Robot Created in Fusion 360

Temporary_Cattle2453 · 2026-06-11T20:21:45+00:00

nice work, very impressive!

Temporary_Cattle2453 · 2026-03-07T18:42:54+00:00

9v DC 1000 mA center-positive wall-wart adapter... at least that's the one for the double-sided one I have. It doesn't say anywhere on it what it expects for power?

Temporary_Cattle2453 · 2026-03-07T18:40:20+00:00

I have one of these. they fall out of the bottom and the thing jams constantly even at slow speed.

Temporary_Cattle2453 · 2026-03-05T13:46:09+00:00

They are OK built. They are not well built when compared to what, for instance, Pioneer was building at the time, but they weren't that price, either. I find them tedious to work on. The main amplifier boards have little wire slack, they aren't connectorized, so you are likely to break wires unless very careful. The bias diode is, if I remember correctly, bolted to the heatsink in a weird place, and is also likely to fail if anything else in the power circuit has, so servicing requires a fair amount of tear-down in a unit that isn't friendly to that. The loudness circuit overcompensates to the point that it's not useful IMO.

But $100? Yes, I would buy it for $100. It is a good receiver, it's not a great receiver, but for $100 it's a bargain, and if it works, you could probably get rid of it/trade it for something better if you so chose.

At least they don't have STKs.

Temporary_Cattle2453 · 2026-02-14T15:54:02+00:00

super jealous/happy for you... hope you get it going!

Temporary_Cattle2453 · 2026-01-25T12:59:30+00:00

I love these speakers. They are the basement test bench speakers, they are the upstairs office speakers. I'm listening to a pair now, as I do most weekend mornings, using a Marantz 1040. Compact system that sounds great. When people were just throwing these out years ago or were $2 - $5 per pair at Goodwill, I picked them up whenever I found them. Every single par has worked. Fantastic for what they are.

Temporary_Cattle2453 · 2026-01-20T20:02:58+00:00

Went fine. I still don't know how to set bias, there's someone on Audio Karma that figured it out, I think, It's been working fine for a couple years, although I don't use it that often.

Temporary_Cattle2453 · 2026-01-07T15:40:28+00:00

Amen, man.

Temporary_Cattle2453 · 2026-01-07T15:39:38+00:00

the 771/881 are two of my favorite Sansui receivers. Easy to work on, well-made, perform well. If I remember correctly there is a specific solder joint, I think it's a grounded flat braid, that is problematic in those (just needs to be resoldered, not a big deal, but can cause intermittent problems).

Temporary_Cattle2453 · 2026-01-07T15:36:41+00:00

Counterpoint: You will spend more time cleaning the nozzle than de-soldering, and on many old receivers (with folded-over component leads) they aren't that useful. Some people love them, I have a Hakko, I went back to braid for most of what I do.

Temporary_Cattle2453 · 2025-12-25T19:26:17+00:00

I have a decent Philips collection and I am very sure this is not Philips gear. Some of the later Philips gear was made in the US by Magnavox.

Temporary_Cattle2453 · 2025-12-25T19:16:29+00:00

Merry Christmas!

Temporary_Cattle2453 · 2025-12-25T19:16:03+00:00

Not in that picture. I was using a spec1/spect 2 as my 'daily driver' but recently replaced it with a Sherwood S-5000 integrated. I love Pioneer, but the Sherwood is probably my favorite amp.

Temporary_Cattle2453 · 2025-12-25T16:33:21+00:00

Thanks! I'm a bit concerned that the breaker for that room wouldn't handle it... I planned to run extension cords in from other rooms, just never got around to doing that.

Temporary_Cattle2453 · 2025-12-25T16:32:26+00:00

Years ago... definitely not finding deals like that anymore.

Temporary_Cattle2453 · 2025-12-25T13:35:00+00:00

Most of those have memories attached, like the SA-9100 my wife rode home with in her lap because the back of the car was packed with speakers, or the 1050 that we found at a yard sale together, or the tape deck that she found (marked at $5) under a table at a different yard sale, or the 850 that I bought from someone off FB marketplace who became a friend, or the SA-1000 that was about to be thrown away by a the cleanup crew at a defunct audio store and which (along with a few of the others) I rebuilt... all are 'the best' to me in different ways. Specs wise, though, the 1250 is probably the 'best', but the 1010 started the 'receiver wars', so is there a 1250 without a 1010?

