Pioneer SX-1010 Work completed and heading home
This evening work was completed on the Pioneer SX-1010 repair project. The owner of the receiver sent a beautifully restored case and side blocks to be installed before it will be hand delivered when I meet with him this weekend. The receiver is now one of the best looking examples of a 70’s Pioneer SX […]
Pioneer SX-838 #2 Pre-service testing
So tonight I had a chance to start on the refurbishment of another Pioneer SX-838. This receiver was sent to me for restoration work since the owner described crackling sound from the balance control. While it is here it will be tested, cleaned up, electrolytics replaced, and any noisy transistors replaced before being tested again. […]
Pioneer SX-636 #2 First Look
This Pioneer SX-636 came in a few weeks ago and was tested on arrival but never really checked out. The exterior of the receiver is excellent. The case is near perfect and the faceplate has just a minor scratch. The only damage was thanks to the shipping a crack in the corner of the dial […]
Sansui 881 Post Service Testing
This week seems to be testing session after testing session. First up the Sansui 881 that was finished having its amp board, and power supply serviced. Testing done before service showed uneven output and a weak channel. This receiver’s factory spec was 60w on an 8 ohm load with both channels driven. First test I […]
Sansui 881 Power Supply
On to the power supply in the Sansui 881. This board is easily accessible from the top and bottom of the receiver. Nichicon PW series caps will be used to replace the polar and ES series for the bipolars. There are two film caps near the relay which will be replaced with Panasonic ESQ film. […]
Sansui 881 amp board
So after a vacation, a few small repairs, and the 1010 repair I am back to the Sansui 881. Parts have been here and everything is ready to go. If you saw the earlier post about testing this receiver it did well but not up to spec or equal. The plan is to replace electrolytics, […]
Pioneer SX-1010 back from the dead
So last post was about the issues facing this Pioneer SX-1010 causing the 10 ohm series resistor on the power supply that feeds the amp boards being fried shut. With more inspection of the transistors and diodes on the amp boards a shorted driver was found on the right side amp board. Replaced the transistor […]
Pioneer SX-1010 receiver arrives and it hits the fan
So last week the Pioneer SX-1010 coming in for replacement of it power supply arrived. Upon inspection and removal of the old power supply board an all to familiar smell of burnt component was noticeable. After removing the suspect board and installing the newly rebuilt one I began bringing the receiver up slowly on the […]
Pioneer SX-1010 Power Supply Rebuild Part 3
Last left off this board was stripped almost completely of components. Now it’s complete again loaded with Fairchild semiconductors and Nichicon PW series capacitors. Most resistors were changed, along with new diodes, Zener diodes, mica washers, and thermal paste. Next step will be when the receiver arrives this week this board will be transplanted in […]
Pioneer SX-1010 Power Supply Rebuild part 2
Last evening finished removing electrolytics from the board and tested resistors. Normally, I would remove a component at a time and replace but since all caps, transistors, and diodes were to be changed it was easier to just remove them all. Upon check resistors a trend started to form. If a resistor is within 10% […]
Pioneer SX-1010 Power Supply Rebuild First Look
A few weeks ago I was contacted by an AudioKarma.org member about his tragic Pioneer SX-1010. He had the receiver completely restored beautifully and in shipping had the power supply board damaged. After sending it back, had another board installed and upon return shipping again the power supply board was damaged again. This last time […]
Sansui 881 – pre-service testing
Today, work was started on a Sansui 881 that will be restored to good reliable working order. This unit has an audible 60hz hum out of the left channel that I suspect is a bad cap or ground. Before getting started I ran a quick test on the power amp to see where the unit […]
Sansui 881 first overview
So with the pioneer sx-838 burning in and waiting for cosmetics I decided to have a look at a Sansui 881 that is up next for servicing. This is an early 70’s am/fm receiver which packs plenty of power for its size. You understand completely though when you try to pick this unit up, it […]
Pioneer SX-838 powered up
So powered up the Pioneer SX-838 last evening slowly on the variac and did a little testing and listening. Before servicing was done amp was putting out 58wpc before clipping at 1khz. Now it is putting out 62. Not a huge difference and honestly will most likely never be noticed as this was a pretty […]
Pioneer SX-838 almost ready
Service complete; the power, and protection boards were serviced with new caps and transistors. New power filter caps replaced and upgraded to 10000uf Nichicon premium. Unit was slowly powered up and rebiased. Maxing out at 62wpc before hard clipping and very equal between the two channels. Receiver will be cleaned up and reassembled and available […]
Pioneer SX-838 power supply rebuild
This evening the SX-838 received a rebuild of the power supply board and power caps. First, the 8000uf power caps were replaced with premium Nichicon 1000uf radial leaded caps. The new caps being a fraction of the size were mounted horizontally in a new clamp. The power supply board was completely recapped and retransistored. Nichicon […]
Pioneer SX-838 pre-restore bench test
So this evening I started with a Pioneer SX-838 for a bench test before starting any restoration work. Sort of gives a baseline for the component to show what it was capable or incapable of before any work was performed. This receiver is in great shape and was well cared for. The previous owner did […]
New projects Pioneer SX-838 and Sansui 881
Took a short break from vintage restoration but back with two fantastic receivers. Pioneer SX-838; the bigger brother of the SX-636 that was done a month ago. This unit boasted a factory 50wpc into 8 ohms and maintains that warm factory sound. This unit is in great shape and actually “works” pretty well. Both channels […]
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