Sc2 v1.07 rear output knob V1
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As you can imagine, I take a dim view of your comment about wanting to sell it!! 😯 As for a 9dB difference, the usual reason for L/R level difference is the linearity of the input and output potentiometers…. they are never perfect and when new they are often as much as 1dB adrift at certain parts of the scale. However, a 9dB difference is virtually impossible and I would look elsewhere for the reason. The most likely cause is an incorrect connection on the input…. For balanced connections 2 is +ve, 3 is -ve and 1 is ground. All must be connected. For unbalanced connection 2 is hot and both 3 and 1 must be grounded…… if pin 3 is left hanging then the level will be at least 6dB low.
So check both input and output connections!
On the earlier V1.05 versions, we sometimes had problems with the output stage going ‘one legged’, but the later V1.07 versions did not suffer from this.
If there is a real electronic fault, I’m happy to let you have the circuit information for that model, or if you would like me to fix it, the deal is that I charge US$50 plus the cost of returning it to you. (I’m assuming you are in the US.)
BTW, when sending equipment to me for fixing, be sure to give it a low value for customs….. the risk of getting it impounded is much higher than the risk of losing it; a $25 valuation ensures it gets here without problems!
That’s good! I do get numbers of engineers with those JM compressors worried about level differences and it’s often a wiring or connector problem. I’m glad yours is OK again. That’s quite a rare piece you have; the very early ones had no output gain control, then I added a control on the back as a temporary measure while we redesigned the fronts to take the new layout. There were probably only about 10 units made like yours. OK, send it to me at the Sound House, Hunsdon Road, Torquay TQ1 1QB, UK, and I will fix it…. The fault is bound to be a faulty compression cell and I do have stocks of the original cells. I don’t have any trips planned at the moment…. Looking back over this thread, if the compressor is working at all on both channels then the problem is certain to be either one of the gain cells is faulty, or, more likely, that it has taken a knock and the relationship between the LEDs and the gain cells has been changed…. one of the gain cells has moved away from the LEDs.
It’s worth removing the plastic covers (on the gain cells); one plastic cover is over a single cell and LED, that one controls the compression meter.
The other cover is over 2 gain cells which are set close to the pair of orange LEDs (you will see when you get the cover off) The gain cells should be close to the LEDs , the closeness controls the amount of compression so compression imbalance can be corrected by moving the cells.
If you are sure you have a faulty cell, I can supply replacement gain cells as they are difficult to get. The price is $5.50 each plus $5 for shipping. (I need to confirm that shipping cost)
It’s worth giving the above a try as sending it back to the UK will take time and effort and shipping is expensive.
If you do decide to send it to me be sure to mark it clearly as being sent for repair otherwise we do get problems with customs.
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