Dreadbox Typhon modification to fix USB grounding hum

[EnochLight]

Anyone who has a Dreadbox Typhon may know about the maddening USB-noise/hum/digital artifacts that can occur if you power your Typhon by the same device that you're running USB-MIDI and analog audio into. It's been driving me mad lately and really killing my workflow, as I consider my Typhon critical to what I want to do, but using it in my setup was just too noisy.

After some back and forth with Dreadbox support, I decided I was going to order the USB Y-cable that splits the data and power for the Nymphes synth they recently released. The thing is, support informed me (by the serial number of my Typhon) that my unit wasn't compatible with the Y-cable unless I did a simple (sort of) modification, which included disassembling the entire synth and removing the bottom motherboard to solder two points together.

No problem!

So here's my journey in photos, in case anyone is interested in doing the repair themselves. Note: without the USB Y-splitter cable, this mod is pointless, so only do it if you 1. reach out to Dreadbox and confirm your serial needs it, and 2. if it does, either conduct the repair yourself if you're comfortable around a soldering iron or hire an electronics repair shop to do it for you.

Massive shout out to Orfeas @ Dreadbox support for their patience, and Jelina in sales who was a pleasure to speak with. I'm sure I could have sent this to Dreadbox and had it serviced, but shipping from the US to Greece would have been pricey, and I'm OK around a soldering iron. Also, massive props to Dreadbox for designing such a "serviceable" synth - this reminds me of the old Roland and Korg stuff from the late 70's/early 80's, when it was absolutely fixable without having a degree in computer science and small electronics repair! Hahahah!





Absolutely had to use one of these, as I'm blind as a bat and I didn't want to have to wear the "jeweler's glasses" over my own glasses...





So here's where Dreadbox support dropped the ball, as the service manual indicated I could pry the knobs off with a flathead screwdriver. Needless to say, I wasn't happy when I scratched my paint, so I placed a piece of thick card between the screw driver and my case...







Only to have this happen! Turns out, I really *AM* blind as a bat, because every damn knob actually has a set screw I only needed to slightly loosen, and the rest of the knobs came right off without any effort. D'oh!!!











After removing the four screws from the top of the case, it slid right off and revealed the first of the two motherboards...



Looks like I have version 1.1 (the service manual Dreadbox sent me was for 1.0, but aside from the set screw/knob issue, everything else was the same)...









^^ THIS RIGHT HERE ^^ That is literally the only two points that you need to short, and it will allow the Y-splitter data/power cable to work properly. I just decided to use some 22 awg wire, strip it, and simply solder it as a bridge. Easy peasy!







^^ This is the same bottom motherboard, but viewing from behind. I'll solder from here.





Threaded the 22 awg wire through the PCB's via holes as instructed by Dreadbox. There's really not any other unused vias. This suggests Dreadbox may have been aware of the potential issue, which is strange it wasn't caught at manufacturing. That said, since some serials are already compatible with the Y-splitter cable, they must have fixed the issue sometime down the line.



READY TO SOLDER!!!



Not my best work, but I never claimed to be an electronics soldering pro. I just need it to work (spoiler: it did)!



Top view from the bottom motherboard. This is exactly how I'd hoped it would look when I was finished.





SNIP SNIP! Gave it a little bris and it was ready to go. Shalom!



If I had any concern, it's that I neglected to clean up the residual flux from my rosin core solder (circled above). That said, if you look at the arrows - this is what Dreadbox did in their own factory, and they left even more flux on the PCB than I did - d'oh!!! Oh well, it's already re-assembled and setup, so hopefully it'll be OK.

For anyone who's interested in how it sounds post-repair, here's a short video comparison:

^^ Here's how it sounded before the repair. YUCK!!! (turn your volume up to hear the buzzzzzzzzz)...

And here's how it sounds after my mod repair above, and using the Nymphes USB Y-splitter data/power cable:

I'm extremely happy with the results! Now it's just the regular "buzz" of my active studio monitors and the noise from my Roland MX-1.

[raymondh]

Well done and Congratulations!! That's really awesome!!

Just need the same fix now for the Roland System-8/boutiques!!

[EnochLight]

Well done and Congratulations!! That's really awesome!!

Just need the same fix now for the Roland System-8/boutiques!!

Thanks raymondh! Thankfully I use my System 8 via USB-audio through my MX-1, and it’s whisper quiet. I didn’t know it had a similar USB-ground hum issue. That sucks.

[Loque]

WTF?

[DaveyG]

Nice work EL and impressive tech support from Dreadbox.

I've solved a similar problem in the past with an inline USB isolator. Not a Y cable - just an inline "dongle" about the size of a memory stick with plug on one end and socket on the other. Cost was about 15 quid and no soldering necessary.

One small critique. Your two solder joints are both what are known as "dry joints", caused by not getting enough heat onto the PCB pads so the solder has only flowed across your wire link rather than onto the PCB pads proper. One or both of the joints are likely to fail at some point in the future but it may be some months/years before that happens so don't sweat it unless the noise returns!

[Heater]

Very nice work and guide. Well done.

[EnochLight]

Nice work EL and impressive tech support from Dreadbox.

I've solved a similar problem in the past with an inline USB isolator. Not a Y cable - just an inline "dongle" about the size of a memory stick with plug on one end and socket on the other. Cost was about 15 quid and no soldering necessary.

