Studio Projects TB1 Tube Microphone

I’m happy to be writing about this mic. You might recall that in the recent blind mic shootout Don Boomer and I did, most of us picked the Studio Projects C1 as our favorite on three out of four voices, and also as a snare mic over seven others. Given the prestigious mics the C1 was up against, I felt a little guilty, as if we had gotten it ‘wrong.’ But in reality, all that was wrong was that I had placed too much faith on hallowed reputations and marketing hype. A mic that sounds good on your voice is just that—regardless of the cost at retail.

PMI Audio Group (designer and distributor of Studio Projects microphones and preamps) sent me three more mics, all from the company's new B series, to review. Sadly, two out of three got lost in UPS! Only the TB1 made it. I was initially disappointed, as I wasn’t really interested in checking out a tube mic with a separate power supply, even one that only costs $299 on the street. But fair is fair, so I set out to get comfortable with this piece of gear. And it’s a good thing—I basically loved it right away, with a few slight reservations.

The B-series mics from SP seems to be their new "budget" line. Interesting that a company that is already perceived by a lot of us as providing impressive bang for the buck would bother to dip down into this price point--the cheapest B series mic is a knockoff of the C1 and it runs about $79, competing with the least-expensive large diaphragm mics I’ve seen. Of the three Bs available, the TB1 is the most expensive—it's sort of a less-expensive version of Studio Projects' $699 T3, and it has dual-triode hand-tested tubes and a multi-pattern variable power supply and a faux-anvil "road case" just like the one the C1 comes in. [an error occurred while processing this directive] It's a large-diaphragm cardiod mic, with (and I quote from their literature) "a 3 um dual capsule for thick warm natural reproduction of the vocal range." Let me continue with more from the “instruction manual” that accompanied it: sensitivity is rated 25V/Pa (-32db re Odb=1V/Pa); Max output is 500V rms @1000Hz, <1% THD; Noise level is 16 dB-A; S/N ratio is 78 dB. Do I personally care about most of these specs? Not really. If you care about them, please feel free to compare, evaluate and discuss them in your mic reviews. Just to make it perfectly clear, I only care about how it sounds, but I fully accept that my philosophy is not always the most satisfying to other buyers, thus the inclusion of specs in this review.

The TB1 comes with an almost petite-looking mic clip that I thought was going to be a joke, but it turned out to fit like a glove, causing me no real concern that the heavy mic would slip out and crash to the floor. Still, I think the mic is a little too heavy for this clip—I tried to do some tricky positioning at one point and the clip kept rotating until I tricked gravity by manipulating the stand.

But in talking with Alan Hyatt of PMI, he showed me how to tighten a hidden screw on the clip which should make it stay in place. He also mentioned that there will soon be a special shock mount holder for the TB1, though I don't know if it will be included in the purchase price.

The mic comes with a special 5-pin mic cable to hook into the power supply. This cable was a bit of a pain—the pins were tiny and thin, and it didn't take much effort to bend them trying to insert the cable into the supply initially. I eventually got it in, but it started off as a hassle.

The mic sat untouched in my studio for over a week, not only because I was waiting for the other two to find their way (they never did), but also because I was kind of nervous—this time, I wouldn't be doing a blind comparison like the last time, but instead focusing on a single mic. I'd prefer to evaluate without knowing what I'm hearing, because I think the knowledge of the brand and model can influence me too much. But hey—I had to get on with it so I could send it least that was my plan! I sat down to test it in use as I might if I’d owned it, recording some vocal/piano demos of songs for the new Michelle Abby project. I already had my main piano mics set up—two AKG 414s running through Studio Projects VTB-1 microphone preamps with the tube set at about 9 o'clock. I pulled the TB1 out of its case, plugged in the power supply, let it warm up for a couple of hours while we went to see One Hour Photo (which has a mostly outstanding film score, by the way), then positioned the mic so I could sing and play at the same time.

You can easily imagine where the mic was sitting, right? In front of my mouth while I was sitting at the piano. The lid of the piano was open to the smallest degree. There was some piano bleed into the vocal mic, but these were rough demos, so it didn't bother me. However, after doing one song this way, I decided to overdub my vocals so I could isolate the mic on my voice (and later on acoustic guitar). [an error occurred while processing this directive] I have to say that my first impression was very positive. My wife Glenda thought my voice sounded great through it, and so did I. I don't hear anything I'd consider to be "tube coloring" per se, but once I compared it to my 414s, the differences became more apparent. I can say with confidence that just going through the pres on my Roland VS2480 24-track digital recorder, the TB-1 sounded far more pleasing to me than the 414s used to on my voice—I always felt like the AKGs were missing a little something, though I definitely could work with them. The TB1 exhibited a kind of silkiness that smoothed out some of the rough edges of my voice—it got better and better the more I experimented. I brought Glenda back in to sing a little and though she sounded perfect to me through the C1, I would have picked the TB1 in a comparative shootout. Her voice is already silky smooth, and this mic just took it to the next level.

It might have been something I ate, but the TB1 seemed extra susceptible to popping so it's kind of a drag that SP doesn't include a windscreen. I remember thinking that I’d definitely use the windscreen that came with my C1 when I wanted to use it to close-mic vocals.

On my steel string Gibson acoustic guitar, the mic sounded—well, OK, but not all that great. It isn't that it wasn't realistic—it was. But there seemed to be some added low-end boxiness that I had to EQ out. This is by no means conclusive, as I barely spent any time positioning the mic. It was still an authentic sound, but not what I was looking for.

My final test was to set the TB1 up right next to my C1, which I have running through a VTB1 preamp. They both sounded great, but the creamy quality of the TB1 was awfully nice, especially on louder passages. I don't have the AT4047 anymore—I only had it for my first shootout—but I'd say it would sit right in the middle of these two other mics in terms of brightness and clarity. The C1 has its famous little bump around 4 kHz (from what I'm told), and the 4047 seem to have some of that but not as much. The TB1 is not a dull mic at all, but it’s also not bright like the C1. I'd say if you had any two of these mics, you probably wouldn’t need the last one, as they all cover at least some of the same ground.

I have NO idea how the TB1 holds up to other $299 mics, but if they are all this good, then the world is an even cooler place than I realized. I wasn't prepared to like this mic—I wasn't looking forward to the hassle of having an external power supply, I didn't really like the cable, the clip is a little snarky and it looks an awful lot like my C1, so I'll probably have to think twice to tell which is which. But it won me over immediately and just kept growing on me till I bought one for myself. It also sounds great on my tom toms, though it picks up an awful lot of cymbal and snare as well. Too bad I don’t like gating my kit—it’s a smaller jazz kit that rings forever. Anyway, thumbs up for this mic. If you’re looking for a bit of sonic cream to smooth out even loud vocals, check it out.

Doug Robinson is a jazz composer and multi-instrumentalist. He has just completed writing and recording his first feature filmscore. Check out his new album, "Let Freedom Swing," at