SX-525 Refurb
- Thread starter Rockmore
- Start date
I'm the moderator of "this" forum, and I was never contacted for a name change request on this thread? I changed it anyway for you, and you're welcome.
Retro
You changed the name before you posted this...
Thanks Retro. (and ya.. I sent several requests for a name change when it got up to about 50 posts and it was obvious it was needed for any other 525 owner and poor souls who may endeavor parts recommendations and endless failure and months worth of grief).
:sigh:
Still left with a useless receiver. Any otherexperts and regulars check in, per the past 50 posts at least. Waiting on the "next step" and how to diagnose.
Also, any of you regulars who can confirm the recommended parts that have been replaced. Not necessarily the caps, but the transistors.
Still left with a useless receiver. Any otherexperts and regulars check in, per the past 50 posts at least. Waiting on the "next step" and how to diagnose.
Also, any of you regulars who can confirm the recommended parts that have been replaced. Not necessarily the caps, but the transistors.
33&athird
Turn on & Tune in
Keeping this question relevent in case the pages roll over with this post. I'm working on a couple things, will check back.
Question for MarktheFixer, on doing some test...
I'm going to put one channel in on multisim, to get the approximate(since multisim is "perfect" in tolerance) dc ratings on the individual transistor legs, and check against my unit to pass onto Rockmore. Another thought was to do some basic AC checking, through a "dumb" signal generator- a test cd with a 120 or so Hz tone, and vary the voltage (I think average aux voltage is 1.3 or 3volts?, not sure) by way of the player...would be a easy, cheap way to have another control variable to test with Rockmore (signal generators are expensive...I don't even have a full one:sigh
. Could use that in comparison to my amplifier running the same thing.Would have to start at the begining of the chain, and move back (control amp awg-001 being a good place, I think).
Any thoughts or ideas, maybe extra testing ideas, or is this going into it too much?:scratch2:...
That's why we both need the service manual.
pin 12 is a feedback connection connected to the far side of the output capacitor. The near side of the output capacitor is connected to pin 10.
YES, there are TWO feedbacks.....
I have posted that I believe you don't have the equipment necessary to diagnose the double error that is boosting gain somewhere in your amplifier circuits.
edit: non - technical - removed - dialing it down a few notches
Then on 2-12-2010 at 11:23 PM I made a conciliatory post about the whole mess and offered to fix it at my home.
Since then I have been waiting to hear that you have gotten the service manual, and shipped the unit to me.
I succinctly outlined the reasons WHY remote troubleshooting was no longer feasible. - not tech - removed -
My original post, found and dug out of a different thread, for easy access for review.
edit - not tech - removed -
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33&athird
Turn on & Tune in
Ah!, that explains quite a bit...I was understanding the feedback loop, but didn't get the "two-feedback" thing. I put the pins numbers in there to keep it related to the schematic...still need to work with it a little:scratch2:...
Be real careful about using that soliciting term MF. You are being asked, directly, to confirm that the 992's you stated are a adequate and acceptable replacement for the 2SA726 transistors specifically for a vintage Pioneer SX-525, and that the TIP41 and 42's @65w are a adequate and acceptable replacement vs your stated KSB596OTU and 526O @30w, specifically for a Pioneer SX-525. There was no mention to repeat or repost the same posts and information already contained in this thread.
Mark and Rockmore,
Frustrations or not, can you both please take it down a notch and stick to the subject at hand before I get rid of this thread completely?
Thanks,
Retro
Frustrations or not, can you both please take it down a notch and stick to the subject at hand before I get rid of this thread completely?
Thanks,
Retro
Done.
Sorry Retro (and everybody else).
I'll keep it technical and edit out my less than technical comments.
Rock - I'd sure appreciate it if you'd edit my quotes in your posts to remove the same non -technical stuff that I removed in my posts.
Sorry Retro (and everybody else).
I'll keep it technical and edit out my less than technical comments.
Rock - I'd sure appreciate it if you'd edit my quotes in your posts to remove the same non -technical stuff that I removed in my posts.
Rockmore, has the service manual arrived yet? No matter if the sx-525 stays by you or is here by me, the information in the service manual is vital.
I figured that scanning in an entire service manual would be a tedious task, and it would add to frustration if for some reason important details were fuzzy and needed to be rescanned, so I was planning on scanning the manual myself and check as I go. Plus since this is Rick's work, once I was finished with your unit (whether it was here by me or still at your place) I would find it more comforting to my moral foibles to know that I had the only scan sourced from his work, and that once I deleted it, it was GONE forever.
I wouldn't hesitate sharing a scan of an ORIGINAL manual, but Rick's work IS Rick's work and I won't pirate it.
As it is, having two of them in existence for a short time (original and scan) does bother my moral foibles.
Which is why I originally suggested an inferior photocopy originally (if i am remembering correctly).
I figured that scanning in an entire service manual would be a tedious task, and it would add to frustration if for some reason important details were fuzzy and needed to be rescanned, so I was planning on scanning the manual myself and check as I go. Plus since this is Rick's work, once I was finished with your unit (whether it was here by me or still at your place) I would find it more comforting to my moral foibles to know that I had the only scan sourced from his work, and that once I deleted it, it was GONE forever.
