Very cool. I’m trying to repair my left channel on my 1280 now (very quiet) and my 1980 (phono 1 not working) Very helpful to see it explained like this.
Glad the video helped! Hoping to get a 1980 one day! For the weak left channel on the 1280, you can test to see if the issue is in the power amp or elsewhere.. on the back of the unit there are the little jumpers across the "pre-out" & "main in".. remove those and grab a set of RCA cables and flip the channels (L to R and R to L) if the weak channel moves to the right side, its not in the pre-amp or power amp. But if it stays on the left, there's an issue somewhere in the pre-amp/power amp for the left channel. If it comes to that, let me know I can provide some areas to check for voltages. For the 1980, make sure the switches are very clean! Dirty switches can cause all kinds of problems. If that doesn't fix it, the phono board may need a rebuild. Thanks for watching!
My left channel stopped working this past weekend. My adapter switch also doesn’t work. If I try the left channel on speaker B or C it’s the same thing. You can faintly hear music on the left channel if you turn the volume up substantially.
The Pioneer SX-1280 runs at a rated 185 watts per channel RMS not 200 Watts Per channel. Lovely clean near mint condition unit you have there. My Pioneer SX-1280 has slight damage to its cooling fins.
@@TinkeringWithT If it has the original incandescent lamps the foil was probably added to reduce or eliminate the heat from the bulbs hitting the cabinet.
Thinking about purchasing one of these beautiful receivers but am hesitant about not being able to replace the power output transistors since they are not manufacred anymore. Would you consider selling your home made power output transistor board with modern transistors installed ?.
You should!! You will love it. The 1280 is a beast! Luckily, there are modern equivalents out there are are pretty cheap. It's the mounting, and wiring that slightly different from the original. I haven't thought about making those boards, that's a good idea! If I have some time in the coming months, I'll see if I can make some. But feel free to reach out with any questions about the boards! If you can find a receiver that still works with the original transistors, they are decent. What kills them is they get overloaded from another source. On mine, I think I traced the root cause to the power supply board. It killed 6 out of the 8 transistors. The protection design on these amps isn't the greatest unfortunately. But if you can find one that still works, rebuild the power supply board, and pre amp boards to help combat this problem! Thanks for watching! I apologize for the late response.
The previous owner had taped some tinfoil to where the lights are for whatever reason. Probably something to do with the bulbs getting hot. I removed it and swapped in some LED's nice and cool! Thanks for watching!
Surprised it didn't come back much sooner with a 10W resistor installed. Higher value resistor is going to increase power dissipation. No excuse for not doing it right the first time.
I have a MONSTER fisher Studio standard 1080 and I'm trying to set the DC offset to zero or as close as I can anyway and I did it on my pioneer Sx 1080 with no problem but this fisher is difficult for some reason I know where the bias adjustments are and as I turn them I get no difference the reading on my meter stay the same and I have it set right to 200mm so im wondering what's going on 🤔 can you help me if possible plus I downloaded the manual and I know I'm in the right spot Plus I see the bias pots 1 by each heatsink plus there are 3 on another board I even tried those with no results I even separated the pins in the back separating the amp from the preamp like was suggested in the manual still no results so I'm puzzled at this point 🤔 can you help me thanks.
That's a sweet unit! Hmmm has any work been done to the unit at all? or is it all original? I'm wondering if the excessive DC offset is coming from some leaky capacitors, or an open resistor somewhere. On some of the Pioneers I know the bias pots are not good quality and can give erratic results. But I think this is a different issue. I'll see if I can find the manual online. Visually inspect the boards to see if any capacitors are bulging, or if there are any abnormal heat marks around a resistor. Hopefully we can get it figured out!
@@TinkeringWithT I've had work done on this unit recently and it works fine I've had every board checked every capacitor changed all I'm trying to do is bring the DC offset down to zero there not above 100 the right channel is at 05.9 and the left channel is at 18.3 I'm Just trying to adjust them to as close to zero as possible but when I move the bias adjustments screw my meter don't move it just stays at the reading it's on for both channels 🤔🤔🤔🤔
@@ReginaldDj1 Ah gotcha! Let me see if I can pull up the service manual for the Fisher. I know on some of the pioneer receivers, if the DC offset won't adjust, there is a jumper wire that can be removed to help lower the voltage reading. It might be the same on the Fisher!
Most likely! When I bought it years ago, the original resistor had opened up. Thought I had 20W resistors, to replace it, but I guess not! Lesson learned for sure.
Ah I’m so sorry! I had some issues with volume on my early videos, so I apologize. I wish I could fix it without deleting it! Maybe I can edit the audio. Let me know if have any questions!
I have no idea😂 it came like that when I bought it! When I was all done rebuilding it, I ripped it off! The only think I could think of was maybe heat dissipation with the old incandescent bulbs? I swapped them out with warm white LED’s so heat isn’t a problem anymore!! Thanks for watching!
This is the 1st video I've watched of yours. Nice work flow of using the basic tests so the obvious culprits are tested first. Great job. I love your approach and in effort offer some advice for safety and ease of your future video repairs, A) Have you created a Dim Bulb setup to help protect your Mains line from large current draws due to shorted internal components? If not, I think we all could highly recommend that to you. B) Or, do you have an Isolation Transformer in your Mains circuit? C) Instead of using a Towel, consider obtaining some of the Silicon mats used in Ovens and lay those onto your bench. Can even secure them down if desired. Here's a link to what I made and I think you would find this would safeguard you when hooking up monster power receivers like the Pioneer SX-1280. (ruclips.net/user/postUgkxDPfI2kwCYa2bHcDoHMKgCsXhL0KkbrlE?si=I5myJqAVV8di68iw)
![Pioneer SX-1080 Service! [Do It Yourself!!] #electronics #vintageaudio #diy](/img/1.gif)
Man that things minty clean and fresh !! Wow !
Very cool. I’m trying to repair my left channel on my 1280 now (very quiet) and my 1980 (phono 1 not working)
Very helpful to see it explained like this.
Glad the video helped! Hoping to get a 1980 one day! For the weak left channel on the 1280, you can test to see if the issue is in the power amp or elsewhere.. on the back of the unit there are the little jumpers across the "pre-out" & "main in".. remove those and grab a set of RCA cables and flip the channels (L to R and R to L) if the weak channel moves to the right side, its not in the pre-amp or power amp. But if it stays on the left, there's an issue somewhere in the pre-amp/power amp for the left channel. If it comes to that, let me know I can provide some areas to check for voltages. For the 1980, make sure the switches are very clean! Dirty switches can cause all kinds of problems. If that doesn't fix it, the phono board may need a rebuild. Thanks for watching!
This video is definitely the best watch on the topic of the 1280 on RUclips, and I’ve watched hours at this point!
@@jamesapplehanz1848 Thanks for your kind words!! I hope you get your receivers figured out! Let me know when you get them jammin' again!
Also, let me know if there are any other areas of the 1280 that you'd like to see a video on!
My left channel stopped working this past weekend. My adapter switch also doesn’t work. If I try the left channel on speaker B or C it’s the same thing. You can faintly hear music on the left channel if you turn the volume up substantially.
GOOD JOB!👍
Thank you!!
Outstanding. A powerful receiver available again.
It sure is a beast!! Thanks for watching!
I'd have been curious about on the bottom how much heat that resistor next to the fuse board had turned the board black, thats a lot of heat-!
Can’t imagine how hot it must have gotten!!
Great receiver.
It sure is! One of my favorites!
The Pioneer SX-1280 runs at a rated 185 watts per channel RMS not 200 Watts Per channel. Lovely clean near mint condition unit you have there. My Pioneer SX-1280 has slight damage to its cooling fins.
Great job. Although the tin foil acroos the lights is a bit shady…
Thanks!! Yeah, as soon as I saw that I had to rip it off. Not sure what the previous owner was trying to accomplish with that! Thanks for watching!
@@TinkeringWithT If it has the original incandescent lamps the foil was probably added to reduce or eliminate the heat from the bulbs hitting the cabinet.
Thinking about purchasing one of these beautiful receivers but am hesitant about not being able to replace the power output transistors since they are not manufacred anymore. Would you consider selling your home made power output transistor board with modern transistors installed ?.
You should!! You will love it. The 1280 is a beast! Luckily, there are modern equivalents out there are are pretty cheap. It's the mounting, and wiring that slightly different from the original. I haven't thought about making those boards, that's a good idea! If I have some time in the coming months, I'll see if I can make some. But feel free to reach out with any questions about the boards! If you can find a receiver that still works with the original transistors, they are decent. What kills them is they get overloaded from another source. On mine, I think I traced the root cause to the power supply board. It killed 6 out of the 8 transistors. The protection design on these amps isn't the greatest unfortunately. But if you can find one that still works, rebuild the power supply board, and pre amp boards to help combat this problem! Thanks for watching! I apologize for the late response.
what is the silver covering that is taped in there ?? Cheers
The previous owner had taped some tinfoil to where the lights are for whatever reason. Probably something to do with the bulbs getting hot. I removed it and swapped in some LED's nice and cool! Thanks for watching!
