Probably the same mod I just did to my Aesthetix Io, swapping most of the Mills Military for Roederstein precision metal film resistors.
The Roederstein's are the standard now. Quieter, lower distortion and superior resolution.
Part of the upgrade on my Io was a slight correction in the RIAA curve. Obviously this would not apply to the Calypso as it is a line stage only.
Those with Io's more than one year old, be aware of this upgrade. It's extremely audible and very inexpensive.
The Roederstein's are the standard now. Quieter, lower distortion and superior resolution.
Part of the upgrade on my Io was a slight correction in the RIAA curve. Obviously this would not apply to the Calypso as it is a line stage only.
Those with Io's more than one year old, be aware of this upgrade. It's extremely audible and very inexpensive.