Otomon Labs - WARNING

Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by rhythmdevils, Jan 13, 2023.

  1. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,523
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    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

    [​IMG]

    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.

    EDIT:

    5.
    One more aspect of Ken's service. The way he packaged the heaviest amp I have ever owned (it is barely possible to pick up the amp it is close to requiring two people) shipped across the world. He did not double box it. He wrapped it in Saran Wrap (so it wouldn't get any visible damage), put it in a box about the size of the amp, and inserted 1 or 2 1/2" white plastic foam sheets on every side of the amp. It obviously got an extreme beating coming all the way from Japan. Even if just shipped within the ConUS, this packing was not enough to keep the amp from getting huge shocks from people trying to carry it. This was not a box that was easy to carry and was surely dropped, mishandled all the time by people who could not barely hold it.

    Here is ai picture of how it was shipped to me minus the Saran Wrap. Not nearly enough. Look at how Eddie Current and Ampsandsound amps, etc, are shipped surrounded by foam in much bigger boxes than this.

    [​IMG]

    =================
    =================

    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?
     
    • Like Like x 15
    • Agreed, ditto, +1 Agreed, ditto, +1 x 2
    • Dislike Dislike x 1
    • List
    Last edited: Apr 6, 2024
  2. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,523
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    Record of email exchanges about this with Ken of Otomon Labs

    Whitney
    Monday, Jan 9

    Hi Ken,
    The amp arrived a week ago or so and I set it up, and it has a very loud buzz through the headphone jack with my iems and my Audeze headphones. It’s very loud. I just had my friend borrow the amp to see if it buzzes at his house as well to try to figure out if it is the power in my house or a problem with the amp.

    The potentiometer also has a very bad channel imbalance that doesn’t go away when you increase the volume. Even with my Audeze’s playin loud, it’s still unbalanced.

    What kind of potentiometer did you use in the amp? I expected that an amp of this price, you would use an Allps at least. But a TKD would have been nice.

    If I ignore the buzz and the channel imbalance, it seems like it sounds very very good. But it’s not usable right now with these issues.

    I wanted to let you know. I’ll see if the amp buzzes at my friend’s house or not.

    Thank you
    Whitney

    ———————————————

    Ken
    Monday, Jan 9

    Hi,

    The buzz may be caused by ground loop in your system, you can avoid the ground loop by remove the earth wire in your power cord.

    As the hum noise appeared so it make the sound unbalanced so first of all you have to remove the ground loop in your system.

    As doing test with headphone you sent, I can not hear any hum or noise.

    By the way there is hum adjuster volume you can use it to reduce hum.

    About the unbalance you can check by changing tubes from right to left channel to see if the unbalance is appeared or not.

    Ken

    —————————————————

    Whitney
    Friday, Jan 13

    Ken,
    I have had a friend of mine take the amplifier you made me to his house to check if it buzzes there or if it my electricity. The amp has the exact same buzz at his house which means it is the amp, not the electricity in my home. The tubes are also not to blame, I have tired multiple tubes for driver, power and rectifier.

    This amp is defective. It has so many problems, it is unusable and it is unacceptable to send me an amp in this condition for this much money. I will list the problems with the amplifier:
    1. There is an extremely loud buzz with the headphones that I told you I would be using the amplifier with, and which I paid $200 to ship to you to check with the amp before sending it to me to avoid this situation. You should have made adjustments to the amp with the headphones I sent you.
    2. There is a severe channel imbalance in the potentiometer that is more extreme than I have ever experienced. It is not just at the beginning of the volume range, it is an imbalance in the whole range. You either used a defective potentiometer or an extremely cheap one.
    3. The gain is way too high to be usable with the headphones I asked you to make this amplifier for, and this is not something that could have changed in shipping. There is hardly any room in the volume range when using my LCD-MX4 and the S12 iems cannot be used, there is not enough volume range. And this is in low gain. You should have noticed this and adjusted the gain to fit the headphones.
    4. There is a very loud popping sound when switching gain. I would put up with this last issue, but I am listing it for completeness.
    I would like a full refund for the amplifier including my shipping costs both ways. There are not only serious issues with the amp that should not be there when first receiving it before ever using it, but you did not even set the gain to work with the headphones I’m using.

    I can Contact PayPal if I need to but I’m hoping you will do the right thing. I will not be quiet about the defects in this amp on the forums and your reputation is on the line here.

