Does Bypassing the front end A/D reduce noise

naka2112

Inspired
It is well known that putting an analog/digital conversion before a distorted tube preamp creates a certain amount of hiss. This is not unique to fractal, as all digital gear can do it. For example, when I put my strymon mobius before my bogner set to a distortion channel, there is some hiss when the pedal is engaged. If I bypass it, the hiss goes away.

Previously, fractal has said that the front end of the FX-8 (pre) can be bypassed separately from the back end (post). This means that you could set up a preset where the front end is bypassed, and have an analog signal going into the front of the amp that is only buffered. This would be useful for distorted presets where guitarists often only uses time based effects in the post position. For cleaner sounding presets, the guitar player could bring back in the front end for compression etc.

So here is my question:

When running the FX-8 in the 4cm, does bypassing the front end of the FX-8 eliminate the extra hiss on higher gain channels?
 
We've been getting questions about whether the FX8 is truly quiet enough to use with a high gain amp. This recording show the noise performance when the FX8 was used with a Les Paul with a Seymour Duncan Distortion Humbucker into a Friedman HBE with the gain on 8. As usual, with nothing but guitar, cable, amp, you get some noise from such a setup due to the amount of gain. To our ears, the FX8 did not add any perceptible noise when it was placed in the signal chain. We could not even tell the difference between FX8 engaged and FX8 on True Bypass. If anything, the HUMBUSTER technology on the FX8 outputs actually REDUCED the 60 cycle component of the noise.
The clip has three sections — not necessarily recorded in this order. Can you guess which is which.
• Guitar, Cable, Amp
• Guitar, FX8, Amp (Empty Preset)
• Guitar, FX8 on TRUE BYPASS, Amp

https://soundcloud.com/fractalaudio/fx8-noise-test

[SOUNDCLOUD]
https://soundcloud.com/fractalaudio/fx8-noise-test[/SOUNDCLOUD]
 
We've been getting questions about whether the FX8 is truly quiet enough to use with a high gain amp. This recording show the noise performance when the FX8 was used with a Les Paul with a Seymour Duncan Distortion Humbucker into a Friedman HBE with the gain on 8. As usual, with nothing but guitar, cable, amp, you get some noise from such a setup due to the amount of gain. To our ears, the FX8 did not add any perceptible noise when it was placed in the signal chain. We could not even tell the difference between FX8 engaged and FX8 on True Bypass. If anything, the HUMBUSTER technology on the FX8 outputs actually REDUCED the 60 cycle component of the noise.
The clip has three sections — not necessarily recorded in this order. Can you guess which is which.
• Guitar, Cable, Amp
• Guitar, FX8, Amp (Empty Preset)
• Guitar, FX8 on TRUE BYPASS, Amp

https://soundcloud.com/fractalaudio/fx8-noise-test

[SOUNDCLOUD]
https://soundcloud.com/fractalaudio/fx8-noise-test[/SOUNDCLOUD]

No offense, but I've been more impressed with the playing in some of your other clips.
 
To answer the OP, yes bypassing the front end does work like other products and will reduce the added noise since it bypasses the converters and associated electronics. However the FX-8 is so quiet that any added noise is virtually imperceptible. Mark's clip above illustrates just how little noise is added. The self-noise of the FX-8 is less than the self-noise of a typical electric guitar so the guitar itself becomes the dominant noise source. This was a challenging design point and I spent a lot of time figuring out how to make an A/D system that could meet that requirement.

So, while you can bypass the front end (if you want to be a purist), it's not really necessary as the unit is so quiet anyways.
 
Can you post tabs for this lick? Or at least a slower version.


We've been getting questions about whether the FX8 is truly quiet enough to use with a high gain amp. This recording show the noise performance when the FX8 was used with a Les Paul with a Seymour Duncan Distortion Humbucker into a Friedman HBE with the gain on 8. As usual, with nothing but guitar, cable, amp, you get some noise from such a setup due to the amount of gain. To our ears, the FX8 did not add any perceptible noise when it was placed in the signal chain. We could not even tell the difference between FX8 engaged and FX8 on True Bypass. If anything, the HUMBUSTER technology on the FX8 outputs actually REDUCED the 60 cycle component of the noise.
The clip has three sections — not necessarily recorded in this order. Can you guess which is which.
• Guitar, Cable, Amp
• Guitar, FX8, Amp (Empty Preset)
• Guitar, FX8 on TRUE BYPASS, Amp

https://soundcloud.com/fractalaudio/fx8-noise-test

[SOUNDCLOUD]
https://soundcloud.com/fractalaudio/fx8-noise-test[/SOUNDCLOUD]
 
Where these clips done with humbuster cables? Id like to know if they really are neccesary, when the fx8 itself is so silent...
 
Where these clips done with humbuster cables? Id like to know if they really are neccesary, when the fx8 itself is so silent...

Yes the clips were using the Humbuster cables. Personally I would recommend using them in a 4cm setup.
 
Hi Mark,
thanks for doing the test! Will you let us know the order? my guess is 1. true bypass, 2. direct and third is empty preset ;)
 
Awesome! I've looked into the given information on this unit and I'd love to know if it has the same pitch delay effects on it. I know I've read that it has most effects from the axe II but I need to know. Does it have effects like the plexi pitch?
 
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