Pioneer Sx-1010: Newbie audiophile needs guidance

Greetings guys. MY FIRST POST EVER!!

I bought a sx-1010. I am just getting into vintage audio/budge audiophile stuff. I picked up mine for $325 and a two hour one way trip to Milwaukee.

It is in decent cosmetic shape, but opening it I can see some blistering caps, a lot of dust, some spider egg sacks and a couple snipped antenna wires. BLARG. HELP!

I am replacing a thrift store SX-636 that I LOVE, but just does not have the power to drive the vintage JBL l112 I found for a STEAL of $300 on Craigslist at Christmas time when someone needed them GONE ASAP.

Back to the SX-1010

It has "issues" Mostly it sounds like it is always in MONO when it should be in stereo. Switching Mono on and off I can ALMOST tell the difference. The channels also fade in and out and there is some scratchiness and fizzle here and there randomly. It needs some TLC.

I just purchased the entire BOM from this thread from Mouser, Digikey. $50 for the Mouser parts, and the Filter caps were around $30 at Digikey.

The only thing I did not get is the relay switch. What is a part number i should get and which parts to adapt to make it fit?

is there anything else I should buy? Those silver things with thermal paste attached to the giant heat sink?



NOW.... I have NO idea what I am doing. I have replaces caps before in small devices, but I have NEVER undertaken a project like this. Also, I don't know how to use a multimeter, don't own any diagnostic tools etc.

I suppose if I take my time, i could do it, but I won't know how to set bias and from what I am reading those three legged things (transistors?) have legs that change orientation and even if I put the new ones in the same orientation the legs might be reversed internally? I will totally blow something up.

BOOOM! :tears:

Is there anyone on this list who LOVES to do this kind of work, knows the ins and outs of the SX-1010 and would like to do the "labor" for me to restore it to 100% working order? I have paid for the parts, and can pay for shipping to/from. Is there anyone here that can help me?

If not, how hard is it to do myself beyond the soldering. I am ok at soldering, but without equipment, how do I make sure i don't blow my speakers up?

If there is such an amazing person who wants the job please let me know and give me an estimate of your costs?

The 1010 isn't the best platform for a total noob to start on, although it can be done. Until One of the Main guys gets on here you need to download some items and study the living hell out of them.

1.) Service manual here

2.) The "COMPLETE" PIONEER TUNING FORK GUIDES. HERE

Get a Digital Multimeter. A Harbor Freight $7.95 one is fine for starters. No need to get a $150.00 Fluke for this.

Learn what Resistors, capacitors, Transistors, diodes are, and the schematic diagrams for them. BTW Those Silver things with the Thermal paste on them are TO-3 size output Transistors. If they are working now, DON'T MESS WITH THEM.

Get some minature tools. Side Cutters (Diagonals), Needle nose (at least 4"), a set of minature screwdrivers, Electronics picks, WELLER Soldering Station for starters. It needs to be adjustable for heat.

DeSoldering tool and or Solder wick.

Tip cleaner/Tip Tinner (Ratshack)
60-40 Solder (ROSIN CORE.......DO NOT USE ACID CORE ON ELECTRONICS!)


This is for starters. As time goes on you may need to get other tools/gear if you stay in it for a hobby. But for right now this will get you started.

If you end up with Mark the Fixer or one of the other Guru's DO EXACTLY what they say, DO NOT GET AHEAD. It will cause BIG PROBLEMS! If you don't understand something ask questions.

For now, go to the local Guitar Center and get a can of DeOxit D-5 (Red Can). Read This link (The Idiots Guide to DeOxit.....Revisited) and CLEAN EVERYTHING that goes ROUNDY ROUND, IN-OUT, UP-DOWN on the Front panel. You need to take off the top, bottom and the front panel to do this as a couple boards needto come out.

Use a Vacuum cleaner and a paint brush to get rid of the dust, dirt, spider nests, etc.