One small critique. Your two solder joints are both what are known as "dry joints", caused by not getting enough heat onto the PCB pads so the solder has only flowed across your wire link rather than onto the PCB pads proper. One or both of the joints are likely to fail at some point in the future but it may be some months/years before that happens so don't sweat it unless the noise returns!

Thanks man. Yeah, us Typhon owners have tried everything from USB isolators to ferrite cables to everything under the sun, but none were effective. It’s just an engineering defect that needs to be corrected.

Good point about the solder job - thanks for illustrating that. I was a little concerned about that as well. But it works for now, so I’m good. If it fails in the future, I’ll re-do the soldering. I’ve got plenty of solder wick laying around.

WTF?

[EnochLight]

[[ UPDATE ]]

For those sending me emails regarding the Typhon mod (or anything else) via the forum, please note: I will not respond to emails. If you have any questions, please post them here or send me a PM via the forum. Thanks!

[Re8et]

Well done and Congratulations!! That's really awesome!!

Just need the same fix now for the Roland System-8/boutiques!!

You can pull any 5v wall transformer into the battery leads, firmware can exclude usb power, and allow for battery only operation.
I havent; tested with modded Y cables though if usb audio-midi still works whilst in battery mode.
Usb hum goes away.

[Lykourg]

I have had, the same issue with a slightly newer typhon, I am not connecting it to the computer at all, still the grounding noise was there and i even tried the splitter that dreadbox provides for some gear but nothing changed. Then i tried an Apc usb plug with a power plug with grounding and I noticed that the noise on only while the screen was on. In the end I sent the output through a stereo D.I. box just to provide the grounding and this is how it’s been solved for me… Now it sounds loud and clear. Hope this can help…

[EnochLight]

In the end I sent the output through a stereo D.I. box just to provide the grounding and this is how it’s been solved for me… Now it sounds loud and clear. Hope this can help…

Nice! Which “stereo D.I. box”? Make/model please.

[PeZiK]

I have a lot of H.W. with ground loop hum through USB. I fixed it all with this

Easy peasy!

P.

[EnochLight]

I have a lot of H.W. with ground loop hum through USB. I fixed it all with this

Easy peasy!

P.

These don't work with the Typhon's issue, unfortunately.

[motuscott]

Holy Complicatos Batman!
Much respect to a ReasonTalker who does not fear the soldering iron.
I used to repair amps and cords on the road, nothing this involved.
Kudos

[PeZiK]

I have a lot of H.W. with ground loop hum through USB. I fixed it all with this

Easy peasy!

P.

These don't work with the Typhon's issue, unfortunately.

I've dreadbox Typhon and Nymphes with ground loop issue and this fixed it for me.

All the Roland Boutiques also have ground loop issues and I've got this on them too.

At least, this works for me.

P.

[EnochLight]

I've dreadbox Typhon and Nymphes with ground loop issue and this fixed it for me.

All the Roland Boutiques also have ground loop issues and I've got this on them too.

At least, this works for me.

P.

You were one of the lucky ones. Most Typhon owners aren't able to get these to eliminate the hum/audio artifacts without modding the PCB as I did if you've got the first-gen board. Maybe you have a later revision?

[retreed]

[...]

I'm extremely happy with the results!

[...]

Hey, your instructions motivated me to finally go solve that issue with my Typhon.
All the unwanted noise is gone from that part of the setup now. Thank you!

[EnochLight]

[...]

I'm extremely happy with the results!

[...]

Hey, your instructions motivated me to finally go solve that issue with my Typhon.
All the unwanted noise is gone from that part of the setup now. Thank you!

Really great to hear - glad I could help!

[Durelsh]

Can you still plugin regular USB power cord after making this mod? Without the use of Y-cord. Or is it Y-cord only after this mod?

[EnochLight]

Can you still plugin regular USB power cord after making this mod? Without the use of Y-cord. Or is it Y-cord only after this mod?

Yea, you can still use a USB power cord like always. But you’ll need the Y-cord to split power and USB-MIDI.

[lextron75]

Hey, I'm just about to do this mod, but I can't seem to get the top circuit board to come out. What am I missing? I've removed the screws and the white plastic screw. Thanks

[EnochLight]

Hey, I'm just about to do this mod, but I can't seem to get the top circuit board to come out. What am I missing? I've removed the screws and the white plastic screw. Thanks

Did you unscrew the two black screws on the LCD screen?

[lextron75]

"Did you unscrew the two black screws on the LCD screen?"

Yeah.. it.was just a case of being brave and careful lifting the top pcb out of its connection socket.
But my bottom pcb,, the 2 points, the holes are soldered closed. Not sure if I have the courage to unsolder them.
Scared I'll burn part of a circuit.

I don't get any hum, just clicking sounds and occasionally the typhon sound just disappears.
I have tried plugging it into a powered hub and an Arturia Minifuse 4, connected to an ipad pro m1.

[lextron75]

OK. Sorry to waste your time. I don't need to solder anything. I just need to change the sample rate of my daw or ipad software to 48Khz

[EnochLight]

OK. Sorry to waste your time. I don't need to solder anything. I just need to change the sample rate of my daw or ipad software to 48Khz

D'oh!!! Well, at least you know how to take apart a Typhon for future service needs. Good to hear you got your issue sorted.