I have noticed that, on some units of The River, the power supply voltages drift slightly over time. Although this drift is small, it can prevent autotune from working properly.
Checking and, if necessary, adjusting these voltages is straightforward. You will need:
- A good Phillips screwdriver.
- A small flat-blade screwdriver with a blade width of 1 to 2 mm. A small piece of hard plastic, carefully shaped to fit, is also perfectly suitable for adjusting the trimmers.
- An accurate multimeter with a display of at least 6,000 counts. Accuracy is essential: the display count alone does not guarantee it, and a basic $10 multimeter will not be suitable.
Step one: opening The Riverhttps://baloran.com/TheRiver/Open_The_River.pdf
Step two: checking and adjusting the voltageshttps://baloran.com/TheRiver/Test_Power_Supply_Reduit.pdf
When facing The River, you will find a row of two or three trimmers approximately 1 cm from the heatsink, very close to the rear of the instrument. These are small rectangular blue plastic components with a brass adjustment screw.
(https://baloran.com/TheRiver/Powersupply.jpg)
The left-hand trimmer adjusts the +15 V supply.
The centre trimmer adjusts the −15 V supply.
On the very earliest units, the right-hand trimmer adjusts the +5 V supply.
Do not touch the trimmer located near the voice board connectors.Check the +15 V supply voltage at the measurement points shown in the PDF. If necessary, adjust it to a value between +14.900 V and +14.950 V.
Next, check the −15 V supply voltage. If necessary, adjust it to a value between −14.950 V and −14.900 V, matching its absolute value as closely as possible to that of the +15 V supply. For example, if you measure +14.925 V on the +15 V supply, aim for −14.925 V on the −15 V supply.
Finally, check the +5 V supply voltage. On early units fitted with the corresponding trimmer, adjust it if necessary to as close as possible to +5.0 V, without exceeding this value.
Close the lid, but leave the screws out for now.
Firmware earlier than version 2.60Reset autotune, then run "Autotune All".
Firmware version 2.60 or laterSwitch off The River and wait several hours until it has cooled down completely, then carry out the "Learning" procedure.
For further information or assistance, please post your questions and comments in this thread so that everyone can benefit ;)