MDC lacquer is soft - easy to cut - and very flatly coated. However, after processing, the high treble - shakers - tambourine - mandolin picking - filigree and lace of reverb tails - etc... in the mothers (and pressings) will be attenuated, compared to the sound of mothers that are grown on fathers that are grown on lacquers (having cuts of the same program) that have a stiffer formula - thereby having more 'plastic memory.' Transcos that work have the best sound - are Trans-parent - but unfortunately the formula sometimes makes 'once-around' whooshes or scrapes or static - especially when QC'ing with headphones.
Indeed, random and repeating noises are sometimes heard in Transco lacquers used for refs - so, not always an e-forming issue - the factory knows this and tries to supply lots that have acceptable surface noise - but we've experienced many Transcos that don't have a noisy groove that nevertheless make noisy mothers. We were able to play back 'shot' lacquers which somehow survived separation and didn't take on any noise, yet the stampers made from them did have unacceptably loud, once-around, scrape-like noises or consistent static - sometimes only in one channel! This has happened with several lots of Transcos at three different labs this year. The surface noise is not visible at 150x, so, they're very small disturbances... Alas, if the issue is only in the metal, the factory can blame the lab when it might still be the lacquer formula that is the cause of normal processing causing invisible, but audible, damage to the walls of the metal groove.
Our MDC cuts did not make stampers with once-around noise, and neither did the few Apollos we tried. But 9 out of 10 Transcos this year have made otherwise good sounding stampers with preposterous noise, requiring many recuts...
One interesting theory is that something about the formula can sometimes make the silver 'grabby.' So, when the father is carefully separated from the lacquer, his silver-coated face (which has reverse-plated onto the nickel matrix) doesn't want to let go of the mandrel. A sector of slightly torn groove walls will result in a 'once-around,' sub-microscopic damage pattern in the father that will telegraph to the mother (since she is grown on the father).
Mossy will recall that someone in Canoga Park had this issue and decided that his pre-plating current was initially too low - he later posted (at Finishing.com) that his electrode connections had become resistive and limited the current until enough nickel had developed on the bottom of the father to present more electrons to the suspended ions at which point the current had a normal value. He stated that once he corrected the initial pre-plating current, the silver was better reverse-plated onto the nickel, so silver groove-tear no longer happened during separation.