mystik cabs
Member
Are the SX 838 any good? worth getting and having one gone through? Or 70's junk?
Pioneer SX 838
- Thread starter mystik cabs
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69sixpackbee
Well-Known Member
getright99
least likely to succeed
The x3x models are great receivers IMO. I had the 939 and kick myself to this day for selling it.
mystik cabs
Member
decent cosmetically but untested..., dates to June, 1974.
Last edited:
michaelhigh
mind's eye music
This receiver was my first object of audio lust as a teen, and I own one now.
Get it if it works and isn't too beat.
Get it if it works and isn't too beat.
wicked1340
Active Member
Me too!
Sharpstik
Stuck in the 70's
You're new to this aren't you, to ask that question ?
mystik cabs
Member
Uh... Yeah, how could you tell? Lol. Anyhow, what's a good price to pay if there is the possibility it'll need work? Apparently it lights up but there is no sound.
gslikker
Super Member
That would be a good price for a faulty unit, indeed. I paid about 70 euro's each for 2 of these last year. (close to US$200 for the two)
They came on the dutch ebay-owned thing apart from each other, were stated defective and although I found it too expensive, my vintage gear greed did win.
Be aware, people used them until they did not work anymore, then put them somewhere in storage, 20 years later take it out or find it back again and suddenly find out people paying money for this old defective junk nowadays..
During those 20 years in storage, other problems might have appeared.
Besides the sound is not very well comparing to other amps I have (so a recap might be audible) my units together had 5 issues. One of them not easy to fix (magnet was loose in the tuning meter!) and I still need to recap.
The other failures: One bad power switch (and knob from another brand) which needed a switch physically the same, two power supply boards one on each defective, and one main amp.
Fortunately, the tuner part was still good on both (it has a good tuner)
So, be aware of the risks you have with any vintage receiver...
Buying something "untested" means the seller is unable to test it because it does not work at all...
They came on the dutch ebay-owned thing apart from each other, were stated defective and although I found it too expensive, my vintage gear greed did win.
Be aware, people used them until they did not work anymore, then put them somewhere in storage, 20 years later take it out or find it back again and suddenly find out people paying money for this old defective junk nowadays..
During those 20 years in storage, other problems might have appeared.
Besides the sound is not very well comparing to other amps I have (so a recap might be audible) my units together had 5 issues. One of them not easy to fix (magnet was loose in the tuning meter!) and I still need to recap.
The other failures: One bad power switch (and knob from another brand) which needed a switch physically the same, two power supply boards one on each defective, and one main amp.
Fortunately, the tuner part was still good on both (it has a good tuner)
So, be aware of the risks you have with any vintage receiver...
Buying something "untested" means the seller is unable to test it because it does not work at all...
mystik cabs
Member
Update: It does indeed have sound, the DNR switches were dirty, I used some DeOxit to get it going. Sounds nice but no activity with the tuner section, meters do not budge, phono and aux (cd) sound great.
gslikker
Super Member
Both AM and FM? Your power supply might be dead for the power of the tuner.
The power board is on the bottom, as far as I remember also only accessible through the bottom.
So it just needs the bottom plate to be removed.
For a tuner repair you will need a very experienced tech, a power supply is easier and especially this one since it is reasonably accessible.
You may have a big resistor (R3, 220 ohm 5 watts) on the power supply board have the board itself burnt and maybe the transistor it feeds (Q1), and also adjacent components. It supplies 13 volts to the tuner.
At least, this was the area in both my receivers was a fault. My units are 220 Volts and nowadays mains is 230 volts, which also adds to the heat...
It is because of a bad design this happens. There is no ventilation, the circuit board is upside down, so all the heat generated spreads out in between the components.
I mounted a new bolted-type resistor agains the metal under the circuit card, it is cooled by the metal above this circuit board (this might read funny but the receiver is upside down while repairing this)
This apart from the other components needing replacement.
You easily can find a service manual pdf on the internet just g??gle "sx-838"and "pdf"
If you are a tech you can do it yourself, if not, have somebody else do it who can, because understanding and measuring the voltages if wrong, and why wrong, is essential.
The power board is on the bottom, as far as I remember also only accessible through the bottom.
So it just needs the bottom plate to be removed.
For a tuner repair you will need a very experienced tech, a power supply is easier and especially this one since it is reasonably accessible.
You may have a big resistor (R3, 220 ohm 5 watts) on the power supply board have the board itself burnt and maybe the transistor it feeds (Q1), and also adjacent components. It supplies 13 volts to the tuner.
At least, this was the area in both my receivers was a fault. My units are 220 Volts and nowadays mains is 230 volts, which also adds to the heat...
It is because of a bad design this happens. There is no ventilation, the circuit board is upside down, so all the heat generated spreads out in between the components.
I mounted a new bolted-type resistor agains the metal under the circuit card, it is cooled by the metal above this circuit board (this might read funny but the receiver is upside down while repairing this)
This apart from the other components needing replacement.
You easily can find a service manual pdf on the internet just g??gle "sx-838"and "pdf"
If you are a tech you can do it yourself, if not, have somebody else do it who can, because understanding and measuring the voltages if wrong, and why wrong, is essential.
mystik cabs
Member
The unit in question in operation, sort of. Sounds pretty good.
Last edited:
try1256
Super Member
The unit in question in operation, sort of. Sounds pretty good.
Is that a PD4700? I have one of those too!!
Sharpstik
Stuck in the 70's
I don't think so.
I have a dozen Pioneers and I have never had this problem, it must be rare.
You've got an antenna hooked up to the FM terminals, right? Won't work without that. Also take the FM Muting off, that locks out all but the strongest stations.
