Help getting in contact with Mikhail...

[003]

For a while now I've been trying to contact Mikhail, about fixing my MPX3. I've been calling him off and on for the past few months, with periods where I did not call.

I would either get the answering machine, which I never got a call back when I left a message, or I would get Jay, who I explained why I needed to talk to Mikhail, and he said he would let him know. Well I would never get called back from that, either. I have tried both phone numbers.

The e-mail is even more useless. Just last night, I sent the following e-mail to both addresses:

Quote:

Hi Mikhail, I have a very old MPX3 SLAM amp, the one with the silver toaster type chassis. It has some problems I would like to have fixed by you. I am not the original owner and I am aware it is well out of warranty so I do know that there would be a cost for this. The problems it has do not make it unuseable, but they are annoying. First, I can hear a faint humming sound from headphones that are plugged in to it. Even with the volume all the way down. Second, when you turn the volume up, there is a constant hum in the left channel, that gets louder as the volume is turned up. I have tried many different combinations of tubes and the problem is exactly the same. And finally, there is a problem with the volume pot. The MPX3 has the SLAM upgrade, so it sounds best with low-impedance headphones. And when you use low-impedance headphones, the volume control is very sensitive, you only turn it up a tiny bit. Well the problem is that when I try to turn the volume down to quieter levels, the right channel drops out completely. At first I though it was the tubes, but I have tried many tubes and they all have the exact same problem. I will be using this amp consistently with the Denon AH-D5000 headphones, which are only 25ohms, so the volume control will be VERY sensitive. It is already extremely sensitive with my temporary 60-ohm Koss KSC35 headphones, and I know pots can sometimes have channel imbalance problems at low volumes, so please make sure the pot it is replaced with is very good about having as little as possible imbalance. I can not afford and do not want the stepped attenuator upgrade, unfortunately. Also, the transformer sometimes hums faintly. Maybe it needs to be tightened or reseated or something. Can you fix the amp for me? Please get back to me. Best regards, Andrew

I do not have very high expectations I will get any replies. I really want the MPX3 fixed, and even if I am able to contact Mikhail, this whole experience makes me feel like it will take quite a long time to have the amp fixed, or I will just never see it again, if I never called back after the repair was arranged and I mailed the amp. Please anybody help me.

 

[nikongod]

i have always found Mikhail easy to get a hold of. odd.

in my limited experience, his "delivery time" is also pretty accurate.

 

[Akathriel]

I think you just need to be more assertive. You say I need to talk to Mikhail, I would say both J and Mikhail are some of the nicest, most soft-spoken guys and if you just stick up for yourself it shouldn't be too hard.

I have to say though I have been pissed to find that the weekend of the National meet they were out Thursday to Tuesday. I assumed someone would be at the office over the weekend but even so it wouldn't have been so frustrating if the message machine indicated this (I always got the standard message). I figured they might be gone from Friday to Monday, but I guess its a longer drive than I thought. Instead, the week after they get back, the message machine plays the standard message half the time and the "we will be out for the national headfi meet from..." the other half.

 

[kmcdonou]

Lately I've found it difficult to get ahold of Mikhail. Email's go unanswered (not that he was ever very good at answering them) and I frequently get Jay, rather than Mikhail.

He must be overwhelmed with stuff lately. I've found his service is slipping as a result. He's had my amp since the end of November for a simple upgrade. I read that he's had another person's amp for 6 months or so getting an upgrade too.

I've always had to wait to get things back from him, but this last time has sort of broken the camel's back. I don't really want to deal with him any more. Don't get me wrong, he's a great guy that makes a great product, but the delay is just too much. I think in the 2.5 years I've had a SP, it has been at his shop (for upgrades) more than I've had it at my house.

I feel your frustration, but don't count on seeing your amp back any time soon if you send it to him. At least it better not come back before mine!!!

