Aguilar DB 680

Offered for sale:

Used Aguilar DB 680 Tube Bass preamp serial number 315.

This preamp is in good condition, fully functional, cosmetically showing some marks from rack installations.

Aguilar states:

The DB 680 is designed and manufactured to provide the most discriminating bass player with a studio and live performance tool worthy of a fine instrument. The DB 680 addresses the contemporary bass player's needs in all studio and live applications, and is as effective for recording as a chain of the most desirable classic studio gear.

The DB 680 has two fully parametric EQs, not semi-parametric, for complete tone shaping possibilities, a tube driven resonance circuit, tube effects loop, and variable balanced outputs. For the road, there's a great sounding crossover, -40 pre- and post-eq outputs for the mixing console and footswitchable inputs and master mute (leaves tuner input on for silent tuning). The chassis of the DB 680 is steel, and can withstand the bumps and grinds of a tour.

Most importantly, the ten tube stages make for a sweet, warm tone and smooth feel beyond compare!

All Aguilar products are hand made in NYC.

Imperial Guitar states:

“We test every used amp and preamp when we buy it and bring it up to our standards before we offer it for sale. Then we burn it in for an hour or so before we ship so that there are no surprises.”

Specifications:

All measurements taken with a line voltage of 120 VAC.

All voltages are RMS.

All noise measurements are unweighted.

Tube complement: Five total; two 12AX7A/7025 high-mu twin triodes

and three 12AU7 medium-mu twin triodes

Input Impedance: 1 M ohm (passive mode)

56 K ohm (active mode)

Output impedance: Normal output = 1K ohm.

Balanced output = 600 ohm

Crossover outputs = 75 ohm.

Signal to noise ratio: -80 db

Power requirement: 100-120-220-240 VAC/50-60 Hz.

Internally selectable. Refer to a qualified service

technician to change voltage selection.

Power consumption: (at 120 VAC): 0.75 A, 87.75 W

Rack size: 2 spaces

Weight: 17 lbs.

INPUTS:

Two Selectable Inputs:

There are two inputs on the front panel of the DB 680. There is an input selector switch

to the right of the inputs. You can switch manually between inputs one and two. The

center position (labeled F/S) is for footswitching, using the provided footswitch. This

feature allows you to keep two basses plugged in, and be able to switch easily and silently

between the two.

Active/Passive Switch:

This switch applies to both inputs. Nine times out of ten you’ll use the passive input. If

your bass’s output distorts the input section, switch to the active position. In the active

position, a 12db pad in the signal path will remedy the situation.

Input Gain Control:

This pot controls the gain of the preamp section. Clean sounds are usually achieved by

setting the input gain around 11 or 12 o’clock. A little bit of musical distortion will occur

if set past one or two o’clock.

Dual Parametric Equalization:

There are two serially arranged active networks, +/-12db. One EQ is set up from 180 Hz,

(low mids), fully variable to 1.2K, (high mids), with fully adjustable bandwidth (Q), and

level controls. The other EQ is set up to be fully variable from 1.3K to 7.5K, (highs),

again with fully variable bandwidth and level (boost and cut). This is the most flexible

arrangement for bass.

What’s so great about fully parametric equalization?

Pleasant sounding equalization tends to be broad bandwidth. This means that

you’re boosting not only the selected "center frequency", but specific surrounding

frequencies as well. This makes for a more "musical" effect than a "fixed" narrow

bandwidth equalization. So why have bandwidth control? Because many useful "cuts" are

narrow or relatively narrow. For example, if you think your bass sound is muddy, you

might want to decrease or cut 200 Hz, a frequency in the low-mids area. But you

probably don’t want to decrease the frequencies around 40 Hz, as that might make your

low end sound weak. Other bass preamps offer only "semi" or "quasi" parametric EQ.

These types of EQ are not as effective because they don’t allow you to "zoom in" as

precisely on the frequencies you wish to affect. The DB 680’s EQ section is as

sophisticated as the finest studio EQs available.

TUBE EQ:

Treble:

Tube driven shelving type, boosts up to 12db. The center frequency is set at

4 kHz.

Bass:

Tube driven shelving type, boosts up to 12db. The center frequency is set at 40 Hz.

