Pepper Shredder 60
Pepper Shredder 60
As the LoV series comes to a close, the Pepper Shredder now comes into play with an extra dose of spice.. Like the Sugar Box, the Pepper Shredder is a full-featured tube preamp that feels most at home working directly with a power amp or in front of a low-gain amp. The power for the two 12AX7/ECC83 tubes is again supplied by the VPump60, and the entire circuit is housed in a compact stomp box.
Due to the combination of the individual stages and the boost functions, four different sound variants are possible, all of which build on each other or are dependent on each other, which makes the circuit itself and the handling of the Pepper Shredder a bit tricky, so you have to get to know the Pepper Shredder a bit better to be able to use it effectively.
So let's take a closer look at the setup: The first stage is always on (if the setup follows our standard plan). The special thing about this stage is that the cathode resistor is adjustable and thus the gain can be set. This stage is the basis and influences all following stages and thus the total gain of the whole preamplifier. If you now switch the preamp "on", the signal is routed via the switch S1 to the two following stages, which are mainly responsible for the overdrive. After the third stage is the tone control, which is almost completely borrowed from the Marshall 2555 and offers a very wide range of tonal possibilities. After the tone control comes the fourth stage, which is responsible for boosting the signal to the desired output level and driving the power amp.
In addition to the adjustable cathode resistor, the first stage has a switchable bypass capacitor. This can be switched on and off with a footswitch. Since this bypass capacitor is always active even when stages two, three and four are switched off, there are four possible settings:
Stage one on and boost off: Gain adjustment via the variable cathode resistor.
Stage one on and Boost on: In this position, a significant increase in volume and overdrive is possible.
All stages on and Boost off: In this position, the full function of the tone control, the gain potentiometer and the master is available.
All Stages On and Boost On: Further increase of gain and volume.
Depending on the setting, the boost will be more or less audible. If you are already working with maximum overdrive, the effect of the boost is relatively small. If, on the other hand, you are playing with reduced overdrive in the basic setting, the influence of the boost is much greater. So: Try different settings - it's worth it!
If you like, you can also connect the S1 before the first stage. In this case, the guitar signal is completely bypassed by the preamp in the "Off" position and the first mode is omitted in the settings described above.
For further fine-tuning of the Pepper Shredder, we recommend that you take a closer look at the circuit and try some different component values, such as the cathode resistors or the coupling capacitors of the first three stages. In this way, further adjustments to personal needs are possible.
The entire preamplifier is largely built on a prefabricated circuit board, which greatly simplifies rebuilding. However, this should not be underestimated, especially when connecting the many potentiometers and the footswitches, if you are not careful, you will have spent a lot of money. But you grow with challenges.
Finally, a note on usage: Since the Pepper Shredder is a full-fledged tube preamp and not an effects unit, the best sonic results are achieved in combination with a pure power amp - whether transistor or tube - or in conjunction with a "low gain" amp. Trying to overdrive a "high gain" amp with the Pepper Shredder often leads to disappointing results. This is not due to the Pepper Shredder itself, but to the combination of two independent preamps in series. This phenomenon can also be observed in combination with other preamplifiers.
Schematic and Layout (DIN A4, 4 Pages PDF)
As mentioned at the beginning, the Vanilla Overdrive 60 is operated with an anode voltage of 60 V DC, which is generated by a modified VPump. A simple 12 V power supply is needed to operate the VPump, which should supply about 1 A of current. The 12 V DC voltage from the power supply is also used to power the tube heaters. There are no special requirements for the power supply, most switching power supplies should be able to be used without problems.
How To Build it
Everything is built on a circuit board in the chassis ch038. The components needed for this project are available in the TT-Shop as a kit
- Before installation, check components for correct values using a multimeter
- for components with polarity, e.g. electrolytic capacitors, pay attention to the installation direction
do not leave cables too long
- use suitable tools, especially soldering irons; soldering guns are usually unsuitable
- pay attention to clean soldering joints
- work carefully and think first, then act
- and if something does not work, do not immediately assume that a component is defective, but try systematically to isolate the fault