Tag: modular

Reverse Landfill Pentamix – DIY Build

Reverse Landfill Pentamix - DIY Build

Reverse Landfill’s unique approach to modular synthesis is something that they are becoming known for. Their cryptic silkscreens on their panels also makes for some interesting patching if one is unfamiliar with the modules. The Pentamix is one of Martijn’s newer modules that helps bring all of the other Reverse Landfill modules together.

A 5-channel audio mixer, the Pentamix’s real magic happens when you patch the inverted output and use the another output to send out to an effect and then back again into the Pentamix.

With its 555 pentagram, this mixer brings a new dimension to ones rack… but enough about the module, let’s get onto the build… 

Resistors and Diodes...

Start with the resistors on this build. There are not very many of them (12 to be exact) and their polarity doesn’t matter. Each resistor set is marked so its easy to figure out what goes where if you can read a BOM.  You can find all of the Pentamix’s documentation on the Reverse Landfill website for quick reference. 

Diodes are next and one thing we love about Martijn’s modules is the extra power protection. The diodes (x2) will protect your module if the power is reversed for any reason. The 2x resistors next to the diodes are there for extra protection. One thing to know about diodes is that their polarity does matter. You want to be sure that the black line on the diode lines up with the silkscreen on the PCB. A quick tack down of these and its time to move onto the IC sockets and caps. 


Synthrotek VERB – DIY Build

Synthrotek VERB- DIY Build

As described by the Synthrotek site, “the Synthrotek Verb is a reverb module like no other. This three PT2399 unit offers a warm tape saturated spring reverb like sound but with the added flair of the subtle modulation which truly makes it shine.” This was enough for us to decide to take on the VERB on for the next build of September 2020.

Unlike a lot of other reverb modules, this one does not require a “tank” to produce its reverb. It relies on the x3 PT2399 circuits that were previous utilized in other delay modules. 

The PT2399 is back … again.

We won’t go into all of the technical jargon like we have in previous builds (see Synthrotek DLY and Waveform Magazine Delay builds), but we will say that the PT2399 is a very versatile IC. It can be used for delay’s, echo’s and even reverbs (as this module uses them).

To keep it simple, the IC takes in analog audio input and converts it into digital stream of bits to add a digital delay to it. This audio delayed audio signal is then provided as output (ie. perfect for these module types).

On with the build ...

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Synthrotek DLY (Delay) – DIY Build

Synthrotek DLY (Delay) - DIY Build

Synthrotek DLY Kit

Delay, echo, reverb and distortion are all common effects for synthesis and in the world of modular synthesis, they make all the difference in the world. Synthrotek have had a long history of effects modules in their lineup and the DLY module is one of their finest.

The DLY is a PT2399 based delay module that can be dialed in to fit the users preferred range of delay due to the independent rate control. 

Another rad feature of the module is that unlike the ECHO module by Synthrotek, the DLY has a true wet/dry mix knob, giving the module its unique character and allowing it to be chained within the effects loop. Since fall was upon us, we decided to take on a couple of the companies legendary effects modules for our latest builds.

The PT2399...

Before we jump into the build video and all that jazz, let’s revisit an old friend of ours.. the PT2399 IC. You might recall a previous build of the Waveform Magazine PT2399 Delay module, where a karaoke module was converted into a delay module.

The Synthrotek DLY utilizes the same chipset. Aforementioned in the Waveform build, the PT2399 is a CMOS echo/delay processor developed by Princeton Technology Corp. It includes an ADC (Analog to Digital converter), 44Kb of RAM to store the samples and a DAC (Digital to Analog converter).

This chip was created as a simple solution to add delay/reverb/echo to karaokes and set-up entertainment systems. What does this all mean? This means that the chip is a perfect candidate for a delay module and the gang at Synthrotek decided to base a module around it.

Onward with the build ...

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Passive Multiples – DIY Quick Builds

Passive Multiples - DIY Quick Builds

Completed Passive Multiples

In the world of modular synthesizers, multiples are a staple in any system. While there are many different manufacturers of multiples, their primary function remains about the same. They are used to duplicate a signal to send it somewhere else in your system. The most common type of multiple is known as the passive multiple, or quick multiple being that it does not require power to function. They are basically a bunch of jacks wired together with no circuitry between them. You plug in your input in one jack and it sends to a series of outputs. It is that simple. 

Passive multiples not only come in a modular form (1U, 3U, 5U etc) but they come in other shapes and sizes. Jumper cables (or stacking cables), passive stars or trees are also other types of multiples. One of our featured previous builds was the Catwalk Series from Waveform Magazine. This was a very unique take on the passive mult being that it did not take up any space in our rack. It simply mounted on top of any other module to act as a  quick bridging module. It is definitely one of our favorite passives to utilize.  Basically, a passive multiple can be anything that can output to more than 1 output jack that takes no power.

~ Pure simplicity at its finest ~

Now, with all this talk of passive mults, there are some downsides to using them. Since they are not powered, unwarranted results could occur with internal circuitry or with throughput to other modules. Some modules have circuitry that is internally buffered and if you patch to one or more outputs, the output voltage could ultimately change causing a drop in signal or wave shape…. but we aren’t going to get too much into that.


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