Download Stereo Spring Reverb/Valve Amplifier User Guide

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Stereo Spring Reverb/Valve Amplifier User Guide
Controls and Switches
P1: MASTER DRIVE
Potentiometer P1 controls the level of the signal that enters the low power valve which drives
the reverb ‘tank’. In low settings the sound is smooth and warm. As P1 is turned up, output
stage valve distortion takes place. A characteristic feature of this unit is that the ‘spring’ in the
‘tank’ is part of this distortion if required. At high P1 settings the sound distortion can be
harsh and intense. TREBLE CUT switch S3 can be used to remove harshness.
S1: INPUT GAIN SWITCH
In conjunction with P1 it enables a more detailed control of the drive gain mentioned above.
P2: AMPLIFIER CONTROL
A mini power valve amp drives the ‘REVERB TANK’. This amp in high P1 settings also
produces non-reverberated valve distortion type of sound, similar to a distortion unit. This
distortion can be anything from smooth to crunchy to extreme. Again it all depends on how
S1/P1 are set. Control P2 mixes the output signal from the output transformer of this amp
before it reaches the input of the ‘REVERB TANK’.
S2: BASS CUT SWITCH
P3: REVERB CONTROL
This control mixes the reverberated signal coming from the reverb return valve amp.
S3: TREBLE CUT SWITCH
Only affects the reverberated signal.
P4: ORIGINAL
Mixes the original, i.e. ‘dry’ signal. So by using P2/P3/P4 any combination of the AMP,
REVERB, and DRY signal can be obtained.
S4: EFFECT ON-OFF
It disconnects the unit-modified signal and brings out the original for comparison.
P5 MASTER OUT
Controls the output level of the unit.
© Theo Argiriadis March 2005
www.tube-electronics.co.uk
S5: TRIODE/PENTODE SWITCH
In triode mode the sound is more transparent & smoother, whilst in pentode it is harsher,
more trebly and distorted.
S6: MAINS SWITCH
When this switch is turned on, the valve heater and the mains LED will light up. See diagram.
S7: STANDBY SWITCH
This must be turned on approximately half a minute after the mains switch S6 has been turned
on, to allow the valves to warm up before the ‘HIGH TENSION (HT) is applied. High tension
is an old terminology for high voltage. When S7 is turned on the HT LED will light up.
Finally, at the rear panel there will be one rotary ‘REVERB TANK INPUT IMPEDANCE
SELECT SWITCH’ per channel, so that most types of available tanks can be used.
© Theo Argiriadis March 2005
www.tube-electronics.co.uk
STEREO SPRING REVERB FRONT PANEL
P1
S1
P2
S2
P3
S3
P4
S4
P5
S5
S6
S6 Mains may not be on
the main unit but on the
power supply box
1
MAIN
LED
Master Drive
Input Gain
Amp Control
Bass Cut
Reverb Control
Treble Cut
Original
Effect on/off
Master Out
Triode/Pentode
S7
2
Standy By
HT
LED
Power Supply Section
The 2nd channel is identical to Ch.1
P1
MAIN INPUT
INPUT
STAGE
(HYBRID)
LOW
POWER
VALVE
AMP
S1
S2
TO REVERB
TANK INPUT
OUTPUT
TRANSFORMER
P4
DRY SIGNAL
(ORIGINAL)
FROM REVERB
TANK OUTPUT
OUTPUT AMP
SIGNAL
IMPEDANCE
SELECT
SWITCH
P3
REVERB RETURN
VALVE PRE-AMP
S3
REVERBERATED
SIGNAL
P2
MIXER AMP
(HYBRID)
P5
OUTPUT
BUFFER
S4
SPRING REVERB BLOCK DIAGRAM
MAIN
OUTPUT
OUT
© Theo Argiriadis March 2005