GO SLOW! Make sure you understand that this will not be an overnight or a weekend job. It will take at least two- three weeks of nightly rounds if not more. PATIENCE IS A VIRTUE, and you NEED every bit you can MUSTER.

Good Luck.

Larry

Ok I guess I am a little more skilled than I thought. I have a basic electronic kit with all those tools, a soldering iron, and deoxit from my day job as a technology manager with computers and stuff. Motherboards and PCI cards have a lot in common with a circuit board in an amp!




Things I do not know are when I should use a different heat setting on my soldering iron.

The parts other than the rely and the filter caps are on order!

rowingcoach said:

... Things I do not know are when I should use a different heat setting on my soldering iron. ...

Click to expand...

http://www.kallhovde.com/pioneer/solidstate-amp-techguide.pdf
http://www.kallhovde.com/pioneer/ocl-amp-techguide.pdf
http://www.kallhovde.com/pioneer/protection-circuit-amp-techguide.pdf
http://www.kallhovde.com/pioneer/dead-units-techguide.pdf

These will give you trouble shooting how to's...Comes in handy.

Sticky on the links, if not already?

The parts have arrived!!!! Wow. There are a lot of parts from the BOM from Mouser.

I plan to start with the Power supply board.

How do I make sure the caps are discharged before I zap myself?

If it's been off for 10 to 30 minutes, all but the big main caps should be flat - the big ones too, but those I would touch my dmm to and read their voltage just in case - iirc they have 3.3k ohm 2 watt bleeder resistors across them at their terminals so they should discharge somewhat quickly. The "just in case" involves bleeders gone bad...

IF you do see voltage on a cap, use a 10 ohm resistor to discharge it, terminal to terminal. There might be a little bounce back of voltage due to dielectric adsorption, don't sweat it.

I only have the protection board and two power boards left to do!

After each board I am turning it on to see if it lights up and the protection switch works. 5, 4, 3, 2, 1. POP! I guess that is good.

ONce I am finished, do I set bias or is it safe to plug in speakers first and see how it sounds THEN adjust bias? What do I need to check that? I have access to some pretty cool scopes and a multimeter


I am having trouble finding a replacement for those bleeder resistors on Digikey. Can someone point out a good one? They look like caps but are resistors?

Thanks.

I am having trouble finding a replacement for those bleeder resistors on Digikey.

Click to expand...

A w/w resistor looks like a ecap? what, because they are both cylindrical? take a closer look at what is written on them or color stripes for most R's
Why do they need to be changed in the first place? do they not measure correctly?
test/adjust offset & bias with no speaker load, do as it says in the SM!

rowingcoach said:

I only have the protection board and two power boards left to do!

After each board I am turning it on to see if it lights up and the protection switch works. 5, 4, 3, 2, 1. POP! I guess that is good.

ONce I am finished, do I set bias or is it safe to plug in speakers first and see how it sounds THEN adjust bias?

Thanks.

Click to expand...

I would use a dim bulb tester to do the above.

dnpainting said:

http://www.kallhovde.com/pioneer/solidstate-amp-techguide.pdf
http://www.kallhovde.com/pioneer/ocl-amp-techguide.pdf
http://www.kallhovde.com/pioneer/protection-circuit-amp-techguide.pdf
http://www.kallhovde.com/pioneer/dead-units-techguide.pdf

These will give you trouble shooting how to's...Comes in handy.

Sticky on the links, if not already?

Click to expand...

Thanks for the links. Very informative.

rcs16 said:

A w/w resistor looks like a ecap? what, because they are both cylindrical? take a closer look at what is written on them or color stripes for most R's
Why do they need to be changed in the first place? do they not measure correctly?
test/adjust offset & bias with no speaker load, do as it says in the SM!

Click to expand...

Yah. Pretty much. It is nothing like any resistor ive ever seen. It looks like a pio cap! Its pretty darn big. It doesnt have any stripes.

