pioneer sx 1010 problems

I know I for 1 have learned a LOT from this thread. Thanks every one and glad to see your sx-1010 is up and running!
 
just out of curiosity? can the main caps be failing and not be audible untill under an extreme load? im listening to my pioneer as i type this, but on a set of smaller speakers. i havent thrown the covers on yet. i figured id test it a few hours first. so far we are at about 8 hr's with no problems. should i consider replacing the main caps before i throw this unit at my cerwin vegas? if so does anyone know the mouser #s
 
ok my main caps came in yesterday. with what im pushing with this unit and the warnings of the life of an electrolytic capacitor,i figured id change the ones in the power and protect circuits. i have found most the #'s but i am wondering??? should i change the transistors in the amp boards? would it be more reliable and function better if i did?
 
no, if it ain't broke (if you can't find anything wrong), don't fix it...
 
ok, but the caps are a good idea right? only the electrolytics.

correct,- a search could also turn up exceptions.... I can't do searches well from here(AKFEST)...

The masters could also post exceptions - but THEY are here at AKfest TOO...
 
at the risk of sounding like a goon!! the transistors in this unit have not been changed in 34 yrs??? is there not an aging problem i have to worry about? it was recomended to change the trans,and zener diodes in the power supply board, but i guess i am confused of why that would not be recomended in the amp and protect boards. i understand the reason behind the cap replacement,,well the electrolytics that is. the unit does work good now but i would like to cover all bases before i put her into finall entertaining posititon
 
at the risk of sounding like a goon!! the transistors in this unit have not been changed in 34 yrs??? is there not an aging problem i have to worry about? it was recomended to change the trans,and zener diodes in the power supply board, but i guess i am confused of why that would not be recomended in the amp and protect boards. i understand the reason behind the cap replacement,,well the electrolytics that is. the unit does work good now but i would like to cover all bases before i put her into finall entertaining posititon

no, it's a good question:

The power supplies are heat stressed, Pioneer runs them hot, and if the ventilation is restricted - they get way too hot, thus replacement is a good idea. The protection circuits Q6 & Q7 transistors are also stressed in different ways, and the modern ztx-1056a replacements are far more robust ( 6 AMPS pulse current, 3 amps continuous), and the extra diode put across pins 9 & 10 helps alleviate some of that stress too.

The amps are NOT run that "close to the edge". there are a few transistors that can inspire mistrust, but the dangers of a wholesale replacement causing damage are greater than the chances of eventual failure. I include MYSELF (not just "noobs") in the group that should think long and hard before doing a complete replacement of transistors in the 1010 amplifiers.

Just as an example, the EchoWars 1250 at the fest that he "did the works on" still had the original outputs - but I didn't ask about the rest of the transistors in the amp....

If it ain't broke - don't fix it.

edit: changed Q5 & Q6 to the correct Q6 & Q7
 
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is there a link i am missing for the diode installation for pins 9&10 in the protect circuit??? also on the main caps, does anyone know the mouser #'s for the resistors that bridge the terminals? my manuall calls for a 3.3k metal oxide 2watt resistor. i searched mouser and cannot find a metal oxide resistor. is it considered a metal film now??
 
IMG_0384.jpg



See it between pin 9 and 10


for a 3.3k metal oxide 2watt resistor. i searched mouser and cannot find a metal oxide resistor. is it considered a metal film now??

It's not particularly critical as long as it will bleed of fairly quickly, but not waste too much energy while the unit is on. EW uses 5.6 K 3 watt I think he said.
 
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A 1N4004 would work fine. Pay attention to the polarity (duh).
JimB
 
is there a link i am missing for the diode installation for pins 9&10 in the protect circuit??? also on the main caps, does anyone know the mouser #'s for the resistors that bridge the terminals? my manuall calls for a 3.3k metal oxide 2watt resistor. i searched mouser and cannot find a metal oxide resistor. is it considered a metal film now??

594-5083NW3K300J
3.3k 2watt metal film resistor 5% $0.32 ea

What is the diode? Mouser part number?

512-1n4004 conventional rectifier 1a 400v $0.06 ea
 
I would like to clarify something, on the Power Supply Board AWR-054 is this listing correct for the diode replacement?

extra parts just in case somebody's looking :
D1 D2 D3 D4 SIB01 100v 1amp
D5 D6 D7 1S1885 100v 1amp
512-1n4004 conventional rectifier 1a 400v $0.06 ea

All 7 Diodes can be replaced using the 1n4004?
I am also rebuild an SX-1010 and just finished the recap of this board as well as replaced the resistors. Diodes next.... so I just thought I would ask now...:music:
 
Those diodes don't fail very often, but yeah...you can replace them with plain-Jane 1N4004's.
 
Thanks EW,
They were just in the parts list for the board rebuild so I ordered them with everything else. Since you say they don't fail very often I will stay away from them. :yes: The board on this 1010 was in fairly bad shape. A couple of the transistors had already been replaced and whoever did it lifted a couple of pads.

I reckon the other diodes are fine to so I will stay away from them. I replaced all the caps as well as the trans..... so this board should be good for a few more years of :music:
 
IMG_0384.jpg



See it between pin 9 and 10




It's not particularly critical as long as it will bleed of fairly quickly, but not waste too much energy while the unit is on. EW uses 5.6 K 3 watt I think he said.

the ztx-1056a is at Q6 & Q7 :scratch2:right and not Q5 & Q6
 
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