EBS TD650 (01) PDF DOCUMENT

Follow these steps to get started with the EBS TD650 bass head:

1. Carefully unpack the bass head.

2. Check that the controls are set fully counter clockwise. Proceed by turning the three filter knobs marked BASS, MIDDLE and TREBLE to mid position. Locate the filter switch and set it to BYPASS. Make also sure that the switch marked Character is in its’ outer position. Now the EBS TD650’s settings are “zeroed” and ready to be personalized.

3. Turn on the POWER switch. Wait for approx. 15 seconds before switching on the STANDBY switch to allow the tube to warm up.

4. Plug in your bass. While plucking the strings as hard as you would during your hardest playing, gradually increase the GAIN knob until the PEAK led starts to flash at peaks.

5. Move over to the VOLUME knob and adjust for the desired output volume.

The EBS TD650 features an enhanced tone shaping circuit that will enable you to create a variety of bass sounds. Follow these steps to build your sound:

1. Toggle the BYPASS switch to its outer position to enable sound shaping.

2. Play your bass. Note that there isn’t any difference in the sound yet.

3. The filters are basically the boost/cut design. This means that the level controls, marked with + and – signs, either boost or cut the selected frequency band. Further, the MIDDLE section has a frequency control for precise adjustment of the midrange.

4. Gradually increase or decrease the level and vary the frequency of the filter sections. Use the BYPASS switch for A/B comparison.

5. Try out the preshape filter CHARACTER. Note that the BYPASS switch does not affect this control.

6. Proceed to the COMP/LIMIT knob. This control adjusts the compression and is useful when playing very dynamic or loud.

7. Turn up the COMP/LIMIT knob to mid and max position. Notice how the peaks in volume will straighten out as you play harder and harder.

8. Now, go on to the BRIGHT next to the filter switch and turn it half way up. Play your bass. The BRIGHT filter is a high pass filter, which works on the highest frequencies of the bass to give enhanced ambiance and presence.

9. Go over to the DRIVE section and turn the DRIVE knob half way up and play. Try also the DRIVE BOOST now. The TUBE MODE switch that engages the real tube gives you a choice between solid state and tube sound.

INPUT

The EBS TD650 features a low noise, high impedance instrument input that can also power active pickups and circuitry (phantom power). If you want to use this function, take away the 9 Volt battery from your bass and strap the + and – pole on the battery holder. Use a standard stereo jack plug when using the phantom powering from the EBS TD650. The power is switchable off via the Input Phantom Power switch on the rear panel.

IMPORTANT: If you are using the phantom powering, make sure the GAIN or the VOLUME knob is set to zero while plugging in the instrument cable.

GAIN

The GAIN control adjusts the instrument’s signal strength to the right operating level in the EBS TD650. For optimum basic signal level, turn up the GAIN knob until the PEAK led starts flashing from the strongest signal from the instrument. A correctly set GAIN is vital for the signal processing to work properly in the EBS TD650.

The EBS TD650 is provided with an effect loop for the use of external units such as box or rack effects. The loop is positioned after the filter and compressor sections, but before the DRIVE section.

Serial Loop:

When connecting your effect between the SEND and SERIAL RETURN jacks, the internal line is bypassed and all signal passes through the external unit and back to the amplifier.

Parallel Loop:

When connecting an effect between the SEND and PARALLEL RETURN jacks, the signal is equally mixed between the send signal and the signal present on the effect return. The PARALLEL RETURN may also be used as a separate input for external units.

Phantom Power:

The effect loop also facilitates the option of phantom power. To activate the phantom power, set the phantom power switch for the loop returns on the rear panel to the outer position.

The COMP/LIMIT on the EBS TD650 is a low noise compressor/limiter that works fast and effectively, tightening up the sound and preventing the bass head from saturating at peaks when approaching the headroom limit. A string may be plucked very hard and fast, without any greater difference in level or side effects.

The COMP/LIMIT knob sets the compression ratio; the higher the ratio, the more compression. The LED intensity dynamically indicates the amount of compression during play.

The filter section of the EBS TD650 contains four enhanced performance filters plus a CHARACTER preshape filter:

CHARACTER: This is a preshape filter that operates independently from the filter section and BYPASS switch. When pressed to its inner position, a boost is achieved in both the bass and treble ranges, while the midrange is being slightly cut.

