yes, the test was made without any effect but it is a stereo sample.
I guess my previous inspection was not so good and I just looked at the initial waveforms on the transients. Another possibility is that something is messing the recording in my setup. Preamps perhaps?
ADAT out mod plz. 
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My buddy and I will be live streaming this upgrade today on twitch. Iāll post a link when I have it.
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We will be starting the stream around 12:45PM EST (about 30 minutes from this post).
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yo, iām watching, canāt comment because twitch isnāt letting me make an account. pretty terrifying process but you guys are keeping spirits high, hah. rooting for ya!
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kick ass!
Congrats! You have any way of comparing before and after?
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Great stream. It was really fun to watch!
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Ditto, kept my attention for like 4 hours 
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Thanks for the stream, not so sure on the singing though!
I contacted the guy, leaving quite close to me. The SPDIF mod is 1000ā¬, almost the price of a new Ot !
I couldnāt watch the stream, is there a video ?
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I think this thread is worthy of a bump. Iām thinking of trying out the op-amp swap. Do we know if the OT MK2 uses different op amp chips?
To be honest, nobody reported the op-amp mod made a real difference. Technically the stock opamp is good enough and I trust the Elektron engineers. Close to zero chance some 5-minutes hack DIY genius beat the Elektron guys who spent months with designing, optimizing, testing Octa circuits.
A much higher chance for a bad result of a chip replacement service. Especially big mess can happen replacing the BJT input opamp for a FET input opamp like it was reported.
Bottom line: I did opamp mod to my own mixer, read a few books, have audio engineering experience. I myself donāt like the Octa sound and really like the Digi sound but itās not that 5-min opamp swap that makes the difference but a totally redesigned system. Starting from power supply, then digital converter chip selection, even circuit board design and trace routing matter. Opamp selection is just one part and not the most critical.
Sorry to be sceptical but that is how things really work.
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Plus in both cases the vast majority of the sound comes from whatās happening at the DSP level rather than the hardware level.
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Recently had my mk1 professionally serviced and modded/upgraded to OPA1644. Thereās HUGE noticeable gain in sweetness and warmth ; This was only noticeable to me at very loud levels, (sound checking venue). Otherwise, the difference is pretty small. The more I pump through this old mk1, the more I think that it was worth having a professional mod it for me. Most will do it for relatively cheap. Just my 2 cents. regardless of how it sounds; itās pretty cool to know that Iāve at least extended itās life by decades 
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- what was in there before the opa 1644 ? I heard noticeable difference when i saw a mod with a video capable opamp.
Interesting - you have a bit more info to share? Pricing, etc?
I have no idea. I just had my local shop intro me to an electrical engineer. I showed him this post:
and he said he had everything to make it happen. All I did was pick it up at the shop.
Pretty sure parts were less than $20. The guy charged me $150. (He was going to charge me $200)
This wasnāt something he had ever done before; but he was well regarded among some modular heads here in my town.
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