Deep Switch:

The deep switch controls a tube driven RLC resonant EQ, fixed at 30 Hz. Two positions

are provided for flexibility. In the left setting (+) 30 Hz has a smaller amount of gain than

in the right setting (++). The (+) setting is great for "fattening up" a bass sound, while the

(++) setting adds loads of bottom.

Bright Switch:

This switch is a passive RC pre-emphasis circuit at 5-7 kHz. The bright switch will add a

brighter timbre to the entire range of your bass.

Tube Effects Loop:

The preamp contains a tube parallel effects loop with an adjustable send and mix control.

On the front panel the send pot controls the level of your bass going to the effect. The

mix pot is actually a tube mixer, which mixes your effected signal back into the preamp.

The effects loop is comprised of both halves of a 12AU7 twin-triode. It is set up in a

parallel mode. The dry and wet signals are fed into each side of the tube grids and mixed

after the individual gain stages. This presents the best signal to noise ratio and sound

quality. When it is set at 100% your entire bass sound is being processed by the effect in

the loop. The loop circuitry is active only when a plug is inserted in either return jack.

Master Output:

This controls the level of the signal going to your power amp.

Crossover section:

The crossover section is to be used with a stereo power amp when you want to separate

the low and high frequencies. The top pot in the crossover section sets the crossover

point. The low master controls the output level for the frequencies below the crossover

point; the high master controls the level for the frequencies above the crossover point.

OUTPUT INTERFACES:

Rear Panel

The preamp features three output interfaces:

Unbalanced Outputs:

Line level outputs controlled by the master volume control. These are full-range outputs

that provide unbalanced tube-buffered output for connection to a power amp. You can

use both if you want to send signal to both sides of a stereo amp, or to two different amps.

High and Low Crossover Outputs:

These provide individual crossover outputs for full bi-amping capability.

XLR Balanced Output:

Unlike conventional DI outputs, this balanced configuration allows you to record directly

to any line input (i.e., tape, hard disk recording system, etc.). No mic-pre is required! The

output level has five positions to cover all possible recording and concert situations. Use

the -40db pre-eq setting in a concert situation where the house mixer is taking a signal into

the house-mixing console. The house mixer is now getting his feed after the preamp

stage, but can use appropriate EQ for the venue. The EQ on stage will still be controlled

by your settings. If the house mixer wants your EQ settings included in the mix, set the

control to -40 post-eq. The -40 level is the correct output level for going into a preamp

on a mixer.

0, +2 and +4 settings are provided for going directly to tape, or any line input. If you

have cranked the input level on the preamp and used the (++) position on the deep switch,

the overall level of the preamp will be greatly increased, and 0db will be plenty of output

gain. If your settings are more conservative, the +2 or +4 settings will provide better

output levels.

Our balanced output uses the highest quality Jensen output transformer. If you hear any

ground noise, change the position of the ground lift switch on the back of the preamp.

Auxiliary Input:

Located on the rear panel. The extra input on the rear panel is useful in a permanent

studio or live rack set-up where one needs to access the unit from behind.

Input thru:

Use this to send the signal from your bass straight through to the input of another bass

head (not a power amp). For example, connect with a vintage bass amp that you want to

record with a microphone, while taking a direct signal from the DB 680. The signal sent

to the input of the amp is a straight pass thru from your bass, unaffected by the DB 680.

This pass thru is not muted by the footswitch.

Tuner Input:

This is another input pass thru, which is great to keep a tuner plugged into. Can be used

when all the other outputs are muted.

Weight lbs.: 18.4 lbs.

Width in.: 19”

Depth in.: 13.5”

Height in.: 3.5”

*Please note: we do our best giving descriptions of used pieces. We have found it impossible to describe every mark on an instrument or amp that is not in the "mint" category. Also, what's important to you may not be important to someone else. For example, you may say, "I don't care what it looks like as long as it plays or sounds well." Another person may say, "Body cosmetics are very important to me so tell me about every scratch, nick and blemish." So, please ask the questions that are most important to you. If you ask they will be answered. They are free and there's no limit. Additional photos can also be made available.

This is a specific item that is also being offered for sale in our brick & mortar location. It is possible that it has just been sold. Please ask if it is still available before purchasing.

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