Treasure or trash MC240
- Thread starter Wardsweb
- Start date
clydeselsor
Lunatic Member
Looking good! :thmbsp:
drillher
Super Member
In my opinion it doesn't matter how original the surface is on the chassis as far as the need to replace the old components.The electrolytic caps in the power supply and elsewhere are most definitely bad.The bumblebee coupling caps are very likely leaky,and the selenium rectifier can fail at any time.I don't understand wanting to have all of the components original if the plan is to use the piece at or near its' full potential.
Dave
Dave
I'm right there with you. :thmbsp:
I'm not building this to collect or sell. It is for me and remember what I always say, "you are the only person who has to like your stereo". So to that end, I like the color look and I will replace every cap in the amp, along with the selenium rectifier. I will be running 7027A instead of the standard 6L6GC.
Westy56
A symphony of paradox
I have tried Sylvania 7027A's, SED winged C's, RCA blk plates and GE's.
The GE 6l6GC is the best sounding of the bunch followed by the SED's to me.
Steve
drillher
Super Member
Jim McShane supplied me with the right high speed replacement diodes as well as Russian PIO coupling caps.I believe that the original bumblebee caps are PIO,so I like the idea of replacing them with PIO.The thread by gogofast on his Mc240 re-build is excellent and very detailed.A tip that I can give you is not to try untwisting the leads of the old components from the solder posts.The posts can be easily broken off.What I did was to cut the lead off close to the post and then used a clock makers cutting broach to open the hole closed by solder so the replacement lead can be passed through,twisted on the post and then soldered.You can use a twist drill in a pin vice if you don't do clock repair.Happy Friday.
Dave
Dave
Thanks for the insight Dave. I'm alreay emailing back and forth with Jim. His schematic was for the 2nd generation so I sent him my 1st gen. There are only two caps in the 2nd gen that are not used on the 1st gen. So, I'll be ordering his suggested replacements for all.
What was it you didn't like about the 7027A? I was looking to get more power out of the amp for some JBL C50 Olympus speakers, but if the 6L6GC sound better, I may have to rethink my choice.
What was it you didn't like about the 7027A? I was looking to get more power out of the amp for some JBL C50 Olympus speakers, but if the 6L6GC sound better, I may have to rethink my choice.
Westy56
A symphony of paradox
You and I are using different speakers. I like the 7027's
The human voice sounds so real with the GE's compared to the others.
I literally got teary eyed and all emotional when I heard Etta James sing Almost Persuaded. That set the hook.
Not one piece of my gear matches the magic (not necessarily flat) dimensional sound of the 240.
I use the deuces to fill in the lower bass that may be missing with the mac.
Steve
7027's were may favorite after years of tube rolling a MC240
+1 on the NOS GE
+1 on the NOS GE
Shhhh! If we keep talking up the superiority of the GE GCs over just about anything else on the planet, they're going to start outpacing the blackplate RCAs in price! Right now they're still fairly inexpensive...
Westy56
A symphony of paradox
Shhhh! If we keep talking up the superiority of the GE GCs over just about anything else on the planet, they're going to start outpacing the blackplate RCAs in price! Right now they're still fairly inexpensive...
In a selfish way, I was regretting the GE comment.
I'm running some black plates in my 70 now. I've always thought them bass shy.
They irritate me like tele smooth plates. :sigh:
Steve
I don't have any issue with the smooth plate Teles (my Fisher 800B is running a mix of Fisher-labeled Tele ribbed and smooth plates in all of the 12A_7 positions), but I absolutely HATE GE's 12A_7 tubes. I picked up two NOS RCA 12AX7s in a big tube lot, and couldn't have been more disappointed to find relabeled GEs inside. :sigh: At least as far as Fisher gear is concerned, it's difficult to impossible to beat Sylvania's 12A_7 tubes.
Personally, I have enough good GE GCs tucked away to keep my Fisher 70A and 70AZ happy for a very long time. I still snap up any I can get at a reasonable cost, though. One of these days they're going to take off on us...
Cool! Where did you find those? Got a link?
These are DIY. The distance between GND & 8 ohm terminals is the same for speaker binding posts. I could have removed the barrier strips and mounted the posts direct to the chassis, but I didn't want to have all the extra holes visible. So, I cut the mounting posts shorter and soldered some solder tabs off some old speaker terminal cups to them.
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Wow, quite the DIY this turned into, and quick, too! You've done a beautiful job on this amp -- it's really gorgeous. :thmbsp:
Very nice!
