Otomon Labs - WARNING I recently commissioned a custom amp from Otomon Labs and the results are beyond horrific and I want to not only warn you all about how Ken makes amps but also how he treats his customers. I also want to make what he has done public for others to see. Ken Uesugi runs Otomon Labs and his website is: http://soundgate.net Ken wound up making this amp for me: http://soundgate.net/product/MTM4OQ...highend As you all know, I’m on a quest to find the best tube amplifiers for planar magnetic headphones. I have come to the conclusion that the tube amplifiers highly recommended here are basically all designed for the headphones that are used most heavily here - the HD650 and HD800. Eddie Current, DNA, etc amps are all designed for electrodynamic headphones. The Afficianado sort of worked with the LCD-4z but fell apart with the LCD-4. The Studio B falls apart with all of my Audeze’s and literally turns to mush. I also had a modded Super 7 that sounded very mediocre with Audeze’s and recessed the midrange. I have tried a lot of other amps too and none of them have worked well with Audeze’s and I know they are capable of more. So after lots of buying and selling popular amps here on SBAF I decided I should get outside the little box of recommended amps here and get something outside the electrodynamic crowd. So I did some research looking elsewhere and found Otomon Labs. His amps looked interesting and in talking to him, it seemed he was an artist who could make an amp that would be designed specifically for my sensitive Audeze headphones (I have a First Watt F4 driven by a tube preamp for my LCD-4 and HE6se). In talking with him, he’s not great at English and I know very little about amp design so I was a very easy customer, I just told him to make me the best sounding amplifier he could for sensitive Audeze headphones that was quiet enough to be used with both sensitive Audeze’s and ortho iems like the S12. He said this would be no problem. And he of course decided to use the most expensive power tube out there, the 300b. But I went along with it as an experiment to see what might come from outside the box thinking. I told him to make all the design decisions based on what would work the best for the headphones I told him I would use it with. I also paid $200 to ship him my modded LCD-MX4 and a pair of S12 ortho iems to test with the amp because that was the best example of what I would use with it and I wanted the amp to work as best as possible with them and be tuned for them. He listened to them with the amp before shipping it to me and said it sounded wonderful and was quiet with both. The only thing I asked for specifically the whole time was OCC Copper internal wiring. He kept responding saying that he would use OFC Copper wiring, and when I corrected him he would always say “yes I meant OCC”. When he sent me the final bill for $3,375 part of the quote read “OFC Copper wire upgrade”. I asked him to clarify that it was OCC and he told me he didn’t know what OCC Copper wire was and made a mistake and it was all OFC internal wiring. (I have to wonder what kind of wire he uses that is not OFC for those who don’t pay for the “OFC Copper wire upgrade’. Tin? 60% Copper wire? Lamp cord?) Also, it’s kind of amazing to be an amp builder who makes this many amps in Japan and not know what OCC Copper wire is, as it was developed in Japan. OCC stands for Ohno Continuous Cast, developed by Dr. Atsumi Ohno in Japan. Here’s an article if you’re interested. https://wallofsound.ca/audioreviews...ntor-of-the-ohno-continuous-cast-occ-process/ So I’m just kind of baffled that an amp builder in Japan doesn’t know what OCC Copper wire is. This raised my eyebrows, but the amp was done and he refunded me for the “wire upgrade” and I paid $400 to ship the amp to me from Japan. It showed up and so did my new production WE 300b tubes and WE 417a input tubes and a bunch of 5U4g rectifiers. I was going all out and wanted this thing to be the best amp ever for my orthos. I excitedly hooked it all up, and man this is the heaviest amp I’ve ever dealt with, being in an iron chassis with a million transformers. It’s barely liftable. I excitedly, but nervously hooked it up and put on some music and plugged in my RD-S12 modded S12 ortho iems. All I could hear was the loudest buzz I have ever heard from an amp. As loud as the music. My RD-4z had a really loud buzz with it to, to the extent that I didn’t feel I could even evaluate the sound. I thought I heard something good going on, but hard to tell. I soon noticed more problems. There wound up being 4 serious issues with the amp. 1. Super loud buzz. I had my friend Josh (@loadexfa) take the amp to his house and see if it buzzed there and it did, so it was not my power. 2. The gain was set incredibly high, so high that even with the gain set to low, there was almost no usable room on the pot with the LCD-4z or LCD-MX4, and no usable range with the S12 (both of which I sent him to test with the amp before shipping it to me) 3. There was a really bad channel imbalance, and it did not go away when the pot was turned up. He either used a super cheap pot which it felt like, as it turned way too easily it kind of just spun with no resistance at all. It was obviously not even a cheap Alps pot. And this is a $3k amp. The $100 Schiit Magni comes with a better pot than whatever he used. Or maybe it was just a defective pot, I don’t know for sure without it being inspected. 4. When switching from high to “low” gain, the switch made an uncomfortably loud popping noise similar to the Monoprice Liquid Gold X. Which is not a deal breaker, I would easily live with this little eccentricity, but it’s still not what I would expect at this price point. I emailed Ken, first just about the buzz so he knew and told him I was having my friend take it to his house to see if it buzzed there. His responses were defensive and aggressive immediately, and it went downhill very fast. I am going to copy and paste our email exchanges after this point here in this thread so they are public. He blamed all the issues on the buzz and told me it was a ground loop and that I needed to use a power cable that lifted the ground. Which is not something I can just pull out of my ass, but regardless, a ground issue has nothing to do with gain or channel imbalance or the pop in the gain switch. Which I tried to tell him. I told him there were 4 separate problems here and even if I fixed the buzz with a ground lift, the amp still was unusable as it was. He eventually wound up calling me “stupid” and promised me that if I took this up with Paypal, I would have to pay to ship the amp back to him, which he didn’t care about because he had another customer who wanted the same amp. He just did not care at all. And he was insulting and rude. I was at first thinking of trying to pay a local DIY’er I know to fix it, if Ken would pay for that, but after a few of his emails I just wanted out. I wanted nothing to do with this man or his amp. He told me he has nothing but happy customers, but the only other person I know who has commissioned an amp from him received an amp with the wrong piece soldered into it, I’m not sure what the details are, but it was a rookie, careless mistake. I’ll ask him and follow up here. He is still stuck with the amp and cannot use it to this day. So be WARNED. Stay away from Otomon Labs amps. He doesn’t know what he is doing, and he does not care about your experience or the quality of amp you receive, he just wants (a lot of) money from you and then he wants you to piss off. He should not be running a business making amplifiers for people, especially not custom amplifiers. I have no idea what I’m going to do. I’m going to try to get PayPal to either force a refund and not make me ship the amp back, or force him to pay for return shipping. Both of those seem unlikely and seem like a lot of energy and a huge PITA. Anyone have any recommendations for my options here?