Ive searched all Digikey for "bleeder" and even went as far as browsing plain resistors. Also the above info about them being 3.3k uf while the writing says 3.3kj (kilo.... What? joules?) is not helping me narrow down what i should be buying.

I THINK> this is what I want?

RES 3.3K OHM 2W 5% AXIAL Digikey part P3.3KW-2BK-ND

Ok so I am nearly finished. I am going to stop in at the RAdioSHack and get the 8OHM resistor, assuming they have those, and do this adjustment. It is not nearly as difficult as I thought it would be. Looks like all I need is a multimeter!?

First, welcome to AK, and good luck with your 1010. Still want one for myself, but the easy-bake oven Pioneer put in those things means I'd have to have one restored, as that's far beyond my abilities.

rowingcoach said:

Ok so I am nearly finished. I am going to stop in at the RAdioSHack and get the 8OHM resistor, assuming they have those, and do this adjustment. It is not nearly as difficult as I thought it would be. Looks like all I need is a multimeter!?

ALIGNING THE POWER AMPLIFIER SECTION

1. Nothing should be connected to the input jacks of the SX-101O, and an 8.\1 dummy resistor should be connected across the speaker terminals.
2. A DC millivolt meter should be connected across between terminal number 19 and earth. 3. Adjustment should be made to bring the voltage to zero.
4. The DC voltmeter should be connected between terminals number 14 and 16.
5. Adjustment should be made to bring the voltage to 50m​

Click to expand...

Don't bother with the 8 ohm resistor, it will make NO difference in the readings for this type of amp - it's use was a stubborn, useless holdover in the minds of the manual writers.

post a picture of that resistor, I'm suspicious.

The resistor identification codes are documented in the Tuning Fork series, posted in the Tuning fork stickied thread up top...
3.3kj is 3300 ohms,
the manual calls it: rs2p 332j
meaning:
rs metal film
2 2 watt
p tubular
332 3300
j 5% tolerance

You should be powering up on a dim bulb tester after every internal change. And the amp should be adjusted (idle, offset) EVERY time the amp OR power supply are worked on, after it passes the dim bulb test.

Complicating things is "tickling the dragon's tail" after any amp work - you ever read up on that?

I'd like to know about tickling the dragon's tail. Sounds kinky. : )

simply a trial set of idle current on the DBT, to see if turning it up blows anything up.

it can be scary on a DBT, and you NEVER leave the pot set - because when plugged in straight the idle current will be too d#@! high.

scary as the bulb will grow brighter, and maybe drop the protection out due to reduced AC voltage input...

I did all the boards and went to set the bias according to the service manual.

Protection clicked just fine after 5 seconds about.

Tested the power boards. ONE channel seemed fine and the volts showed right around 0.000v. (+/- .001 )

The other channel however... i think it is open? The Voltmeter was jumping around ALL over the place. negative, positive, high and low numbers. That means something is wrong!?

I took the problem board back out. It looks as if the back side of the board had something spilled on it. I can scrape off some type of light coating with the flat edge of a screw driver. None of the other boards had this. I worked to get off all that I could, then I cleaned the back of the board with some light cleaner that dries without any buildup. The board looked fine and nice and clean.

I connected the power board back up and turned on the Amp and POP. Something sparked. It was two fuses in the back side. The main fuse in the fuse holder and then some other in-line fuse soldered into the back housed inside some kind of decaying rubber tube.

Ok... what did I do? Was it that power board? Everything was fine until I tried to clean it.

Anyone have a spare? I am wondering if this is why I got the ax-1010 for $300 to begin with, the dude KNEW it had something split on it and the power board was a ticking bomb?

ah man, I am sure MTF or one of the other resident geniuses will chime in.

Keep positive. You're getting closer. :thmbsp:

I have one if you want it. PM me! Its the older revision with the STV's on the Amp board heatsink. Not the remote one attached to the large driver heatsink.