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soundroom H Y B R I D H E A D AGUILAR © 2003 Bass Player Magazine, reprinted with permission from United Entertainment Media, Inc. W I T H 7 5 0 - W A T T P O W E R A M P A pair of piercingly bright LEDs indicate whether the DB 750 is in diagnostic, mute, or operational status. DB 750 The DEEP switch can add lowend fullness to a soloed bridge The flexible effect loop has variable SEND and pickup. Use the BRIGHT switch to RETURN levels, with a push/pull pot to accommogive slap tones a crisper edge date instrument-level or line-level effects and a or enhance the detail of darkerpush/pull pot for parallel or series operation. sounding basses and cabinets. BY TERRY BUDDINGH under poor lighting conditions. For speaker connection, Aguilar chose Neutrik Speakons exclusively. Speakons are better able to O ver the last seven years, Aguilar has built a solid reputation deliver high-power signals than q" jacks and plugs, which were orig- by designing high-quality speaker cabinets and all-tube inally intended for lower-level applications. bass amps, preamps, and DIs. The DB 750, a high- The DB 750 is expensive, but when I peeked inside its no- powered head with a solid-state output stage, marks a nonsense exterior, I began to understand why. Removing the top noteworthy shift in direction: While its tube-driven preamp circuitry plate exposes a chassis jam-packed with beautifully rendered cir- borrows from earlier Aguilar designs, the MOSFET output stage pro- cuitry. It’s obvious a lot of painstaking work went into its design, and the quality of workmanship is exceptional. vides a significant power boost. Not wanting to sacrifice fidelity for power, Aguilar Elegantly prepared wire harnesses con- designed its first solid-state power- nect the three printed circuit boards, amp section to have low distortion that which pack in the high-quality com- provides clear detail and dynamic ponents that contribute to the DB 750’s sensitivity even when fully cranked. extensive self-diagnostic capability, big power, and tone. For example, the Hidden Treasure power supply’s hefty toroidal trans- Like Aguilar’s other gear, the rack- former and eight large filter capacitors mountable DB 750 has an austere (hidden below the top PC board) pro- external design, and its metal-flake vide a substantial voltage reservoir. enamel steel front panel sports utili- Unlike a lower-capacity power supply, tarian knobs and switches. The DI’s the 750’s robust power supply does jack and controls are conveniently not compromise the amp’s headroom mounted on the front, as are the effect- and dynamic punch when demand is greatest. loop controls; there’s no fumbling around behind the amp when you need to check important switch positions, although some of the front panel’s let- The DB 750’s internal components are of an exceptionally high quality. Aguilar’s attention to detail is admirable— note the carefully harnessed wiring. BASS PLAYER J A N U A R Y the 750’s full width and draws heat away from the 12 MOSFET output tering is quite tiny and difficult to read 58 At the rear of the chassis interior, a large internal heatsink runs across 2 0 0 3 T E C H S P E C S Sorry, no 1/4" speaker jacks. Neutrik Speakon jacks more reliably handle the DB 750’s high power output. transistors. Two high-capacity cooling fans draw bottom was always tight and clear. The onboard DI air through the amp’s side vents and expel it out kept the soundman happy. For warm fingerstyle the back. The fans run at full speed at all times funk tone, he used the 750’s DEEP switch and boosted to efficiently dissipate the heat, and they are the mids to 3 o’clock. To brighten up his tone for moderately noisy. I prefer a variable-speed fan, slap passages, he engaged the well-voiced BRIGHT as the 750’s noise would be excessive in some switch and backed off the robust BASS control. environments. I recorded tracks via the DB 750’s DI to DAT and found it to be quiet and musical in both pre- On The Job and post-EQ modes. The all-tube circuitry and We tested the DB 750 on numerous gigs, ranging high-quality Jensen output transformer faithfully from low-volume jazz settings to loud outdoor convey the DB 750’s sonic subtleties while rival- venues, with various basses and cabinets. Pow- ing the sound quality of expensive outboard DIs. ering up the amp begins the approximately 45- Back in the BP Soundroom, I experimented with second self-diagnostic procedure. Once the overdriven rock tones. A ’71 Fender P-Bass with heavy-duty input and output relays are engaged an Ampeg SVT 