Purchased an ESQ-1

Hi everyone. I found a cheap Esq-1 and snatched it up. It is being shipped from LA to Milwaukee…fingers crossed. It was a Guitar Center purchase so the photos were kinda bad. But the guy on the phone is the one that did all the testing. And I can return it to my local store if there are issues. Anyway, does anyone have any advice on what to look for to ensure its fully working? I looked up some threads here an elsewhere and learned a bit, but I wanted to see if y’all had any tips to share. It doesn’t come with any cartridges. It was described as fully working and in good condition. They promised they would pack it up nice and secure…again…fingers crossed.

Switch it on and make sure all 8 Voices play. If so - congratulations and welcome to the Club!

The only problems I have had with them were:

  • Dead voices (easy to check).
  • Low battery (the synth will complain if this happens).

Theres a Battery in the ESQ? I thought i would run on punched cards?

My SQ80 runs on either steam or old VHS tapes.

Check all 8 voices and the display.

Might have to update from Video 2000 :wink:

You will have to replace the battery, and that isn’t too bad. I have an SQ 80, and it is a bit annoying to get to, but it is the same as any other replacement. You may consider getting a CMOS battery clip to make future replacements easy. Not much else to say.
Sending bunk midi waveform data outside of the normal range adds the “hidden waves” without a chip upgrade. That is about all I can think of for now.

Thanks everyone. I’ll take a look at the battery when I get it. I did my poly61 battery without any isses. Does anyone know if something like the BCr2000 will work with this synth? I have been using it on my DW and its like a new synth. Not that I’m relying on this or that this is super important, but it could be cool. I have not looked into it.

If it has SYSEX, yes. That is the beauty of the BCR2000, but editing the ESQ/SQ is very easy with the dedicated buttons. Not to mention the slider and up/down value buttons. The filter cutoff may not update until the next note is pressed though. You can get around this with a mod wheel cutoff assignment in the filter page.
There isn’t a mod matrix, but one or two modulation options per page. With so many LFOs, ENVs, and key tracking/velocity options it is almost not enough!

@sammy123 which DW synth do you have?


@toneburst. I have the DW8000. Great synth.

@audiohoarder I have heard that the settings don’t update in real time. The DSS-1 has some similar “limitations.” I figured things would be simpler to edit with that nice display.

@sammy123 aw, cool. I had an EX-8000 for a while. Had to let it go to save space, but it was a nice synth, especially, as you say, with a MIDI controller setup to tweak parameters via sysex.


The TX-81Z is similar, apparently, in that parameters are only updated when a new note is played.


@sammy123: The screen is great, that is for sure. You can move any parameter live by assigning the mod wheel to it. No note triggering necessary.

>Sending bunk midi waveform data outside of the normal range adds the “hidden waves” without >a chip upgrade.

Is that true? I thought the extra waveforms where in the latest version of the os, but you still had to do some hardware mods to access them on a esq-1?

@herrprof: I have an SQ80, so it may not work on the ESQ1, but it should. They will just be different waveforms. Unless the bytes the shift reads are silent.
Here are some quotes form this thread.

“You can do it via MIDI for all SQ-80/ESQ-1 models, Rainer Buchty hacked the OS slightly to make it accessible from the panel. Basically it’s a variety of random-ish re-arrangements of the multisamples already in ROM. It should be more fun with the SQ-80 since it uses many longer samples that are already capable of strange stuff (i.e. misbehaving when used with sync or AM).”

“If it’s like the ESQ-1 you don’t need a special ROM to do this. You can just send it a sysex dump with a patch using an “invalid” osc wave number.”

An easy way to do this would be to load an SQ80 patch using a higher osc wave value than available on the ESQ.

The big page about it made it seemed like you had to upgrade the ram:

No not necessary, look here for more info.

Basically, it is reading a sequence of bytes outside of the wavetable bytes as if they were wave tables. There are a few ways to achieve this listed in that link. If you want, I can send you and SQ 80 patch with some random waves outside the range of the ESQ for testing.

Ah good to know… so with this there is no real bonus over a sq-80?