*** SALE PENDING ON AUDIOGON ***
FS: Rare pair Quad 405 Macmod (Steve McCormack/ Mod Squad) Monoblocks – rebuilt and updated This is a rare pair of Macmod monoblocks – the product that made Steve Mccormack famous and let to the creation of the Mod Squad. Steve Mccormack took a pair of Quad 405 stereo amps, and made the ultimate version of these current dumping amps – 2 monoblocks – by removing a lot of the protection and limiting circuitry and upgrading the components. Quoting from quad405 (dot) com:
“MAC MOD 405
The respected audio designer Steve McCormack (USA) soon realized that the basic concept of the Quad 405 ("Current-Dumping") was great, but the idea was destroyed by crummy parts and a drastic protection circuitry. In consequence he offered a modification kit for the 405. The ultimate Mac Mod were mono amps. The modification contained the following changes :
•Current Limiting removed
•Improved IC fitted (LM 318)
•Faster Drivers ( Motorola MJE 15031 )
•Faster Output Devices ( Motorola 2N3773 )
•Improved Resistors (metal-film 1% by Resista Mk3 or Corning RN-60 )
•Improved Capacitors (Wonder Caps, Wima, dipped mica)
•Improved Wiring (Audioquest) and Plugs (Tiffany) The Mac Mod 405 surpasses the original 405 in every respect : It was a great sounding amp which could compete with the most advanced high end amps in these days. Harry Pearson of the "Absolute Sound" magazine wrote an enthusiastic review about it. I still regard it a pity that Quad-UK did not overtake the Mac Mod as standard, because the improved 405 is an exceptional amplifier. The only caveat about the complete Mac Mod is, that the ultimate version (= mono amps) has too much power for the delicate ESL-57 (protection circuitry mandatory !), though power output is quite right for the ESL-63.” A few years ago, I opened up my Macmods to inspect them, and discovered that the power supply caps were leaking. As a result, I rebuilt them, and they should now be ready for a few more decades of service. There are a few more details that are not mentioned in the list above. McCormack had installed a + and - voltage regulator on the board, quite a few bypass caps, ferrite beads. IEC plugs, and probably other mods as well. None of my changes are drastic: I replaced the power supply caps with 40,000uf (4x10k uf) Nichicon CE caps, the LM318 was replaced with a chip holder (so you can roll opamps) and OPA604AP, the diodes were replaced by ultrafast soft recovery diodes, and the caps were replaced by Panasonic FM low ESR caps. I did not change any of the cap values from what Steve McCormack had used This amp has never sounded better! Due to age, physical condition is 5/10. PLEASE DO NOT BUY THIS IF YOU CANNOT PAY IMMEDIATELY WITH PAYPAL. I WILL NOT ACCEPT ANY OTHER FORM OF PAYMENT. THEY ARE HEAVY. SHIPPING WILL BE VIA INSURED FEDEX GROUND. PLEASE ADD ANOTHER 3% FOR PAYPAL. I WILL BE OUT OF TOWN 3/11 to 3/16, SO SHIPPING WILL BE EITHER ON SAT 3/10 IF PAYMENT IS RECEIVED BY THEN, or SAT 3/17. I MIGHT NOT BE ABLE TO RESPOND TO EMAILS DURING THIS PERIOD, BUT OFFERS AFTER THE 10th WILL BE JUDGED CHRONOLOGICALLY.
| 
