SX-750 recap

[gyrene]

I'm about to delve into a recap on my SX-750 but do not have a schematic or service manual for it.
I tried hifiengine.com but they only have one for the sx650.So I thought I'd use the parts list from the 650 and then fill in with whatever else I need as they reveal themselves to me during the process.
Does anyone have a parts list for a 750 that they could put online here or email me.
And what about those two big beer cans in there? the 15,000uf 50v ones? will current 21st century replacements be the same dimensions or have they miniaturized those babies too?
Thanks.
Should I take pictures as I go along and make a thread on this?
Whatdaythingk?
And BTW what do you all think about upgrading the opamp?Benefits? Of course you know what I'm looking for here...astounding performance because I'm upgrading a 32 year old device with a 21st century i.c.
I see someone has done it with good results going from a ta136P to an opa2604 with some slight modification as far as mounting goes.Here is the link:http://www.diyaudio.com/forums/parts/46179-replacement-ta7136p.html
Any thoughts?

 

[markthefixer]

www.kallhovde.com/pioneer/

of COURSE the new caps are smaller, that would be too easy.....

the only reason(s) I would do an opamp conversion is inability to get 7136's or someone ASKED me to.
IMHO there won't be much of an audible difference on the 750.
but don't let that stop you.... :stupid:

 

[gyrene]

"Well thank you so much" said Gyrene bowing slightly at the waist.
Got it and stored it on my desktop.
As for the op amp I'll just leave them alone.I don't see what could go wrong with them.I mean they have a half life of maybe 50M years of so and what symptoms would I realize anyway necessitating a replacement.
It was just a curious thought.
After all its all about the music and glorious reproduction!

 

[gyrene]

Let me add this to the mix.
Is it worth re mounting the transistors on the heat sinks?
Or leave well enough alone?

 

[larryderouin]

Up to you. If it were me, and there were no problems, I'd leave well enough alone. But if you're having overheating problems there or one blew out, I'd go ahead and put new Mica's and grease in there. Be REALLY CAREFUL! and only do one at a time.

 

[Sam Cogley]

I usually just open up whatever it is I want to recap and make an inventory of what's on the boards. Sometimes those parts lists aren't exactly accurate.

 

[gyrene]

Oh man...now you tell me.I was trying to be grown up about it and read the list off a PDF file and copy it down.Then go make an order.
BTW while reading some of these numbers I came across a cap marked .47p
The p is for pico farad right?
Everything else should be micro farad otherwise known as uF.
Correctomundo?Just checking because I don't do this for a living or twice a week or anything like that.
And I'm leaving the heat sinks alone.

 

[markthefixer]

I looked at the list A BIT when I posted the link, the BEST thing for you to do is to gather the list of the electrolytic(ONLY)caps in the receiver, starting with the service manual's data (it will TELL you), then VISUALLY VERIFY each and every one, as the manual is just a starting point.

Then POST the list, most caps from 1uF and above will be UPW Nichicon numbers, and 0.1uf through 1uF electrolytic caps will be replaced with stacked film numbers. There will be MAYBE a few exceptions I will search for.

Non-electrolytic caps (below 0.1uf usually) do NOT need replacing, they don't dry out like electrolytic caps - electrolytic caps are little metal cans with rubber end seals, and eventually over decades, they DO dry out. Anything that doesn't look like a little metal can with an end crimp should be left alone.

Look at carve-it's post on the tuning fork guides, the capacitor ones have drawings and pictures of the various types.
Don't go cross-eyed at the really technical stuff, at worst, find the pictures....
http://www.audiokarma.org/forums/showpost.php?p=3012505&postcount=11


Then I will go through my list of replacement part numbers and paste them in.

example:
bare minimum:
100uf 35v ................(and I will add 647-UPW1H101MPD, 100uf 50v $0.22 ea)

better:
aaa-999 C7 100uf 16v ................(and I will add 647-UPW1H101MPD, 100uf 50v $0.22 ea)

best:
awf-021 C17 3.3uf 50v ceanl 3r3p 50

ceanl etc is from the bill of materials in the service manual, and it tells me it is an electrolytic cap, both leads coming out of the bottom, and is best as a low leakage (UKL instead of a UPW) capacitor. IF there ARE any in there...

Doing the "best" choice will save me a LOT of time looking them up in the service manual.


edit: we'll include thermal paste and new mica insulators - if you're ever going to crank it, dried out thermal paste could cost you a set of output transistors and perhaps a bit more....
It's nowhere near order placing time...

 

[gyrene]

O.K. I have my list compiled and need some advice.
Of course I want the best product so as to reproduce the best audio signal.
But what the hell do I know?
I have had several motorcycles but my current ride is a 1992 FLTCU.Thats a Tour Glide and I love it.
I have many guns too but my two favorites are a 1911 and a S&W .357
Shotgun? Winchester model 1912 in twelve gauge.
Rifle? M-1 Garand.
You get the idea,right?
So what am I looking for?
I read on here about Elna and thats what is in some of my amps/recievers.
Read about...I think ....BlackGold maybe?Nichicon...whatever.
Does the capacitor actually assist in making a certain sound?
Like mellow or bright and which are they and how could I know?
If I'm buying 115 capacitors should I want them to all be the same brand?
Thank you

 

[markthefixer]

Go back and read my last post......

