The JKJ Electronics CV-5


Quite sometime ago, I acquired a JKJ Electronics CV-5 for use with my EML-400/401. While I had plenty of experience with Kenton's ProSolo, I needed a solution that would track at the 1.2v/oct that the EML required.

I figured that I'm long past due in sharing my thoughts of the CV-5.

For reference, I'm referring to JKJ Electronics. Kyle Jarger is the owner and king geek.

First Thoughts

Coming out of the box, the first thing that I noticed about the CV-5 is it's size. It's clearly the largest single channel MIDI->CV convertor around, measuring 6.3" W X 3.0" H X 9.9" D. While not as compact as the competition, it's physical size serves to hint at the power under the hood.

Plugging in and setting up was a breeze. When Kyle shipped the CV-5, he knew that my target application was the EML, so he pre-scaled the box to 1.2v/oct. Firing up the box only involved plugging in the wall wart, and running a pair of 1/4" cables for CV and GATE to the EML, and then running the Audio_OUT from the EML to the CV-5...

Huh? You run the audio back to the CV-5?

Yep... The CV-5 has a panning circuit built-in... Run a mono signal in, and then run the Left and Right OUTs from the CV-5 to your mixer. By default the CV-5 will listen to MIDI PAN_POSITION (MIDI Controller 10) and react accordingly. This is VERY cool... More later. :)

Using the CV-5

As any good MIDI->CV convertor should be, "using" the CV-5 is brainless. Set the MIDI channel via the front panel rotary switch (1-16, no OMNI mode), head for your master controller, and start playing. The GATES gate, the CVs fly, the mod wheel modulates, and you're happening. :)

The fun of the CV-5 comes from the various modulation options, controller assignments, panning control, and 2nd channel features... Yes, there is an interesting 2nd channel hiding under the hood here.


The special features of the CV-5 are best set out in a bullet-point fashion, there are many things to set this convertor apart from the rest.

  • LFO from Heaven
    The main LFO in the CV-5 offers 13 different waveforms to choose from, including a very cool "8-stage" set. If you run one of the 8 stage waveforms to the Filter CV, you can get a much more interesting effect than merely sweeping the filter cutoff with a static waveform. It's a bit hard to describe, but there's more "life" to the sweep. The LFO has very smooth waveforms, even at high speeds.

  • Dedicated 2nd LFO for Vibrato
    There is a second LFO in the unit which can be used for vibrato. This is a fix frequency Triangle wave running at 6hz. This is a very welcome addition since it frees up the main LFO for doing various special case work such as Sample and Hold effects or sync'd ramp sweeps.

  • Simultaneous GATE/S-Trig
    Both voltage GATEs and Switch Triggers are available at the same time on the machine. This is great for complex setups where you want to trigger an envelope on a machine that is different that your primary synth.

  • Additional MIDI->CV Resources
    Under the hood in the CV-5 is a variety of additional MIDI->CV conversion. There are three additional CV outputs which can be configured in a number of different operating modes. These are in addition to the dedicated main channel pitch and filter CV outputs:

  • AUX - C16 & C17
    In this mode, you are given three additional CV signals which you can route in and around your synth. The CV outputs are set to track the AUX controller, and MIDI controllers 16 and 17.

  • Duophonic CV
    In this mode, two outputs remain assigned to MIDI controllers 16 and 17, while the third CV out is used to handle duophonic synths. The 2nd CV out will track the lowest MIDI note being played, while the primary CV out will track the highest. Note that there is no separation of GATE signal here, this is a pure duophonic mode for use on modular synths and multi-VCO machines as the ARP Odyssey.

  • 2nd Channel
    This mode gives a 2nd channel of MIDI->CV conversion with dedicated pitch, GATE, and filter outputs. The conversion tracks on the MIDI channel just above the main channel number. These are some limitations here, in that there is no LFO, Portamento, or pitch bend on this channel. But, with the dedicated GATE, this mode can be very useful in providing secondary control of various aspects in a modular system, or dedicated control of secondary envelope generators.

  • Sequencer Control
    Sequencer Control is probably one of the most powerful features of the CV-5. Most other MIDI->CV controllers may provide a GATE output for triggering a sequencer, but generally that GATE just tracks MIDI clocks. The CV-5 has a VERY full implementation of sequencer control, including a separate clock divider for the SEQ_CLOCK output. There's also a dedicated RUN output which fires when the MIDI START or CONTINUE command is received.

  • Dedicated Filter Control CV
    One thing to make clear is that independent of the various modes of the second MIDI->CV channel, the CV-5 always has a secondary CV output. This is able to be controlled by many sources, including pitch CV.