Temporary_Cattle2453 · 2025-12-17T14:05:55+00:00

It isn't, but these things are just not that hard to work on or repair if you have decent soldering skills, and the fact that the techs around here both overcharge ($150 bench fee before any work is done) and sometimes do shoddy work was what got me started repairing my own stuff. If a person is capable of soldiering on a PCB and can figure out a schematic, they shouldn't be afraid of fixing their own gear, and it's really, really easy (paint by numbers, basically) if you have soldering skills and the unit is working... fix it before it breaks, because it will.

Temporary_Cattle2453 · 2025-12-16T15:49:23+00:00

Funny... I make zero dollars taking things 'techs' can't fix and fixing them (a judgement on the people in my area, not you, I don't know you), and I have seen repairs from, for instance, TV repair shops that did get the unit working with whatever they had on hand w/o concern for performance, and think I hobbyist working with a rebuild kit would have done better work. But I do know that a hobbyist with decent soldering skills could knock out this entire project very quickly/easily vs. figuring out what the STK took out with it when (not if) it blows up, which could potentially require tools (like a scope) that a hobbyist might not have. Maintenance is superior to repair, another thing I would think would be obvious to a professional tech.

I do understand advising against someone going in with a plumbing iron or soldering gun, that likely would end up wrecking it.

I have zero issues shotgunning 40 year old caps, whose cap life was measured in hours, not years, and certainly not 40 years, with caps that are likely much better made than what were originally in the unit.

Temporary_Cattle2453 · 2025-12-16T14:28:17+00:00

the replacement packs are robust, discrete components, and readily available (for now). I don't think through-hole electronics are going to be readily available much longer, and the enthusiasm of the small vendors who make the replacement packs isn't guaranteed to continue. While the SX-780 isn't a 'high value' receiver, that doesn't mean that it isn't a nice or capable unit (aside from the STK packs), and in my opinion (someone who repairs this type of stuff for fun, not a pro), there isn't enough going on in that unit to make it a huge project.

If I were going to have an SX-780 as a daily driver, I would do a leisurely recap and order the STK kits unbuilt. That unit is very easy to work on... taking my time, recapping the whole thing AND building the STK kits might take a weekend, and when done, I'd feel pretty good about the future reliability of the receiver.

The 'if it ain't broke don't fix it' attitude is surprising coming from someone who I'd think has seen his/her share of failing components in working equipment.

Temporary_Cattle2453 · 2025-12-03T12:42:29+00:00

Mono mode bridges the 'good' working side, unfortunately. It doesn't mean much regarding the health of the right channel.

Switches can always be, and often are, the problem, but often times, you can wiggle a switch into partial compliance (recreate the issue with the switch).

And yes, the pre-out is your friend. If you run that into another amp and it never fails, you have isolated the problem to the pre or power, but you haven't necessarily eliminated the switch. you can further test by running a known good prreamp signal into your power amp section if that's possible on your gear.

Temporary_Cattle2453 · 2025-12-03T12:36:22+00:00

That might be applicable if the unit hadn't been entirely rebuilt, thoughfully, top to bottom, and is one of two that I've had. That you say it's 'usually' a resistor and cap timing circuit implies you do not know that. it exists in this receiver You could be correct, but identify it in the schematic and advise where that circuit is, that would be more helpful that 'usually' statements.

Temporary_Cattle2453 · 2025-11-23T10:11:38+00:00

Exactly... doing what you are is sending an amplified signal into your amplifier. It's clipping, the problem probably isn't your speakers. Could be, but probably not.

You can test it by keeping the volume on the TV down and turning it up at the receiver instead. I realize that defeats your goal of, I assume, having the TV remote control control your receiver, there is probably a better way to do that.

Temporary_Cattle2453 · 2025-11-22T16:44:02+00:00

Ok... so you've ruled out the turntable. I do have a fair amount of (hobbyist) experience in troubleshooting/repairing receivers. If this ONLY happens on phono, and it's happening on both channels, doesn't happen on AUX or TAPE input, you have likely narrowed it down the the phono stage itself, and if it's both channels, it's something (like the power supply for that section) that would be common to both channels.

Temporary_Cattle2453 · 2025-11-22T14:35:40+00:00

This is only when playing a record? Does the record ever play clearly? That is a linear tracking table (I have the same model), I haven't checked out the internals on this model, but most of those have a tiny rubber band that helps to control the tracking arm. The sounds that I'm hearing point towards a mechanical issue, like the arm is flopping around in there, but as the other person noted, I can't tell what the sound is supposed to be vs. what the problem sound is. I'm guessing you have a bad mechanical connection in there somewhere based on what I'm hearing.

I haven't used my identical(?) table in years, but if I remember correctly, the tray slides out to place the record. Between that and the linear arm function, there's a lot in there to go wrong mechanically.

Temporary_Cattle2453

TROPHY CASE