Rotel RA-820, Old friend gone Lame....

[heikie]

Hi,
I am going to lend my dad my 2nd A/V reciever for his retirement home and went into the attic and dusted of my Rotel RA-820 to fill in while the A/V reciever is on vacation. (thanks to mtrycrafts for the advice on cabling dad's setup)

The RA-820 was the first amp that I bought (many moons ago) and I have a soft spot in my heart for it.

So, I brought it downstairs and hooked it into the pair of Paridigm 5se and it powered on and produces audio to the left channel only. This is using CD, Tuner and Phono sources. I swapped the left and right speakers and cables and I changed all of the 4 internal fuses. Still only left audio.

If I turn the balance knob to the right there is no sound until I shut the power off and the audio comes on briefly and then shuts off. It is like it is getting power via a discharge.

As I look at the speakers that were returned by my sister with the amp a couple of years ago, she had borrowed it for a while, the foam on the drivers has dis-integrated(cheap Kenwood loaners). Not sure if the speakers were overdriven or if the foam just rotted away. The amp was in a box inside a sealed plastic bag.

Anyhow, I was wondering if anyone had some tips on troubleshooting / diagnosing a problem like this. I have a multimeter and a soldering iron.

Some fond memories of 15+ years with this amp:

Playing football on the other side of the university dorm listening to this amp with the speakers pointed outside the window.

The call from my sister from the family cottage asking why the stereo did not work, I asked her to check the speaker cables. She had of course hooked them up to the amp but not the speakers. The cables were of course touching ends. I went up the next weekend, replaced all 4 fuses and voila good as new.

Playing music with the knob to the stop on the right with a big comfy chair in a warehouse.

Holding the amp to the light and seeing right through it. (teeny little curcuit board)

Other amps (Rotel, NAD, Yamaha all much bigger and more powerful) have come and passed but the RA-820 is like that old pair of jeans, it may not be pretty or the best but it is always comfortable.

I really appreciate any advice that anyone has to offer......
Thanks in advance....

 

[The Numenorian]

no advice but I'd just like to say...

-AWWWW-

I can't wait to make memories with my first external amp...

 

[dexxas]

I have the same Amp

The History of it is i bought it in a flea market for £30 [$49 .27 cents] immaculate no problems at all

my question is whats the point of the headphone socket

it dose not cut out the speakers

if you had it in a rack you would not want to get behind it to pull the speaker cable out each time. There is no speaker of on switch .

I also Have a fatman I valve 13 watt per channel Amp that sounds fantastic gets right down to serious bass is great with classical music and jazz, superb all rounder.

I have it connected to Mission 732 speakers through a Cambridge Dacmagic, Atlas equator connector

i am presently undecided which to have as main amp The Rotel is far more Fun to listen to. Though the fatman a far better serious amp.

why i am undecided? for anyone who knows the scissor sisters track Comfortably Numb. when you play it on the Rotel, its fun listen. When you play it through the fatman, It digs up some real low frequencies, The Rotel least mine cant get to. Is that a bad thing?

Not decided which i prefer

Anyone else have these decisions to make

 

[TLS Guy]

Hi,
I am going to lend my dad my 2nd A/V reciever for his retirement home and went into the attic and dusted of my Rotel RA-820 to fill in while the A/V reciever is on vacation. (thanks to mtrycrafts for the advice on cabling dad's setup)

The RA-820 was the first amp that I bought (many moons ago) and I have a soft spot in my heart for it.

So, I brought it downstairs and hooked it into the pair of Paridigm 5se and it powered on and produces audio to the left channel only. This is using CD, Tuner and Phono sources. I swapped the left and right speakers and cables and I changed all of the 4 internal fuses. Still only left audio.

If I turn the balance knob to the right there is no sound until I shut the power off and the audio comes on briefly and then shuts off. It is like it is getting power via a discharge.

As I look at the speakers that were returned by my sister with the amp a couple of years ago, she had borrowed it for a while, the foam on the drivers has dis-integrated(cheap Kenwood loaners). Not sure if the speakers were overdriven or if the foam just rotted away. The amp was in a box inside a sealed plastic bag.

Anyhow, I was wondering if anyone had some tips on troubleshooting / diagnosing a problem like this. I have a multimeter and a soldering iron.

Some fond memories of 15+ years with this amp:

Playing football on the other side of the university dorm listening to this amp with the speakers pointed outside the window.

The call from my sister from the family cottage asking why the stereo did not work, I asked her to check the speaker cables. She had of course hooked them up to the amp but not the speakers. The cables were of course touching ends. I went up the next weekend, replaced all 4 fuses and voila good as new.

Playing music with the knob to the stop on the right with a big comfy chair in a warehouse.

Holding the amp to the light and seeing right through it. (teeny little curcuit board)

Other amps (Rotel, NAD, Yamaha all much bigger and more powerful) have come and passed but the RA-820 is like that old pair of jeans, it may not be pretty or the best but it is always comfortable.

I really appreciate any advice that anyone has to offer......
Thanks in advance....

I would bet the output stage on that amp is burn out and its shutting down. When this happens there are often a bunch of other components that need replacing as well as the power transistors.

In addition to the equipment you have you will need a circuit for the unit, a FET or tube VOM, a signal generator and scope to fix it.

 

[nick berrow]

Obviously way too late to help out with the original problem but this still might help others-certainly saved my RA-820B from the skip!

http://www.youplala.net/2017/07/11/replacing-the-electrolytic-capacitors-on-a-rotel-ra-820bx-integrated-amplifier/

Thanks to Nico for the original post-a well-documented repair piece that worked for me with only changing the power caps (2X10000uF and 2x2200uF) that had all obviously leaked electrolyte. A single channel problem could still be one of the smaller caps in the Amp or phono stage. Well worth a try for the sake of a few quid on caps and 30 minutes of soldering.