kevzep
Its all about the Music
Well, I used to own this G22000, and its been away with another owner for 6 years. The guy who owned it, needed to sell and I simply couldn't come up with the funds quick enough.
However, a good friend of mine could, so for the sake of "keeping it in the circle", he bought it, I went and retrieved it and life is good.
I get to spend this week with it, as it needs a bit of work.
As most of you know these things are huge, it is almost too large for my bench, hahaha....
This far I have found and resolved these things.
1, The tuner was so far out of alignment, it gave me a good challenge getting it back, I have a love/hate relationship with Sansui's alignment instructions, sometimes you have to get creative and figure out what their whacky instructions actually mean. Notes are, its pretty much the same tuner as the G9000, same front end, same IF, Multiplex is a bit different and the meter drive for signal and tune are different. It uses the same IF board as the G9000 too.
2, When I had it, I replaced the driver transistors with 30mhz MJE15033/32 due to operator error took one channel out, at the time I never thought about it, but in actual fact the originals, 2SC2238 and 2SA968 are 100mhz devices, so the MJE's limit the performance of the amplifier.
I located some NOS devices and fitted those, dialled in the DC offset and Bias.
I ran it up both channels driven, it makes 244 watts per channel, THD is 0.001% up to just over 220watts and then it creeps up to 0.003%
Pretty impressive.
3, I didn't notice when I originally turned it on yesterday, but there are issues with the protection circuit, there is no time delay when you turn on, no Protector flashing, it just goes straight on, boom!!
Not good!!
So far I have found a dead Zener in the circuit which trips the protection, so its had no current or DC protection, it could never have worked in this condition. When I had it last it was working!!
So I am working through the rest of the issue now that the protection will actually trip which it could not have before.
So its not coming easy finding the issue, but I will find it. This morning I will trip the protection by disconnecting the input to the drive board, this loses its earth reference, and the DC offset slowly drifts up to rather large amounts of voltage, so that will do the trick, once we know its working and the vibrator is working for the protector indicator, and the protection is working and holding the speaker relays off, we can work on this time delay issue...
Af few pic's along the way....
These things are so huge, easy to forget.
However, a good friend of mine could, so for the sake of "keeping it in the circle", he bought it, I went and retrieved it and life is good.
I get to spend this week with it, as it needs a bit of work.
As most of you know these things are huge, it is almost too large for my bench, hahaha....
This far I have found and resolved these things.
1, The tuner was so far out of alignment, it gave me a good challenge getting it back, I have a love/hate relationship with Sansui's alignment instructions, sometimes you have to get creative and figure out what their whacky instructions actually mean. Notes are, its pretty much the same tuner as the G9000, same front end, same IF, Multiplex is a bit different and the meter drive for signal and tune are different. It uses the same IF board as the G9000 too.
2, When I had it, I replaced the driver transistors with 30mhz MJE15033/32 due to operator error took one channel out, at the time I never thought about it, but in actual fact the originals, 2SC2238 and 2SA968 are 100mhz devices, so the MJE's limit the performance of the amplifier.
I located some NOS devices and fitted those, dialled in the DC offset and Bias.
I ran it up both channels driven, it makes 244 watts per channel, THD is 0.001% up to just over 220watts and then it creeps up to 0.003%
Pretty impressive.
3, I didn't notice when I originally turned it on yesterday, but there are issues with the protection circuit, there is no time delay when you turn on, no Protector flashing, it just goes straight on, boom!!
Not good!!
So far I have found a dead Zener in the circuit which trips the protection, so its had no current or DC protection, it could never have worked in this condition. When I had it last it was working!!
So I am working through the rest of the issue now that the protection will actually trip which it could not have before.
So its not coming easy finding the issue, but I will find it. This morning I will trip the protection by disconnecting the input to the drive board, this loses its earth reference, and the DC offset slowly drifts up to rather large amounts of voltage, so that will do the trick, once we know its working and the vibrator is working for the protector indicator, and the protection is working and holding the speaker relays off, we can work on this time delay issue...
Af few pic's along the way....
These things are so huge, easy to forget.