Music Angel XD-850MKIII 300b integrated amp

[mjaymc]

Ok, I know I shouldn't have but I bought this amplifier. I am intelligent but uneducated in electronics except for the basics.

When this thing arrived at my home (in Israel) I plugged it into 220V electrical outlet. We have standard European system here. I'm an American but at least I understand that much. I bought this device to use in Israel.

It worked great, sounded nice for about 3 weeks. And then a fuse blew. I replaced the fuse and it istantly blew again. So, being the smartass, dumbass that I am I put foil over the burned fuse to see what would happen. The amp played beautiful music but then smoke began coming out of the power transformer. (at least that's what I think it is) I disconnected it immediately from the electricity and no one in Israel seems to have a clue about anything but transistors.

Should I buy a new transformer online and simply solder it into place with the same connections?

Thanks for your help.

[century tek]

To me, it sounds like one of two things. Crappy designed rectifier tube with poor quality control when made, and/or the first power filter capacitor is breaking down under stress. Is the Music Angel amplifier you are talking about one of those chinese or korean made amps from hong kong? I have never had anything good to say about those things. Other people swear up & down that they are the best amps ever, and other people say they are just junk. The "junk" people have said that they will play for a few weeks or maybe a year at best, then something happens. What category do you fall in?

[andyjevans]

Is this the amp with DCC90 (3a5) into 2a3 into 300b?

A few people bought these in London, and they sound great - this is an all-DHT amp and an excellent tube combination.

But friends here also had problems. There must be threads about this amp - it would be worth rebuilding it but you'd have to give it to someone really familiar with tubes. It has an unconventional biasing system for the 3a5 for starters. Unfortunately I believe it has PCBs which are harder to tweak than point to point wiring.

If it were mine I'd use an outboard filament supply for the first two stages and swap the 3a5 for something like an 01A or ideally a 26. But all this would mean you were pretty familiar with what to do.

Andy

[mjaymc]

Thanks guys. I've got the RCA complete electronics school on disk. It may take me a year to get through it. Quite a bit more difficult than building a PC.

[mjaymc]

I consider it junk at this point. But I have the basics to rebuild it my way. I just need to educate myself.

[Audiofanatic]

Hi I found this on the net.
I don't know if it's the same amp.

Music Angel XD 850 MK III - ELEKTOR.fr | Électronique : Analogique Numérique Embarqué Microcontrôleurs Audio Test Mesure

BTW I don't speak French


Audiofanatic

[mjaymc]

Music Angel Naked 002.jpg

[zman01]

mjaymc, be careful with insides of your amp - be sure to go all of the safety instructions - u can find some guidelines at this forum. I've read that their is enough current stored inside tube amp components to kill a human being.

[DJDestiny]

Originally Posted by mjaymc

Thanks guys. I've got the RCA complete electronics school on disk. It may take me a year to get through it. Quite a bit more difficult than building a PC.

Building a PC , isn't hard at all , let me tell you , making a regulated power supply is much TOUGHER then building a PC , and that's honestly , easy .
But anyway , i'm not to comment on you , i'm quite bad , can't design a circuit properly .

But who cares ? I'm a student in secondary school and they do not teach anything beyond how to make a moisture sensor .
Sure , i might be just plain talking , i built myself a 8W guitar amp

[mjaymc]

Thanks for your input guys.