Anyhow, I'm interested in performing the bias mod for using high output tape.
has anyone here tried doing this?
i could only find dribs and drabs of info, such as this thing someone over at the tape op board said:
Greg recently relayed to me the procedure for modifying my MS-16 for high-output tapes. All you need to do is replace C42 on each channel's card with a ~200pF cap. I used some polyester film ones from DigiKey. It was extremely easy to do and progressed quite rapidly. It took me about an hour to do all 16.
and this quote from jim williams of audio upgrades:
I rebuilt many of these in LA back in the 80's and early 90's. Yes, it's a solid performer. No, it's not very revealing. Yes, that can be fixed. Mods I did to open them up included 600v /us LT1358 opamps for the 1 v/us slew rate 4558's that it comes with. The EQ caps were replaced with Wima FKP-2 polyprops. The bias feeder cap was changed to Wima 1k v FKP-2 so the bias could be set to +9 operating level. Set it up to +9 and it kicks. You also get a 75 db s/n ratio without the useless dbx noise (sound) reduction. I set bias using the Audio Precision analyzer with a THD vs frequency test. I got THD down to .2% at +9 db from the stock .55% at +3 db. The top end was flat out to 22k hz dipping a bit after that but still recording well into the 25k hz zone.