The P is guru of logistics also.
=> www.diyaudio.com/forums/solid-state/90045-serial-parallel.html#post1054816
=> www.diyaudio.com/forums/solid-state/90045-serial-parallel.html#post1054816
Lambda, I know this is an old post. I just acquired a Forte Model 3 amp and want to convert it into class a. Wonder if you can give us instructions and maybe photos of the class a conversion of your Forte amp. Thanks.
It's been awhile. The Forte 3 had the
two transformer secondaries in series and the two channels shared
the single DC supply.
I unscrewed and reconfigured the leads to give
two DC power supplies -- one for each channel with
each one using its own secondary.
I didn't have to replace or buy anything -- just replug what was there.
Be careful when you bring the amp up because the bias pots
are very sensitive. I blew a couple of rail fuses.
two transformer secondaries in series and the two channels shared
the single DC supply.
I unscrewed and reconfigured the leads to give
two DC power supplies -- one for each channel with
each one using its own secondary.
I didn't have to replace or buy anything -- just replug what was there.
Be careful when you bring the amp up because the bias pots
are very sensitive. I blew a couple of rail fuses.
Buying a Forte 1 or 3 with cold heatsinks
is a common problem. Mine had that too.
In most cases, you just need to increase the bias
by turning the pot on each circuit board.
You have to be very careful because they are VERY sensitive.
As I mentioned, I blew out a couple of rail fuses before I got it right. Increase the bias until the heatsinks can only be touched a few seconds. There is a post on this forum, on how to use a voltmeter to get the
right bias on this amp.
Also, make sure that the thermistors are in contact with the heatsink.
Mine had one loose which negatively affected the sound.
is a common problem. Mine had that too.
In most cases, you just need to increase the bias
by turning the pot on each circuit board.
You have to be very careful because they are VERY sensitive.
As I mentioned, I blew out a couple of rail fuses before I got it right. Increase the bias until the heatsinks can only be touched a few seconds. There is a post on this forum, on how to use a voltmeter to get the
right bias on this amp.
Also, make sure that the thermistors are in contact with the heatsink.
Mine had one loose which negatively affected the sound.
Forte and power cord
If you want to change the power cord to one of these "black Magic" types what in heaven's name are you going to do with the cables running from your wall socket to the breaker board in your home and then the larger challenge is how to change the cables from your breaker board to the transformer which feeds your home (and others). Then you need to consider changing the cables from the local transformer to the main power lines. Oh and I forgot what about changing the primary wire (just plain old copper wire) in the power transformer?
Do you honestly believe that changing 1 metre or so of power cable will change the sound in your speakers where you have many kilometres/miles of dumb copper wire between your amplifier and the power source?
It is the same as putting one great tire on your car and leaving the other three as junk and expect that now your car will handle like a race car.
Electrons are dumb!
If you want to change the power cord to one of these "black Magic" types what in heaven's name are you going to do with the cables running from your wall socket to the breaker board in your home and then the larger challenge is how to change the cables from your breaker board to the transformer which feeds your home (and others). Then you need to consider changing the cables from the local transformer to the main power lines. Oh and I forgot what about changing the primary wire (just plain old copper wire) in the power transformer?
Do you honestly believe that changing 1 metre or so of power cable will change the sound in your speakers where you have many kilometres/miles of dumb copper wire between your amplifier and the power source?
It is the same as putting one great tire on your car and leaving the other three as junk and expect that now your car will handle like a race car.
Electrons are dumb!
Do you know what the bias value is for Forte 3? Tried googling it, can't find it. Thanks.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.