TECHNICAL INFORMATION

o    BRITISH MADE

TwinStomp products are designed and manufactured in Shropshire, England using only the best materials available. All products meet the EC Council Directive 2004/108/EC Electromagnetic Compatibility requirements and are RoHS compliant using the strict component and materials controls. 

o    CIRCUIT

TwinStomp BOOSTER MkII and ACTIVE A/B-Y MkII pedals both use improved versions of the Mosfet Booster circuit popularised by Jack Orman.  The circuit is the best for providing clean boost without colouring your guitar's basic tone.  It is not an overdrive circuit because it does not produce artificial overdrive, however the gain from this circuit is able to push valve amplifiers into creamy / crunchy overdrive sounds and is therefore a must for valve amplifier owners.  It also allows very clean boost for any guitar pickup to compensate for line losses and provide more volume into any type of amplifier - guitar or bass - valve or solid state. 

On the standard BOOSTER MkII the modifications allow for the provision of 2 independent boost output settings and for the power source line to be switched.  The adjustable gain boost channels are designed to give x2 to x5 Voltage Gain (5dB - 15db) on Channel 1 and x2 to x13 Voltage Gain (5dB - 22.5dB) on Channel 2 as standard.  Note: Up to 22.5dB is guaranteed on Channel 2, most units offer significantly more.  Reduced gain levels can be supplied to special order.

Our booster provides very even gain throughout the audio frequency range ensuring that the guitar's tone is retained at all gain settings.

The ACTIVE A/B-Y MkII pedal provides just a little clean boost (up to 4db in A-B mode and 4db in Y mode) to compensate for line losses and provide sufficient headroom to allow balancing and volume control at the pedal.              The compensation is designed to ensure that the settings you make to each amplifier are the same when switching to Y mode.

TwinStomp S21 OVERDRIVE has a unique TwinStomp Effects designed circuit using a dual op-amp for both overdrives whilst minimising the semiconductors through which the guitar signal passes, allowing crystal clear amplification. 

o    COMPONENTS

TwinStomp products only use the highest specification components purchased from reliable sources.  Manufacturers data sheets are available for all items including wiring and insulation materials.

        -    Semiconductors

              Fairchild, Texas Instruments and Vishay are specified.

        -    Capacitors

              High specification polyester film capacitors are used for signal transmission.

              Ceramic capacitors are used for RFI suppression and feedback.

Aluminium film electrolytic capacitors capable of carrying well in excess of the service voltages are used for smoothing and gain control.

        -    Resistors

              Metal or carbon film resistors are used for voltage control.

        -    Potentiometers

              Only Alpha potentiometers are specified.  Extremely smooth and reliable.

        -    Jack Sockets

              Only Neutrik sockets are specified. Our experience has shown these to be extremely robust and the most reliable.

 -    Switches

3PDT Stomp switches are Electro Harmonix style which have been found to be extremely reliable.

Power on-off switch is a UL approved DPDT toggle with silver plated contacts and parallel wired for reliability.  Power on-off surges are limited by a smoothing circuit.

             The 9Vdc power connector/switch is rear mounted to allow quality soldering of the connections out of the case.

             Reverse voltage protection is provided.

o    WIRING

All connections are "Hand wired".  In order to minimise junction connection problems no crimp or push-on connectors used in the construction.  Inter PCB wiring is supported by threading through clearance holes in the PCBs to ensure that the connections are not under any strain at any time.  Wiring to switches and sockets is held firmly by cable ties. There are no switches in the signal path.

o    SOLDERING

      Lead free solder is used throughout and is specified on components.

o    PCBs

TwinStomp pedals each have two printed circuit boards manufactured by a UK ISO9001:2008 approved supplier on FR4 glass material to provide rigid and reliable fixing for components.

o    CASE / ENCLOSURE

The case of TwinStomp products is investment cast to high precision in stainless steel.  This ensures that all sockets and switches have excellent electrical contact with the case and provides good screening against air borne noise.

The case is extremely strong and provides mounting for non-slip rubber feet.  These can be removed to provide mounting holes for fixing the case to a pedal board.  The case will support the weight of a 4 x 4 vehicle without crushing.

The case is extremely corrosion resistant with a finish that will last forever.

o    UNIQUE BATTERY HOLDER (Patented GB 2449236)

Because all TwinStomp effects pedals sound slightly better when battery operated, with less stage clutter, we have developed a unique method of accessing the 9 volt PP3 battery.  On our effects your battery can be replaced without removing the base of the case and without requiring any tools.  This means that your pedal can be permanently fixed to a pedal board and you still have access to the battery! 

Why do most effects sound slightly better when battery powered?  There are two main reasons:

-    Battery supply voltage although gradually reducing as the battery discharges is very smooth.  A 115Vac or 240Vac mains transformed 9Vdc supply will always have a small amount of 50 or 60 Hz or harmonic ripple.

-    We recommend 9Vdc power supplies which have a fully isolated 9Vdc line and 0V return.  On cheaper un-isolated power supplies you may have a double earth (ground) return path.  One earth (ground) path through the return screening of the guitar lead, effects lead and guitar amplifier and a second earth (ground) path through the return of the 9Vdc power supply.  This may cause earth (ground) loop noise, which is solved by using quality isolated power supplies.

o    9dc VOLT SUPPLY

Although we advocate the use of TwinStomp products with 9 Volt PP3 battery we do provide a 9 Volt dc supply input socket. 

This socket can be used with an external 9Vdc source, either battery or mains operated and the PP3 internal battery does not need to be removed as the socket has an internal switch to disconnect the battery.  However please note - A FULLY DISCHARGED BATTERY SHOULD NEVER BE LEFT IN THE BATTERY HOLDER AS BATTERY LEAKAGE WILL DAMAGE YOUR CASE!

TwinStomp products have reverse voltage protection and smoothing in the 9dc volt supply circuit in order to eliminate On-Off switch noise and these features also provide additional smoothing for the working circuits.

o    TESTING

Pedals are fully tested twice, before and after assembly into the case.  Every pedal has a full functional test into quality valve and solid state amplifiers in addition to wave form testing using a Function Generator, Oscilloscope and Digital Voltmeter.

We supply the main test results on the Test Certificate supplied with each pedal.   Each pedal is permanently Serial Numbered and we keep full build configuration and test results on our data base records.