it most probably had fake since the outputs transitors "Toshiba" are NLA for a while now....i dont know where the service parts came from since i was not the one who did inital repair on it.
it played fine and well for 5 years solid and rocked well too few times so its kinda worrying.
i do have proper test/repair equipment believe me.
i will investigate open pots. it may had overheated too but when it blew it was barely playing and was most probalby dead cold.
it played fine and well for 5 years solid and rocked well too few times so its kinda worrying.
i do have proper test/repair equipment believe me.
i will investigate open pots. it may had overheated too but when it blew it was barely playing and was most probalby dead cold.
Hi Pat,
I believe you. It is the other folks out there I am worried about. These days I check everything someone else did. I often find serious issues. A customer thinks everything was done properly if it makes noise and doesn't immediately burn out.
I bought a Yamaha PC2002 for myself "working fine". It came from a major recording studio I know. It failed THD specs badly, upon opening it I found (among many things), one channel had blown. The idiot fixed it by removing one shorted NPN and one shorted PNP output. Didn't even leave the screws, no new grease on the others. Looked on the other channel, wrong mixed outputs. Serviced in Toronto, wonderful. Two new sets of output transistors and other work. Now it performs better than average. The studio tech didn't do the work, it was purchased from another studio in Toronto. He didn't check it.
You cannot trust anyone these days Pat. Very few people understand how to repair an amplifier.
I believe you. It is the other folks out there I am worried about. These days I check everything someone else did. I often find serious issues. A customer thinks everything was done properly if it makes noise and doesn't immediately burn out.
I bought a Yamaha PC2002 for myself "working fine". It came from a major recording studio I know. It failed THD specs badly, upon opening it I found (among many things), one channel had blown. The idiot fixed it by removing one shorted NPN and one shorted PNP output. Didn't even leave the screws, no new grease on the others. Looked on the other channel, wrong mixed outputs. Serviced in Toronto, wonderful. Two new sets of output transistors and other work. Now it performs better than average. The studio tech didn't do the work, it was purchased from another studio in Toronto. He didn't check it.
You cannot trust anyone these days Pat. Very few people understand how to repair an amplifier.
i am on the fence right now to decide to fix the 220 or not, since i am not able to find proper source of the MT-200. I also realised that the main pcb is like a 230....subtle difference, miller caps added here and there,...
Same thing happened when i fixed two BGW7000 with the elusive 2n3773. There is a ton of 2n3773 for sale on ebay. They are all counterfeit. I characterised them on a Techtronix curve tracer and they all failed. I poped open a few and the silicon die is like 4x smaller than "real" ones....luckily i found some nos ones from a french seller and confirmed they where the right ones, with a price too....the BGW's rock on since then...i have a thread somewhere about that on other forums (10 years ago)....this situation just get worse with time imho, it gets harder to maintain old equipment like that.
Same thing happened when i fixed two BGW7000 with the elusive 2n3773. There is a ton of 2n3773 for sale on ebay. They are all counterfeit. I characterised them on a Techtronix curve tracer and they all failed. I poped open a few and the silicon die is like 4x smaller than "real" ones....luckily i found some nos ones from a french seller and confirmed they where the right ones, with a price too....the BGW's rock on since then...i have a thread somewhere about that on other forums (10 years ago)....this situation just get worse with time imho, it gets harder to maintain old equipment like that.
I use current transistors for repair where possible. You're right about old transistor numbers most often being fakes, even ICs! It isn't worth even trying parts from unknown sources. Yes, the 230 is very close to the 220, mostly cosmetic differences. I'll just say, avoid the 440 and 450 amplifiers.
BGW's are good amplifiers. Reliable, good performers.
Where are you located? I hate to see something hit the trash in case you don't want to repair it.
BGW's are good amplifiers. Reliable, good performers.
Where are you located? I hate to see something hit the trash in case you don't want to repair it.
i am in Quebec. its been in the trash for 10 years before i gave it to my friend who fixed it and then gave it back to me loool...i plan to fix it for sure, i like this amp because it is dead silent.
Hi Pat,
Good then.
Try to figure out how to mount current semiconductors to that heat sink. I've looked at them wondering what to do if an output fails in the future. Lately I haven't had to replace any, but I am out of the originals. Using more, smaller outputs may be the answer, or mounting the larger packages sideways and maybe using a new PCB for the output section.
Good then.
