CA-3000 the hunt begins

[vigman]

Speed tech First looksie!
So I got it round noon today and started straight up ripping it open..

Unit was in storage for a LONG time…
And not in the desert.. so there is a WEE bit O rust on a FEW of the screws..
Inside was just FILTHY…..6 wipes just to get the inside bottom clean ( er ).

AC switch is just wanked… Cut & bypass.

PS voltages were a bit weird ( power down & check it out )…
1ST just about EVERY CONNECTOR has some electrolysis on it. So a quick burnish on just about EVERYTHING I could get my hands on … touch up and clean.
So the CA-3000 has SLIVER PINS.. not GOLD ?
PS STABLE…. 1 meter kicking ( right ) showing input no out.
No voltage to the reed relay ( quick bypass ) …
HEY it wouldn't be a Mike project without CLIP LEADS!

AUDIO… 1 channel of crappy audio….
Volume control is in SAD SHAPE, EXTRA SUPER CRUNCHY
(with a side of burnt bacon ) work that about 50 time up and down it seems to like 2:30.. still no left….

Work the filter switches and low cut @ 20hz now I have left audio.. check other functions…

Yep blown transistor (s) in filter circuit ( moving on )….
Muting works good ( lever on switch broke )
Balance Spritz spritz ( ahhh better )
Channel flip..Spritz spritz ( ahhh better )

Work everything else to a FRIZZ smoother…. Cept that volume control…

Only 1 meter light works…. snap in 5 blue LED's ( yeah I know ….. GREEN )

So now I'm looking at the meter circuit No left meter in any mode … meter ok seems like source isn't there ( more on that later ) ….

So now it's kinda stable… hook it up to the bigger system in the shop…. it's not BAD… but it's not GREAT….

Clean a few more connectors that I missed… better…

So now I'm just listening and CLEANING…. this MUST have been owned by a cigar chain smoker.. I smoke but I clean my stuff… This has almost a dark yellow tar….

It doesn't " SMELL " though and it cleans up with alcohol and some elbow grease..
( 3 hrs ) and I have a LONG way to go….

So it makes audio.
It needs a LOT of work .
But it's my new BABY !!!!!

 

[vigman]

Neg 24 for left channel failing… arrgghhh

 

[Hyperion]

Looking forward to some pics Mike

 

[vigman]

You saw the 4 earlier John ?
So new Gremlin #1 left channel power supply reg board…
The neg 24 would ( for no OBVIOUS reason ) decide to drift…
The TO-220's are screwed tight ( yea gotta go back for re GOO ) …
Gonna be at it HARD this AM…….
Man, storage of these units in a semi humid zone is not a good thing.
The " BLACK DEATH " is everywhere on the inter connect pins….

 

[Hyperion]

Damn - missed 'em !

OK - more pics - if you can.

 

[vigman]

Coming up ( later ) …
ALWAYS more pix…
NOW it's starting to SOUND like a CA-3000…. YEAH!
Many funky solder connections for the output pins on the mani PS board ( CRINGE )

 

[Hyperion]

Well done Mike! - you certainly got into this one FAST !

 

[vigman]

MOOOOOOvin

From this AM we are here…. both 20/24 volt voltage reg boards re done
( see if you can catch the mistake on the Right channel tee hee hee )
and what's with the PS offset?? WHY the 4 volt diff ?

Next picture is the JUNK on the pins and this isn't a BAD one..

AND

HP board partially rebuilt…. ( time to order STUFF… AGAIN )

Impressions….
Power supply re caping & the HP board recap made a HUGH difference in output QUALITY… It's now got some HEFT where it was kinda thin outta the gate.. ( even with the 20 hz filter stuck in ) … Moving on to the Next reg board for 45 volt.

Oh who has data for how many of these were made.. is there a way to get a rough idea where in the production run mine is based on the SN??

 

[vigman]

All stop ~

Been at this since 5:30am (PST) and starting to get a bit punchy so BEFORE making a mistake.. ALL STOP BUT all 3 regs are done… and a little listening test while I let the reg's drift into CAL ( over 20 min they are ALL moving ~ 1 volt.. and going UP ) Right now the Pre is feeding my Fisher 400 going to L-100's ( Oh yeah Oh yeah ) Pix #1 everything that came out so far ( except a few that jumped in the bin ) Pix #2 49 Volt board done N dusted Pix #3 a group shot of all 3…. Next front panel removal & de SKANK, Low filter repair, meter driver repair, and look at the really F ed up power switch...

 

[Hyperion]

Wow ! great (fast) work !

You also demonstrate a very useful attribute - to know when to stop, for a while at least

 

[vigman]

Ok so I didn't stop.. I just stopped doing CRITICAL stuff......
I pulled out the front panel and have the filter board laying out ready for transistor replacement ( Post nap ) .

Under the heading you learn something new every day:
On the CA-3000 power switch one side in the AC control ( power ) the OTHER side is the feed for the reed relays..WHO KNEW??!!

So the reed muting relay NOW passes audio.. loose 2 clip leads add one.
The power switch is just SHITE... cracked, missing internal parts....

Hey Madge.. That Sansui pre amp top end is silky smooth and so soft.....
Mike your front panel is soaking in it....

 

[vigman]

Filters fixed….. a few FUNKY solder connections… but the good news my board has the factory pins going from top to bottom on the PCB's YEAH!

Side note where the coils are GLUED to the filter board is VERY close to 2 of the " feed through's " and corroded 2 connections.. BAD… all better now.

Starting on the meter board.. someones been in here before.. there is a mod….
So far the IC is good and the meter is good ( hooked it to the other channel ) now … something in the middle…Hmmmmmm

 

[JOMARK911]

I see you get quite busy with the queen. Go on.

 

[vigman]

Got METERS ?

Well that's done N dusted.. PHEW What a day!
C-11 and it's counterpart 1uf 50V NP was just FRACKED….
Since I changed 1 side the ballistics and sensivity changed ALOT so I did the other side.. I have em EYEBALLED in ( cal tomorrow )…

There is still a cold solder connection in the filter board.. if I give the board a good THWACK the left cuts out but comes right back… Don't like it , not gonna have it.

Next stop… take apart the master volume control….it's not " happy "… it works but needs a bot more finger pressure and a GOOD CLEANING!

But its sounding better and better..
ALL STOP ( no really )

 

[JOMARK911]

It's a fine sounding pre amp. One of the finest's i've heard.
What is that on the meters? blue leds?

 

[vigman]

Yep Blue LED's, the original bulbs were all blown cept 1.
I WAS thinking about BLUE in the 20K but they are to dim…
Gonna go green ( just gotta order em )

 

[vigman]

And the OTHER Oh by the way… the power rail that drives the reed mute relay… comes up SO SLOW the left turns on @ 7 volts and the right @ 10 so it's a 2 or so seconds before I get both ….Odd...

 

[Hyperion]

Oversize capacitor somewhere, in PSU or line filtering along the way?

Mike - you remind me of me - except I am slower and not as good

 

[vigman]

The unit looks MOSTLY un molested….. but never say never..
I'm thinking funky "R" somewhere… but hey the 1UF NP in the meter section wasn't my 1st choice in sussing out the meter " issue "...
John I take that as a compliment CHEERS~

 

[vigman]

Wax on wax off

Everyone is still snoozing here so I can't make noise…
But I did wax the front panel… 1st coat, MUCH better… not perfect.
but WAY better than 5 layers of cigar tar...