In the past year or so, a small boutique amp company out of Northern California quietly started to cause a stir with its new high quality tube DI. Noble is an amp company with incredible ideas and gear built to back those ideas up. Jack Roan is the mastermind behind these creations. Fast forward to this past April when Noble released the revamped version of the DI, making it sleeker and giving it a power boost. I caught up with Jack to ask him about the Noble DI, as well as some information about what goes on under the hood of these crazy boxes we trust our signal identities to. Jack shared more important info than I could have ever hoped. Enjoy!
BF: How did you get started making amplification gear?
Jack: Well… it all started way back when I… Ha ha, yeah, it’s been a while actually. I picked up the guitar early in high school and quickly got very interested in the electronic aspects of creating music and live sound and recording gear. Things like, how does a pickup really work, why is that board channel picking up an AM radio station and how do I fix it, and, what’s the difference between instrument and speaker cables, they look the same you know. Stuff like that. So through music and the associated gear I got interested in electronics and went to college to pursue that. But they don’t teach you about audio gear in school (probably because there’s no money there, ha ha!), and so after a B.S. in physics and a masters in RF circuit design, I came out of college designing cell phone chips and wireless LAN semiconductor stuff. It was cool but there was always that mental itch in the back of my mind, it bugged me whenever I plugged in a guitar that I still didn’t fully know how all that stuff worked.
What finally drove me to build the first amp, I was playing in this band backing a singer-songwriter, and we’d rehearse in her living room; her on acoustic guitar just singing, no PA, no monitors, and the amp I had was waaay overkill. I just couldn’t turn it down enough. So I got a schematic for a five watt amp on the internet and when I finally looked into it I was like “hey, this isn’t hard at all, I totally understand this!” It’s actually really similar to RF design. So I don’t know why I waited so long to go there, but once I did, I couldn’t stop. When you find that thing you were made to do you’ll know it. But I’ve been fortunate to have that formal college background first, because I’m not just tied to replicating internet schematics like a lot of builders out there; I can actually design new stuff from the ground up and I think that’s one thing that’s made Noble a success so far; we’re doing stuff that no one else is doing. Like the preamp DI. And as a musician, I also love getting to know other musicians personally and interacting with their lives and being able to love them through the high quality of our gear.
BF: What made the next goal of Noble to create such a high-class DI?
Jack: You know it kind of happened by accident. I was making these great guitar amps and meeting with artists and bands and the bass players were literally begging me to build a bass amp. It really surprised me actually! So I started looking at what they were working with and in nearly every case these guys were lugging around these huge great vintage amps but running a DI on the pedalboard before the signal even gets to the amp. So they’re over there in the corner obsessing about their EQ and “did any knobs get moved during load in?” and sound checking and tweaking and in the end it’s all just a huge monitor for themselves. The house gets none of that, since the house feed is coming right off the pedalboard. So I started brewing this idea of a tube preamp on the pedalboard; it took a lot of thinking and work to get it to where it is today, but it’s here now!
BF: You’re placing such emphasis on bass for the DI. Are you thinking about how probably 90% of front-of-house bass sound, worldwide, has nothing to do with speakers? You really don’t even need to think about making a full bass amp if you didn’t want to.
Jack: Totally! With this preamp DI on your pedalboard you can run direct like a boss. Of course there are still gigs where you need an amp, so we’re cooking up something for that too.
BF: You’ve said the Noble preamp plays well with amps, but is best for an amp-less situation or when using in-ear monitoring. What makes that work best?
Jack: I think what makes it best for that is actually the lack of other gear that is good in that situation! I want to punch whoever is out there lying to bass players, “You don’t need an amp, just run direct.” Stop it! Those are totally different things! The amp is part of the instrument. Specifically, the preamp! You still need a preamp.
