Pioneer SX990 - Repair & Restoration - 1 of 3 

Good call on those bias trimmers. I've rebuilt more than a few of the early Pioneers, and about 40% of them come to me with bad bias trimmers and shorted outputs. Love the sound. I have an SX-2500, which I won't be parting with.

This new channel is off to a terrific start. Well done! I look forward to parts two and three.

I have owned two of these. And yes, these sound great!

I would replace all trimmers, they fail often. In my SX-990 I used BC161/141 for TO-39 transistors. Good job!

Woo hoo comment #1 and subscriber #3 💪🏼. Got a feeling this is gonna be a great channel, love these helpful vintage audio repair vids.

Hi Wil, Excellent vid! What is the frequency of your Ultrasonic cleaner? I have damaged some solid aluminum knobs using an ultrasonic cleaner that is 40kHz (55c for 20 min) and read that you need 78kHz for aluminum.