Hi All
I have been given a Summit Audio MPC100A , Reported fault is no output
On checking i can see that 3 watt 75R resistor is getting so hot its dropped out the board
There are 2 modules OP1- OP2, one or both are Bad, Can see that one is burnt up
I have no diagram and probably won't get one
I have contact summit audio, but don't expect a reply
Do you know where i can get replacement output modules
many thanks
JB
I have been given a Summit Audio MPC100A , Reported fault is no output
On checking i can see that 3 watt 75R resistor is getting so hot its dropped out the board
There are 2 modules OP1- OP2, one or both are Bad, Can see that one is burnt up
I have no diagram and probably won't get one
I have contact summit audio, but don't expect a reply
Do you know where i can get replacement output modules
many thanks
JB
Hi,
The modules are 'SA990', Summit own version of discrete aop '990' ( John Hardy's daop).
You need to contact Summit about them as you won't find substitute or can't use an other 990 kind to replace them.
They are most probably nested within a dc servo loop ( servo opamp is a op297 or op97) and there is some adjustements needed ( trimpot for the op297 probably the one on the upper left in your picture).
I've got a procedure description if you need it.
Is there a studio near your location? If there is try to reach the one responsible for maintenance in the crew and ask him if he can contact Summit for you, it might help to source the SA990. Sometimes it makes access to schematic easier too but i would not bet too much on it... worth a try though.
The modules are 'SA990', Summit own version of discrete aop '990' ( John Hardy's daop).
You need to contact Summit about them as you won't find substitute or can't use an other 990 kind to replace them.
They are most probably nested within a dc servo loop ( servo opamp is a op297 or op97) and there is some adjustements needed ( trimpot for the op297 probably the one on the upper left in your picture).
I've got a procedure description if you need it.
Is there a studio near your location? If there is try to reach the one responsible for maintenance in the crew and ask him if he can contact Summit for you, it might help to source the SA990. Sometimes it makes access to schematic easier too but i would not bet too much on it... worth a try though.
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I just took a look at my schematic collection and i've got schemo of TLA100.
The 990 are used as line drivers in these one and i would expect the same from the MPC100 ( at least the 75r resistor is present too and the adjusting trim should be 20k).
It's always funny to see those advertised as tube compressor when there is a vca ( or maybe an optocell) and the tube is only 'one stage' ( common cathode followed by cathode follower) within an ocean of opamp. 🙂
The 990 are used as line drivers in these one and i would expect the same from the MPC100 ( at least the 75r resistor is present too and the adjusting trim should be 20k).
It's always funny to see those advertised as tube compressor when there is a vca ( or maybe an optocell) and the tube is only 'one stage' ( common cathode followed by cathode follower) within an ocean of opamp. 🙂