electric.wreck
New member
A little background, then onto my question --
I run an analog home studio with a Tascam M-520 and a Tascam TSR-8 at the center of it all. Although this is my first post (on any forum actually), I've found so much help and useful information from so many of you.
I'm posting this because a) I'm at my wits end, and b) there doesn't seem to be a good source of information/pictures of the RS-20 (besides what is in the manual).
This particular unit has a problem with (seemingly random) self-oscillation(?). I run it from the M-520 AUX send 1-2 (-10dbV setting on the RS-20), then back into channels 17 & 18. At any given moment, it starts feeding back into itself -- not a squeal, more like a cracking rumble. At times, this occurs when it has been turned on only for 5 minutes; and other times it can run for 3 hours before it starts oscillating (even with no signal going in).
Things I've tried, but haven't worked:
-- Racked and separated from all other gear while still powered through the same outlet as all other gear (plugging it into other outlets causes noise)
-- Adjusted internal trim (R42 & R46) as per manual
-- Cleaned what was the remains of deteriorated foam in and all around the springs (I thought the cause could have been tiny particles riding on the springs)
-- Secured the coils on the transducers (to which the springs attach) with a dot of superglue to ensure there is no movement/vibration
-- Checked wires and connections -- both internal and external. Nothing seems out of the ordinary
-- Opened the unit while it is feeding back. When I hold my finger down on the channel A springs, it reduces the noise, but the oscillation won't stop; and I still feel a charge moving through the springs (with no signal being sent from the console). Holding down the springs on channel B has no effect, just continued feedback
-- Also during feedback, disconnected inputs and outputs, but lights on the front panel still indicate signal (oscillation)
If any of you own one of these and have the patience to open it up and compare -- am I missing anything? Should there be shielding around the transformer? Any advice/experience?
Thanks in advance!
I run an analog home studio with a Tascam M-520 and a Tascam TSR-8 at the center of it all. Although this is my first post (on any forum actually), I've found so much help and useful information from so many of you.
I'm posting this because a) I'm at my wits end, and b) there doesn't seem to be a good source of information/pictures of the RS-20 (besides what is in the manual).
This particular unit has a problem with (seemingly random) self-oscillation(?). I run it from the M-520 AUX send 1-2 (-10dbV setting on the RS-20), then back into channels 17 & 18. At any given moment, it starts feeding back into itself -- not a squeal, more like a cracking rumble. At times, this occurs when it has been turned on only for 5 minutes; and other times it can run for 3 hours before it starts oscillating (even with no signal going in).
Things I've tried, but haven't worked:
-- Racked and separated from all other gear while still powered through the same outlet as all other gear (plugging it into other outlets causes noise)
-- Adjusted internal trim (R42 & R46) as per manual
-- Cleaned what was the remains of deteriorated foam in and all around the springs (I thought the cause could have been tiny particles riding on the springs)
-- Secured the coils on the transducers (to which the springs attach) with a dot of superglue to ensure there is no movement/vibration
-- Checked wires and connections -- both internal and external. Nothing seems out of the ordinary
-- Opened the unit while it is feeding back. When I hold my finger down on the channel A springs, it reduces the noise, but the oscillation won't stop; and I still feel a charge moving through the springs (with no signal being sent from the console). Holding down the springs on channel B has no effect, just continued feedback
-- Also during feedback, disconnected inputs and outputs, but lights on the front panel still indicate signal (oscillation)
If any of you own one of these and have the patience to open it up and compare -- am I missing anything? Should there be shielding around the transformer? Any advice/experience?
Thanks in advance!