BASS: This is a ‘shelving’ type 12dB/oct slope phase compensated bass filter with a wide gain range.

MIDDLE: This filter has an extended frequency range of 50-3k Hz and facilitates total control over the mids with a wide bandwidth for a natural, non-peaking result. At its minimum setting, this filter provides a notch function, suitable for cutting an exact frequency.

TREBLE: This is a ‘bell’ type filter peaking at 5 kHz, controlling the higher mids and treble registers, giving presence and ambiance to the sound.

BRIGHT: This is an advanced high pass filter capable of producing bright high treble timbre, without adding practically any noise.

DRIVE: The DRIVE knob controls the amount of gain in the tube or in the tube emulation stage, and provides an extra gain all the way up to 34 dB. The gain is compensated over this section, producing a warm overdrive while the output remains more or less constant. This control also compresses the sound when turning up level to maximum, producing pure limitation.

BOOST DRIVE: This switch makes possible a choice of two different overdrive types. When this switch is in its inner position a flat, or linear, gain is achieved with the DRIVE knob. However, when this switch is in the outer position, the frequencies below 350 Hz are bypassed, producing a warmer distortion without saturation, allowing the player to add more low bass than with conventional bass amps. The bass is compensated over the tube stage, giving the same bass response up to mid distorted sounds.

TUBE MODE: This switch controls which DRIVE circuit that should be used. In the outer position, the tube emulating solid-state circuit is selected, and in the inner position the tube is selected.

A NOTE ABOUT TUBES: Although the ECC83 (12AX7) is a long life tube, it is recommended to replace the tube once a year to guarantee perfect operation.

TUNER OUT: This low impedance output is suitable for driving tuners. The signal from this output is identical to the instrument’s signal.

LINE OUT: This is a full-range output that will drive multiple power amps, extending the power of the system.

VOLUME: The VOLUME knob controls all volume in the unit, controlling the power amp and LINE output. The balanced output (XLR) is not affected by the setting of this knob.

AMP INPUT: This input connects directly to the power amplifier of the TD650. The VOLUME has no effect when this input is used.

The BALANCED OUTPUT on the EBS TD650 is a high-quality balanced output, designed to be electronically floating. It functions as a line box for connecting to PA mixing consoles or to studio or broadcast recording units. It includes several options:

Gnd Lift: Lifting ground is a great aid in many occasions. When required, set the Gnd Lift switch at the front panel to its inner position to disconnect the ground from the output.

Post Eq: The Post Eq switch at the front selects the signal source. In the inner position, this switch selects the overall sound including effects. Otherwise, in the lower position, an uncolored sound is taken immediately after the input and gain sections.

Speaker Simulator: The EBS TD650 features a speaker simulator for the balanced output. This feature is tuned together with a speaker cabinet in order to send the same sound image from the head as heard on stage. Press the Spkr Sim button to activate the speaker simulator.

The internal accelerated power amp in the EBS TD650 is of the MOSFET design, giving natural sound reproduction and high power output with exceptional clarity.

The incorporated soft clip system provides tube-like distortion characteristics, protects the power amp from saturation, and increases its output performance and sound quality.

The power amp makes possible maximum continuous power output, reducing the maximum temperature of the unit by the use of a temperature-controlled cooling system.

IMPORTANT: Make sure not to cover the ventilation cutouts on the rear panel.

Here are some sample sound settings for the EBS TD650, with knob positions described using a clock face (7 o’clock is minimum, 5 o’clock is maximum):

ALLROUND:

Character: OFF

Comp/Limit: 9 o’clock

Filter Bypass: ON

Drive: 9 o’clock

Tube Mode: Tube (inner position)

Boost Drive: OFF (outer position)

HEAVY:

Character: ON

Comp/Limit: 12 o’clock

Filter Bypass: OFF

Bass: 3 o’clock

Middle: 10 o’clock, Freq: 1 o’clock (approx. 800 Hz)

Treble: 2 o’clock

Bright: OFF

Drive: 3 o’clock

Tube Mode: Solid State (outer position)

