Hagerman Technology LLC: Clarinet Vacuum Tube Linestage DIY Kit

"Clarinet" Linestage (discontinued)

The Clarinet vacuum tube linestage employs a very musical SRPP topology, which provides both high linearity and low output impedance. Construction is solid and sonics are superb, easily competing with units many times its cost. Components are of the highest quality, no corners were cut in this design. The Clarinet is very accommodating to tube rolling so you can tune sonics to your taste.

Three inputs and two outputs (one for subwoofer) provide the flexibility you need for most systems. Balance and volume controls round out the system.

Expert DIYers can build this preamplifier themselves. The half-kit version will cost you approximately $500 in raw parts (this ain't no discount design). Use parts from your existing stock or upgrade to exotic and other boutique parts. The universal type power transformer accomodate worldwide operation.

Read this review from audio asylum, another one, and some actual customer testimonials.

Completed Clarinet

Completed Circuit Board

Features

All vacuum tube signal path
Pure Class A single-ended amplifier stages
No feedback
SRPP circuit for linearity and low output impedance
Vacuum tube B+ rectification
DC heaters
Dual outputs (one for subwoofer)
Single box design

Specifications

Gain	+15dB
Input Impedance	100k
Output Impedance	3k ohm
Bandwidth (-3dB)	10Hz to 100kHz
Distortion	0.08% @1kHz @1Vrms
SNR	83dB A-weighted
Phase	Inverted
Size	7.25" x 11.65" (PCB)
Weight	7 lbs
Power	25W
Input Voltage	100V, 110V, 120V, 200V, 220V, 240V
Tubes	12AU7 (ECC82) x 2, 5Y3 x 1

Reviewer Excerpts

"The Clarinet preamplifier is agile, detailed, and warm without being euphonic. It has excellent soundstaging, tonal balance, presence, and palpability. It is far better than any of the other kit preamplifiers I have heard to date, and is worth your serious consideration. Tube rollers will enjoy this preamp, as the differences between good Telefunken, Amperex, Mazda, and other 12AU7/ECC82s are quite apparent. Really good ones will make this preamp sing." - Kevin Kennedy

Measurements

The Clarinet not only sounds superb, it has impeccable measurements too. Below is the 10kHz square wave performance. Very fast and clean, no ringing or instability. The distortion is clearly 2nd order in nature with very little odd harmonic content.

Square wave response and distortion

Downloads

Customer Testimonials

The Clarinet brings phenomenal texture and emotion to the music, and generates shocking depth in my system. Well worth a look, if you are hunting an affordable tube based line stage that will bring out the best in the rest of your gear.
Thought you might like to know that everything went fine with the Clarinet. The enclosure is really nice and better than you described. I am auditioning it now and my first impression is - smooth. I bought the Clarinet with confidence because I really liked your design/quality of the Bugle.
First off, of all the preamps I've tried in my system the Clarinet is hands down the best. Listening to it last night was one of those "jaws agape" experiences for me....incredible clarity, detail retrieval like nothing I've experienced in my system, midrange texture and tonality that makes you stop and replay passages just to confirm your initial impressions. The Clarinet is an all-around performer...I love it.
I popped in one of my familiar CDs and all I can say is Wow, what a great sounding amplifier!
I did not expect the Clarinet to sound as airy and open as my purely passive preamp. In fact It probably is not quite as open and large a soundfield, but it is a hell of a lot more dynamic and has great slam. In this way I think the Clarinet is superior to the purely passive and the buffered passive preamps I enjoyed during the last 20 years. Dang Jim you designed a fine line stage for an affordable price. It really rocks the joint.
The sound is transparent, wide soundstage, and excellent PRAT.
BTW this Clarinet kicks ass! I have never thought this much sound could be available for such a resonable investment of time and money. I am in hogs heaven to be sure.