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Vienna Chorus FAQ

Can you explain how chorusing works?

The choral effect is created by splitting two signals whereby one is delayed and modulated by an internal clock. When the two signals are brought back together, they interact creating the chorus effect. Changing the speed of the clock and intensity lets you set the chorus from a slight effect to intense.

What is the difference between analog and digital chorus?

Digital chorusing works by converting the analog sound into digital, creating the effect in the digital domain and then returning it back into the analog signal path. The Vienna Chorus is 100% analog. This means that we create the choral effect using old, discontinued analog bucket brigade chips to store the signal and delay it, thus retaining the analog signal throughout the process.

How would you characterize the difference in tone?

Digital chorus pedals like the Boss CE5 provide a wide frequency response with more bass and more top end while the Vienna is more focused in the mid range. Digital chorus pedals are equipped with filters to remove the top end and bass so that the sound better approximates the sound of an analogue chorus. Both sound great depending on what you are looking for.

Why do some guitarists prefer the sound of analog chorus?

When you convert the signal to digital, you literally remove the guitar from the signal path. It essentially changes the feel of the guitar which for some just does not cut it. Try playing your guitar through a Marshall JCM800 and then connect to a modeling amp and you will immediately understand. Both are good… one is more organic.

If analog sounds better, why are most chorus pedals digital?

Several reasons: First is noise. Analog chorus pedals tend to be extremely noisy and getting rid of the noise is painstaking to say the least. It took us three weeks to figure out the design and over a year to get rid of the noise. Most companies will abandon the effort by going digital. The other problem is that these bucket-brigade chips are no longer being produced. They have been replaced by 'computers'. And with the advent of the lead-free initiative called ROHS, if not properly addressed, using old chips can be a problem.

Is the Vienna ROHS compliant?

Yes. All components inside the Vienna are 100% compliant except the Panasonic MN3007 bucket brigade chip. This has been socketed so that it can be removed. Should someone decide to discard the Vienna, Radial will buy back the chip so that it does not end up in a landfill.

What happens if the chip in the Vienna stops working? Can I still get parts?

Yes. We have stockpiled thousands to build these products and support customers should a ssrvice replacement be required.

Can you explain the 'Turbo mode' feature?

The usual chorus effect is created using a triangle wave to modulate the signal. With Turbo mode, we change the clock frequency and modulation to create a more radical effect. It both widens the tone while increasing the effect. It's fun!

Does the Turbo mode affect both channels?

Yes. But the depth range is sufficient that you can turn the effect way down on one channel if you are trying to create two very different effects such as a slight choral on channel-A and an intense warble on channel-B.

Why is the Vienna Chorus mono?

Most guitar players use one amp on stage. And for the most part, those that use more than one amp also use an ABY selector like the Switchbone, Twin-City or BigShot ABY to select the amps. ABY switchers take a mono input and split it to the amps. So the only time one could possibly use the stereo out from a chorus would be if one is using two identical amps in stereo all the time. We felt that given our goal to make the Vienna as compact as possible, having two channels would be more advantageous than having a stereo output which would rarely if ever be used.

Is the Vienna True-Bypass?

No. Chorus pedals – whether analog or digital – require buffering as part of their circuit so that they can mix the modulated signal with the original guitar tone to create the effect. Hard switching such as a true-bypass would introduce a loud pop or transient into the signal path when the pedal is activated. The Vienna employs EIS – Electronic Impulse Switching – to eliminate the mechanical aspect of a switch that tends to cause problems over time. This ramps up the effect so that the transition is inaudible.

What is EIS Electronic Impulse Switching?

Although the switches on the Bones look like regular switches, they are in fact special non-latching momentary switches that activate an internal electronic switch which does the actual signal switching. Because this avoids mechanical switching, problems such as wear and tear, or contacts sticking, are significantly reduced. The result: you get longer trouble-free switch life.

How can I achieve true-Bypass with a chorus pedal?

If you are adamant about true-bypass switching, then a better approach would be to employ a tool like the BigShot EFX effects loop insert pedal. This is designed to pull all of the pedals out of the signal chain when not in use for true-bypass performance.

Can I use the Vienna Chorus with bass or other instruments?

Yes of course. It sounds great on bass and amazing on acoustic guitar. If you are using an active bass, guitar or keyboard, make sure you do not overdrive the input beyond the range. If you hear distortion, turn down your instrument to compensate.

Where is the best place to position the Vienna in a pedalboard chain?

Most modulating effects like phase shifters, flangers, delays and chorus pedals sound better when placed after distortion pedals. So as a rule, one would start with a wah or fuzz, then distortion, then chorus and then ABY selector.

Can I use the Vienna with a 9V battery?

No. It is designed to be used with a Boss-style 9V power supply which is readily available at all music stores. When pushed hard, batteries quickly go dead and are not eco-friendly.

How close to the Boss CE-2 is the Vienna Chorus circuit?

They both employ the same identical Panasonic bucket brigade chips, but we have improved the modulation circuit to allow you to increase the effect and worked extensively at lowering the background noise.