8x10 sounded huge with a snarling and the status LED stops blinking, the amp is ready. midrange grind, and the ample headroom provided While the diagnostics help prevent potential equip- wicked chest-pounding punch that was forceful, ment damage when the DB 750 is suddenly pow- yet focused. By raising the GAIN knob settings and ered down, one staffer thought this was an lowering annoyingly long time to wait, especially when the the DB 750’s preamp. It was easy to find the amp was accidentally unplugged during a sound- dynamic “sweet spot” where the tone transfers check. At 46 pounds, the hefty DB 750 is a two- from clean (when played with a moderate touch) hander—rackmounting is recommended. to a bit dirty when played more aggressively. While MASTER, I coaxed woolly overdrive out of With a Fender Jazz Bass and an Aguilar GS- overdriving the preamp can create grind and growl, 112 cab at a quiet jazz gig, I was impressed by the the super-clean power amp still provides tons of DB 750’s sensitivity to subtle dynamic inflections. uncompressed dynamic impact. Pretty cool. Its abundance of clean power provides effortless If you prefer to precisely sculpt your tone, you reaction to dynamic changes, and its ultra-fast may find the DB 750’s preamp, which lacks the transient response conveys accents with startling graphic and parametric EQ found on many other crispness. The DB 750’s high sensitivity to musi- amps, simplistic. Nevertheless, the straight- cal detail can be refreshing if you’re accustomed forward tone controls are effective and thought- to an amp with more limited dynamic response. fully voiced, and I was always able to dial in The DB 750 puts its best foot forward when gig-appropriate sounds with ease. cranked. At a high-volume R&B gig, with a Lakland 55-94 5-string and an Epifani 3x10, the DB 750 retained its distinctively clear and detailed character without a hint of strain. I kept an eye on the clip indicator light, and it never blinked. The Aguilar exhibited tight bottom-end control with well-defined and focused fundamentals, even in a Simple Pleasures Aguilar DB 750 List price: $2,895 Score 1 2 3 4 5 Construction: ● ● ●●● ● ●●● Electronics: ● ● ●●● ● ●●● ● Ease of Use: ● ● ●●● ● ●●● ● ● ●●● ● ●●● ● Sound: ● ● ●●● ● ●●● Value: 5-string’s lowest register. Another staffer who used the DB 750 on several gigs commended its copious headroom and punch. Using a Roscoe LG-3005 at a mediumsize club, he thought the DB 750 never sounded strained and that the Although good tone is substantially a product of technique and musicality, it certainly helps to have a well-designed, no-compromise, and carefully constructed amp like the DB 750 at your disposal. Its price Power rating: 975 watts RMS into 2Ω minimum load, 750 watts RMS into 4Ω, 425 watts RMS into 8Ω (all with <0.01% THD) Input impedance: 1MΩ passive, 68kΩ active ACTIVE/PASSIVE switch: Provides 6dB attenuation in ACTIVE mode Tone controls: TREBLE: ±12dB @ 4kHz; MID: ± 12dB @ 400Hz; BASS: ±12dB @ 40Hz; DEEP switch: +3dB of broadband boost @ 30Hz; BRIGHT switch: passive RC pre-emphasis @ 5kHz–7kHz XLR DI output: Tube-driven Jensen DI transformer with PRE/POST and GROUND LIFT switches Tube complement: Three Russian-made Sovtek 12AX7As and one Chinese-made 12AU7 Dimensions: 19" x 14r" x 5q" (three rack spaces) Weight: 46 lbs and weight may be excessive for the player doing casuals Pros: Effortless headroom; tremendous tone. Cons: Fan noise may be a problem in quiet environments. The Aguilar DB 750 is a hybrid head; it combines an all-tube preamp with a solid-state power amp. All of the preamp functions, including the effect loop and DI circuitry, are tube powered. The DI features a Jensen transformer comparable to those used in expensive DI boxes. To ensure dependable operation, Aguilar equipped the DB 750 with extensive start-up protection circuitry that checks for outputstage problems and extends tube longevity by gradually ramping up the high plate voltage delivered to the preamp tubes. For international use, the DB 750 can be internally reconfigured to operate on 100-, 120-, 220-, or 230-volt AC lines. (This procedure should be implemented only by a qualified tech, as 220-volt and 230-volt operation requires changing the circuit breaker/ power switch.) and coffeehouses. If you have the money and muscles, though, the DB 750’s exceptional tone, enormous power, and high fidelity definitely warrant a test drive. Made in: U.S.A. List price: $2,895 Option: Mute footswitch ($100) Warranty: Ten years limited 800-304-1875 www.aguilaramp.com BP J A N U A R Y 2 0 0 3 BASS PLAYER 59