 

[gyrene]

Man we must be typing over each other...
Interesting...I actually did not know I was doing this with someone.Cool.
For what its worth I'd choose the "best" option too.
I'm not sure what this is all about where you said..."...edit: we'll include thermal paste and new mica insulators - if you're ever going to crank it, dried out thermal paste could cost you a set of output transistors and perhaps a bit more....
It's nowhere near order placing time... "
Whats the thermal paste all about?
Where does it go?
Oh...wait...its starting to occur to me...its for the transistors on the heat sinks right?
I think I used to call that heat sink transfer something or other.????Just a little dab will do ya.

As far as posting the list...are you asking me to type up a list of capacitors with their values and part numbers and post it here? And then you will check it against your upgrade list? How can I do that? I tried cutting from the PDF document but don't really know how to get that done.I cut it and posted it to the clipboard but thats as far as I can get.I don't know how to lift a portion of a PDF document and post it anywhere.So that part leaves me a little bit stuck.

HEY! I JUST NOTICE YOUR AVATAR! Now let me ask you this...does that avatar inspire confidence?Huh? C'mon,man.
Its like when I went to see my neurosurgeon and he had his baseball hat on backwards.Just kidding...relax.I'm just funning ya.I like the boys too and Old Popeye's and Kojak and Wonder Woman too.
Lets roll.

 

[Redikilowatt]

Gyrene,
The pros have directed you to the 750 PDFs, but I have original schematics if it would help.

Roger

 

[gyrene]

UH...yeah! C'mon man! Lets copy those babies.
Thanks Red

 

[Sam Cogley]

I use Nichicon caps from Mouser.com with great results in my solid-state work. I have a 750 that's been waiting on a recap for a long time - I'll get around to it one of these days.

 

[markthefixer]

Far less than half the caps are electrolytics, and a lot of typing can just be cut and paste. I do some editing offline, get the lists the way I want them to appear, then copy and paste the whole block.

Just remember the forum software only allows a maximum of two spaces side by side. If the elements are consistent, they can be lifted into a spreadsheet easily.

Lifting text off of a .pdf - unh unh, I just type...

 

[gyrene]

Alright bear with me on this.Could be awhile before I get'r done.Might take a day or more.

 

[gyrene]

O.K. mark looks like the service manual calls for 62 electrolytics.
Here goes:From page 46 of the service manual
c1 15,000 50v ach 057
c2 15000 50v ach 057
from page 50
c1 2.2 25v csza 2r2m 25
c2 2.2 25v csza 2r2m 25
c3 10 35v cea 100p 35

c5 100 35v cea 101p 35
c7 1 25v csza 010m 25
from page 52
c1 .47 25v cssa r47m 25
c2 .47 25v cssa r47m 25
c3 100 6v cea 101p6
from page 56
c1 1 25v csza 010m 25
c2 1 25v csza 010m 25
c7 220 6v cea 221 p6
c8 220 6v cea 221 p6
c9 100 35v cea 101p35
c10 100 35v cea 101p 35
c13 220 6v cea 221p6
c14 220 6v cea 221 p6
from page 60
c1 .22 10vcssa r22m 10
c2 .22 10v cssa r22m 10
c3 330 6v cea 331 p6
c4 330 6v cea 331 p6
c5 3.3 10v cea 3r3p10
c6 220 16v cea 221 p16

c7 220 16v cea 221 p16
c8 100 35v cea 101p 35


c9 100 50v cea 101p50
c10 100 50v cea 101p 50
c11 4.7 35v cea 4r7p 35
c12 220 16v cea 221p 16
c13 110 35v cea 101p 35
c15 100 50v cea 101p 50
c16 100 50v cea 101p 50
c17 330 50v cea 101p 50
c18 330 50vcea 331p 50
from page 62
c1 470 10v cea 471 p10
c2 .01 250v acg 001
c3 .01 250v acg 001
c4 .01 250v acg 001
c5 .01 250v acg 001
c6 .01 250v acg 001
c7 .01 250v acg 001
from page 69
c27 .47 50v cea r479 50
from page 70
c41 100 16v cea 101p 16
c42 220 16v cea 221p16
c45 4.7 16v csza 4r7m16
c46 1 25v csza 010m 25
c47 3.3 10v csza 3r3m 10
c48 .22 35v csza r22m 35
c54 220 6v cea 221p6
c60 4.7 35v cea 4r 7p 35
c61 47 6v cea 470p6
c62 220 16v ccdi 221k 50
c66 .1 35v csza 0r1m 35
c80 10 16v cea 100p16
c81 10 16v cea 100p 16
c82 1 25v csza 010m 25
c83 1 25v csza 010m 25
c84 220 25v cea 221p 25
c85 220 25v cea 221p 25
c86 4.7 16v ceanl 4r7m 16p
c88 100 6v cea 101p6
c89 100 6v cea 101p6

c98 2.2 25v csza 2r2m 25
c99 2.2 25v csza 2r2m 25
c102 2.225v csza 2r2m 25
c105 2.2 25v csza 2r2m 25
c106 220 35v cea 221p 35
c111 10 16v cea 100p 16
from page 72
c3 100 10v cea 101p 10