The way I see it there are three parts to any amp: the preamp, the power amp, and the speaker cabinet. The preamp is where you get all the tone shaping and character, EQ control, attack, compression, overtones, etc. The power amp is only there to drive the speaker cabinet really. Some venues, churches especially, are not even allowing bass amps on stage, to keep control of the sound dynamics in the room. So when you get into a big venue with a good PA and adequate monitoring, sure, maybe you don’t need a cabinet, but you still need a preamp. You still need a preamp! Someone’s been robbing bass players of half their instrument and we’re out to set that right.
And with in-ears you really hear everything with a new clarity, but also you’re hearing it from the soundboard, not from the stage, so when you drop some tubes into that signal path, with the clarity of in-ears, WOW. It’s like a whole new world opens up compared to a plain old DI. The Noble preamp DI is a legit +350V vacuum tube preamp in a pedalboard form factor, with six regulated 9Vdc power outputs for your other pedals, and a super high quality Jensen DI transformer on the backend.
BF: Explain the Jensen transformer to me. It’s one of your main advertised features, but players might not know what the big deal is. And what’s the difference between passive DI and active? Specifically, why the Noble is passive even when it needs power? (That can be mighty confusing.)
Jack: Ha ha! Sure, man. Let me back up real quick and talk first about what a DI does, and why you need one. It’s all about impedance. A DI transforms the high impedance single-ended signal that comes from your bass and pedal effects, into a low impedance balanced signal that can run over long cables without loosing clarity or picking up noise.
The most straightforward way to do this is with a transformer, which is basically just a special piece of steel with wire wrapped all around it, but way more complicated than that. In fact, as simple as it sounds, there are so many intricacies and subtle things to be aware of with audio transformers to ensure they aren’t picking up hum or other RF noise and to make sure your bandwidth is wide enough so you’re not loosing highs or lows.
The Jensen company has been around for over forty years and they are top notch. Like Noble, all their product is built by hand in California. Check out their client list, it’s huge and covers tons of industry giants like Fender, Moog, Tesla, the FBI, Nasa, Disneyland, and Eddie Van Halen, to name a few. For their tiny niche, they are the best. And it matters! In our case we were looking for a wide frequency response with low distortion and phase deviation, rather than a specific color, and this is exactly what Jensen is known for: absolute signal purity. Their DI transformer is legendary and has been used in the top DI boxes around the world for years.
As far as why the Noble is a passive DI but still needs power – the DI part, the single ended to balanced signal conversion, is done with the transformer; it does not need to be powered. But the tube preamp that comes before the transformer in the signal path, that does need to be powered, of course.
Now why is a passive DI better for us? A couple reasons: One, like tubes, transformers also have subtle distortions, usually in the odd-ordered harmonics (3rd, 5th, 7th, etc) that are musical, that sound pleasing to the ear. The Jensen sound isn’t overly colored, but it does have a sort of “beef” that really works on bass. Second, any active circuit is going to add noise, it’s just inevitable. And if there’s one thing I’m obsessive about, it’s preventing noise. I want the absolute lowest noise signal path, so that alone ruled out any type of active DI circuit.
Another reason I personally like working with Jensen is the culture of education that they propagate. Go to their site, jensen-transformers.com, and they’ve got a bunch of application notes, schematics, design tips, etc. They put that stuff out there because they believe an educated customer is a better customer, and that’s exactly in-line with what we believe at Noble as well, so it’s been a good fit on that side for us too.
One other note on the topic of DIs is ground/lift. Most good DIs have a ground/lift switch that either passes the soundboard ground through to the instrument (via pin 1 of the XLR cable), or it breaks that connection. With the Noble preamp DI your instrument and your pedalboard are already grounded through the power cable, so you should generally leave the switch lifted (UP) to avoid a noisy ground loop. But every venue is different and sometimes the stage ground is screwed up, missing, or noisy, so you may need to flip the switch down to connect to the soundboard ground to fix that issue. But most of the time you should leave it lifted.
BF: The most intriguing thing to me about the Noble DI is how much power it runs on, +350 volts. I don’t think people realize how much the amount of power running through a piece of gear contributes to the fidelity and clarity.
Jack: Absolutely, it’s all about headroom. That’s the same reason some pedals are now running at +18V, instead of +9V.
