• gtr
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  • Registered: 2010-04-07
  • Posts: 10

Topic: Re-Amping query - help needed

Hi, I am using a Fireface UC and have a Radial X-Amp. The X-Amp is basically a device which is used for re-aming. It converts the balanced line level signal from an audio interface to match the input of the guitar amplifier. Now, I tried using the X-Amp with the Fireface and it works fine. However, I also tried using the output from my Fireface directly with the guitar amp and I must say that the results seemed to be the same.

Is there a real difference to using a re-amping device with the Fireface? Are there any real benefits or can I just do without the re-amping device? Maybe there are situations which I haven't encountered yet and in which the re-amping device will definately be a must? Any help would be greatly appreciated as I am considering returning the re-amper to the store.

Thanks!

  • gtr
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  • Registered: 2010-04-07
  • Posts: 10

Re: Re-Amping query - help needed

Some more information on my query... this is the reasoning behind my question: I am thinking in impedance terms, and I'm being convinced that i'd be better off not using the re-amper at all... for two reasons.

To start with the FF output impedance is 75 Ohms (as stated in FF UC manual page 84). The Radial X-Amp has an input impedance of 600 Ohms. In general it is better to have a high mismatch between the source and the receiver (the source being of a lower impedance than the receiver). In this case there is not such a high mismatch between the impedances, so the X-amp has more 'work' to do.

Secondly, the output impedance of the X-amp is 10 kOhms!!! Now this is the typical output impedance of a passive guitar so its definately well suited for inputting into a guitar amplifier as they are designed to have a high input impedance to be able to accept high impedances of electric guitars. However, the output impedance of 10kOhms of the X-amp is much higher than the 75Ohm output of the FF!

The lower impedance of the source (compared to a high impedance of the receiver) creates a high mismatch which also assures the preservation of signal level and a high frequency response. Therefore using the lowest possible impedance output is best... hence use the line out of the FF.

Any feedback would be greatly appreciated. And if the above reasoning is right, then the FF UC is truly a great and straightforward product since it allows for easy interfacing without needing neither a DI or a re-amping unit at all.