JVC RC-550 “EL DIABLO”: Playing with Devil

[Jorge]

straight off eBay this poor Devil was in pretty miserable condition, broken antenna and paint from some construction site, bad motor plus the usual of melted belts and rust. Cassette mechanism, as received:

I tried everything I had at my disposal as plastic jets modeller: Windex, alcohol, acetone, lacquer thinners, Naphta, Goof-Off, turpentine, but the only thing which saved me from scraping this licorice goo was lowly generic Paint Thinner. Paint Thinner removed this licorice without any pre-soaking or scrubbing: pure Magic!

Cassette mechanism fully disassembled, metal parts cleaned and oiled, rubber tyres rejuvenated with Naphta

Sintered brass cleaned with acetone, then impregnated with oil. Oily cotton stick was left in place for a few days

Pinchroller was in good shape, treatment with Naphta seems to have restored its original state. Center pin is flattened from both ends, I am not too crazy about getting a new pinchroller.

Motor grommets got Naphta treatment as well

Original belts, stretched and hardened. New belts from Turntable Needles are SBR7.2 and FBS10.5

Motor had a dead spot, plus neither motor nor control board give any provision for adjusting play speed. New motor from Pacific Stereo was bought, with CW rotation and 2.5mm shaft mod. Motor is advertised at tapeheads.net: Universal, extremely high-quality replacement cassette capstan motor available NOW!

plastic shim was used to reset the pulley at the same height

Getting new JVC antenna was pure luck: one eBay seller responded to my request by selling me like-new RC-550 antenna!
The second part of restoration was more fun because everything already worked.
To keep my “idle hands” busy I opted for a full recap of the main board.....

SORRY, I AM NOT ALLOWED TO POST MORE PHOTOS HERE


The whole story is at square-2.com:
JVC RC-550 “EL DIABLO”

 

[mancardo]

Holy crap.....nice job Jorge!!

 

[jimmyjimmy19702010]

Beautifully thorough restoration! I wonder if the mid speaker being wired out of phase was due to an assembly error?!

 

[deech]

Way to go Jorge !
Feels so refreshing to see a 550 restored from head to toe.
You rectified it from head to toe. Its a different Beast from the inside only in its old shell.
Well done and thanks for the pictures, they show the progress in detail.

 

[caution]

Beautifully thorough restoration! I wonder if the mid speaker being wired out of phase was due to an assembly error?!

If you look at the capacitor values, they're crossing the mid with a 10uF and the tweet with a 3.3uF. Isn't that fairly standard practice?

 

[T-STER]

Beautiful iconic 550 restored to working order, love it!

 

[Jorge]

Thank you guys!! Yes, for now this is my favorite bbox with just the right amount of "battle damage" to make it usable, not another bookshelf dust-collector.

Beautifully thorough restoration! I wonder if the mid speaker being wired out of phase was due to an assembly error?!

I believe not, it is wired according to the SM. Unless, of course, there was a typo and no one noticed and then production started... I found quite a few mistakes in Discman's SMs, sometimes inconsistencies in caps polarity between SM and markings on the board, but here I believe it was done intentionally. To hard-wire that "dip" we (well, at least me!) would always set into any equalizer 30 years ago

Talking about typos and caps polarity, C43 is a good example (top-right corner). All of a sudden, its polarity is not marked on the board (this is why you need a lot of photos from "before" or SM even for simple recap) and its number in the SM is C143, not C43

 

[Jorge]

Today El Diablo got RC-414 as a 'mini-me" to keep him company:

little bugger had a tough life: first worked to death (capstan's brass sleeve got worn into oval shape from 2mm to almost 2.5mm across!) and then thrown into garbage. One smart-arse listed him on ebay, another idiot (me) bought it
Restoration lasted three months, and here it is: restored and repainted into the colors of my liking: silver and matt black instead of gray; red acoustic cloth for the speaker

Garfield's fat ass, sorry, Big Heart! covers un-repaintable scratch

 

[BassHead]

Perfect beach box, strap it up...get on the bike and be gone! I've been taking my 550 everywhere I go, but I'm realizing that it's just not that portable!!

I've been searching the mini's to find a style I like...and this one is a winner!!