hi all
i have just brought an american market yamaha a45 with a 110v supply (we have 230v here in nz) and a problem with the pretection relay coming on (common problem with these, no big deal)
it is a distant relative of the yamaha avx-20 amp that i have had for more than 20 years, and loving yamaha gear i couldnt resist buying what is a rare piece in my country (guy brought it in california and moved here)
im looking to mod it a bit:
rewire speakers b switch to bypass tone and balance etc to go direct to the main amp
add relays for source switching instead of chips
add internal tube phono stage and remove op amp
add tube preamp stage and remove main preamp
remove 120v transformers (main and standby) and replace with 230v units with a bigger main
which brings me to my question, i believe this amp to be 2x100wrms output, due to the fact that i am forced to revise the power supply, i was looking at building a massive power supply in a seperate cabinet to power this unit, in short, do you think grossly oversizing the stock supply (obviously adding a high voltage supply for the preamp tubes)by twice or three times would improve performace to a degree that it would be worth it?
its hard to gague by just looking at it, but if im right, the larger the supply, the less likely there is to be distortion at higher volumes?
i have alot of transformers including a massive toroid with all the right voltages for this amp (24v and 24-0-24) from a big denon 5 channel amp, that wont fit in the yamaha case, what are your opinions on this?
the power transitors are toshiba 2sa1302 and toshiba 2sc3281 one each channel in push pull (looks like)
thanks in advance guys, here is some pics:
mike
i have just brought an american market yamaha a45 with a 110v supply (we have 230v here in nz) and a problem with the pretection relay coming on (common problem with these, no big deal)
it is a distant relative of the yamaha avx-20 amp that i have had for more than 20 years, and loving yamaha gear i couldnt resist buying what is a rare piece in my country (guy brought it in california and moved here)
im looking to mod it a bit:
rewire speakers b switch to bypass tone and balance etc to go direct to the main amp
add relays for source switching instead of chips
add internal tube phono stage and remove op amp
add tube preamp stage and remove main preamp
remove 120v transformers (main and standby) and replace with 230v units with a bigger main
which brings me to my question, i believe this amp to be 2x100wrms output, due to the fact that i am forced to revise the power supply, i was looking at building a massive power supply in a seperate cabinet to power this unit, in short, do you think grossly oversizing the stock supply (obviously adding a high voltage supply for the preamp tubes)by twice or three times would improve performace to a degree that it would be worth it?
its hard to gague by just looking at it, but if im right, the larger the supply, the less likely there is to be distortion at higher volumes?
i have alot of transformers including a massive toroid with all the right voltages for this amp (24v and 24-0-24) from a big denon 5 channel amp, that wont fit in the yamaha case, what are your opinions on this?
the power transitors are toshiba 2sa1302 and toshiba 2sc3281 one each channel in push pull (looks like)
thanks in advance guys, here is some pics:
mike

