Let's have a look at the Doepfer A-101-8 Photo Phasing, a Eurorack
phaser module. Doepfer's website also calls it the Opto Phaser,
which sounds even cooler. Why "opto"? It uses little lights to modulate the
phasing effect. They're housed in a black box on the back of the module,
although at least on mine the box isn't quite light-tight:
But then again it spends most of its time in the darkness of a Eurorack case.
I have to admit that I know nothing about electronics. Why does the A-101-8
have little lights? Why not a wire, or a digital circuit? I have no idea.
The A-101-8 is a clone of a 1970s effects box by a chap called Gert Schulte
called the Compact Phasing A, which used
little incandescent lightbulbs
to control the intensity of the phaser. Apparently the lightbulbs had a tiny
little delay before they lit up, which smoothed out the peaks and troughs of
the phasing effect. Fascinating stuff. This video does a very good job of demonstrating the original, which has a
sound I would describe as delicate and surprisingly transparent, to an extent
that it's tempting to send everything through the effect - synth, drums,
guitar, everything:
Phasing was new and exotic at the beginning of the 1970s, and for whatever
reason the Compact Phasing A caught on, at least in Germany. It's all
over a clutch of classic 1970s kosmische musik albums, presumably
because it was a local product, and was thus the first thing Edgar Froese and
Ralf Hutter saw when they popped into the local music shop. It makes a
memorable appearance towards the beginning of "Birth of Liquid Plejades" on
Tangerine Dream's Zeit, where the band use it to phase some
cellos. Tangerine Dream went on to plaster it all over Phaedra,
where it made their Mellotrons sound like outer space, and later the same year
Kraftwerk's Autobahn seemingly had everything fed into the phaser
bar the vocals.
It's an addictive effect, a lot like a flanger but less metallic, more
ooshy-sounding. In particular the Compact Phasing A has a wide phasing
range, so it tends to sound normal normal normal PHASING! normal normal normal
PHASING! rather than non-stop phasing. Even when it's unsubtle, it's subtle.
Doepfer already sells a phaser, the A-101-3, but it's huge, taking up 30hp,
whereas the A-101-8 is only 4hp. It was announced back in 2023. It's a
Eurorack module, but it can process external inputs just fine, so you can use
it as a general phaser effect, although you'll need a way to power the module
and some way to provide modulation.
In this image I've installed it in a smaller case, as part of a one-oscillator
mini-synthesiser:
They say that modular synthesisers are addictive. Just look at the little modules.
They aren't expensive individually, but the cost mounts up. And before you know
it, you need a bigger case. Or a second case. And there's a gap in the
second case, so you need to fill it with more modules. Then you're homeless.
But look at the blanking plate. Look at the blanking plate. The 8hp blanking plate, and the 1hp blanking
strip next to it. Those two plates are the sign of reason. That was the point where my sensible
brain held up its hand and said "no more". Let it be known that I amassed
207hp of Eurorack modules and STOPPED. Why? Because I, ASHLEY POMEROY, OUTRANK
TRANK.
I stopped. I stopped buying Eurorack modules before I plunged myself into financial oblivion. Admittedly I did buy the Doepfer A-101-8, which is the subject of this post, but that was a one-off. I haven't bought any other modules since then, which was eight days ago. I have an iron will. I can stop. I have stopped. I outrank trank.
Most phasers, including the original Compact Phasing A, use a
sinewave LFO to make the effect gradually pulse in intensity, but the A-101-8
will accept any modulation input. In the following video I also use gates run
through a sample and hold module to trigger the effect. If you use a square
wave LFO the end result sounds like someone tapping on a wah-wah pedal.
The controls are self-explanatory. The MANUAL knob manually controls the sweep,
and applies a baseline level of modulation. The CV knob controls the power of
the control voltage input on the modulation. The FEEDBACK knob controls the
amount of output signal that feeds back back into the module. The effect is subtle
until around the 3 O'Clock position. Any higher than that and
the A-101-8 outputs an unpleasantly loud shrieking noise.
Why are there three red LEDs on the middle PCB, just underneath the MAN and CV
knobs? Again, I have no idea. If I had been transmitted back to the Middle
Ages I would have been unable to jump-start Britain's electronics industry.
Doepfer sells a dedicated pre-amp, the A-119 External Input, but for
all the demos on this page I connected my audio interface directly to the
module with a 3.5mm patch cable and a mono 3.5mm / 1/4" jack adapter, tweaking the input level knob to suit.
There are two outputs. Output 1 is the original signal plus phasing. Output 2
is the original signal plus feedback. If you plug both outputs into two
channels of your mixer or audio interface the end result is a sweepy stereo
effect, and so I tend to use the A-101-8 as the final module in the signal
chain.
Here's a tune that uses the A-101-8 extensively, on the bassline and G-Force's
M-Tron. It's a pastiche of Tangerine Dream's style at the very end of the
1970s, beginning of the 1980s, as they were switching from analogue to
digital, albeit with simpler sequencing. Think of it as the theme tune to an
imaginary action TV show starring a cop who has a souped-up fax machine:
I mean, Streethawk had a motorcycle, Knight Rider had a car, Airwolf had a helicopter. And The Highwayman had a truck. Nobody had a fax machine. Fax machines were huge in the 1980s, but I don't recall a single television crimefighter who had a souped-up fax machine. Imagine the scene. The criminals burst into the secret lair of our hero. They raise their guns... and then the fax machine shoots out paper at supersonic speed, cutting the guns in half. The criminals raise their hands and surrender. I think the idea has potential.
Still, that is the A-101-8 Photo Phasing. It has a distinctive sound, subtle and delicate. It's surprisingly versatile, and of course if you want to sound like Kraftwerk or Tangerine Dream circa 1974, it will do that. Bad stuff? Mine picks up electrical interference from my wi-fi hub. So I moved the case slightly further aware from the wi-fi hub. Problem solved.
You know, a phaser is like a little roller coaster ride. One moment you're
trundling down the track, and then you do a loop, and then you're trundling
down the track again. The anticipation is exciting.
