Cornet3 - MM Vacuum Tube Phono Preamp
Originally available as a Kickstarter project, the Cornet3 delivers high performance on a budget. The circuit topology features common cathode class-A gain stages with no feedback, passive equalization, and cathode follower output buffers with constant current sink loading. Power is supplied by a regulated wall-wart driving a boost converter (running at about 50kHz) to generate the high voltage rail required for proper tube biasing.
- 44dB gain (1kHz)
- 47k ohm input impedance
- 1k ohm output impedance
- +/-1dB RIAA accuracy (30Hz to 30kHz)
- 10Hz to 600kHz bandwidth (-3dB)
- 77dBA signal-to-noise (ref 5mV)
- 30dB overload (ref 5mV @1kHz)
- 5 x 7 x 1 inches
- 120V/240V operation 17W
- 12AX7 x 2, 12AU7 x 1
- "Hooked up the Cornet3 last evening and it was good despite tubes not run-in! It was dead quiet and better than the in-built phono mm on amp. Sound wise it was good and this can only get better. Many thanks."
- "Just a quick note in praise of my Cornet3, which I've had for a month or two. I was using a Pro-Ject Phono Box S, which was an audible upgrade from the internal phono stage in my Rotel integrated amp. The Cornet3 is a noticeable step up again. The most dramatic difference is with solo piano music, which sounded flat and dull before (I assumed it was the nature of the recordings), but now sounds like a real piano. Acoustic music of all kinds sounds more natural as well. But the improvement in noticeable in every type of music. It really takes the edginess off of cymbals that can make rock music tiring after a while."
- "I received the cornet3 a little over 2 weeks ago (after approx. 2 months of research). I am very happy with it. Talking Heads, Dire Straits, Sade, Steely Dan and various jazz artists all sound great. Led Zep II last night - so good. There is so much 'more music' than I previously was able to hear."
- "Just a quick note to thank you for another superb product. My Cornet3 has been happily playing for 2-weeks now and seems to be getting better each day. For MM playback it now replaces the well-reviewed Lehman Black-Cube, which I find lacks some vibrancy, dimensionality and tonal color in comparison. I rolled in a couple of NOS Raytheon 12AX7's and a Bugle Boy 12AU7 over the weekend. This produced a notable and worthwhile sonic change."
- "I have a Cornet3 that I built last year. It’s been one the best additions to my hifi in it’s ability to revitalize my music collection."
- "As an aside, and a testament to your design, I've been comparing the Cornet3 to a Fi Yph (made by Don Garber). The Yph uses 6922 tubes, is handcrafted, 18 months lead time, costs ~$1100, and looks super cool. It's a cult item. But the gain, noise floor, and dynamics of the Cornet3 blow the 3x more-expensive Fi out of the water, at least with my cartridge. I don't know if it's a difference in the tubes used or the power supply or what, but it's not subtle at all."
- "Just wanted to let you know that the Cornet 3 arrived on Monday. I’ve listened to some of my audiophile records using it (Ray Brown and Laurindo Almeida, Time Out by Dave Brubeck, the Mosaic box set of Clifford Brown and Max Roach), and I must say I’m amazed by the improvement in the sound. Thanks very much!"
- "Incredible bass reproduction in this thing, rock solid and punchy. Definitely the best phono I have ever owned in every way, I am addicted."
- "Remarkably quiet in operation ... well done, a decent kit that sounds good."
- "Jim my Cornet3 is absolutely amazing!"
- "What a nice unit this is. I've been listening all evening and it really has a wonderful sound. Now I get the 'tube' preference that so many folks preach about."
- "WOW, this is a fantastic phono preamp. I was using a 'big name' British $1200 solid state preamp and it is no contest. The Brit has more gain and is more dynamic, but in every other way the Cornet3 wins - more resolution, detail, and 'life' in the music. This is a winner, congratulations, well done."
- "I am really enjoying my new Cornet3 kit. Worked great the first time I powered it on. I only wish I was home more often to enjoy it."
- "Received & built my C3 kit today. Easy build, fired right up, breaking in nicely; sounds great with Denon DL-A100 & Bob's Devices Sowter SUT. Tube-rolling and IC-swapping to follow. Sounds sweeter by the minute ... I think you've got a winner & are going to be spending a lot of time at the soldering station. It's a good time to be in analog, and you've got an excellent product range. Good luck, and thanks for sharing!"
- "Got my Cornet3 parts yesterday...populated the board with some of the components to check the fit last night ... excellent!!! Gonna start with the smaller resistors later this afternoon. Nicely packaged and love the board layout...looking forward to the build."
- "Just put the Cornet3 into my system after the build ... listening to Dire Straits' Love Over Gold ... I am happy so far, with no burn in time ... there is Love, and Gold ... thanks Jim."
- "OK, so I am one of the lucky ones to receive my pre-assembled Cornet3 the week before last. My observations are that if you have not received yours, you really have something to look forward to. For starters, the unit was dead quiet in my system, which has Avantgarde horns sensitive to the slightest hum. The sound is quite unbelievable, even before full burn in. I could trot out a bunch of audiophile adjectives, but instead will say that it draws you into the music and keeps you playing that 'one more song' until the sun comes up. I have ordered some Telefunken NOS tubes from Kevin Deal to replace the stock tubes, but I could easily live with the Cornet3 the way it ships. Thanks, Jim and best wishes to the rest of your supporters."
- "Last week, I received my assembled Cornet3. In that package arrived a completely renewed, revamped and refreshing audio system. I thought nothing of my phono stage, but bought what I thought was a decent Pro-Ject Phono Box MM unit for around $100. But my disappointment persisted. Until this unit arrived. Warm, full range, rich. Fantastic. Thanks, Jim, for a new and exciting audio setup."
- "Cornet3 sounds fantastic, by the way. Even with the stock tubes. Played it for a week or two, then swapped in some 1950's RCAs and some early 1960's Mullards. Now I am totally torn as to which ones I like better. Magnificent job you did."