Problems with my Tri-Vista 300--Need some help

Thanks a lot, chris. I'll see what I can do.

Thanks Merganser. I really like the amp and want the problem fixed. I tried contacting MF by phone and they're hard to reach these days--probably because of the holidays. Are there any other ways to contact them other than the one phone number posted on their website? Thanks.

This has gotten quite ugly. I took the amp in for repairs to a shop in the electronics market here that handles all kinds of brands. I just got a call last evening with some very bad news. It seems that two of the six trivistor tubes used in the amp have gone bad already--only a bit more than a month after my purchase and brand spanking new. He also said the source selector wasn't working properly and would need to be replaced, but naturally he doesn't have spare parts for the machine because trivistor tubes simply aren't floating around. These tubes are supposed to last twenty years! How could they go kaput in only a month? What am I to do?

thanks for all the replies, everybody. We don't need to get into the merits or lack thereof of MF gear. I think they make great stuff and have a lot of integrity. But this is a rather odd problem that shouldn't be happening with a new piece of gear.

Merganser, I too, thought there were only four tubes in the amp located in the preamp stage. that's what I saw when I opened it up, but he said there were two more. Very strange. I'm going to the shop tomorrow to check out the problem. And I suspect you are very right about the source selector.

Jeffjarvis, I checked all the fuses out and the problem isn't there. While there are scams in many places in the world, I sincerely don't think this is the problem here. this guy does an incredible amount of repairs in this market with all kinds of gear.

thanks for all of your concern. I'll keep you posted as to how all of this develops. Best wishes on the new year.

Quick update. Looks like the local repair guy will be able to replace the tubes without a hitch. He tested them and said two were faulty. Called MF and they said it was their first experience with such a thing. Meanwhile, I have an order in with a tube company out of Chicago, which is temporarily out of stock. Also checked with two other companies, including Tubeworld, both out of stock. Tubeworld told me to check back in a month!

So the latest is that I'm having to wait an inordinate amount of time because the seemingly readily available tubes have been bought out for the time being. Amp has been waiting in the shop now for two weeks. Anybody have a couple of tubes to spare me? Thanks.

Thanks Chris. Looks like I may have finally hit paydirt over here. Triode Electronics in Chicago finally came through after two weeks it seems. Going to have these tubes on Friday. I was getting worried after substantial waiting that they wouldn't be able to get them. Ordered ten for six dollars each. Cheapest I've seen: www.triodeelectronics.com

MF will supply the tubes but they want to see the originals first. At least that's what the dealer said in Hong Kong. Pretty inconvenient. I'll post again after I get them by fedex next week and take them to the shop.

I want to thank everyone once again for your replies on this thread. I managed to get my amp back today with new tubes. Indeed, the original trivistors were faulty and are now replaced. Probably the first instance of bad tubes on this gear.

Secondly, there is indeed a big problem with the source selector on this machine now. Wasn't when I initially took it into the shop, but I don't doubt the repairman's integrity. I brought it back home and when i turn it on, it travels the circuit around the sources, but rather than settling on the most recent source, as normal, it starts to click repeatedly against either the top or bottom of the source array. I finally grabbed the selector and tried to forceably put it on the proper source. Finally, it stopped this strange behavior and I could listen to music again. I'm going to have to get a new selector chip and replace it in the amp. Has anyone else had a similar problem with this amp? Thanks.

check that. Inexplicably, the source selector has started to work properly again. Don't know why. Who can figure out the idiosyncrasies of circuits and electricity. I'll keep my fingers crossed in hopes that the selector continues to work properly. In any case, what a gorgeous sounding amp.

Timf, I thank you very much for your post. It seems as though our problems are very comparable both in development and solution. Like I said, who can truly grasp the strangeness of circuits and electricity. Even the best equipment can develop such strange, seemingly uncaused problems.