At low volumes up to 15-18, the left channel of the amplifier plays quieter than the right. Increasing the volume evens out the sound. This happens the first time you turn it on. What could it be?
I am experiencing the same issue myself also with the left channel. Bumping the volume to 22-25 solves this issues, but this is not a satisfactory fix.
This is my second amplifier with this problem. The first one was exchanged for me under warranty.
I actually have same issue, and it showed up after i replaced my MA Gold 100 speakers with Focal Aria 926.
According to the guy working for authorized service centre in Poland, it’s a known issue - seemingly this amp doesn’t “like” some loads/speakers.
It can be fixed (according to the guy) by replacing speaker relay.
Initially i was afraid it started developing one of the output transistor’s failure (which might give similar symptoms), but now that i know it’s relay, i stopped worrying about it. If it breaks or start to be annoying i will just replace the relay. As my amp warranty is over, i don’t feel like paying them 100€ for relay replacement
Thanks for the answers, I understand what the problem is.
Yes, the problem turned out to be oxidation of the relay contacts. I removed the relay cover and cleaned the contacts and the problem went away. It’s strange that the new amplifier already has dirty contacts.
wow. Do you live in a very humid environment ? Relays usually take many many years to oxidize enough to require service. I have worked on quite a few vintage receivers and tape decks with relays over 30 years old that were still working fine. Did the cover appear cracked on anything ?
Unfortunately this issue seems to be common, and from what i understood it doesn’t happen with all the speakers for some strange reason.
So i would say this is caused by some design issue, which is causing relay not to use enough force in some cases? Probably the way they are driving/feeding the coils. But of course i might be wrong here
Sounds probable. My speakers are not known to be an easy drive and I have had no trouble so far. I would like to see a pic of the speaker relay Arcam used.
I had no issues when i had my previous Monitor Audio Gold 100 5G. Issue showed up when i changed them to Focal Aria 926.
I spoke to local Arcam’s authorized service center and they said it’s a known issue with some speakers.
So only thing i can think of is driving relay’s coil, which is somehow dependant on the load, and with some loads there’s just not enough current, thus relay force.
I can’t remember what it was, but i know relays are actually rather good quality.
As I already wrote, this is my second amplifier with such a problem, but the first one had the loss of the left channel while listening at low volume. On the second amplifier, when turned on first, the left or right channel was quieter. I changed the acoustics, but it didn’t help. I’m currently using tannoy revolution xt6f. I think the relay was stored in a damp environment, made in Thailand. The relay cover can be removed very easily by pressing right and left. So far the problem has not returned. It seemed to me that the sound somehow improved. I cleaned it with a thin pencil eraser, and then ran a strip of paper with pure alcohol along the edges twice. Panasonic ala2pf24 relay, sold here for $8, used in gas boilers…
Yes, but we are just wondering why it depends on the load, and even Arcam’s authorized service center confirms that. So it’s not only about what relay is used, but also how it’s powered. Otherwise how could this behavior depend on the load/speakers used?
Anyway thanks for the tip, i will get it cleaned one day. Might also replace it later on.
Thanks Vkov for the picture and explanation. This is far from a normal problem from my years of tinkering with electronics with a 3 year old amp. Since the amp is set up to only drive one set of speakers this relay is probably used to cut the output when DC is detected or the amps thermal limit is reached. I will look up the part and see if a nice sealed one with gold contacts can be subbed in.
I’ve had a similar issue, where the left and right channels are unbalanced at low volumes, which can sometimes be fixed after turning up the volume, or turning on and off silent mode. In view of the above reasons, I think it is caused by oxidation of the output relay contacts. So I opened the amplifier cover, opened the black relay housing under the amplifier output terminal, and sanded the relay contacts with sandpaper, which solved the above problem. Hope it helps.
Well I went ahead and opened mine to verify the same relay was in there. Sure enough it was. And my sources Digikey and Mouser both mark it obsolete. Wonderful. The data sheet on this relay is still on the web sites. But instead of spending an hour or so cross referencing the relay I ordered a set of them off of Ebay. Hopefully I won’t need them, but this relay is indeed in the signal path. I noticed in the data sheet its intended use is to interrupt speaker connections. So I can’t blame Arcam for this one at this point. If later a different relay has to be substituted you could mount a little board to the back of the speaker connection board and hard wire it into the main board if the same size and pin out can’t be found. I also noticed the amp is full of Chinese caps. So probably within 10 years those should be all replaced if you are still using the little beast.
Indeed it seems obsolete, although i could still find it in few stores in Poland.
As you said, it’s used in case of any protection kicks in, but not only than. It also disconnects speakers when amp is powered off or in stand by, and i think also when muted.
It is rather good relay and meant for audio, so i would blame implementation really.
Pinout is rather standard for this kind of relat, so it’s only a matter of finding correct size. Maybe Omron would have something? They have good relays.
Yes that would be my choice. I was fiddling with the filters on Mouser and I think Panasonic has a replacement. Look at Panasonic JW2ASN-DC24V and see if you think it would be suitable. I will just put my new relay when it arrives in a bag with desicant and put it away. But I have a feeling I will need to address this issue some day.
I’m not sure, as only did a quick search, but if it doesn’t come in other form factor, than it’s too big.
Electricaly it’s a fit, and even better due to better contacts material (silver-based vs tin-based on original one).
But according to drawings it’s bigger, thus would need some modifications.
Would be perfect to find something that would be a direct fit, if it exists
Perhaps this relay fits G5PA-2 Omron 24VDC