That is pretty much what my psu does, even with fresh batteries now, I sent an email to Tobias @ TE, waiting to hear back.
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Re the volume knob being backwards - it is actually a balance control when you have left and right connected and not using the internal speaker, but since the internal speaker is mono fully CCW is full volume whether using the left or right input.
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it comes with TRS cables - however, I was using standard mono TS 3.5mm cables from my modular with no problems.
Got the CV module for the Z and some stereo breakout cables. A little disappointed that CV2 & 3 don’t seem to output pitch information, but it is cool to have the encoders be able to control parameters. Would love to drive more than one OSC at a time from external control, will have to look into that more.
Has anyone found a decent power supply for the unit? I’m not finding a 12v 1.7mm center-neg PSUs…
Same here, they don’t seem to be common, I had an old laptop style PSU which was the correct voltage and amperage but had to replace the power connector by cutting the right size one from another PSU and soldering it on. The Volca range use the same power connector but are only 9v and reversed polarity (centre +, outer -)
Probably best bet is to get one of those multi voltage, multi replaceable tip universal power supplies.
Was able to find a wall adapter on Amazon that should fit which I originally missed.
Looks like my PSU is broken in the meantime - one of the chips seems to have cracked/broken. The voltage seems to be out of wack now, as the oscillators all drift in and out of tune without any LFO. I’m getting the high pitched squeal when turning it on now, too. Goes away after a few seconds.
Bummer. Hoping it’s just voltage regulation for the batteries, and the wall PSU might bypass it? I emailed TE to see about a replacement. Chips on the PSU get very hot when powered on so I might not push my luck in the meantime.
I think the PSU is not up to the job TBH, I am still waiting to hear back, I really want to use batteries most of the time but it isn’t possible 
Both of the leftmost chips look cracked/failed. It could be caused by overheating or mechanical damage; it’s tough to tell without physically seeing them. I’ll check mine when I receive it next week.
If the external PSU plugs into the battery pack it may not bypass those components - it likely still needs some signal smoothing prior to sending through the modules, but again I haven’t received mine so I can’t check…
Hopefully TE can provide some details on the setup.
Awesome to hear, thanks!
Good luck with TE giving details…I’ve talked to them for almost 3 months and asked them in every mail, if the second batch of OP-Z has different buttons. (Altogether I asked that question more than 5 times)
Do you think they answered that question even once?
NOOOOOOOOOOOOOOO
FWIW my friend got an OP-Z in November and the button layout is the exact same. Probably second batch since I think it was sold out on launch, but who knows…
what do you mean by button layout? I am talking about the double-trigger issues, that many people have. Many of my buttons need to be pressed very hard, otherwise they double-trigger.
Hi guys, just wanted to report that I also am having the PSU issues (Whining, malfunctioning synth - started after maybe 3 hours of use) – I emailed TE about it, they told me to replace the batteries. I did that and got another few hours of use, then it started up again. Leads me to believe that maybe the battery life is just really horrible? I don’t know much about electronics but if someone does, would it make sense for the synth to go through batteries that quickly?
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Yes.
There is a lot going on witch all the cv and gate /trig.
Batteries are more like for special occasions i guess.
Same here, but new batteries are giving the same problem as soon as I put them in, I tested the old batteries with a battery meter and they were not significantly depleted.
I just got a reply from TE asking about the new batteries and if the problem occurs after a few hours or straight away.
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I built mine today.
I also had the whining sound in the beginning. Put in fresh batteries and it was gone.
I also tried using an external power supply, but it did not work at all. Can somebody confirm it working?
One other really weird thing:
When I leave the filter frequence knob fully CCW for a while and then open it to full CC, I can clearly hear that the filter does not open immediately. It takes some seconds to fully open, it’s like a long slew on the frequency knob … When I patch CV into one of the control inputs, it seems to react fast and as expected.
… anyone experiencing this?
Same whining issue on my setup. It is a classic “struggling switched mode power supply” noise.
From what I’ve seen so far on my multimeter: when the “whining” starts, it means battery voltage is too low and the PSU is struggling to keep a 12V output, and heats up a lot in the process, leading to failure if you insist - hence the cracked chips in the pictures above.
My advice: as soon as you hear this noise, turn the power off and change your batteries, so that the PSU board does not overheat and break.
Quick survey: for those who have been hearing this noise, were you using rechargeable batteries or not? My guess is that almost everyone who has been hearing this early in battery life was using rechargeable batteries, which have a lower voltage even when new… I’m willing to bet TE mostly tested their PO400 using alkaline batteries, but the PSU design is not well adapted for rechargeable, which is a pity.
… or maybe they did mess up the design of the PSU and hopefully replace the first batch…
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I’ve been through two sets of 8 brand new alkaline(non rechargeable) AA batteries in roughly 3 days of playing with it. Guess I need to find a external power supply that will fit. 
Yes, I noticed the same glitch on the filter.
I got my multimeter inline and measured the current draw on the batteries to get a proper idea of the sort of battery life we can expect:
-
13.8V input: 300mA draw (13.8V is a classic value for lithium batteries and usually OK)
-
12V input: 350 mA draw
-
8.5V : > 500 mA
Under 8V, power switches off if powered externally, but not when on battery. I measured a voltage as low as 7.5V on the battery pack with AA NiMH, and presumably current going further up, which explains the overheating of the inductors (the cracked chips). ‘Whining’ appears when the pack is down to around that voltage.
With a 350mA draw at 12V, a good battery pack should last about 5 hours max, does that sound like what people have been seeing?
My suggestion: if this problem happens to you, reach out to TE by opening a ticket (https://support.teenage.engineering/) so that they get an idea of how many people are having this issue…
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