There are other tube pedals out there, but most of them try to run the tube at very low voltages: 9V, 12V, etc. That’s fine for an effect, but I wanted to do a legit tube frontend, similar to what you’d find in a vintage Fender or Ampeg, in a small enclosure that was pedalboard-friendly. This was actually a huge design challenge; we worked with several manufacturers before getting a toroidal power transformer small enough to fit in the space allotted and deliver the high voltage that tubes need to sound their best. And unlike those vintage amps, we designed a regulated power supply that slowly ramps up the high voltage after the tubes have had time to warm up, so you don’t need to worry about a standby switch. It helps the tubes last a long time, and also cuts the noise way down. It’s amazing how quiet this preamp is. Over 100dB signal to noise ratio.
BF: What do you think that the DI has to offer that you can’t already get from an Avalon U5 or a Reddi, for instance?
Jack: Those are both great boxes, but actually I think their approach is quite different than ours. The reddi is a nice DI but it’s just a DI, it’s not a preamp. There are no EQ controls, and it doesn’t fit on a pedalboard or travel well. I think it’s like three times heavier than our preamp DI? I’d take one of those to a street fight, but for a fly date you’ll want something a lot smaller and more flexible.
The U5 is also a different design philosophy, I think they are going for the cleanest, most pristine, lowest distortion signal path. Which all seems really good except that’s not what you want in a instrument preamp. When you hear an acoustic instrument, guitar or violin or double bass, like when you hear it in real life, in the same room, you’re hearing way more than just that string vibrating. All the wood vibrates too, and each piece has different oscillation modes and they add in all these other frequencies and harmonics that are more than just what you get from the single string or note. With an electric instrument you don’t really get that, since the pickup is only “hearing” the vibration of the string. That’s where tubes come in. Tubes aren’t perfect, but their distortions, their imperfections, are musical, so it adds to the sound of the bass. Adds harmonics, overtones, a bit of sustain, some compression. It adds character! All good stuff. The electric bass was invented in the day of tube amplification, and a tube amp is part of the sound that is written in our collective memory of what a good bass should sound like.
The guys who have tried all three (ours, the reddi, and the U5) say the U5 is too sterile, and the reddi is really punchy but almost too colored, like it does one thing really well but if that’s not your thing, well, you’re stuck. Our preamp DI is articulate and has a great “3D” tube console sound, but you’ve also got a really musical EQ to add in a bit of bass, treble, or mid notch (boost both bass and treble for mid notch), so it can get punchy too. It’s up to you. And of the three, ours is the smallest and lightest BY FAR. What’s the U5, like, 10-12 lbs I think. Same with the reddi. They’ve massive! And they don’t even power any other pedals…
BF: To that same end, having six 9V outputs to power pedals is insane. It’s as if you’re almost daring players to even try and put strain on the amount of power.
Jack: Ha ha! Well I hope not, but yeah! I totally believe in pedals and that every bass player should have a pedalboard. The quantity and quality of pedal effects are amazing and it’s one of the most intuitive form factors to work with. A good pedalboard will add extra dimension to your instrument and your playing, and certain effects are essential in some styles of music. Even if it’s just a tuner and a wireless unit, we want to support that and make it easy for bass and acoustic guitar players to put together a great pedal rig, starting with a high quality regulated 9Vdc power supply. So I felt that was an essential piece of what we were building.
BF: Anything else bassists should be looking forward to from Noble?
Jack: Oh man, we’re just getting started. We’ve got a 1000W bass rig in the works (the preamp DI followed by a class D power amp), as well as releasing the preamp DI in a 2U half width rackable enclosure. We’ve also got a small phantom power pedal that Tim Lefebvre has been testing out for us. It interfaces an XLR cable to the 1/4” input of the preamp that turns it into a pedalboard mic pre so you can run condenser mics through pedals and through the preamp DI.
BF: All of that sounds great. It’ll be nice to watch you grow this one DI into a full line of top notch bass gear.
Jack: Thanks, Matt. I’ll let you guys know!