Boost Drive: ON (inner position)

FUNKY:

Character: ON

Comp/Limit: 1 o’clock

Filter Bypass: OFF

Bass: 2 o’clock

Middle: 7 o’clock (notch), Freq: 1 o’clock (approx. 800 Hz)

Treble: 3 o’clock

Bright: 3 o’clock

Drive: OFF

SLAP:

Character: ON

Comp/Limit: 10 o’clock

Filter Bypass: OFF

Bass: 3 o’clock

Middle: 7 o’clock (notch), Freq: 1 o’clock (approx. 800 Hz)

Treble: 3 o’clock

Bright: 2 o’clock

Drive: 9 o’clock

Tube Mode: Tube (inner position)

Boost Drive: ON (inner position)

FRETLESS:

Character: OFF

Comp/Limit: 1 o’clock

Filter Bypass: OFF

Bass: 2 o’clock

Middle: 2 o’clock, Freq: 1 o’clock (approx. 800 Hz)

Treble: 2 o’clock

Bright: 9 o’clock

Drive: 1 o’clock

Tube Mode: Tube (inner position)

Boost Drive: OFF (outer position)

The following are the technical specifications for the EBS TD650 Professional 650W Tube Definition Bass Head.

INPUT

Input Impedance	1 Mohms // 100 pF
Phantom Power	10V, 20 mA max.

GAIN

Gain Range (min/center/max)	-∞ / +6 / +26 dB
Gain Peak LED	+10 dBv
Frequency Response (+0/-3 dB)	35 – 20k Hz

CHARACTER FILTER

Filter Type	Shelving High/Low Pass
Gain	+6 dB @ 75 Hz -2.5 dB @ 800 Hz +3 dB @ 6 kHz

COMP/LIMIT

Compressor Gain	0 dB
Attenuation (max)	24 dB
Compression Ratio (max)	3:1
Attack (80%) (typ)	<10 ms
Release (80%) (typ)	100 ms

FILTER SECTION

Bass Filter Type	12 dB/oct. Shelving
Bass Filter Gain Range	+/- 15 dB @ 100 Hz
Middle Filter Type	Bandpass Filter
Middle Filter Frequency Range	50 – 3k Hz
Middle Filter Gain Range	+/- 12 dB @ 600 Hz (Notch -15 dB min)
Treble Filter Type	Bell
Treble Filter Gain Range	+/- 15 dB @ 6 kHz
Bright Filter Type	High Pass
Bright Filter Gain Range	-0 / +20 dB @ 10 kHz

DRIVE SECTION

Gain Range (min/max)	0 / 34 dB
Low End Compensation (Boost off)	< 350 Hz
Modes	Solid State / Tube
Tube Type	ECC83 (European type)

BALANCED OUTPUT

Output Level (nominal)	-10 dBv
Output Impedance	< 10 ohms current lim.
Frequency Response (+0/-3 dB)	35 – 20k Hz
Dynamic Range (linear/A-w.)	102/105 dB typ.
XLR Connections	1-GND, 2-Hot, 3-Cold
Options	Pre/Post Eq, GND Lift, Speaker Simulator

EFFECTS LOOP

Loop Signal Level (nominal)	-10 dBv
Gain	Unity (1:1)
Output Impedance (Send)	<100 ohms
Input Impedance (Returns)	47 kohms // 100 pF
Phantom Power (optional)	10V, 20 mA

TUNER OUT

Output Impedance	< 25 kohms
Signal Level	As Instrument

LINE OUT

Output Impedance	< 5 kohms
Nominal Signal Level	0 dBv

AMP INPUT

Input Impedance	10 kohms
Sensitivity	32 dB (40x)

POWER AMP

Continuous/Dynamic Output Power @ 4 ohms Impedance	400 / 460 W RMS
Continuous/Dynamic Output Power @ 2 ohms Impedance	530 / 650 W RMS

AUXILIARY INFO

Power Requirements (max)	700 W
Mains Protection	T5A Fuse (230V) T10A Fuse (100/120V)
Dimensions (WxDxH)	48 cm x 36 cm x 13 cm 19″ x 14″ x 5.2″(3U)
Weight	12 kg (27 lbs.)