I wouldn't hesitate sharing a scan of an ORIGINAL manual, but Rick's work IS Rick's work and I won't pirate it.
As it is, having two of them in existence for a short time (original and scan) does bother my moral foibles.
Which is why I originally suggested an inferior photocopy originally (if i am remembering correctly).
Mark-
Please confirm that the 992's you stated are a adequate and acceptable replacement for the 2SA726 transistors specifically for a vintage Pioneer SX-525, and that the TIP41 and 42's @65w are a adequate and acceptable replacement vs your stated KSB596OTU and 526O @30w, specifically for a Pioneer SX-525. There was no mention to repeat or repost the same posts and information already contained in this thread.
Please confirm that the 992's you stated are a adequate and acceptable replacement for the 2SA726 transistors specifically for a vintage Pioneer SX-525, and that the TIP41 and 42's @65w are a adequate and acceptable replacement vs your stated KSB596OTU and 526O @30w, specifically for a Pioneer SX-525. There was no mention to repeat or repost the same posts and information already contained in this thread.
I confirm that the stated choice of the mouser.com part # 512-KSA992FBU transistors are an adequate and acceptable replacement for the 2SA726 transistors specifically used in a vintage Pioneer SX-525 power amplifier circuit.
I confirm that that the stated choices of the mouser.com part # 863-TIP41CG and mouser.com part # 863-TIP42CG are an adequate and acceptable replacement for the 2SA489 and 2SC789 transistors specifically used in a vintage Pioneer SX-525 power amplifier circuit.
I confirm that the stated choices of the mouser.com part # 512-KSB596OTU and mouser.com part # 512-KSD526O are an adequate and acceptable replacement for the 2SA489 and 2SC789 transistors specifically used in a vintage Pioneer SX-525 power amplifier circuit.
Is that specific enough?
ara:
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Switchblade
Super Member
Rockmore_ You are posting and asking FOR FREE advice in a free forum. Please be respectful to a man who is trying to help you fix your problem. If you don't want his advice, don't ask. If I was MTF I'd fold up my tent right now. DON'T SCREW IT UP FOR THE REST OF US!
tucsonmike
Don't tase me, bro!
No need to apologize, mark.
You've showed 10 times more patience than i would've.
you can lead a horse to water...
You've showed 10 times more patience than i would've.
you can lead a horse to water...
aussiedan
Ambition beyond ability
+1
Your'e getting a lot of man hours put into your amp, Rock. All "pro-bono".
Mark and the others are helping you for nothing - dont expect a warranty.
If you stick with it, they will also. They understand the frustration. Then your amp will sing.
aussiedan
Ambition beyond ability
Rockmore,
Mark has presonally steered me straight on my first trip here.
For which I still owe him a beer or 3.
(I'll get stateside one day Mark, and come good)
Have a look at the posts in this forum, then look to see how many MTF responds to.
Each guy he helps wants to fix their stuff, just like you. Keeping the info as consise as you can saves his time. Don'y worry if he dosn't ask how the weather is.
And don't forget about 33,1/3 and the others. These guys have done all sorts of s--t for your SX-525.
Ok, so you havn't reached the destination yet. Enjoy the journey instead. Enjoy the expert tutoring you are lucky to get. The negative comments are character building - don't take them to heart.
Be a legend, not a martyr, then use the dacing bananna (that is, fix it, then tell everyone)
Remember mate, you opened the box, these guys are trying to help you shut the lid. They will see you right. Just kick back, no one knows it all.
By the sound of it, you are an attorney or lawyer? You are an expert in your feild, no doubt. We all do our own thing, but if ya wanna fix pioneer stuff....
you get the drift.:thmbsp:
If you can restore a piece of vintage audio gear, you are doing well.
What sort of music do you plan to listen to, after it's rockin'? (well music it what is all about, so therefore, on topic your honor!)
Danny.
Mark has presonally steered me straight on my first trip here.
For which I still owe him a beer or 3.
(I'll get stateside one day Mark, and come good)
Have a look at the posts in this forum, then look to see how many MTF responds to.
Each guy he helps wants to fix their stuff, just like you. Keeping the info as consise as you can saves his time. Don'y worry if he dosn't ask how the weather is.
And don't forget about 33,1/3 and the others. These guys have done all sorts of s--t for your SX-525.
Ok, so you havn't reached the destination yet. Enjoy the journey instead. Enjoy the expert tutoring you are lucky to get. The negative comments are character building - don't take them to heart.
Be a legend, not a martyr, then use the dacing bananna (that is, fix it, then tell everyone)
Remember mate, you opened the box, these guys are trying to help you shut the lid. They will see you right. Just kick back, no one knows it all.
By the sound of it, you are an attorney or lawyer? You are an expert in your feild, no doubt. We all do our own thing, but if ya wanna fix pioneer stuff....
you get the drift.:thmbsp:
If you can restore a piece of vintage audio gear, you are doing well.
What sort of music do you plan to listen to, after it's rockin'? (well music it what is all about, so therefore, on topic your honor!)
Danny.