 

[SK138]

I am also having similar problem getting hold of Mikhail as well. I called and left voice mails and sent him numerous emails. I ordered some tubes and tube adapter over a month ago. I got an email from him over two weeks ago asking me if I got the order and I replied back saying I didn't get it and still expect it soon and I never heard back since.

I know he is very busy but I thought his service would be little better than Xin. I hate to think what would happen if my beloved Toaster MPX3 needs service like yours. I know it will get done but I don't want to wait months without any words. Good luck and I hope you will get it resolved soon.

 

[003]

Quote:

Originally Posted by kmcdonou /img/forum/go_quote.gif He's had my amp since the end of November for a simple upgrade. I read that he's had another person's amp for 6 months or so getting an upgrade too.

Umm... err. Is there any members of head-fi who would be willing to take a look at my amp instead?

 

[cotdt]

You need to replace the volume pot, with something better matched and add some extra attenuation, like -20dB. Not sure what is causing the hum, though. There's like dozens of potential reasons that cause tube amp hum. Aren't you only 16 years old? How do you afford all this stuff?

 

[003]

Well, I start by never keeping more than one (expensive) headphone at a time, and I also don't spend money on expensive cables. I use the standard acoustic research interconnects from best buy. I have done tests with expensive, exotic, RCA interconnects, as well as HD650 replacement cables (when I used to have an HD650), and have come to the personal conclusion that cables do not make a difference, but I don't want to get into that here.

I cant do the work myself, everything I have tried to solder I have ended up killing (luckily, only cheap radios). Maybe it has something to do with the fact I get all my soldering equipment from radioshack, but I do not want to start testing that theory on my MPX3. Also -- I got the MPX3 much cheaper then they normally cost. Only $600 total, including a box full of different tubes, including rare and expensive ones at no extra cost.

And, I have a job.

But anyway, once you have eliminated the tubes as the source of humming, doesn't that really narrow the things it could be? The constant hum is VERY soft, and can really only be heard if you press the headphones to your ears, and the hum in the left channel only shows up when the volume is turned up more than double a volume that could be considered in any way shape or form safe, but it would still be nice to have fixed.

And the transformer hum is VERY minor. It doesn't really bother me. I just mentioned it for the sake of being thorough.

 

[cotdt]

Since you have the SLAM upgrade, couldn't you just adjust the feedback? Adding more feedback should reduce the gain and hum. Tube amps in general have some slight hum, but with a good power supply and proper gain, they should be inaudible. BTW, are you using the Noble volume pot or a stepped attenuator?

 

[003]

What is the feedback, how do you adjust it?

Mine has the volume pot, no stepped attenuator. I don't think this channel imbalance would exist with an SA.

 

[jamato8]

Quote:

Originally Posted by cotdt /img/forum/go_quote.gif Since you have the SLAM upgrade, couldn't you just adjust the feedback? Adding more feedback should reduce the gain and hum. Tube amps in general have some slight hum, but with a good power supply and proper gain, they should be inaudible. BTW, are you using the Noble volume pot or a stepped attenuator?

Normally adding more feed back closes in the sound so why do something that can improve bass but decrease overal sound quality? I agree with tubes there is normally some hum, just the nature of the beast but good rectification and filtering can go a long ways towards clearing this up. Also good grounding technique, like star grounding and going back to the ps cap for grounding really helps. Sometimes the fix is easy, sometimes not.

 

[003]

The constant hum is not so much what bothers me. I think it is either related to the transformer or grounding. But the hum in the left channel is what bothers me, and just because I listen at a volume where it is not audible does not mean there is not a problem.

I also mention the constant hum, because the MPX3 is advertised as being a brick wall between a ground loop and humming.

And I still don't know what feedback is or how to adjust it.

 

[shplorgh]

I payed for an amp upgrade in december and still nothing. Good luck.

 

[003]

*stomach turns*

 

[shplorgh]

Getting a response isn't the hard part if I call, but I keep getting the runaround (almost done, next week, etc)...