More information about Paradox TZF2 Green
Redesign
While preparing to bring Paradox TZF2 back into production, I took the
opportunity to redesign the circuit boards for easier assembly and to
accommodate different parts. While I was at it, I made a couple of changes and
added some features. These include Envelope controlled speed, Stereo outputs,
and Buffered bypass.
Envelope
Controlled Speed
Create speed variations with the dynamics of your playing. To
do this, set the Ramp selector switch in the center position. Turn the SPEED
knob down and increase the Envelope knob while making sound. You will see the
speed LED blinking faster. When Envelope Controlled Speed is selected, the
SPEED knob can be used to set the slowest speed. Also, the RAMP activation
switch is disabled.
Stereo Output
The output jack carries a
stereo signal that can be connected to a stereo plug that splits the output to
two amps. The stereo field is the product of the fixed delay, same polarity at
both outputs, mixed with modulated delay with opposing polarity at the outputs.
One side gets a negative flange while the other side gets a positive flange.
Switching the polarity switch will swap sides. Summing the two signals will
cancel the effect completely. Note: Paradox TZF2 Green is not a true-stereo
pedal and it does not process stereo signals. You can order a breakout adaptor here, or you can order the Amazon part on your own. Hosa YPP-117 1/4" TRS to Dual 1/4" TSF Stereo Breakout Cable
Buffered Bypass
After making the original Paradox TZF with true bypass relays, and TZF2
with a true bypass foot switch, I decided to make TZF2 Green with buffered
bypass. The noise reduction circuitry never played well with true bypass, and I
don’t have a lot of faith in the stereo true bypass switches (4PDT) that are
currently around as far as reliability and continued availability. TZF2 Green’s
buffered bypass is clean, quiet, and will drive your signal down the chain like a
good buffer should. The foot switch used is a standard SPST, click on/click
off.
About the
Paradox TZF2 design
To get the
through-zero effect, two analog delay lines are required. One is a fixed delay, which offsets the reference signal in time. The modulated delay is able to sweep through delay times
shorter and longer than where the fixed delay is sitting. This is how the
through-zero effect is created. The original Foxrox Paradox TZF (2002) was the
very first flanger pedal to create this effect. Prior to that, you would need
to carefully configure multiple delay units to get the effect in real time. Otherwise
the only way was during mix-down, using parallel tape decks.
Running two
analog delay circuits in one pedal creates the potential for oscillation. The
oscillators that drive the delay lines run at different frequencies and they
sit in close proximity, inside the pedal. The frequencies are above the hearing
range, but when they mix together they can create artifacts that sound like
whistling in the background. The correct term is Heterodyne, and it’s commonly
heard in AM radios.
Because of
the potential for oscillation, Paradox TZF2 uses an elaborate noise reduction
scheme as well as extensive power supply filtering. The noise reduction
includes pre-emphasis/de-emphasis as well as input/output companders for each
delay.
Whistling sounds (oscillation)
Even with
all of these precautions, there are situations where TZF2 can interact with
other sources that can result in audible oscillation or noise. These include:
1) Digital devices. Most will be fine, but some of them put out a lot of high
frequencies and you may run across something that just won’t play well with
TZF2. One example - My Digitech Jamman looper puts out so much digital noise
right above the hearing range that it disables the noise reduction in
TZF2. The same is true for my Soundcraft Notepad mixer. Other devices, like a Boss digital reverb and a DOD digital delay cause no problem at all.
2) Fluorescent lighting. I once spent hours troubleshooting an oscillation problem
while setting up gear in my shop. When I got to the gig, the problem was gone.
Back in the shop, it’s gone...until I turned on the fluorescent lights over my
work bench! I discovered that they not only caused oscillation in my flanger,
they also caused noise in all of my drive pedals.
3) Digital
(switching) power supplies. I have found that the currently available digital power
supplies are very quiet, but there are older ones out there that can cause all
kinds of noise in pedals. If you have oscillation or noise problems in your
system and you use wall wart adaptors, that’s where you should start your
trouble shooting. A power supply running in parallel (daisy chain) with other devices can also be the source of noise and oscillation.
4) Cables
and wire routing. If you have old, flaky cables and patch cords, there’s a
chance you could experience noise and oscillation. If these wires run side by
side with power supply wires, it can get pretty bad. Try rearranging wires and swapping them around.
TZF Plug-in
module
The delay processing
and noise reduction circuitry is all located on a plug-in module. This includes
the MN3007 BBD chips and the compander circuitry. Careful parts placement,
circuit routing and many hours of design work and prototyping went into getting
this module right. This kind of analog circuitry is prone to audible
distortion, noise and oscillation and no corners were cut in order to minimize
or avoid those pitfalls completely.
Due to their
delay range, the MN3007 analog delay chip was chosen as the delay for all of
the Paradox TZF pedals built in the past. In today’s world they are rare and
extremely expensive, if you can find real ones. There is a huge offering of
counterfeit MN3007s going for low
prices and the ones you’ll find on eBay are almost all fake and do not work. Some
of them actually function as MN3207, but will heat up and burn out if you try
to apply power because the chips are not voltage-compatible.
For these
reasons, I custom-ordered a batch of MN3007s made by Xvive. These are
authentic reproductions, not cheap counterfeits. I confirmed first hand that they
perform and sound exactly like the vintage parts, and thanks to modern
standards, they are much more reliable. They are 100% compatible as replacements for pedals that rely on the original parts made by Matsushita/Panasonic.
In the unlikely event there is a problem with a Paradox TZF2 and it seems like it’s on the TZF Plug-in module, it can be swapped without having to send the pedal in for
repair. The original-model TZF2s (purple) use a very similar module, however they
are NOT interchangeable.
This is an original MN3007, manufactured by Matsushita, decades ago. These are hard to find and very expensive.
This is a new-production MN3007 manufactured by Xvive. Aside from their appearance, they are identical to the original parts. And they are also quite expensive.
The first TZF2s are being built with vintage Matsushita MN3007s that I had in stock from the original run of Paradox TZF2. Once they are used up, production will pause. We are expecting a shipment of new MN3007s from Xvive at the end of June, 2023. After that, the chips will be plentiful and production will pick back up.
[ITEMPRICE]