    Thank you
    Whitney Dafoe

    ——————————————

    Ken
    Friday, Jan 13

    Hi,

    The ground loop is not changed as you change the environment. As I told you before, did you remove the mass wire in your power cable ? The solution is very easy but you bring the amp to another house which does not make any difference at all. I dont know why you did the more difficult method and dont listen to what I said.

    There are many customers who meet the same problem as you and it can be resolved by removing the mass wire in the power cable. The ground loop is caused by the difference voltage between devices and first of all if you dont resolve this problem, everything inside the amp does not work properly. If you hear the buzz sound from one of your headphones then every headphone will have the same thing so dont waste the time to try with many other headphones. It does not help.

    Im so sorry because you met that problem, Im sure that the amp does not have any problem, but it seems that you dont want to listen to what I said to resolve the problem. Do you think Im stupid enough to send an item thousands of kilometers away when it is defective ? I know the Paypal rule and it is really stupid to do such a thing.

    If I did not have your phone then it is quite a different story, but I have your headphones you sent, I did the test with it and make sure that there is no problem for both of your headphones. Of course I did a test with many other technical tester and be sure nothing was wrong before sending it to you. The screen hum in your amp in my technical tester is only 0.03mV, but due to what you said the screen hum must be 1-2mV. It is impossible thing to my amp.

    I did tell you that the amp is very high power, you need high current for your headphones, that is why it is very high power and as I told you , you can use a switch to change to lower gain mode and use volume to adjust it to fit with your ear.

    Finally, if you are not happy with the amp, send it back to me. If you dont want me to do troubleshooting to find out the problem and think that you do everything to resolve the problem but it is impossible to resolve it, I accept a full refund for the item. You can open the case in paypal, I will refund all your money that I got from you. You have to send the item back to me without damage . Paypal will not ask me to cover shipping fee sending back the item so I think you have to cover that fee.

    ————————————————

    Whitney
    Friday, Jan 13

    You are telling me that removing the ground will change the gain of the amplifier?

    I am not stupid enough to believe that. I paid $200 to ship two sensitive headphones to you to make sure the amplifier worked with them, and you left the gain set so high there is no usable volume range with these headphones. There is no excuse for this. You should have opened up the amp and lowered the gain.

    And the pot imbalance is not going to disappear if the buzz goes away either. You used a super cheap volume pot. I should have paid you to put a TKD pot in the amp, but I assumed you would at least use a Blue Velvet like all $1000+ amplifiers use.

    And the pop switching between gain is not a good sign of good amplifier design either.

    I have a power cable coming in the mail that lifts the ground wire and I will try this, but it will not resolve the above issues. I will have to pay to have the amp fixed locally by having someone replace the volume pot with a good one and lower the gain of the amplifier. I’m not willing to pay to have an amplifier fixed that came to me broken and designed poorly especially when you had the headphones there to test the gain and make it appropriate for the headphones you had there. This amp is not usable with the S12 I sent you and you knew that. But you made no changes to the gain.

    I’m not going to put a preamp in front of the amplifier to fix the gain that you should have lowered yourself.

    Gain has nothing to do with power. A powerful amplifier can still be set to have low gain so the volume knob is usable.

    You are making excuses for bad amplifier design and not putting any care into the design of this amp. Anyone with any experience would have lowered the gain to work with the headphones I told you over and over that I was having you make this amplifier specifically for. And which I paid $200 to ship to you just to avoid an issue like this.

    Whitney

    —————————————————

    Ken
    Friday, Jan 13

    What ? If you are not stupid to believe that thing you must confirm to me.

    The biggest problem is buzz sound, if you don’t resolve that problem, everything in your amp is not correct. That is first thing you must resolve. The buzz sound may be caused from ground loop or something else but in almost case it is caused by ground loop and one of solution is remove the mass wire from power cord.

    The ground loop appears in almost environment, it always happens with customer who want to use expensive power cord.

    Do you want me troubleshooting to find out problem or want to send it back for full refund. There is another customer want that amp so it is not a problem to me if you send it back.

    If you want me resolve problem, just do what I said and tell me the result. Not bring item go around, or try it with another headphones, it does not resolve problem for sure.

    Wait for your mail.

    ————————————————

    Whitney
    Friday, Jan 13

    Did you read my email?