 

[markthefixer]

Then I will go through my list of replacement part numbers and paste them in.

example:
bare minimum:
100uf 35v ................(and I will add 647-UPW1H101MPD, 100uf 50v $0.22 ea)

better:
aaa-999 C7 100uf 16v ................(and I will add 647-UPW1H101MPD, 100uf 50v $0.22 ea)

best:
awf-021 C17 3.3uf 50v ceanl 3r3p 50 <<I NEED all of this on the SAME line, due to time saving tricks I do, inhaling the data into a spreadsheet, massaging it and sorting it, getting the caps,resorting back to the original order, and posting the results...

ceanl etc is from the bill of materials in the service manual, and it tells me it is an electrolytic cap, both leads coming out of the bottom, and is best as a low leakage (UKL instead of a UPW) capacitor. IF there ARE any in there...

Doing the "best" choice will save me a LOT of time looking them up in the service manual.

NOT doing the "best" choice will result in considerable delays until I can scrape up enough time to do it (upgrade the info) myself.... before I can reasonably select caps for you. The cea's are standard caps, the css and csz's are significant (solid caps: aluminum for coupling and tantalum (low leakage, low esr), while ceanl are low leakage caps and SOMETIMES DO make a difference...)
If I'm gonna do it, I'm gonna do my BEST to be right....

All this would have been clear if you had:

Look at carve-it's post on the tuning fork guides, the capacitor ones have drawings and pictures of the various types.
Don't go cross-eyed at the really technical stuff, at worst, find the pictures....
http://www.audiokarma.org/forums/showpost.php?p=3012505&postcount=11

People here have learned to re-read my posts carefully for details, and usually their questions ARE answered in the overlooked details..... I don't type because I like the sound of the keys clicking.....


As for the avatar - long story (EchoWars awarded it to me years ago) - but sometimes repair threads more resemble a stooge's routine...

 

[gyrene]

I'm not sure because I'm the new guy here and this is the cyber world but I think I just got chewed out by the professor.
Did I get chewed out professor?
For not reading the dead link you provided?
As for the prefixes to each cap.I downloaded the service manual you linked me to and it has no "bill of materials" in it.So I don't how to fix that part.Tell me and I will help you.Do you have a service manual with a bill of materials?Link me to it.I'll do the hard work.
As far as typing to hear the sound of the keys clickiing...good line.
Just so you know I too do not type to hear the sound of the keys.
In fact with the Motor Neuron Disease I have and the resulting loss of hand strength typing at all is a real PITA and so will the disassembly,desoldering and resoldering be a real PITA.In fact lifting the unit onto the bench to start the work is a bit risky.But hey...whats life with no risks right?
If you have something else you'd like to do mark thats cool with me.
If you want to procede in a mutually respectful manner thats even better.
Whats it gonna be doc?

 

[markthefixer]

I don't (at least try not to) chew people out. If it sounded like that I am genuinely SORRY.
I try hard not to carry any negative attitudes or vibes through in my posts....
What's written in haste has to be repented FOREVER, as it lives on forever in print....
Just like what President Harry Truman's secretary shielded him from, until that time one (a critical review of his daughters singing inspired a letter that should have been written on asbestos) got through...

My mission is to educate...

I'm SORRY that I didn't check the link that was pulled through with the quote.... I'm investigating why it didn't work.
The link IS working in the earlier post in this thread, which I was trying to draw your attention to.
Because it WILL answer some of your questions, plus it will show you why I need that extra info to do a good job.
edit: the link was printed with a ..... in the middle instead of the correct complete string. It's fixed now. Gotta remember that for later....

Recapping can be deceptively complex.

http://www.audiokarma.org/forums/showpost.php?p=3012505&postcount=11

Ok, I just checked the www.kallhovde.com/pioneer/ site's sx-750 service manual and it does have parts lists following the individual board schematics.

The following example comes from page 52 of 79 of the 75 meg hi-res service manual. The tone control assembly is called AWG-046.


AWG-046 C1 0.47uf 25v cssa r47m 25
AWG-046 C2 0.47uf 25v cssa r47m 25
AWG-046 C3 100uf 6v cea 101p 6
AWG-046 C4 100uf 6v cea 101p 6
AWG-046 C7 220uf 35v cea 221p 35
AWG-046 C8 220uf 35v cea 221p 35
AWG-046 C9 4.7uf 25v ceanl 4r7p 25
AWG-046 C10 4.7uf 25v ceanl 4r7p 25

c1 and c2 will get a stacked film cap, c3, c4, c7, c8 will get general purpose caps, and C9, C10 get low leakage caps.

Three different types.... not eightn of the same.... without those cssa, cea and ceanl designations, I wouldn't have known any different until I looked them all up.

this post is now finally complete 5:04 pm