Wonky Cayin HA-1A MK2
Contact listing creator xTelepathetic
Listing ID: 50274 Views: 893
For Sale / Trade  450.00 USD
Condition
As-is/Parts
Negotiability
Or best offer
Ships to
  1. United States of America
Looking to sell a strangely behaving Cayin HA-1A MK2 tube amp. I purchased this unit from a user on Head-Fi and once I received it, it started exhibiting buzzing and humming. According to the previous owner, there was never any noise while the unit was in his possession. I have tried changing the input (CD -> AUX and vice versa), using different output impedances, using different headphone outputs, using a different power cable, plugging it directly into a wall outlet instead of an outlet extension, adding a ground loop noise isolator between my source and the Cayin, using different combinations of tubes, and moving the unit to different locations in my home. Despite all of this, the unit experiences a hum when it is in my possession. The hum is minimal when the lowest output impedance is selected and strongest at the highest output impedance.

I took the Cayin to a local repairman specializing in guitar tube amplifiers to get some basic troubleshooting. this is what I was told:
There is a 120Hz hum output by both channel outputs. Probing the tube sockets, there is too high of a voltage across the control grid of the tubes which can damage them Finally, the main PCB of the amp has a constant non-zero DC voltage. Resistors that should experience a voltage drop have no voltage drop.
I sent the Cayin to Fuchs Audio for further diagnosis and potential repair only to be told that there is nothing wrong with it (check the timestamp for proof; will forward the unredacted invoice to any potential buyers). They were unable to replicate any noise, static, hum, or hiss. However, upon getting the amp back and trying it in my home, the noise immediately appeared and is apparent. It is unlistenable to when in my possession and I am hoping to sell it and get some of the money that I spent on it back.

The Cayin HA-1A MK2 is being sold AS IS with no promise of intended functionality. The Cayin amp may sound perfect to you with zero noise. You may have a terrible experience like I had, one that leaves you scratching your head wondering why only you can hear the noise and in awe of the fact that a tube amp and everyone you talk to is gaslighting you into thinking that it is functioning normally. I do not know why it makes static. It may or may not make static noises if you buy it.- I can promise you nothing. Aside from the static, the only things wrong with the Cayin HA-1A MK2 are a burnt-out LED under the right EL84 tube, minor scratches on the top and sides of the case, and a chip in the wood on the top all visible in the timestamp photos.

I have since purchased a Feliks Elise MK2 and use it in the same location as the Cayin. There is 0 hum/hiss/static/noise. It is pitch black like a solid state amp under the same operating conditions, using the same audio stack, same RCA cables, and same power cable plugged into the same power outlet. Hence, I am hoping to let this go and recoup a little bit of the money that I have spent on it.

To summarize:
- Wonky Cayin HA-1A MK2 that may or may not have static. It may decide it likes you and behaves. It may decide it hates you and wants to torment you endlessly. I do not know.
- Purchased originally in 2019; No longer covered by warranty. Any repairs will be at YOUR expense
- Includes the original box and all accessories (manual, spare fuses, power cord, and original vacuum tubes)
- Signs on use through minor scratches on the sides and top surfaces

This wonderful nightmare can be yours for $450 OBO Shipped CONUS. This weighs 26 lbs- I will not ship it outside the CONUS unless YOU pay to ship it. If you decide that you want this for some reason, you can bundle it with all the tubes that I have as well for an extra $200 (4 pairs of matched 12AU7s, 1 pair of matched EL84s, 4 12DT5s). I will take trades for headphones, like Sash Tres headphones, Sennheiser headphones, Grados, Clears, or Raidances (I will add PayPal), IEMs, and matched pairs of high-end 6SN7GT vacuum tubes.

If you have any questions please reach out! Thank you for looking!
Listed by: xTelepathetic (2)
Listed: 2023-07-02
Last edited: 2023-08-23
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Contact listing creator xTelepathetic

xTelepathetic

New Head-Fier
Have you tried a ground loop isolator? Is there a way to replace the internal power supply?
I added one between my DAC and the Cayin in the RCA inputs and it did nothing. I’m borrowing a ground hum isolator to see if that works. No way to replace the internal power supply.. fuches said that it worked fine for them though so, who knows
 

xTelepathetic

New Head-Fier
I had the exact same problem with a Firestone Audio Little Country III, worked fine here(even though I hated its tuby sound lol) but it hummed like hell for my buyer, apparently it's a matter of impedance or something, some tubes don't play nice with some phones c'est la vie

not my buyer: https://www.head-fi.org/threads/noi...dio-little-country-iii-amp-tube-noise.655009/
I think you may be on to something. I tried with a pair of DA Ether Flow 1.1s and there is 0 hum or hiss. However, the output impedance selector does not change the sound when using them. I sent the Cayin to a buddy of mine to try and he gets the hum with his HE6SEv2 too. I wonder if it may somehow be cable related as well, as the DCA cable I have is noticeable thicker and has a more solid 1/4" termination than the cords with my other headphones.
 

Capt. Z

500+ Head-Fier
Sounds like you either pick up noise with your RCA cable or a ground loop problem. I would first listen to the amp without any RCA hooked up to eliminate the RCA cables. If there is noise I would just LIFT (unhook) the ground on the AC plug or use an 3 to 2 prong AC adapter. If it still persist there could be a cold/loose solder connection anywhere inside. Good luck.
 

xTelepathetic

New Head-Fier
Sounds like you either pick up noise with your RCA cable or a ground loop problem. I would first listen to the amp without any RCA hooked up to eliminate the RCA cables. If there is noise I would just LIFT (unhook) the ground on the AC plug or use an 3 to 2 prong AC adapter. If it still persist there could be a cold/loose solder connection anywhere inside. Good luck.
Hey, thank you for the response! I have tried listening to the amp without the RCA cables and there is still noise. Interestingly, there is no noise whenever the preamp output is used- only when the headphone outputs are. Trying the amp without a ground and only using the hot and neutral wires is a good idea. What is annoying to me is that I have had fuches look at the amp and they say that there is nothing wrong with it yet myself and a friend both can hear the noise.
 

Capt. Z

500+ Head-Fier
I have had a similar issue before as well and it turned out to be a bad cap in the power supply. However, if that was the case with your amp it would have shown up at the repair shop. It also could have been a bad connection somewhere in the amp, but then again that should have shown up in the repair shop. So most likely it has to do the the ground and the best way to check that is to listen to the amp without anything but the headphones connected, which you did. So my next step would be to disconnect the ground on the AC plug or use a cheater plug to lift the ground of the AC line. Let us know how it turns out. Maybe in the set up in the repair shop they did not have that ground loop issue, but in your and your friends house you may have a ground loop issue. Happy detective work and hopefully you be able to get your amp functioning again. It's always great when that happens. :L3000:
 

Capt. Z

500+ Head-Fier
Just wondering if you had any success?
 

xTelepathetic

New Head-Fier
Just wondering if you had any success?
My buddy has the amp at the moment. I am waiting for him to pick up a grounding adapter and get back to me. It would sure be nice if it fixes it as I would LOVE to sell this as working and get more of my money back LOL
 
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