    There are 4 problems with this amplifier and they are all separate. You are only talking about the buzz by lifting the ground.

    The gain is still too high

    The potentiometer is still defective

    There is still a pop when changing gain.

    If you try to blame me for problems with your amp it will not go well for you, I will make a thread on SBAF about this and post all your emails to me and it will rank high in google. People will know how you treat your customers and how you design amplifiers.

    I tried to be nice about this, but you blaming me and ignoring the problems is not ok.

    Whitney

    —————————————————

    Ken
    Friday, Jan 13

    If you have big noise from the amp, what you hear from the amp is not properly.

    If you want me troubleshoot the problem then resolve one by one.

    I sold hundreds of amp per year. All of them have very good feedback until now, so if you want to blame me with one bad feedback, it does not have any problem at all. Your amp will be sold to another guy immediately so people will know what is the truth.


    ————————————————

    Ken
    Friday, Jan 13

    Addition:

    The potentiometer is TDK ones.

    As changing gain you need to low down the volume as small as possible, if you let it loud, the pop sound will appear. It is very normal.

    If the gain is too high, you can hear music with lower volume. That is why volume is installed in the amp.

    —————————————————

    Whitney
    Friday, Jan 13

    Once again noise from the amp cannot change the gain or make the potentiometer dysfunctional.

    There are 4 separate problems with this amp.

    I would like a full refund including shipping back to Japan. I am not paying $400 usd to ship a broken amp back to you. You can refund me in full and I will keep the broken amp, or you can refund me and pay for return shipping to Japan.

    Thank you
    Whitney

    —————————————————

    Ken
    Friday, Jan 13

    I think you don’t want to discuss with me to resolve problem. I told you that we will troubleshooting to find out where is problem one by one and you ask me resolve 4 problem at the same time. It is really stupid.

    And talking more will be a waste of time. It is my big mistake of me to sell item to you.

    If you want money back you need to send back the amp to me. Pay the shipping fee sending back item. If you open a case via PayPal, you will have to do do the same thing. I think you are smart enough to know the PayPal rule.

    You want me send you back all your money and keep the amp ??? I don’t know you are too smart or too stupid but that solution is not available in the earth. And of course I don’t pay for sending item back because I know exactly that my amp does not have any problem.

    —————————————————

    Whitney
    Friday, Jan 13

    Fixing the buzz will not fix the channel imbalance or the gain which is way too high (and you knew it was way too high because you had my headphones there), or the popping when the gain switch is flipped.

    I don’t know how you sell amplifiers when you treat people who paid you thousands of dollars like this. Calling me “stupid” is beyond belief.

    I will make this email thread public and contact paypal.

    Whitney

    ————————————————

    I am sorry for the drama, I just want this whole experience to be public so none of you buy an amp from him and get stuck in the situation I’m in, likely wasting a lot of money.
     
    • Like Like x 1
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List
  3. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,523
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    He just sent another email...

    Ken
    Jan 13

    If you said that you already fixed buzz sound problem and another problems are still there then I think you are smart but you still repeat the same thing many many times. For what ?

    And now you though that I still tried to send the amp to you although I had your headphone, did test the amp with it and must know problem before ??? Why did I do that ? As you send back item, I lose the shipping fee sending item to you, lose the customer, lose many other things, right ?

    I have never met a person like you. You claimed about problem but don’t cooperate to me to resolve it, tried to fix the problem by bringing it and going aground and then want to send back item and ask me pay for all fees.

    I really don’t want to sell the amp to you. Don’t do any other thing. Send it back to me as soon as possible and I will send back all money that you paid to me, no other way. Over !
     
    Last edited: Jan 13, 2023
  4. AdvanTech

    AdvanTech Friend

    Pyrate BWC
    Joined:
    May 13, 2016
    Likes Received:
    1,681
    Trophy Points:
    93
    Location:
    NYC
    What the hell.. his website is absolutely painful. Is he trying to make money from his products or those wretched ads?

    Sorry about the experience, sounds terrible.
     
  5. ColtMrFire

    ColtMrFire Writes better fan fics than you

    Pyrate
    Joined:
    Jun 16, 2016
    Likes Received:
    6,241
    Trophy Points:
    113
    Location:
    Austin, TX
    Sorry you had to be a guinea pig for this awful experiment. But it does speak to the idea of only spending significant money on gear (or anything) from reputable outfits. There's a reason people like Donald, Craig, Alex and the Schiit gang are shilled (for lack of a better term) on these audio forums... they have high quality products and for the most part, quality customer service. I understand most of these guys products aren't planar focused, but that's all the more reason for people to do as much research as possible when branching out to these rando "companies" who charge an arm and a leg for fancy looking gear meant to gain access to the wallets of unsuspecting audiophiles...

    This hobby has gotten out of control in this respect. It is just another market vultures can swoop in and feed on.
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 7
    • Like Like x 1
    • List
  6. RestoredSparda

    RestoredSparda Friend

    Pyrate
    Joined:
    Jan 7, 2021
    Likes Received:
    3,843
    Trophy Points:
    93
    Location:
    WI
    I would recommend attempting his troubleshooting steps before getting too angry with him. Besides the broken English he seems sincerely trying to figure out the issue. If it's still shit after trying his suggestions then get a refund.

    I am also a bit dubious that the issue is what he thinks it is, but it can't hurt to try and then make a decision. The other issues you mentioned certainly won't be fixed by a removing the earth wire, however.

    As others mentioned, it's sort of insane he designed the amp to have a broken ground but does not mention this to you? Idk, super strange.

    EDIT: Glad he offered to refund. I would take him up on the offer and never look back.
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 14
    • Like Like x 3
    • List
    Last edited: Jan 13, 2023
  7. Clemmaster

    Clemmaster Friend

    Pyrate Contributor
    Joined:
    Sep 28, 2015
    Likes Received:
    3,284
    Trophy Points:
    113
    Did you ever try the mass-less power cable? Or just get and isolation transformer?

    Any chance something could have moved inside the amp during transit?

    Also, I don’t think he called you stupid, he was just quoting what you said :)
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 5
    • Like Like x 4
    • List
  8. bboris77

    bboris77 Friend

    Pyrate
    Joined:
    Dec 12, 2015
    Likes Received:
    778
    Trophy Points:
    93
    This person is absolutely incredible - suggesting to a customer to hack open the 3-prong power cable and remove the ground wire?! Ummmm, why did he then build an amplifier that requires a ground connection? The least dangerous option would have been to suggest using the EBTech HumX.
     
    • Like Like x 4
    • Agreed, ditto, +1 Agreed, ditto, +1 x 2
    • List
  9. Clemmaster

    Clemmaster Friend

    Pyrate Contributor
    Joined:
    Sep 28, 2015
    Likes Received:
    3,284
    Trophy Points:
    113
    Not sure how he tested a 120V amp in Japan, but he probably had to use a transformer which might have prevented him from seeing the issue.
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 9
    • Like Like x 7
    • List
  10. bboris77

    bboris77 Friend

    Pyrate
    Joined:
    Dec 12, 2015
    Likes Received:
    778
    Trophy Points:
    93
    And a VERY simple way of testing for ground loops would be to disconnect this amp from any other devices (DACs or whatever). Plug it into the power using the 3-prong power cord, plug in your headphones and turn it up. If it still buzzes it is NOT a ground loop because there is no f..king loop. :)
     
  11. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,523
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    His responses are all just excuses. So we spend hours troubleshooting and fix the buzz. Then what? The amp is still unusable and I can't replace a potentiometer myself. So we are still left with two options: me paying someone here to fix the amp or shipping it back to him. Neither of which I should pay for when it arrived like this.

    He just made a shitty amp and doesn't want to take responsibility for it, that's all this is. My ass he used a "TDK" pot. Or maybe there's a channel imbalance because he used a "TDK pot"
     
  12. Biodegraded

    Biodegraded Friend

    Pyrate Contributor
    Joined:
    May 28, 2017
    Likes Received:
    8,275
    Trophy Points:
    113
    Location:
    Vancouver BC
    Related question, but might not be relevant to the problems: from the description of the amp on the website I presume there's a switch somewhere inside to set input voltage. If so, check to see that it's currently at 117.
     
