When HHB unleashed its purple-faced processors on the world not long ago, the industry welcomed yet another line of high-quality tube gear. The HHB Classic 80 isn’t the first Classic series processor we’ve tested in Pro Audio Review – we looked at the Classic 70 tube EQ in the 6/99 issue, (p. 70).
Product PointsApplications: Studio recording
Key Features: All-tube gain stages; transformer input stage; three-position high- and low-pass filters; output attenuator; tube drive indicator; instrument input
Contact: HHB at 310-319-1111
The Classic 80 ($1,850) is a stereo tube mic preamp that treats the signal to three passes through the glowing glass. The trip through the Classic 80 goes something like this: transformer-coupled input stage, EF86 pentode main gain stage, two 12AX7 triode stages for gain and trim, solid-state balanced output stage. A front panel instrument input bypasses the input transformer.
The Classic 80 uses a stepped gain knob marked off at 20, 30, 40 and 50 dB of gain. This feeds a gain trim knob continuously variable between -12 dB and +12 dB; this knob has a center detent for unity gain. A large output level knob attenuates the signal before the output, with maximum output at the full clockwise position.
Along the way, the signal passes through second-order (12 dB/octave) low-pass and high-pass filters. Each filter knob has three frequency settings in addition to off. For the high-pass filter, these frequencies are 50 Hz, 100 Hz and 150 Hz. Low-pass frequencies include 5 kHz, 10 kHz and 15 kHz.
Both channels offer switchable phantom power, while Channel 1 also offers a phase reverse switch. Presiding over all the knobs is a backlit VU meter that shows output level. Additional level indicators include a tube drive LED and second peak LED. The tube drive indicator begins to glow at 0 dB, growing progressively brighter up to +12 dB. The HHB’s peak indicator lights when a signal gets within 5 dB of clipping.
Around back, the Classic 80 offers unbalanced 1/4″ outputs as well as balanced XLR jacks. A switch on the back panel lets the user select between +4 dBu and +18 dBu at the XLR output and lifts the 1/4″ output from -10 dBu to +4 dBu.
Ergonomically, the Classic 80 is a winner. There’s plenty of space to maneuver around the preamp’s sturdy knobs and buttons. Detented knobs click solidly into place while the continuously variable controls have a smooth feel. Legends are clear and easy to read. The hefty HHB looks and feels well-made and the preamp’s internal construction is neat and tidy.
The Classic 80 sounds as good as it looks and feels. When the tubes are just idling along, the preamp has a wonderfully open, transparent sound. The Classic 80 has the clarity I usually expect from a top-dollar solid-state preamp, without any harshness or edginess-smooth detail.
The Classic 80 doesn’t have the thunderous bottom end of some preamps, but there’s plenty of bass to balance the clear, open upper-mid and treble range. Some tube preamps sound a little thick in the low-mids to my ear; I was glad to hear the Classic 80 maintain its articulate sound even into the lower registers.
When driving the preamp’s tubes harder, its character changes noticeably. With the drive indicator glowing, the Classic 80 begins to sound a little fuller and darker. A slushy sound, but not with a bad connotation – the preamp simply relaxes a bit, seeming less concerned with catching every detail of the input signal. For vocals, higher tube drive settings can actually accentuate sibilance while adding a touch of compression.
Instruments plugged straight into the purple panel exhibited the same effects-clean and open at low tube gains, looser and more compressed at high tube gains. The HHB dished up some very sweet direct guitar and bass tones.
I really liked the Classic 80’s three-knob approach to gain. Being able to attenuate the output with the large level knob makes it easy to dial in the exact amount of tube distortion and harmonics independent of output level. Take the attenuator all the way up (to unity gain) for the cleanest-possible signal; back it off to make the tubes work harder.
The Classic 80’s high- and low-pass filters did their work without unduly affecting the signal (unless that is desired). This brings me to my only wish for the Classic 80: continuously variable filters with a broader range. High- and low-pass filters can be great sound-sculpting tools, and I would have appreciated sweepable frequencies into the 1 kHz range for both (as found on the Classic 70 tube EQ).
HHB has a great product on its hands with the Classic 80 tube preamp. Though new, the preamp has the look and feel of a classic. Most importantly, the preamp offers a wide range of sounds from pristine detail to smooth, loose tube saturation.
The Classic 80 delivers the best of both worlds, which makes it well worth a listen for those folks shopping the upper price range of the tube mic preamp market.