One other happy discovery with Noble to share....
First, I asked Jack about the built-in "low cut" switch, how it compares to a High Pass Filter (HPF) like the Fdeck, and what his theory was for its use. He said:
As for the low cut switch, yes this is a high pass filter or HPF. A first order HPF drops at 6dB/octave (or 10dB/decade). Adding additional filter components can increase this to 12dB/octave for a 2nd order filter, 18dB/octave for 3rd order, 24dB/octave for a 4th order filter, etc.
Most solid state filters will be 2nd or 4th order, thus the 12dB or 24dB/octave slopes that you noted. Solid state filters can be made very small and cheaply with opamps, where tube circuits are big and would need more tubes to increase the filter order. 90Hz is the correct “corner frequency” for the Noble HPF but it rolls off so slowly that it takes several octaves to get down to business.
My original idea was to try to dip the bass around the range of the kick drum (60-80Hz usually), but of course guys have found all sorts of uses for that switch like Tim Lefebvre cutting the lows and then jacking the bass knob or Ian Allison told me in a boomy room he likes to cut the bass with the switch and dial some back in to taste with the knob. As far as how to use with an external HPF, I’d say just go with what sounds best to you and your band and your FOH. There’s typically no right answer in art.
I used to use Fdeck Series 2 and 3 HPFs when I gigged acoustic bass guitar and then acquired a double bass. The HPF was incredibly useful for cutting the low end junk generated by piezo pickups. I sold the acoustic instruments and am now exclusively electric, but had also sold my HPFs presuming they would not be as helpful.
What triggered my questions was a recent repurchase of a Genz Benz Shuttle 3.0 amp due to a memory of its incredible tone. I've mainly been using the Noble through power amps or the effects loop of an integrated pre/power amp. Leaving Noble out of the chain, when I plugged in my Barefaced Super Twin 212, immediately I heard a refined difference compared to running the Noble through a power amp. As a Noble Convert, I immediately wondered with alarm, "How can this amp possibly sound better than a Noble?" Further investigation revealed the Shuttle 3.0's preamp has a built in HPF fixed around 35-40Hz. Deducing the HPF was the happy culprit, I ordered Fdeck's
HPF-Pre Series 3 Mini to test the sonic theory. When I plugged in the new HPF @ 35Hz, it instantly was obvious that the HPF
was the difference in sound. When I set the Fdeck to 90Hz, the sound was similar to using just the Noble's low cut switch. That tone is a bit too thin for my ears, but as Jack points out, can be used for interesting applications. This experience is just in my quiet home studio, so I predict it will have the same benefit for live sound. Such a simple solution! After playing around, the 55Hz setting sounds more full and open than 35Hz. Who would have thought??
The HPF-Pre is powered by Noble's 14v jack and Jack's custom cable that boosts it to 18v. The HPF-Pre runs on 9v, but a higher voltage helps provide headroom, according to Francis Deck.
To wrap this story up, I conveyed the experience to Jack, who responded:
That makes sense. The Fdeck pedal is a great way to get exactly the low end control you want, and it’s small and easy to add to your pedal board.
The moral of the story is Noble is still the #1 tube preamp but sometimes can get a little extra help from a sibling device. For you pedalboard sluts, here's what's now on the Nano+:
