That 5 watt resistor on the power supply board made the board darkened cause it gets quite hot. When I work on these units I change the resistor to a panel mount type and relocate it to the chassis.
Another interesting video, thanks a lot. I suggest you treat yourself to a good old fashioned moving coil multimeter. They are generally inexpensive and there is something much more intuitive setting dc offsets and bias current when watching needle move!
It was very interesting to watch your video on your SX-838. I have the same receiver, but it is a different version. I was not aware there was more than one version. My receiver does not have push button switches to select speakers as it is incorporated into the power switch. Also, the output transistor assembly with the pcb board on mine, comes out of the receiver as one piece by removing 4 screws.
Found a far more modest SX-990 at a flea market, and it still is making music. Wife works from home, and that 990 sounds pretty good in her home office.
Hey Aidan, For me this is one of your best Pioneer SX tune-up/restore videos. Absolutely great job! Very nice details on the process. I too am a big fan of the Pioneer SX series. Really nice presentation, super nice workbench area in the room as well.
Nice job man.. I LOVE this series. I don't listen to mine loud.. as you said, low-mid levels it's just awesome !! bass-heavy and clear treble is correct. I switch to the Nikko Alpha/Beta/Gamma stack for cranking up louder. But I enjoy the Pioneer receiver more often because the largest percentage of my listening is with lower volumes. I really like how you leave your real world goof in the videos, I make goof too when I work on stuff, like you I do catch myself and correct things.. and yes I snapped off my tuning indicator and had to glue it too ! Uhhg. Nice job keep up this informative style it's valuable to a lot of us in your audience :- )
Aiden, those dial indicators are cursed. I broke the same one on my first SX-434 twice. Aside from it being a little shorter, and maybe slightly crooked, it works just fine now.
Awesome job👍 I have a xs650 playing through pioneer hpm 100s. Everything seems fine but concerned because age. Fm is so so. Wish I had someone to give it a health check.
Nice job Aidan👍👍 This SX-838 sounds and looks good to me as well as getting a nice bump in power without a full blown restoration. Always interesting to see how much time and work it takes to repair or restore one of these receivers. I think this receiver "refresh" should have been broken down into several videos with a little less editing out/fast forwarding through the manual labor. More video time, more better for us😉 Great video, thanks for the work as always.
These are non polarized chassis but I'm getting 98VAC from front panel to earth ground on receptacle. I've found two different schematics showing two fuses but a 2.2M resistor to ground on white primary. Mine is missing that resistor.
Nice addressing of the common issues... Just wanted to point out as i did in another one of your videos.. On the amp board...Q5 and Q6 are your "class A" pre drive/current source transistors and are not "bias" transistors. This model does not use a bias transistor. The bias ladder is nothing more than a stack thermal diode in conjunction with a potentiometer between the two drive halves. The Class A driver they used in this unit, the 2SC1451 are really reliable devices and i never see them go bad in this model at all. On the lower power units they used certain matsushita transistors that were known to intermittently open their junctions causing issues but not these C1451's made by NEC.. Totally rock solid through and through.. i suggest to leave them be in the future... Just focus on the differential pairs...
This video was interesting to me, because I purchased the Pioneer SX-838 in 1972 when I was working at an audio store part-time while in college. Employees got 50% off MSRP as a courtesy direct from the manufacturer/distributor, which was even less than cost for units purchased by the retailer for resale. I used it to drive KLH Model 5 speakers and also had a Thorens TD-160 turntable. I replaced the SX-838 in 1982 with a Hafler pre-amp (DH-110) and power amp (DH-220) that I assembled from kits. I forget what I did with my SX-838 or whether there were any problems with it when I stopped using it.
I'm not sure how old you are, but you can learn how to do this. Take an electronics class to learn the theory and build from there using the internet as a resource.
Good Morning I would like to know which model sounds better a Sx 838 or SX750 and which one is built better and which one has less problems . I was wondering if you would know the answer to these questions I enjoy watching your videos I've learned a lot I wish you the best.
any idea what would cause the FM radio to just stop putting out any sound after a few minutes of running? the signal needle also drops to 0. after leaving it off for a few minutes it works again and then will eventually cut off again.
Really enjoy your videos Aidan! I have a Pioneer vintage system including an RT909 reel to reel, an RT707 reel to reel, and a Pioneer SA7700 amp that I bought brand new back in the day. The amp still works and I purchased a restore kit with caps, transistors, relay, etc. I replace the 2 large filter caps and swapped the VU meters lights to LED. However I do not feel comfortable replacing the other smaller caps and transistors yet. Recently when powering up, the protection relay clicks, but then within a few minutes it clicks back off and the VU meter lights dim. A few seonds later it clicks back on and the lights get bright again. It will do this several times until it warms up and then it is fine. I have not checked the DC offset yet but will do that eventually. Question: Do you restore other peoples vintage gear? If so how much, and based on the relay issue, where do you think I should look first? Thank you! Chris from Winter Garden Florida.
Hi Aiden -- How's the New House Going ? Got a quick question before I try to tackle my Pioneers: What's Your Go-To source for Service Manuals & Schematics for these receivers you restore? Thanks in Advance.
HELLO, I'M NEW TO AUDIO REPAIR. I'M FIXING THE PIONEER SX 838. I'M REPLACING THE D313 TRANSISTORS. ONE IS SHORTED. I'M USING TIP41CG REPLACEMENTS. DO I NEED TO USE MICA INSULATERS & HEAT SINK PASTE?
I just stumbled on your channel and watched a bunch of videos, good stuff. I noticed you have a new bench that I like and want one. Can you tell me what brand it is? Also I would love to see a work area and tool update for people like me looking to get into this hobby. Thank you so much!
I think the re-cap thing can get out of control, I replaced every cap in my sx727 and all of the originals, other than the sky blue sanyo’s, tested fine. The original filter caps actually tested better than the new “audio grade” replacements. Perhaps there are other qualities that the purple cap tester doesn’t measure?
To be clear, it's the solvent that is drying up. The "5" in "D5" means 5% actual deoxit and 95% solvent/propellant to get the deoxit where it needs to go inside the switch. You can use the gear right away since it's non conductive. The solvent will evaporate after like 15 minutes though depending on your room conditions.
@@AHFixIt Thanks for getting back. I used some on one of my pots, but I was afraid it would short out-- so I left it overnight so it would evaporate. I am glad that I asked.
If only I could entrust you with two Pioneer 720H HDD DVD recorders which have a recurring power supply problem on all of these recorders of this brand.
Good afternoon I have the same receiver and I would like to have it going through I live within half hour of Providence Rhode Island do you do any work on the side or do you have anyone in that area you could recommend
Hello from Meaford Ontario Canada : I notice you use Kemet for filter caps and I know they are European and excellent quality, with all the selection of quality filter caps from ChemiCon to Nichicon to Mundorf. ..why do you use Kemet?
Well honestly, I think the sx-838 is one of the worse receiver that is seriously stripped down 939 and 1010. I probably take a 737 over an 838. I used to own an entire line if x3x receivers. Faceplate wise, they're all the same size (838, 939, 1010). As of now, I still own 636, 737, 1010.
I always laugh when I see SANKEN transistors. ..SANKEN is Sanyo and almost every Japanese manufacturer of hifi uses SANKEN aka Sanyo . Harmon Kardon used SANKEN Yamaha DENON ROTEL etc. etc etc All Sanyo
![Blox Fruits Dragon Rework Update [Full Stream]](http://i.ytimg.com/vi/EqDAp8udhm0/mqdefault.jpg)
I always like getting up, pouring a cup of coffee, and finding a new Ah-fixit video.
Ice unit, I still have and use my SX737 I bought in the 70’s…. Near mint condition….. I love this era….
That 5 watt resistor on the power supply board made the board darkened cause it gets quite hot. When I work on these units I change the resistor to a panel mount type and relocate it to the chassis.
For sure. Offloading it from the circuit board is a great idea!
Another interesting video, thanks a lot. I suggest you treat yourself to a good old fashioned moving coil multimeter. They are generally inexpensive and there is something much more intuitive setting dc offsets and bias current when watching needle move!
I came across an SX-636 about 5-6 years ago at a record store for $125 bucks. It need a little work but in the end I paid about $200 total for it.
A really nice job. That may be simple for you, but you are one heck of a technician.
I love how the SX-1010 sounds! Out of all of my receivers including my McIntosh, my pioneer SX-1010 is best
I would agree. They have a much more warm sound than the SX -50 or sx-80 series
It was very interesting to watch your video on your SX-838. I have the same receiver, but it is a different version. I was not aware there was more than one version. My receiver does not have push button switches to select speakers as it is incorporated into the power switch. Also, the output transistor assembly with the pcb board on mine, comes out of the receiver as one piece by removing 4 screws.
Found a far more modest SX-990 at a flea market, and it still is making music. Wife works from home, and that 990 sounds pretty good in her home office.
Hey Aidan, For me this is one of your best Pioneer SX tune-up/restore videos. Absolutely great job! Very nice details on the process.
I too am a big fan of the Pioneer SX series. Really nice presentation, super nice workbench area in the room as well.
Nice job man.. I LOVE this series. I don't listen to mine loud.. as you said, low-mid levels it's just awesome !! bass-heavy and clear treble is correct. I switch to the Nikko Alpha/Beta/Gamma stack for cranking up louder. But I enjoy the Pioneer receiver more often because the largest percentage of my listening is with lower volumes. I really like how you leave your real world goof in the videos, I make goof too when I work on stuff, like you I do catch myself and correct things.. and yes I snapped off my tuning indicator and had to glue it too ! Uhhg. Nice job keep up this informative style it's valuable to a lot of us in your audience :- )
Love the new workspace Aidan, it certainly looks like you have more space to work on
The ceramic power supply resistor is too close to the PCB it should have space below thats why the board its burnt.
Aiden, those dial indicators are cursed. I broke the same one on my first SX-434 twice. Aside from it being a little shorter, and maybe slightly crooked, it works just fine now.
Great job! Love the attention to detail. It should go for another 50 years!
Awesome job👍 I have a xs650 playing through pioneer hpm 100s. Everything seems fine but concerned because age. Fm is so so. Wish I had someone to give it a health check.
Nice job Aidan👍👍 This SX-838 sounds and looks good to me as well as getting a nice bump in power without a full blown restoration. Always interesting to see how much time and work it takes to repair or restore one of these receivers. I think this receiver "refresh" should have been broken down into several videos with a little less editing out/fast forwarding through the manual labor. More video time, more better for us😉 Great video, thanks for the work as always.
Great video, Aiden...Thanks so much!
Nice video, I have an SX838 powering KLH Sixes. Listen at low to moderate volumes. Pretty good!
I like the sound quite a bit.
Great video. I’m a newbie and restoring my first vintage stereo.
These are non polarized chassis but I'm getting 98VAC from front panel to earth ground on receptacle. I've found two different schematics showing two fuses but a 2.2M resistor to ground on white primary. Mine is missing that resistor.
Nice addressing of the common issues... Just wanted to point out as i did in another one of your videos.. On the amp board...Q5 and Q6 are your "class A" pre drive/current source transistors and are not "bias" transistors. This model does not use a bias transistor. The bias ladder is nothing more than a stack thermal diode in conjunction with a potentiometer between the two drive halves. The Class A driver they used in this unit, the 2SC1451 are really reliable devices and i never see them go bad in this model at all. On the lower power units they used certain matsushita transistors that were known to intermittently open their junctions causing issues but not these C1451's made by NEC.. Totally rock solid through and through.. i suggest to leave them be in the future... Just focus on the differential pairs...
This video was interesting to me, because I purchased the Pioneer SX-838 in 1972 when I was working at an audio store part-time while in college. Employees got 50% off MSRP as a courtesy direct from the manufacturer/distributor, which was even less than cost for units purchased by the retailer for resale. I used it to drive KLH Model 5 speakers and also had a Thorens TD-160 turntable. I replaced the SX-838 in 1982 with a Hafler pre-amp (DH-110) and power amp (DH-220) that I assembled from kits. I forget what I did with my SX-838 or whether there were any problems with it when I stopped using it.
I still have my SX-828, I bought new in the 1970's.
Man! As much as I would like to learn how to do this stuff, I know my limitations. Good job.
I'm not sure how old you are, but you can learn how to do this. Take an electronics class to learn the theory and build from there using the internet as a resource.
@@Silent-Lucidity 66
I use a 2-part epoxy for a broken tuner dial indicator.
I wish you would have shown how to adjust the bias. My 939 is expected tomorrow and plan to do at least a partial restoration.
Good job dude, love your videos ❤
I sold quite a few back in 73 to 76? 😎
Nice receiver
Yer quite a smart young feller.
Good Morning I would like to know which model sounds better a Sx 838 or SX750 and which one is built better and which one has less problems . I was wondering if you would know the answer to these questions I enjoy watching your videos I've learned a lot I wish you the best.
I have an sx 750, 737, 828. I have to give the edge to the 50 series. Seems to me that's where pioneer reached their peak. Just my thoughts though
At 37:12 into your video when removing the output transistor s you tilted the heat sink back and a mica shim fell in behind
any idea what would cause the FM radio to just stop putting out any sound after a few minutes of running? the signal needle also drops to 0. after leaving it off for a few minutes it works again and then will eventually cut off again.
Really enjoy your videos Aidan! I have a Pioneer vintage system including an RT909 reel to reel, an RT707 reel to reel, and a Pioneer SA7700 amp that I bought brand new back in the day. The amp still works and I purchased a restore kit with caps, transistors, relay, etc. I replace the 2 large filter caps and swapped the VU meters lights to LED. However I do not feel comfortable replacing the other smaller caps and transistors yet. Recently when powering up, the protection relay clicks, but then within a few minutes it clicks back off and the VU meter lights dim. A few seonds later it clicks back on and the lights get bright again. It will do this several times until it warms up and then it is fine. I have not checked the DC offset yet but will do that eventually. Question: Do you restore other peoples vintage gear? If so how much, and based on the relay issue, where do you think I should look first?
