I installed a 1/4 trk play head on my 2 trk HS B-77 Revox with a micro switch to select between play heads. Its a great machine. In addition I replaced the fixed tape guide spacers with roller bearings to reduce tape issues passing through the entry and exit guides. Is the machine as good as my 300 with 354 electronics, no, is it as good as a my Ag 500-2/4 no, is it as good as the Ag 440's Audio classics has for sale, no, is it as good as my AG 300-2/4 no. But for a consumer machine it does a great job. But If I had a choice, I would have either a ATR 104 ampex or a MR-70-2. The MR-70 could capture sound that tube folks really could love, where the ATR series reduced W&F and speed accuracy were fantastic. The SS state sound wasn't that bad either, in fact it was superb.