Found a Pioneer SX-1050 in the wild today... What should I check/do first?
- Thread starter MOEB74
- Start date
Blue Shadow
Waiting for Vintage Gear from this century
Of course it is normal for it to get warm running no signal. Lamps and the electronics warm up with electricity going through em.
Eastham
More Class-A than ever!
So long as it's not so hot that it's uncomfortable for your hand to hold on it it's fine. My SX-5560 (Black SX-750) used to get up to 50c on the top vents at idle.
Alright then... Its only over the heatsink area tho. But fair enough.
I don't know about the 1050, but the 1250 gets uncomfortably hot above the power amplifiers just idling, which is characteristic of Class A operation. You can see several ceramic resistors mounted down there, don't touch these when it's been running (hot hot hot).
I think that the 1050 power supply and amplifiers are similar to the 1250's.
I think that the 1050 power supply and amplifiers are similar to the 1250's.
I did the dc offset check and came back very good. 2.5mv and 7.8mv. at least seems very good... I don't know if I want to mess with adjusting it as I'm afraid of smoking it, thus costing me more money...
kaplang
Works for me !
Ze
zero is what you want but your readings are good. If it were me I'd go with it but I am sure their will be some disagreements. I am not a full blow electronics tec. but I know enough to be dangerous. I have yet to have an amp on my bench with a Zero DC offset but I am sure it can be done.
kaplang
Works for me !
Yes!
patra710
Active Member
I rebuilt one of these, I found a complete parts list here on this forum. There are many transistors that I change out. The two big filter caps ran about $30 each and I replaced all of the output transistors, eight of them at around $5 each. The rest of the parts didn't cost to much. Mine did run quite warm when I first got it but ran well when I finished. There are a ton of information on this stereo in this forum. And this stereo really rock and roll when finished. I do have a youtube video on my work on this stereo.
I couldn't have rebuilt this stereo without the help of the great people on this forum.
Hey guys just some info here. So I hooked it up tonight and honestly sounds bad. Scratchy fader and the right channel is lower than the left, the volume is low until about half way, there is like no bass then a little adjustment and too much bass.... I'm comparing this is a known sa-400 Technics.
I've tested the pioneer on KLH model Fives and Dynaco A25s, both sounded ehh on the pioneer versus the Technics.
Could this just need a deoxit treatment or is this a capacitor issue?
I've tested the pioneer on KLH model Fives and Dynaco A25s, both sounded ehh on the pioneer versus the Technics.
Could this just need a deoxit treatment or is this a capacitor issue?
well...you really should shoot it up first...clean every pot and switch, D5 all around, then whack the fadery with F5.
THEN go after hard parts, only after you check idle currents and offsets and the like.
gotta know what we are dealing with
THEN go after hard parts, only after you check idle currents and offsets and the like.
gotta know what we are dealing with
Honestly... Lord willing, I can find someone else in MD and I'll have them just go through it/recap it. It seems like it's a unit worth keeping
Offset is good at say 8mv and 3mv
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Eastham
More Class-A than ever!
Like Quaddriver said, dirty switches and potentometers, also could be the speaker relay, bad solder joints or dirty contacts on that.