Thank you! Chris from Winter Garden Florida.
I want to know where i can buy the replacement parts? Any good site? Great video!! 🤟
I need to have my dad’s sx-737 taken in for a full overhaul. What would the cost be? He bought it new in while stationed in Germany in’73
Hi Aiden -- How's the New House Going ? Got a quick question before I try to tackle my Pioneers: What's Your Go-To source for Service Manuals & Schematics for these receivers you restore? Thanks in Advance.
Nice job. It's got pre outs! ❤ did u try the pre amp stage to external amp?
ELNA CEROPHYN CAPACITORS ARE AWESOME FOR THE PRICE ...they take 100 hrs to break in and sound epic
HELLO, I'M NEW TO AUDIO REPAIR. I'M FIXING THE PIONEER SX 838. I'M REPLACING THE D313 TRANSISTORS. ONE IS SHORTED. I'M USING TIP41CG REPLACEMENTS. DO I NEED TO USE MICA INSULATERS & HEAT SINK PASTE?
If you're talking about the driver transistors on the small heatsinks, they do not need mica but they would benefit from paste
I just stumbled on your channel and watched a bunch of videos, good stuff. I noticed you have a new bench that I like and want one. Can you tell me what brand it is? Also I would love to see a work area and tool update for people like me looking to get into this hobby. Thank you so much!
Home Depot husky 72" adjustable height
@@AHFixIt sweet thank you
So what's the name of our
' favorite song'?
I think the re-cap thing can get out of control, I replaced every cap in my sx727 and all of the originals, other than the sky blue sanyo’s, tested fine. The original filter caps actually tested better than the new “audio grade” replacements. Perhaps there are other qualities that the purple cap tester doesn’t measure?
No reason to use audio grade for filter caps. Use something with high ripple current.
Usually the sky blue sanyo caps are the ones that are bad
They allow DC to go buy them and then they also measure like a resistor
Great video. I have a NOOB question. How long do you wait for the DeOxit to dry up? Or do you just use it right away?
To be clear, it's the solvent that is drying up. The "5" in "D5" means 5% actual deoxit and 95% solvent/propellant to get the deoxit where it needs to go inside the switch. You can use the gear right away since it's non conductive. The solvent will evaporate after like 15 minutes though depending on your room conditions.
@@AHFixIt Thanks for getting back. I used some on one of my pots, but I was afraid it would short out-- so I left it overnight so it would evaporate. I am glad that I asked.
What does a full resto cost on one of these ?
Just curious
If only I could entrust you with two Pioneer 720H HDD DVD recorders which have a recurring power supply problem on all of these recorders of this brand.
Good afternoon I have the same receiver and I would like to have it going through I live within half hour of Providence Rhode Island do you do any work on the side or do you have anyone in that area you could recommend
Hello from Meaford Ontario Canada : I notice you use Kemet for filter caps and I know they are European and excellent quality, with all the selection of quality filter caps from ChemiCon to Nichicon to Mundorf. ..why do you use Kemet?
Everybody has their own favorites but yeah for filtering AC it's not going to make a bit of difference on sound quality that's for sure
What did you charge to do all that work? Just asking so I get an idea of what it cost to do maintenance on a similar unit.
ELNA is prob a pretty good cap co. ? but time is time,. i have seen ELNA's many times in photo-flash units for some reason,. NICE VIDEO!
What do you think about model SX-939.?
Never heard one! Probably very similar to this though.
@@AHFixIt salesman said that brother of SX-1010 (70watt output)
What in the world happened to your thumb ?
Oops, sorry if I mispelled your name.
For God's sake , I hope it is and you are too, reliable that is...Shema!!!.
Well honestly, I think the sx-838 is one of the worse receiver that is seriously stripped down 939 and 1010. I probably take a 737 over an 838. I used to own an entire line if x3x receivers. Faceplate wise, they're all the same size (838, 939, 1010). As of now, I still own 636, 737, 1010.
Save 20 mins and just spray the switches and pots. Assume they need cleaning. They always do.
Argh! Pointer wires put overtop the tuning string. Triggered. 🤨
not the first to go in here PHRASING
I always laugh when I see SANKEN transistors. ..SANKEN is Sanyo and almost every Japanese manufacturer of hifi uses SANKEN aka Sanyo . Harmon Kardon used SANKEN Yamaha DENON ROTEL etc. etc etc All Sanyo
I'm # 420
2SC869 replacement is required
please elaborate, thanks