Voluntary Recall on Noisy Hypno Units ( Pre Dec 2020 )

We are issuing a voluntary recall on Hypnos shipped on or before Dec 2020 which show the following issue:

Your Hypno is showing jitter (see video below) when no cv inputs/midi is plugged in.

To test this you should set shape A to a single color line and watch the video without touching the unit. If any of the controls jump in the span of about 40/60sec your unit is affected by this issue.

If this is the case:

Please send an email to support@sleepycircuits.com with:

  1. Your Sleepy order number, or retailer name and order number if purchased elsewhere

  2. Your most up to date mailing address

  3. A one sentence description of the issue you are experiencing

Domestic (U.S.) customers will be issued a return label then your unit will be received, repaired, re-tested and mailed right back to you as quickly as humanly possible.

International (non-U.S.) customers will need to arrange for shipping their unit to us, but we will reimburse you for any costs incurred. We kindly request you ship using the most economical method available; we won’t reimburse expedited or special services. It is imperative that you mark the shipment as a repair/return on any customs declarations.

You will be provided detailed instructions on how to return your Hypno for repair, please follow them closely before sending your unit to us. You MUST have your repair RMA authorized with us first, do NOT send us your unit until after that.

Repaired units will have better CV response, no longer show any jittering and will be retested for any other outstanding problems if you choose to mention them in your email.

There is no time limit on this recall, so if you choose to deal with this later feel free to do so at your leisure.

If the solution is not satisfying to you we are issuing full refunds on affected units purchased from Sleepy (assuming the units are packed with care and received in good condition). NOTE: We cannot issue refunds on units purchased from retailers. Please contact them directly to arrange a return/refund.

How Did this Happen?!

Some Background:

The Dec 2020 batch of Hypnos was assembled and tested by a Contract Manufacturer for Sleepy and we were exploring how we can scale operations to make Hypno stock more stable. This had a batch of noisier power system components since they where acquired from a different source and the hired manufacturer did not make us aware of the jittering issues (I tested 10 of 100 units received from them and those did not show the issues so I was convinced the units where operating up to spec).

We will now be testing everything in house (lesson learned).

The Solution:

I found a problem with the schematic which can be solved by replacing a single SMD resistor, so the fix is very quick. A decoupling capacitor is simply out of place. This doesn’t make any difference on most units but it appears to highlight noise in outlier power circuitry now that we are manufacturing in greater quantities.

Can this be solved with a software update?

Yes, BUT this would degrade CV performance for all units so we will NOT do this and instead make sure every unit is operating to our standard with a hardware fix.

I am very sorry about this :frowning:

I take the blame for screwing this up and will do whatever it takes to make it right. I have also invested in hiring help with the recall so that this gets solved as quickly as possible. We will be keeping back some stock in case we identify units that are not fixable and require a unit replacement.

I am very sorry this happened and I hope this show of transparency and dedication to a proper solution is received well by the community.

Ronald Sardarian
Sleepy Circuits CEO

Please feel free to comment below if you have any questions.


Thank you for taking care of this issue!


Thank you for this, my hypno has this issue too. when I get some time I will recall mine.


Any chance there will be a DIY guide for the fix? Trying to avoid the possibility of going through customs again.


Hey pkar. Due to the complexity of Hypno’s design, we will not be releasing a DIY guide for this fix. But the good news is that you shouldn’t incur any customs fees for a repair shipment, and we’ll take care of the shipping both ways. If, by chance, you’re charged import fees then Sleepy will be happy to refund you so there’s no out of pocket cost.

Hi all, please be informed that international customers will now be asked to arrange shipping back to the US on their own, but Sleepy Circuits will reimburse the cost. Unfortunately this is the most practical method we could devise for the circumstances. The main post has been updated to reflect this. Please contact us with any questions.

My hypno has this issue too. I’ve sent a couple of emails with the required information over the last week or so, but still haven’t received a response. Parhaps they’re going to your spam folder? Or is there another email address I can reach you?

Thank you for the recall repair, everything is much smoother with the hardware fix and the newest firmware. :smiling_face_with_three_hearts:

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Yay! I’m glad its working well for you :smiley:

Please let me know if you find any bugs in 2.1.5 there are already a few listed in the relevant thread

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Just got mine back. So glad to be able to Hypno again. :slight_smile:

It’s a definite improvement and very much appreciated!


Got mine back, it’s working great, thanks!