    • Like Like x 2
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List
  13. uniqusrname

    uniqusrname Acquaintance

    Joined:
    Jan 26, 2017
    Likes Received:
    36
    Trophy Points:
    25
    Location:
    Fremont, CA
    I think channel imbalance and loud noise could be due to ground not connected to one of the channels. If the noise doesnt change in loudness with pot movement. I can take a look at internals to confirm the same, it could be an easy fix. I also have a power cable with ground lifted, funnily it came with Stax amp I imported from Japan. :)
     
    • Like Like x 5
    • Epic Epic x 1
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List
  14. k4rstar

    k4rstar Britney fan club president

    Pyrate BWC
    Joined:
    Jun 11, 2016
    Likes Received:
    6,997
    Trophy Points:
    113
    Location:
    Toronto, Canada
    After reading the email chain I'm not sure this thread was warranted, at least not in this manner. I get that you are frustrated but it seems he is trying to help you and you have not actually addressed his suggestions. It's a process to troubleshoot technical problems back and forth over email.

    If you have a ground loop in a tube circuit with cathode bias, that can affect the gain and make the operation of the pre-amp stage unstable. It can also cause channel imbalance. These points are especially true in amps that use bus ground connections which is pretty common for Japanese builders. I only use two-prong power cables with my tube amps.

    I think you should have waited for a resolution of either returning the amp or fixing it before posting the thread. If you don't want the amp anymore which it sounds like you don't, just open a paypal case and return it.
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 12
    • Like Like x 9
    • Respectfully Disagree Respectfully Disagree x 1
    • List
  15. Clemmaster

    Clemmaster Friend

    Pyrate Contributor
    Joined:
    Sep 28, 2015
    Likes Received:
    3,284
    Trophy Points:
    113
    I did a quick google search and it sounds like Japan rarely ever use ground for electronics and appliances (only AC and bigger appliances).
     
    • Like Like x 3
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List
  16. Ksaurav402

    Ksaurav402 Friend

    Pyrate Contributor
    Joined:
    May 7, 2019
    Likes Received:
    2,178
    Trophy Points:
    93
    Location:
    NY
    add all your devices connected to amp to one power strip to have same ground, wouldn't it solve the problem of ground loop? No need to remove earth cable
     
  17. Pancakes

    Pancakes Friend

    Pyrate Contributor
    Joined:
    Aug 13, 2020
    Likes Received:
    1,445
    Trophy Points:
    93
    Location:
    Atl
    To me the comment that (paraphrasing) "many customers experience this and fix it with a ground lifter" says that he doesn't know what he's doing.

    What other company tells their customers that in order to use their products they need to lift ground????

    Yes, sometimes in unique situations ground needs to be lifted. But that's in unique situations not a bad design choice.
     
    • Like Like x 2
    • Agreed, ditto, +1 Agreed, ditto, +1 x 2
    • List
    Last edited: Jan 13, 2023
  18. Josh Schor

    Josh Schor Friend

    Pyrate Contributor
    Joined:
    Jul 13, 2020
    Likes Received:
    998
    Trophy Points:
    93
    Location:
    Ann Arbor Mi
    HI Whitney
    This is a total pain in the ass and so disappointing. I have had similar situations, not the rude part but the amp not as requested part. I just sent it back ate the shipping if I had to and moved on. If paypal can force him to pay for shipping he may be a spitful person and take forever to refund your money, its a diffucult situation. I would suggest to do whatever is nessessary to get it back to him ASAP.
    best,
    Josh
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 2
    • Like Like x 1
    • List
  19. Merrick

    Merrick A lidless ear

    Pyrate
    Joined:
    Jan 6, 2016
    Likes Received:
    12,629
    Trophy Points:
    113
    Location:
    Portland, OR
    So does this mean no SBAF loaner tour?
     
    • Epic Epic x 9
    • Like Like x 7
    • List
  20. Azimuth

    Azimuth FKA rtaylor76, Friend

    Pyrate
    Joined:
    Nov 9, 2015
    Likes Received:
    7,032
    Trophy Points:
    113
    Location:
    Nashville, TN
    Home Page:
    Many megawatt (>50W) guitar amps have a ground lift switch. This does NOT lift the chassis ground from earth ground on the three pronged power plug. What it does do is remove the input ground to the ground of the amp. I am running into same ground loop issues with my QS Headphone Amplifier.

    But yes, if you remove the input and it still buzzes, then it is not a ground loop issue.

    The other stuff are bigger issues than ground loop issues.
     
    • Like Like x 2
    • Agreed, ditto, +1 Agreed, ditto, +1 x 2
    • List

Share This Page