to create a setup including a proper option of rercording the pure electric guitar signal. I would like to monitor through an Amp or modeller which might change due to backline in live situations etc. keeping the monitoring pretty modular while maintaining a consistant DI sound with one and the same device , I would say. (to be later edited in the DAW with Plug Ins, being reamped etc.)
Most concerning for me is the impedance topic. How does varying DI Boxes (varying impedances, active and passive) react to the output signal of the guitar jack?
What is the proper method to record good electric guitar DI sound?
THX!!
Perhaps the approach I personally use to track guitars may be of some help. For simplicity I like to monitor through my practice amp (Yamaha THR10II) when tracking, but I also want to record the cleanest possible guitar DI signal which I can reamp later with my half-stack. I also want to minimize passthrough latency while also minimizing the CPU load on my DAW PC.
The way I do this is:
1) Connect the guitar to instrument/Hi-Z input of my RME Babyface audio interface
2) Configure RME TotalMix to route Hi-Z input directly to one of the analog outputs (e.g. AN1) - i.e. the so called "direct" or "hardware" monitoring
3) Connect the AN1 output of Babyface to the Yamaha THR10II guitar input via a "reamp" isolation box (basically a 1:1 balanced to unbalanced transformer in a box) - this means what I play into my audio interface is sent to my amp directly
4) Configure RME TotalMix to route DAW stereo master bus to the secondary analog output (e.g. AN3&4) and connect that to Aux input of the Yamaha THR10II (another isolation box might be needed here if you get ground loops) - this means that whatever plays on my PC is heard also through my amp (but without the guitar amp model applied)
With this setup I can monitor both guitar and the backing track via the practice amp, and control their relative volume balance directly on the amp's volume knobs, while tracking absolutely pure DI dignal direct from the guitar to the PC. Passthrough latency is also very low (1-2ms), as is PC CPU load, since I only use RME TotalMix "direct monitoring" feature without relying on DAW SW monitoring (which otherwise can introduce significant extra latency and/or tax the PC CPU).
Most concerning for me is the impedance topic. How does varying DI Boxes (varying impedances, active and passive) react to the output signal of the guitar jack?
Guitars with passive pickups have unusually high output impedance, meaning that an unusually high input impedance is also required to preserve high-frequency content. This is why guitar amps / DI boxes / guitar pedals / audio interface instrument inputs often have >500k ohm input impedances.
This is also why long, high-capacitance guitar cables can sound different to each other - when combined with the high output impedance of guitar pickup they can cause low-passing within the audible part of the spectrum (e.g.
see this article). This is one of the very few exceptions where cables CAN make an audible difference (again, this is only due to the relatively unusual output impedance characteristic of guitar passive pickups; it doesn't happen with buffered sources). It is also why poorly-designed guitar cables can be more susceptible to handling noise.
Note that guitars with active pickups have low output impedance and therefore produce much more consistent output, which doesn't depend nearly as much on cable length, input impedance of next stage, or cable construction architecture. Note also that this is why some guitarists using passive pickups like to also use 'buffer' pedals in their rigs - it allows use of much longer cable runs post-buffer.
So in short, the "right way" to record guitar is to record into a very high-impedance input (either by using a Hi-Z/Instrument input on the sound card, OR by using a DI box into a line/microphone input).
If you want to preserve the purest guitar signal possible you should use a short (and ideally low-capacitance) guitar cable; but if you want to closely emulate the sound you get with a real amp you should use the same guitar cable you'd normally use with that amp (so you get similar low-pass effect).
Hope this helps!