SonoruS (reVox) PR99 R2R Playback Mod

To indulge myself in the Tape Project Master tapes, I started off by buying a Technics RS1520 from J-Corder and shortly afterwards shipped it to the UK to Tim de Pavarachini for his full modifications. While I was waiting for this machine to return I came across SonoruS who mentioned that he had modified a reVox PR99 and would I like to have a listen. The reVox is much nicer functionally than the Technics, the PR99 mk II and III both have a real time digital display that shows hours, minutes, seconds that can be read even across the room. The Z function allows the machine to be set in repeat mode for a portion of music, a whole song or a whole tape. For demonstration purposes its v handy to be able to locate tacks, just by rewinding to a predetermined point. As for sonics, once SonoruS demonstrated the differences between the modified Studer A810 and the modified PR99 mk I; we pressed ahead and I bought a MK II and a mk III and had SonoruS modify the mk II for Playback & Record and the mk III for Playback only. (If you need to record, we could discuss the MK II instead, though it will be more expensive) Our experience of the SonoruS mods is that the modified player is better defined, more articulate bass, it is also more extended. As the SonoruS is quieter, it digs out more inner detail, along with greater dynamic range. The midrange ; high frequencies also benefit from much greater transparency. The soundstage is wider, deeper & more three dimensional. Normal American reVox B77 /PR 99 are not ready for The Tape Project Tapes; as a normal American market machine's EQ is set up for NAB. The Tape Project are using the European IEC or CCIR EQ. Master Tapes are also available from Opus 3 and Groove Note and others. Here is a brief over-view of what was done to my reVox PR99 mk II and mk III by SonoruS: 1. Service the basic machine; lubricate the pots, replace light bulbs, switches - bring back to original spec. 2. Modify the playback board; change NAB to IEC EQ, the audio / record(optional) PCBs are completely revised - 150+ new parts are added. 3. Modify the Power Supply so that the Audio electronics are buffered from any noise on the AC. 4. Remove the muting circuit, while the tape is fast forwarding / rewinding. Arian feels that the muting circuit veils playback somewhat so he has removed it entirely. 5. Rewire the monitor circuit so that the playback is now direct from the heads, leave all the existing inputs /outputs alone, add a new pair of RCA outputs. OFC Copper in Teflon dielectric cabling used. The major change between the MK I and the later MK II and III is that the earlier machine had a much simpler circuit for the playback PCB, so the sound travels through less components. So in the case of the Sonorus PR99 mkII or III, it uses a heavily modified mk I Playback PCB. The power supply is buffered so that the ground signal no longer passes through the audio circuit. On a stock machine, noise in the AC line could corrupt the audio signal. A modified SonoruS PR99 is more articulate sounding than a stock Studer A810. Scott Johnson supplied the RC receiver, its mounted on top, its the black box between the reels, with the red LED. Scott supplies a basic Sony RC that controls, STOP, PLAY, FF & REVERSE. Its enough - a pity that it does not control the Z functions. However Arian needed to modify power supply line on the RC connector to get the Receiver to work properly. As we borrow a SonoruS ATR10 for CES &; Newport every year, we no longer need the two PR99, so we are selling the PR99 MK III as seen in the photos. It was recently serviced by SonoruS and is ready to ship. Price includes: Remote Control (generic RC) & Receiver Copy of the Owner's Manual Power Cord NAB Adapters 1 Pick Up Reel (Empty) Please do not hesitate to ask any questions. High Rez images can be sent on request. Paypal plus 3.5%. Personal cheque is fine, though it will need to clear before shipping. Collection from San Juan Capistrano is OK. Thanks