Greetings,

Here's my second post in 5 minutes :)))

I'm thinking of possibilities to upgrade my Mac 1700, as many people like its SS pre/amp sound and I'm thinking that either my ear is defective (might just be) or there's plenty space for some critical parts replacement as most likely they're all original (it's actually in quite collectible shape).

Experience taught me that power supply upgrades / maintenance have the most pregnant effect in the sense of bringing back to spec / improvement due to new technology.

For the power amplifier (4000/50), searching here I found two recommendations, a Mallory Computer Grade cap that sounds OK as a choice to me, and a Panasonic EE series that sounds better to me but has to be near extinction, as I did not manage to find it in stock anywhere. Any other choices you guys / gals favor? Physical size, certainly, has to be at least very near original cap's size.

Regarding the multisection filtering cap for the HV PS (tuner), anybody's aware of an exact replacement? The other route, also indicated here, is using multiple Nichicon PW series caps for each section. Any other solutions apparent to anybody reading this?

My other handy trick is replacing the rectifiers with UF / MUR ultrafast type.

Any other suggestions for maintenance / upgrades for this receiver are welcome. Same stands for my other affair, tuner MR-65.

Thaank you!
Best regards,
Radu.

There's only a handful of those multi section caps available so you kinda have to figure out how to make those work or roll your own from existing production little caps.

Finding a large can cap is a little different as there are many available but actually finding one that is close to the same value and size is the problem. Sometimes, flippling through the Mouser catalag or staring at page after page of Digikey slowling loading pdf pages can yeild something worthwhile.

I actually have a pair of those Mallory can caps sitting on the shelf although they're 4800/75v with a baby blue sleeves. I must have gotten distracted and never installed them.

Can't get too excited about changing the diodes but if I was replacing a bunch of stuff underneath, I might pitch the old ones and put in the new.

I'm listening to some classical on the MR-71 now, however. It has new diodes, so go figure.

Murray

There is a nice thread on a 1700 restoration in here somewhere.



Carl

Carl,

I found two (extremely) good posts on these capacitors.

You know, when you're trying to get such a thing done, the most time-consuming part of this task is searching through all sellers for the capacitors / brand you would klnow and like, then read pages and pages of specifications to match to your existing parts or available space, and before you know it, you wasted all afternoons until deep in the night for a good three weeks or something.

That is the reason why the best sharing one can do is list part numbers with source to get it from, so only a few people would spend their time researching and all others would benefit from this kind of sharing.

So, anyway, one (extremely informative) post goes as far as attaching a parts list sourced mostly from digikey and partially from mouser (the 4000uF from digikey, for instance, not being available at this point), and another post that presents a Mallory cap that also seems to be a perfect match.

I happen to like Panasonic electrolythics more than Mallory's.

There's no resource on the multisection, though (except for the 'Panasonic article', that lists individual Nichicon FW for each section).

I guess I'm inviting everybody to share their research and findings. I promise to give good consideration to posting here as systematic a post as I can if my research gets me anywhere worth everybody's time.

Best,
Radu.

tubesandmore.com has several multisection can caps and a few 2 section caps from JJ and perhaps other manufacturers. Tubedepot.com has a few 2 section caps too.

I guess that there are others selling the C&E multi section caps as well.

Murray