  • Panning Control
    As talked about a bit before, the Panning circuit in the CV-5 really sets this box apart from anything else on the market today. You can feed a mono signal in, and then get a LEFT and RIGHT signal out. The position of the pan is set to follow the MIDI PAN controller (#10), but can also be setup to follow the LFO or MIDI controller 4. Panning under an LFO sync'd to MIDI clocks is EXCELLENT! Also, the overall gain of the audio circuit is set to track the MIDI VOLUME controller (#7).

    Something that was pointed out to me (thanks Kevin!) is that the panning circuit makes for a great way to setup a MIDI controlled effects mix!

    Setup the audio path as:

  • Synth to Audio_IN
  • Left_OUT to Mixer Channel 1
  • Right_OUT to Effect_IN
  • Effect_OUT to Mixer Channel 2

  • Set the effect for 100% wet. Then, by panning hard left you will get a 100% dry mix, panning center will be a 50/50 balance, and panning hard right will be 100% wet. Very Nice!

  • Flexible Portamento
    Outside of Portamento simply being ON or OFF, there are three modes of what to do with a note that is sliding and the key is released. You can select from "Stops on Key Up" (the pitch stops gliding when the key is let up like on most analog synths), "Finishes on Key Up" (the note continues to glide to it's destination), or "Finishes only on Legato notes" (pitch will glide only when the previous note is held - Very musical!).

  • Exponential Portamento
    While other folks are running a linear Portamento, the CV-5 offers exponential shaping. To hear it is to understand why this is a nice feature.

  • Musical LFO sync
    It's always nice to see someone realize that musicians don't like relating to MIDI clock ticks when trying to setup LFO synchronization. On the CV-5, you specify LFO sync values in terms of meter such as 1/16, 1/8, etc...

  • Mixable Modulation Sources
    You can set up a mix of modulation sources, such as LFO, Aftertouch and Pitchbend all running to the same destination.

  • DIN Sync
    Roland style 24ppq DIN Sync is available on the unit as standard.

  • Complete On-The-Fly Configurability
    The CV-5 is configured via sending program changes to the unit, and as such some very interesting effects can be had. For example, change the LFO waveform, speed, and MIDI sync options on the fly for a sudden "ramp to nowhere" effect in the middle of a tune. Or at the end of a tune, switch suddenly to "Portamento continues on Key Up" for a nice fading trailer on a lead line.

  • Configuration Memory
    Once you setup the CV-5, the configuration will be saved to a EEPROM based memory to become the power-up configuration. EEPROM memory in short means NO BACKUP BATTERIES TO REPLACE! Wah Hoo!

  • Internal Mounting Comes Easily
    With the fact that the CV-5 does *NOT* have a slick digital interface for a front panel, comes a feature... This board would be incredibly easy to internally mount in a synth. Since all of the programming and setup is done via MIDI Program Changes, there is no day-to-day need to have access to the box.

  • Hz/v Option
    For those that need it, a Hz/v option is available for the unit.

  • Downs

    Ehh, there's always something negative to say about everything and as such, I have some nit-pick things about the CV-5, but nothing major...

  • No MIDI data light
    Sigh... This is something that, while adding to the "blinky lights" feature of any setup, really is useful to make sure that something is getting to the box.

  • Trim pots used for Tune, Scale, Filter and CV2
    As I mentioned way up at the top, I didn't *have* to go through a tuning/scaling process, but just to say I did, I did. The process that's laid out in the manual is concise and works well. But there's a bit of wiggling back and forth that has to be done with trimmers. I prefer a digital approach to this task, but you can often zero-in on a hard to trim machine a lot better with trimmers. It's a love/hate relationship. :)

  • Manual is...
    I've sent Kyle a number of suggestions on the manual. I should point out that all of the information that you will ever need is here, including hookup and performance notes, and even a sample GATE->STrig conversion circuit! Most of my comments to him were centered around organization suggestions.

  • Summary

    There is no single channel MIDI->CV convertor made that is more flexible than the CV-5. It is truly a great box. There are things that you can do with this box that a Kenton ProSolo can only think about doing. I will admit that the one feature that I've had to grow to love is the ability to reconfigure the box on the fly. This is something that Kyle had to show me the "coolness" of, but now that it's here, watch out... Being able to change the sync of the EML's sequencer on-the-fly is very cool.

    The CV-5 is priced at $249, and the CV-4 (which is basically a CV-5 minus the audio circuits) is $199.

    Highly recommended.

    For more specific information or to place an order, head to JKJ Electronics

    Looking for a great Multi-Channel MIDI->CV convertor? See the Encore Expressionist

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    Copyright 1998, Mark Pulver -