Waveboy GRAINSTORM EPS16+ fix

Just in case anyone comes across this bug and can miraculously find a replacement chip -

I picked up a little rough around the edges EPS16+ recently and I’ve been tweaking it back into shape. After installing a new drive, some new sliders, some new tact switches, and getting my hands on some floppies, I noticed an eBay auction for (x5) of the Waveboy Effects disks for a decent amount. The pic showed what appeared to be legit labels so why not?

Got them in the mail and started messing around. On the Soniq Demolition disk there’s the GRAINSTORM effect (granular synthesis type effect) which has a notorious issue with some EPS16+ producing fairly loud and random noise with the effect on an instrument playing in the background. All the other effects work, but there was supposedly some bug with a run of EPS16+ that doesn’t work with this particular effect. And, yes, mine was one of these. Kind of a bummer.

Through an email exchange with Garth from Chicken Systems, some internet sleuthing, and noticing a post on here about other Ensoniq ESP chips being compatible in EPS16+, I surmised the issue was possibly the ESP chip. Amazingly coincidentally, I found a replacement chip listed on eBay, ordered it with a quickness, put it in, and GRAINSTORM works in all its sonic mangling/warbling glory! All the other effects seem to work as well, stock and other disks.

For reference, here’s the chips I took out and put in:

Original ESP chip (didn’t work with GRAINSTORM):

5510 0001 02

Replacement ESP chip (works with GRAINSTORM):

FR07154 K9306

1 Like

I have the same thing happening on my EPS16+. The effect works fine on my ASR10 of course.

I have a spare SQ1 board that has that newer EPS chip. I’ll swap than one and test it out.

1 Like

Very curious to hear your results!

I tested the stock effects which all seemed to be normal, the Soniq Demolition disk and the Parallels disk (all worked). Upgrading the power supply currently, so can’t really go too deep into testing the other Waveboy effects disks further till I get that done.

Right. The other effects seemed fine. I had noticed this on SamplerZone’s site a couple of months ago, but they did not say what chipsets. Since you posted your results, it looks like mystery solved.

IMPORTANT NOTE: There is a bug in early 16-PLUS chipsets that cause the main GRAINSTORM effect to sound improperly. There is no way to determine which chipsets or serial numbers are affected, so please contact us if you receive this product and the GRAINSTORM effect exhibits this problem.

Also, when you replaced you chip, did you resolder the capacitor that was on the old chip?

And just a FYI, the replacement chip from my SQ1 extra parts board worked like a champ. I did not solder on the capacitor from the old chip either. If it’s needed, I’ll do that.

1 Like

No, didn’t solder the cap. Thought I’d give it a shot without and it worked fine.

Glad to hear it worked for you too!

1 Like

Same here. I do not believe the solder cap is required on the new chips.

1 Like

Appears so. What really clued me in to replacing it with the newer chip was this site:


They listed the chip as a replacement for the older EPS16+ ESP chip. I assumed that it would either ship with the cap soldered or they’d have to make some mention of it. Hence, figured the cap wasn’t necessary.

1 Like