I have a Marantz 1060 amp cannibalized out in the barn that may have a volume control still on it. The manual states it is part number RM0254021, a variable 250K ohm resistor. I also have the service manual for the Marantz 2230, which states it uses the same part. It may be possible that the 2270 uses the same part. I'll have to check tomorrow it the volume control is still intact. I'll let you have it if it looks like it's good. I'll be in touch.