The heatsinks are hard anodized and if the coating is in good condition, it doesn't require any additional insulators.
Double-check the solder connections for all of the heatsink mounted semiconductors (especially the rectifiers). They tend to break but appear to be OK unless you look carefully or move the semiconductor body.
The transistor against the side of the heatsink is for the fan. Make sure it's tight against the heatsink and there is sufficient compound between the transistor and the sink.
Double-check the solder connections for all of the heatsink mounted semiconductors (especially the rectifiers). They tend to break but appear to be OK unless you look carefully or move the semiconductor body.
The transistor against the side of the heatsink is for the fan. Make sure it's tight against the heatsink and there is sufficient compound between the transistor and the sink.
Dirty switch, gain set lower than the other channels, bad input signal line connection...
It's rare that an op-amp is defective causing low gain. Generally, they'll have too much DC offset or the signal is clipped.
If you try to remove any op-amp, cut the legs free from the body of the op-amp, heat the legs from the top (not touching the board with the iron) and remove the legs. Desolder the pads from the side of the board that has the most copper. Never touch the pads with the iron. Apply enough new solder to allow you to heat the solder connection without touching the pads. These old boards are very sensitive to heat.
Email me if you want the schematic diagram.
babin_perry@yahoo.com
It's rare that an op-amp is defective causing low gain. Generally, they'll have too much DC offset or the signal is clipped.
If you try to remove any op-amp, cut the legs free from the body of the op-amp, heat the legs from the top (not touching the board with the iron) and remove the legs. Desolder the pads from the side of the board that has the most copper. Never touch the pads with the iron. Apply enough new solder to allow you to heat the solder connection without touching the pads. These old boards are very sensitive to heat.
Email me if you want the schematic diagram.
babin_perry@yahoo.com
A friend purchased the AGA7.5 fuses from the following company. They were a fraction of the price at Mouser. They are not available from the online catalog but if you go to page 2 of the 'Product Catalog', you'll see them. Email them or call them to order.
Terminal Resolutions has Wire Terminals, Automotive Wire, Battery Terminals & Electrical Supplies
Product Catalog
http://www.terminalresolutions.com/circuitsection.pdf
Terminal Resolutions has Wire Terminals, Automotive Wire, Battery Terminals & Electrical Supplies
Product Catalog
http://www.terminalresolutions.com/circuitsection.pdf
Thanks Perry,
i found the fuse's also at a hardware store where i live bought a box of 20 for $10.00.
My next question is that this amp blows the a06's and a56's when you hook a speaker up to the amp.
wondering what do i check?
Im gonna replace all the outputs in this amp also since when i got the amp i noticed all of the are out of different amps like 3 have one date code then 3 more have another date code and some are new
i found the fuse's also at a hardware store where i live bought a box of 20 for $10.00.
My next question is that this amp blows the a06's and a56's when you hook a speaker up to the amp.
wondering what do i check?
Im gonna replace all the outputs in this amp also since when i got the amp i noticed all of the are out of different amps like 3 have one date code then 3 more have another date code and some are new
Which A06s/56s is it blowing?
Does it blow them if you power it up with no speakers?
Any time you have to replace blown outputs in these amps, you should also replace the driver transistors. Even if the outputs are not blown, I'd suggest that you replace the drivers since you're replacing all of the outputs.
Does it blow them if you power it up with no speakers?
Any time you have to replace blown outputs in these amps, you should also replace the driver transistors. Even if the outputs are not blown, I'd suggest that you replace the drivers since you're replacing all of the outputs.
Ok back to this amp it kept blowing the outputs in it everytime i replaced the bad one and the two beside it. I replaced all of the outputs, all the drivers,all the opamps, and a couple resistors and 2 caps.
My next question is should i check anything else in this amp before putting it back in the sink and powering it up?
My next question is should i check anything else in this amp before putting it back in the sink and powering it up?
With new outputs, drivers and fuses in the defective channel and all transistors clamped down. measure the DC voltage with the black probe on leg 3 of the outputs and the red probe on leg 1 of the same output. Do this for all 6 in the defective channel and post the voltages.
Of course, have the current limiting resistor in the B+ line.
Of course, have the current limiting resistor in the B+ line.
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