Pair of McIntosh MC40 tube amplifiers, generally regarded as the
finest sounding Macs after the marvelous MC-225.These sound magnificent, with considerable love and expense expended on upgrading the power supply and signal path components without altering the basic topology. This applies to both amplifiers: Power supply caps are now premium Elna Cerafines
caps: 100uF/500V and 47/47uF/500V bypassed with Kimber Kaps for a fast, tight, powerful bass response with zero hum and noise, (original spec: 60/35/15) Hexfreds ultra-fast-recovery diodes provide a superior tone to the original silicon rectifiers - smooth and grain-free, more tubelike, the best attributes of tube rectifiers and solid state. This alone made a very audible difference for the better. - see http://www.soundstage.com/maxdb/maxdb091998.htm Resistors were checked for accuracy. If on-spec, they were left in.
I replaced some with precision Holcos. Power resistors were fine and stayed in - carbon comp, best for this application. The volume control was removed and the hole was filled with Kimber's Ultraplate Rhodium plated RCA jack with Teflon dielectric. Wired directly to the 12AX7 tube with silver cable. There is no volume control now - nor will you need one. I did install trimpots for fine level control but these are not wired in at present. They match exactly. Bypass and coupling caps are Kimber metallized polypropylenes,
some of the best sounding caps for accurate, transparent audio.
The stock MC40 (as do most Mac tube amps) had a slightly woolly sound
and these caps clear up the mids without compromising the overall warmth
and musicality of these remarkable amplifiers.
re Kimber Kaps:
("The key to making a great sounding cap is in the details, and this is where the Kimber Kaps excel. By using high-purity tinned copper leads, a proprietary lead/foil bonding process, and a special heat treatment, all harshness and graininess is eliminated. The low dissipation factor of the extremely pure polypropylene dielectric and the heavy-duty metallized film eliminates signal degradation for precise sound reproduction. The Kimber Kaps are known for their clarity and natural presentation, providing the highest degree of performance..."
also check http://www.russandrews.com/product-KIMBER-Kaps-5900.htm The output tubes are matched pairs of GE 7581A's with flesh colored bases (not cheap - see http://www.vacuumtubes.com/6l6.html), tested and measuring a strong 85 + on a B&K 747 where 65 is acceptable.
The input tubes will be NOS Mullard ECC83, in their original boxes. Others are E-H select. You won't find a better sounding pair of MC40's anywhere - and having
independent circuits and power supplies makes the superior to the formidable MC240 which is two of these in one chassis sharing a common PS. Having a pair of monoblocks allows you to put them close to each speaker with a minimum of signal robbing speaker cable, and a longer low-voltage, line-level interconnect to each amplifier where resistance is not a factor.
Input resistance is about 100K, so a few ohms in the cable are insignificant. Low capacitance, however, is of utmost importance.
(like mine: http://marc.stager.com/silver/) There is some pitting in the chrome and they could use a good polishing. I didn't want to damage the silkscreen so I didn't try to pretty them up. If you are looking for a pair of magnificent sounding McIntosh tube amplifiers to listen to, you won't find a better sounding McIntosh than these at any price - nor any new production amplifier at anywhere near this price... which is $1800 for the pair. If you stop by to pick them you're welcome to have a listen. Please don't hesitate to call with any questions or comments. re. Audioasylum feedback: I'm relatively new here, but at eBay my
feedback ia 194 100%
http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback2&userid=stager_sound&ftab=AllFeedback Marc Stager
) ) ) ) )
Stager Sound Systems
New York City
http://marc.stager.com/silver
tel: 212-595-4065
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