The volume in the right channel on my CR3020 is really, really low. If I isolate it with the balance control and gradually turn the volume up it presents intermittent crackles and is garbled with very little increase in sound coming from the music source. I noticed that the protection relay switch is extremely slow to come out of protection so perhaps that is the culprit. In researching the issue all I could find was Merrylander's post from June 2011 which stated that the CR-3020 has four relays, one is the soft start relay that takes two 10 ohm 5 watt resistors out of the transformer primary after the big filter caps have had a chance to charge a bit. The other three are for each of the speaker outputs, A, B or C, why one each I have no idea. The 3020 takes a bit longer to come out of protection than earlier models, quite normal for this beast. It can either come with the same output transistors as the CR-1020 (except two of each per channel) or the Sanken equivalents 2SA747B and 2SC1116B. On the power amp boards there are seven fusistors that sometimes change value and cause problems, best replaced with 1/4 watt resistors or in the case of the 68 ohm one a 1/2 watt. The other values are 390, 100, 47 and 4.7 ohms. Additionally while this beast is in the shop can any of you Yamaha Gurus suggest additional things to look for an or "freshen up"? Not looking to do a serious refurb as I subscribe to the adage of if it ain't broke don't try to fix it. By the way according to the previous owner of this particular unit it was gone through by Merrylander 6 or 7 years ago and when he asked Rob about the unusual delay in the protect relay he indicated that it was quite normal for the 3020 to take a bit longer to come out of protection than the earlier models (1020 & 2020). Guess maybe now its time to check that protect relay. Also could any of the Yamaha experts, (avionic, oilmaster, Mr. Yamaha) recommend a suitable replacement relay. Thanks in advance for any info and or suggestions - Jim
Time to figure out what is wrong with my CR3020
- Thread starter 10sguru
- Start date
There are three protect relays (speaker relays).
Try exercising the coupler switch on the rear panel. And listen for any audible difference.. If that doesn't pan out. Get a separate amplifier or pre-amplifier. Using the pre-out / main-in RCA's on the rear panel of the 3020. Lets determine if this is and power amplifier issue or pre-amplifier issue.
speaker protect relays 3 each.
https://www.mouser.com/ProductDetai...=sGAEpiMZZMtSzCF3XBhmW8KXvo/AizVDhZPnFU7Xxys=
https://www.mouser.com/ProductDetai...=sGAEpiMZZMtSzCF3XBhmW8KXvo/AizVDhZPnFU7Xxys=
Rob has probably already freshened it up 7 years ago. I wouldn't imagine it needs any more freshening up. Except for maybe a gallon of deoxit.
More than 4. Rob didn't count all the reed relays. There is at least 3 of those as well.
Actually after reading Rob's post about a separate relay for each speaker A, B, C it suddenly dawned on me to try B & C. Will report back later this evening. Thanks for the extremely helpful advice.
If it still acts the same. That rules out the protect relay.
Replacement. See post #4
While the tech is in there probably should replace the C relay even though it appears to be working properly, correct?Replacement. See post #4
Probably be prudent.
Did he mention a replacement part number?
Unfortunately not. Just thought as you said, it might be prudent, to replace it as well while it's in the shop.
clinic-audio
all on YAMAHA untill 1990
Replacement is better than cleaning