Nice explanation,i just got myself a sx 626. It has a little hum on all imputs,i suspect on ground loop issues.
Awesome! The 626 is a sweet receiver. I'm thinking the same.. hopefully you get it all figured out! Thanks for watching
Surprised it didn't come back much sooner with a 10W resistor installed. Higher value resistor is going to increase power dissipation. No excuse for not doing it right the first time.
Very True! It was my fault. I had a brain fart when re assembling and thought what I had were 20W! Lesson Learned for sure. Thanks for watching!
Your output volume is to low can barley hear from computer internal speakers up to 100 percent max.
Thanks for letting me know! Sorry about that. I'll be sure to make it louder in other videos! Thanks for watching!
@@TinkeringWithT No problem ,Thanks for concern.
Yes by all means check resistors/transistors/transformer/fuse/capacitors
Diodes
Definitely! You never know with these old units! Thanks for watching!
I have a MONSTER fisher Studio standard 1080 and I'm trying to set the DC offset to zero or as close as I can anyway and I did it on my pioneer Sx 1080 with no problem but this fisher is difficult for some reason I know where the bias adjustments are and as I turn them I get no difference the reading on my meter stay the same and I have it set right to 200mm so im wondering what's going on 🤔 can you help me if possible plus I downloaded the manual and I know I'm in the right spot Plus I see the bias pots 1 by each heatsink plus there are 3 on another board I even tried those with no results I even separated the pins in the back separating the amp from the preamp like was suggested in the manual still no results so I'm puzzled at this point 🤔 can you help me thanks.
That's a sweet unit! Hmmm has any work been done to the unit at all? or is it all original? I'm wondering if the excessive DC offset is coming from some leaky capacitors, or an open resistor somewhere. On some of the Pioneers I know the bias pots are not good quality and can give erratic results. But I think this is a different issue. I'll see if I can find the manual online. Visually inspect the boards to see if any capacitors are bulging, or if there are any abnormal heat marks around a resistor. Hopefully we can get it figured out!
@@TinkeringWithT I've had work done on this unit recently and it works fine I've had every board checked every capacitor changed all I'm trying to do is bring the DC offset down to zero there not above 100 the right channel is at 05.9 and the left channel is at 18.3 I'm Just trying to adjust them to as close to zero as possible but when I move the bias adjustments screw my meter don't move it just stays at the reading it's on for both channels 🤔🤔🤔🤔
My pioneer is fine I'm trying to adjust the DC offset on my Fisher Studio standard 1080
@@ReginaldDj1 Ah gotcha! Let me see if I can pull up the service manual for the Fisher. I know on some of the pioneer receivers, if the DC offset won't adjust, there is a jumper wire that can be removed to help lower the voltage reading. It might be the same on the Fisher!
What did you say ?
So, if you had put in the correct resistor in the first place, this never would have happened.
Most likely! When I bought it years ago, the original resistor had opened up. Thought I had 20W resistors, to replace it, but I guess not! Lesson learned for sure.
man i really want to watch this.. but the volume is to low..
Ah I’m so sorry! I had some issues with volume on my early videos, so I apologize. I wish I could fix it without deleting it! Maybe I can edit the audio. Let me know if have any questions!
What the heck is going on with all that tinfoil covering the dial lights?????
I have no idea😂 it came like that when I bought it! When I was all done rebuilding it, I ripped it off! The only think I could think of was maybe heat dissipation with the old incandescent bulbs? I swapped them out with warm white LED’s so heat isn’t a problem anymore!! Thanks for watching!
Can you please increase your volume?...un watchable meh
I’m so sorry!! The first couple of videos on my channel had some issues with the volume level. Too bad I can’t fix it without re-uploading
Please invest in a mic. It's so hard to hear you. Camera mics are rubbish.
This is the 1st video I've watched of yours. Nice work flow of using the basic tests so the obvious culprits are tested first. Great job. I love your approach and in effort offer some advice for safety and ease of your future video repairs, A) Have you created a Dim Bulb setup to help protect your Mains line from large current draws due to shorted internal components? If not, I think we all could highly recommend that to you. B) Or, do you have an Isolation Transformer in your Mains circuit? C) Instead of using a Towel, consider obtaining some of the Silicon mats used in Ovens and lay those onto your bench. Can even secure them down if desired.
Here's a link to what I made and I think you would find this would safeguard you when hooking up monster power receivers like the Pioneer SX-1280. (ruclips.net/user/postUgkxDPfI2kwCYa2bHcDoHMKgCsXhL0KkbrlE?si=I5myJqAVV8di68iw)
I CAN SEE ITS BEEN RECAPPED.
Yeah! All new caps!!