Try to figure out how to mount current semiconductors to that heat sink. I've looked at them wondering what to do if an output fails in the future. Lately I haven't had to replace any, but I am out of the originals. Using more, smaller outputs may be the answer, or mounting the larger packages sideways and maybe using a new PCB for the output section.
there are some peoples who suggest theses, but afaik they are counterfeit as well imho
https://www.ebay.ca/itm/332302574204
https://www.ebay.ca/itm/332302574204
Sorry to hear that Pat.
You have a Proximity? I have one here, and repaired one decades ago. Those are fire hazards, I would not connect it to anything.
I'm not sure about them. I have doubts. You can test them as soon as you receive them I guess.
You have a Proximity? I have one here, and repaired one decades ago. Those are fire hazards, I would not connect it to anything.
I'm not sure about them. I have doubts. You can test them as soon as you receive them I guess.
i trashed all that was about the proximity. they kept burning on regular basis, was part of a friend DJ set-up who was carrying them all around with the BGW's.Only the BGW survived, and the Nikko and the freaking heavy QSC clone (CASII), and a Rodec Mixmaster. I have all thoses now.
i kept only the power transformers of the Proximity, i think.
i kept only the power transformers of the Proximity, i think.
lol!
The transformer and the case is the only safe thing about that terrible design! No speaker protection at all. Not enough cooling. Just awful.
The one I repaired caused five fires in one room at the same time. It was insurance and I agreed to repair it only if they promised to prevent its use ever again. I did repairs for this insurance company and they said they had to repair it. I refuse to service them normally.
The transformer and the case is the only safe thing about that terrible design! No speaker protection at all. Not enough cooling. Just awful.
The one I repaired caused five fires in one room at the same time. It was insurance and I agreed to repair it only if they promised to prevent its use ever again. I did repairs for this insurance company and they said they had to repair it. I refuse to service them normally.
Marcel, you're telling them how to get a 100db plus signal to noise ratio !!
Low gain after the volume control is key.
Low gain after the volume control is key.
I have a Nikko TRM-650 integrated amp, from which I removed the power-amp stage, now being used as a pre-amp. While the power-amps sound was not really nice compared to todays high standard, the pre-amp section is very transparent and absolutely silent. So I would be very surprised when a Nikko pre-amp of the same aera would have heavy hiss. Seems there is something wrong with it. I would first remove any "improvements" done to active parts.
The Nikko engineers were very competent IMO, not like the Chinese hobbyists which design todays audio gear. By the way, happy new year LJM!
The Nikko engineers were very competent IMO, not like the Chinese hobbyists which design todays audio gear. By the way, happy new year LJM!
lol!
Hi Turbowatch2,
You now have a big, heavy preamp!
Are you thinking of installing an excellent DIY amplifier section?
Hi Turbowatch2,
You now have a big, heavy preamp!
Are you thinking of installing an excellent DIY amplifier section?
After removing the power amp PCB and testing the pre-out, there is a stereo LM3886 board waiting to go in there. Voltage and size will fit.
The power amp just sounded much worse then I remebered from years ago. A-B compared to a cheap D-amp it was ugly. That was surprising but clearly audible with a full range speaker I used to test it. I didn't want to bother with the stone old amp for some minor improvement. It comes from a time were "all amplifiers sound the same" was not discovered. The LM3886 is just a very nice amp chip, reliable, great safety and not expensive.
The power amp just sounded much worse then I remebered from years ago. A-B compared to a cheap D-amp it was ugly. That was surprising but clearly audible with a full range speaker I used to test it. I didn't want to bother with the stone old amp for some minor improvement. It comes from a time were "all amplifiers sound the same" was not discovered. The LM3886 is just a very nice amp chip, reliable, great safety and not expensive.
I used to have complete Nikko system, plus some receivers. Two preamps i had were very quiet. I replaced back to back capacitors in signal path with either mp cap if value was small, or real bipolar cap if it required big value. Both pre sounded great. I gave one to a friend and sold other on ebay. It was original full fet model, highly collectable.
Hi adason,
Yep, the earlier stuff was pretty good. I sold the last Alpha III in Canada, Mosfet amp. I had an Alpha II ('cause I couldn't find an Alpha III).
Hi Turbowatch2,
I think that amp is broken in some way. They may not have been the best, but they were better than many amps. I'd have to review the diagram for your model to really see.
Yep, the earlier stuff was pretty good. I sold the last Alpha III in Canada, Mosfet amp. I had an Alpha II ('cause I couldn't find an Alpha III).
Hi Turbowatch2,
I think that amp is broken in some way. They may not have been the best, but they were better than many amps. I'd have to review the diagram for your model to really see.
preamp was noisey prior to the resistor changes and opamp swap. the fact is that it is less noisey since my changes. so i wont go back.