TZ Pedalboard 2.0

Currently, the setup can be divided in two paths:

• Path A:
  • Fender Pro Reverb.
• Path B:
  • Marshall 1987X,
  • Ibanez CS9 in the FX loop,
  • Ibanez AD9 in the FX loop.

In front of both amps are:

• Wah Vox V847,
• Ibanez TubeScreamer TS9.

Switching between the amps is realized with Lehle Dual A/B amp switch.

To eliminate the necessity of plugging and unplugging the cables during the concert, pedalboard will be equipped with inputs for two guitars and a footswitch to choose one of them.

Before we started to plan all the pedalboard i had to deal with some technical problems that occurred. The most troubling and annoying problems were:

• Lehle's switching noises, click and pops generated in the switching moment,
• Problems with cooperation between the Lehle Dual and Vox wah pedal.

Step 1 - removing the Lehle's switching noises.

Lehle Dual switch is a very well concepted device. It's sonically transparent and built with best quality components. The only one disadvantage, which is supposedly fixed in the newer versions are switching noises. The source of the problem is a switching element used in Dual - an electromagnetic relay. Relays are great as switches, but they have one unpleasant feature, they generate spikes in the switching moment which is often coupled into the audio signal. The problem was solved by designing and installing a special piece of circuitry that cuts out the spikes from the output signal and makes the switching more smooth. After the mod the switching is heard more like a quick fading between two sounds.

Step 2 - Wah output impedance buffer.

During the tests we encountered another problem. The Wah pedal did not work properly when connected to the Dual's input. The sound became useless and a low frequency oscillation occurred at the lowest position of the wah pedal. The source of the problem was the inductive character of the Dual's input (there's a line isolating transformer inside) and a quite high output impedance of the wah. Additional impedance buffer was built into the wah and the problem was completely solved.

Step 3 - planning the new pedalboard.

As in the previous version, all jack sockets used to connect the pedalboard with the rest of the setup are grouped in one box placed in the front of the pedalboard. The box is a Hammond black powder coated steel chassis.

Jacks and switches placed on the front panel are:

• G1, G2 - two inputs for two guitars,
• 3 jacks to connect the input of the amp A and its FX loop,
• 3 jacks to connect the input of the amp B and its FX loop,
• global power switch,
• global 230V AC power socket.

Placed on the top:

• 2 LED indicators showing which guitar input is active,
• footswitch G1/G2 for selecting the guitar input,
• footswitch Tune - turns on the Tuner and mutes all sounds.

Besides the in/out jacks and switches the box contains:

• high quality impedance buffer, signal splitter and a phantom power for the tuner,
• 9V DC power supply used to power the pedals placed in front of both amps (Wah and TS9),
• 9V DC power socket for future applications,
• separate 10V DC power supply to power all devices that are potential click sources (Lehle Dual, internal switching circuits),
• FX loop return signal muting modules, they keep the silence during the tuning.

The pedalboard was 3D modeled to discuss the placing of its all elements:

Step 4 - assembly.

The base of the pedalboard is Rockcase 23010A. All elements are fixed using velcro. The most important thing when putting all rig together is a proper ground and power routing, which ensures that, there won't be any ground loops resulting in low frequency hum, the switching noise is eliminated or minimized to acceptable value.

Step 5 - testing.