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Wow! The coupling caps were nicely done but the power supply should be redone..A McShaned 240 last year that was done sold for 3275.00. It was a clean chassis and the guy did a nice build on it.
Honest amplification is better than excessive 2nd order distortion anytime.
Edits: 08/28/14Follow Ups:
Looks like a mix of Sprague Orange Drop & K40Y-9 coupling caps. I use K40Y-9 a lot, but Orange Drops is a no go in the amps & receivers I rebuild. I use a mix of K40Y-9 and vintage Vitamin Q. Some times I may use Mundorf sliver/oil on the power tube grids, but is more expensive.
An upgraded power supply is important. That MC-240 power supply does not appear upgraded in the least.
I increase the original capacitance values and add chokes were room exists in vintage rebuilds. For voltage doublers in Fishers, I open up the original can cap with the black sleeve and install two 680uF @ 250 volt caps inside.
For tube rectifier Fishers such as the EL84 based model 100 Control amp, I install a 4HY choke and extra filter cap under the chassis.
First off, the term "orange drops" is used to describe a bunch of caps with significantly different performance and construction characteristics. The 716P caps provided in my kit are film/foil polypropylene with tinned copper leads. They provide excellent performance, and work quite well in conjunction with the other caps in the kit. The lesser quality "orange drops" (225PS, 715P, 6PS, etc.) aren't as good, but the 716Ps are quite good despite the fact that they aren't "audiophile" or "boutique" caps.
"An upgraded power supply is important. That MC-240 power supply does not appear upgraded in the least."
Then you don't know what you are looking at. While the original caps were left in place for whatever reason, the power supply has fast diodes replacing the originals, voltage doubler caps that are VERY low ESR 105 C Panasonics - that are significantly (a bit over 3X) larger than original, and larger value JJ dual section caps replacing the 50 year old originals in the B+. The bias supply has a fast/soft recovery diode replacing the stock rectifier, and far better (and larger value) capacitance after the diode.
The resistors in the PS are all uprated from stock for long term durability.
The reviews I get from my audio path cap and power supply cap kits are exceptional.
The statement you made - "That MC-240 power supply does not appear upgraded in the least." is 100% incorrect. The installation wasn't what I'd like or what I'd recommend, but the parts/kits he used are top performers, and the result is a significant upgrade in performance for the amp. If you want to use different parts/topologies/etc. that's fine. But don't make statements like you did unless you know what you are looking at.
The power supply has good parts, but the execution could be improved. I posted a pic of one that is older and uses slightly different parts, but the execution is excellent. Mikey did this one, you can tell by the vast number of K40s in it! But look at how nicely the power supply was done.
Yes
Thanks for putting that up Jim...I posted that only because they are using your great name to sell it and I don't want people to think you promote this type of workmanship..I was very tempted to email the guy and say,how dare you.
Honest amplification is better than excessive 2nd order distortion anytime.
Thanks Mike. You did a super job on that 240, people should know how nicely they can be done. You showed them how!
Thanks Jim..
I'm finishing up another one as well that I will post.. I use the dual 100 F&T and the JJs but I now put two double section extra decoupling caps in even with the level 2 mods.The single 12AX7 up front is the only tube that is powered by either the left or right channel,depending on how it's split up.
That one I did on your site has Vitamin Qs and K40s...That is before I know to mix the caps.
Honest amplification is better than excessive 2nd order distortion anytime.
Sorry I misunderstood.
Sad to see one of those even had to come up for sale. At this point it kinda isn't a good thing.
charles
Proud owner of a Mikasized Sherwood S5000 - WITH IR volume control!!!!
That Sherwood is a nice amp but it's no MAC240. I sold both in the day.
Briggs
I don't think Charles was making a comparison between the Mc240 and the Sherwood..I think he was saying that it's sad that one had to come up with a rebuild like that..The components he used were fine but to execute the power supply as was done is an abomination..
The Sherwood Charles has is much better than when it was new as are these amps on rebuild when done correctly.
Honest amplification is better than excessive 2nd order distortion anytime.
Sorry -- I misunderstood. I also put my initial apology in the wrong spot.
I hope to do better as the day progresses!
Coupling caps look ok, but that bracket is a total hack job. Why not replace it all correctly, cleanly and neatly, and for heaven's sake do the power resistors......my 2 cents....
don
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