MacKlipsch Posted March 5, 2001 Author Share Posted March 5, 2001 John, What did you do to modify your 240? Quote Link to comment Share on other sites More sharing options...
johns02 Posted March 5, 2001 Share Posted March 5, 2001 Contrary to popular belief I rebuilt my MC240 with all new parts except the transformers. Hand matched all resistors to less than .1% Like Al's crossover design I mixed up the capacitors with Solen,hovland,sprague. New, faster higher current diodes. The power supply is the major mod. I used bypass caps and beefed up the power supply caps using "Welbourne Labs" "Rule of thumb" on power supply design(20-40 times the output power on caps for tubes). Makes sense because of todays recordings are much more dynamic than 1960's recordings. The normal design had 200uf on outputs and 60 uf on preamp tubes. I went to 800uf and 240uf with 1uf bypass caps. Its sort of like ALK's crossovers, get rid of the cheap old parts. The bypass caps do put a little more strain on power supply but McIntosh transformer is conservativly rated. This may be voodoo to some but in my opinion it was well worth the difference in sound. In my opinion the original parts sounded muddy and slow because of the out of spec caps (higher esr from age). Though some may like this sound I chose to change these parts. Besides would you trust a 30year old amp in your house? I also used all 1% presision flameproof resistors. The important or valuable part of these amps are the bifilar transformers. Quote Link to comment Share on other sites More sharing options...
JCturboT Posted March 5, 2001 Share Posted March 5, 2001 John, What Kef speakers are you running with your gear?Always like the 104/2...How do they sound with the Klipsch? Jeff Quote Link to comment Share on other sites More sharing options...
johns02 Posted March 6, 2001 Share Posted March 6, 2001 I'm using KEF 2way in walls w/8" woofer To answer the other question: They sound great with the Klipsch as a surround system but are adjusted 7-1/2db on side channels below the KHorns to get the same levels. Quote Link to comment Share on other sites More sharing options...
MarkF Posted March 6, 2001 Share Posted March 6, 2001 Al K. What ever happened to your Dad's 7C and 10B? My dad has his original 10B. Still works great. He is also still enjoying ALK crossovers. Actually we both are. Mark Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted March 9, 2001 Share Posted March 9, 2001 Mark, My dad's Marantz stuff got sold a long time ago. I got a lot more back for them then he paid but not like they are going for now! I wish I had waited a few more years! AL K. Quote Link to comment Share on other sites More sharing options...
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