Rotel RA01 Amplifier Repair (With Audio Tutorial)

[@mikepxg6406]

Always amazes me that the circuit design is the same as a 1980s Rotel RA-820BX3 . And apart from a few minor tweaks and rebadging the design never really changed in over 2 decades. In fact some of the earlier iterations had Black Gate Caps fitted as standard and IMHO sounded better.

[@chrissmith7069]

Great tutorial Gary. Thx for sharing!! 😊

[@jaycee1980]

Interesting that you say the Onsemi devices do not work - they took over Sanyo, so you'd think they'd be the same! I've often found Rotel amps are a bit "on the edge" regarding stability... so it's no surprise that a slight change in the output device characteristics would make it oscillate. Another thing I often do with these amps is replace the bridge rectifier with a higher current part. They often used 4A rated bridges and sometimes the bridges fail if the amplifier is run hard. Similarly, the pass transistors used for the low voltage supplies often run too hot due to their TO-92 package size, and I substitute them for something in TO-126 - BD139/140 work well enough

[@AudioAmplifierServicing]

Thank you for sharing your experience on the channel

[@TheHitmn]

Hello, Great tutorial here!!! I'im here because of a rotel repair - rap 1580 ... I'm searching for the green resistor 0.22 ohm and can't find it. I can't find 5 ring resistor: red red silver gold black. I find 4 ring red red silver gold that is 0.22 ohm. I see you used the same ... Can you help ?

[@AudioAmplifierServicing]

@TheHitmn Hi the service manual will confirm the resistance, wattage and tolerance of the resistor. The colour codes you mention for the 5 bands do not match the resistor colour code chart. www.calculator.net/resistor-calculator.html As long as you fit a ceramic flame proof resistor there should be no issue. I would advise only purchasing the replacement resistor from a reputable supplier. There are a lot of counterfeit components on the market.

[@TheHitmn]

On this video are the same! Because of that I'm asking...

[@AudioAmplifierServicing]

​@TheHitmn Not sure I understand your question. Are you asking where to purchase the resistors as shown in the video.