Pioneer Sa-9900 in the worst state i've ever seen an amp

[reddish75]

Here's the board pretty much finished, I tend to flit between projects so it's taken a while just to get this board finished. I ended up using the heatsinks that been bodged untill I find sutible ones as I needed an anchor point for the t0-126 transistors, it looks a little messy as I've had to point to point most of the traces around the pass transistors but it'll get the job done.

2018-07-12_12-28-03 by chris reddish, on Flickr
2018-07-12_12-28-21 by chris reddish, on Flickr
2018-07-12_12-29-09 by chris reddish, on Flickr
2018-07-12_12-28-40 by chris reddish, on Flickr

 

[onwardjames]

Great work, Reddish! Now put some pants on when you solder, lol!!

Following with best wishes and great interest.

@larryderouin - You allowed that Sansui to beat you?? Jeez, cannot imagine that level of damage.

 

[reddish75]

I'm going to tackle the input board next and I'm looking to replace the Phono sockets while it's out, does anyone have a part number for ones that fit?

 

[Rsclj]

We seem to be running the same project in series...my board was bad...yours is way beyond bad...very nicely done

 

[restorer-john]

I like your taped precut tinned copper wire lengths for machine insertion. Where did you get them? I've always used reels of tinned copper.

 

[reddish75]

We seem to be running the same project in series...my board was bad...yours is way beyond bad...very nicely done

And just to make you feel better about your amp here's some more pics of what I have to contend with

2018-07-17_08-25-17 by chris reddish, on Flickr
2018-07-17_08-25-43 by chris reddish, on Flickr
2018-07-17_08-26-01 by chris reddish, on Flickr
2018-07-17_08-31-20 by chris reddish, on Flickr

 

[reddish75]

I like your taped precut tinned copper wire lengths for machine insertion. Where did you get them? I've always used reels of tinned copper.

I found them on eBay a few years ago, here's a link to a current listing https://www.ebay.co.uk/itm/Approx-4...ire+Jumper&_from=R40&rt=nc&_trksid=m570.l1313

 

[Rsclj]

And just to make you feel better about your amp here's some more pics of what I have to contend with

2018-07-17_08-25-17 by chris reddish, on Flickr
2018-07-17_08-25-43 by chris reddish, on Flickr
2018-07-17_08-26-01 by chris reddish, on Flickr
2018-07-17_08-31-20 by chris reddish, on Flickr

Damn man...you got yourself into a fine mess Ollie...it looks like you are doing a bang up job

 

[reddish75]

Trying to keep up on the restoration but time isn't my friend at the moment but I have managed to get the second psu board complete the Awr 0770, this one wasn't in terrible condition, just one damaged trace where the 10k pots had been replaced before, the wire wraps, however, are a completely different story.

First job remove whats left of the wire wraps and label them, remove all components to be replaced then as nearly all the solder joints were dry completely unsolder every joint, clean everything replace components resolder and.......... a pretty damn good looking board again.

2018-07-22_09-01-21 by chris reddish, on Flickr
2018-07-22_09-01-41 by chris reddish, on Flickr
2018-07-22_09-01-03 by chris reddish, on Flickr
2018-07-22_09-00-48 by chris reddish, on Flickr
2018-07-22_09-00-34 by chris reddish, on Flickr
2018-07-22_09-00-09 by chris reddish, on Flickr
2018-07-22_09-00-20 by chris reddish, on Flickr

 

[onwardjames]

That's beautiful work!!

 

[UncleBingo]

Hi,

Having bought a Sa-9900 as faulty I thought it would be easy enough to repair as I've restored quite a few vintage amps just not any pioneers, anyway I've opened it up and WOW what a mess, someone's been in there and completely butchered it, some of the highlights of the many problems are all transformer wires have been cut and rejoined insulated with electrical insulation tape, one of the bass control shafts been replaced and then ridiculous amounts of solder used to secure this in place (pics to come on this one) and lots of components replaced with what I can only think was a blowtorch.

So I'm going to need some help and pointers on this one!

I'm starting with the power supply regulator card on which I will need almost new everything, I'll start with the transistors I need cross references for everything if someone could help me with that and also the best caps to use and possible some pointers of how best to sort the trace side of the board (you'll see what I mean in the pics below and yes that is blu-tac).

Obviously a Tasmanian Devil...

 

[Watthour]

I wasn't aware that a stick welder was an accepted method of connecting components to a foil trace on a board. Those "before" photos obviously prove otherwise.

Seriously, though, I wonder is someone attempted to use low-lead alloy solder, not knowing the consequences.

 

[reddish75]

Time to make a start on the input board while I wait on parts, I managed to source a used input and tone control board to scavenge parts from mainly a new function switch shaft which on the 9900 is broken, the boards were from a SA-9500.

The input board comes off In a complete module with very few wire removals (in this amp that doesn't overly matter) taking this off reveled the main part of the chassis is bent so added that to the list.

With the module removed first job was to remove the switches from the donor pcb (I will add this is physically identical to the 9900 one but with layout differences that I couldn't be bothered to work into) when removed it would be completely pointless if I didn't clean them before installation, brasso is your friend here, see below pics,

2018-07-25_01-07-42 by chris reddish, on Flickr
2018-07-25_01-08-08 by chris reddish, on Flickr
2018-07-25_01-08-33 by chris reddish, on Flickr
2018-07-25_01-09-06 by chris reddish, on Flickr
2018-07-25_01-09-32 by chris reddish, on Flickr
2018-07-25_01-10-09 by chris reddish, on Flickr
2018-07-25_01-10-31 by chris reddish, on Flickr
2018-07-25_01-11-23 by chris reddish, on Flickr
2018-07-25_01-11-43 by chris reddish, on Flickr
2018-07-25_01-12-17 by chris reddish, on Flickr

 

[Goldie99]

Excellent work on the switches !

 

[reddish75]

Impedance selector pot (sealed) cleaned and lubricated, phono level pot cleaned and lubricated, easy access to clean this one.

2018-07-25_08-02-01 by chris reddish, on Flickr

 

[Rsclj]

nice work!!

 

[Watthour]

That's nearly pornographic. Nice eye on the details.

You mentioned early on that this amp was in the worst state you have ever seen. ALL of my receivers are that way, but then again, I live in Ill-Noise.

 

[Rsclj]

that Brasso tip was a godsend...thanks!

 

[Rsclj]

did you open the volume attenuator?

 

[Hipocrates]

Inspiring work man!