All PCB work is now complete on second Pioneer SX-838 receiver. Faceplate was pulled, control board had electrolytics replaces along with tantulum caps. All controls were cleaned well and lubed. The balance control causing distortion was the original issue the owner had with the receiver. The dial glass was not secured in the faceplate as the glue had deteriorated over the years so it was cleaned up and glued back in place. Knobs and faceplate were cleaned up look shiny again.

The amplifier was biased and had very little drift. All parts back together threw on the scope and fantastic results. The amp section is putting out 10-18wpc higher than factory spec before hard clipping even at the stressful 20kHz. When driven individually the channels push out 78 watts of power! Hooked the unit up for the start of break in and within three hours the soundstage opened up and that awesome Pioneer punchiness showed through. The receiver is back to its original glory and it is loud. Allowed the amp to run for several hours and normal heat dissipating.

Will run the amp for a few more long sessions to ensure quality and break in the new components. There are still a few lamps to replace and the service will be complete. Here is a few shots of the before and after of the control board. Not an easy board to get to.





4 Responses

  1. Hi Mike,
    Just to let you know, the receiver sounds great with my Bose 901 speakers. I listened mainly to my MP3 player, but would now like to listen to my vinyl collection again (after about 30 years!). My Dual 1228 turntable had a couple problems, so I got a Technics SL-D202 turntable from the original owner. The Audio Technica AT43 Ea cartridge stylus was shot, so I replaced it with the Ortofon OM5E that was on my Dual 1228. Now the Ortofon stylus is shot and I need a new one. Can you recommend whether I should just get a new stylus for the AT43Ea, the Ortofon , an AT12Sa or Series III cartridge that I also have, or get a completely new cartridge and stylus? What do you think would be the best way to go? Thank you in advance for your anticipated reply.
    Bob Young

    1. Hi Bob, great to hear from you and glad your enjoying that 838. I usually recommend a new cartridge unless your very attached to the vintage ones. The cost may not be all that far apart.

      One of my favorite budget friendly carts at the moment is the Shure m97xe. You can pick one up for around $80. The m97 tracks incredibly well even on rough warped albums. For an even tighter budgeted approach I also like the Ortofon Omega which is usually around $35. It does not track quite as well as the Shire but the sound quality is excellent.

      Another item I use that I can’t stop raving about is the Spin Clean record cleaning system. Cleans up old albums and gets a lot of the snaps and pops out.

      Let me know what you decide and if you have any other questions ask away. If you would like a replacement stylus for either of your existing carts let me know and I’ll reference a replacement.

      1. Hi Mike,
        Thanks for the quick repley and helpful information. I am going to get the AT97Xe and the record washer. I have read good reviews on both, and your recommendation confirms it.

        1. Sounds like you will be right back to enjoying that vinyl. Please report back and let me know how things go. I really like cleaning the album with the spin clean then I use an Audioquest carbon fiber antistatic brush to remove any surface dust quickly before dropping the tonearm. The brush is another great vinyl lovers toy.

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