cyrus 2

[Colin66]

Now I've replaced all the electrolytics when I switch on I get a loud humming, adjusting volume control makes no difference....

Caps are original values except the large power ones which I changed to 10,000uF 63V...

Any ideas anyone?

Thanks

[Colin66]

....humming has stopped.... both fuses have blown. I'd disconnected the speakers and left the amp on, I'd guess around minute or two before I heard a quiet, unfamiliar noise that must have been the fuses popping......

[richie00boy]

Maybe the bridge rectifier was on it's way out and has now killed the output devices.

[AndrewT]

could one or some of the new polarised capacitors be inserted the wrong way around?

[Colin66]

...well as it happens I've noticed that C43/44 are in fact bipolar (the ones I removed were not), i'd just fitted the replacement same way as old...though these are only 6V...

Struggling to understand why so many things on this PCA are different from the schematic. I put it in for repair around 10yrs ago and wondering whether I got the same one back...

Thanks for the feedback, I'll persevere bit longer...

[radiance]

Hi, just to let to know that with the help of this board I managed to service my Cyrus II, Iss07, with success! Thanks to everyone. After having recapped the amp, I still had some problems e.g. loosing sound from right channel. I managed to gain sound again by switching the source selector but that did not help that long. After getting a hint from another guy I soldered out the ALPS source selector switch, opened it and saw the mess... The metal silver contacts were oxidized and black. So I decided to take very fine lapping paper and metal polishing paste and cleaned/polished the two contact bars as well as the gold contacts which ride upon them when moved by the switch. This was worth all the effort, the amps sounds like new. I can recommend this procedure to anyone having problems with one or two channel dropping out. Contact spray won´t help here!

Best regards

Rad

[soldersmoker]

It's 2010, time for another post on this long-running thread!

I recently purchased a C1 (the TOG version) here in the 'States, and I also purchased a 500W-rated voltage converter for our 117V mains (for a 220V Cyrus One). First impressions have been very good, possibly because I'm using very efficient speakers--Klipsch Heresy's--so the amp doesn't have to work very hard to get plenty loud. The amp and the converter stay very cool over long periods of use. I like how this little integrated sounds even more than my Superphon Revelation/Dynaco ST-70 combo. The ST-70 is rewired in triode mode and has a number of mods. So it kills me a little to admit that I like the Cyrus more . . .

I'm shocked that my Denon DL-103 works in the MM stage (but it sounds worse when switched to MC, though it's subjectively about 10dB louder). I also have a DB Systems MC phono pre, and the DL-103 sounds just a tiny bit better through the pre into a line input. The seller thought I had to be wrong when I reported my experience. Anyway, I felt this needed to be documented in case anybody else could take advantage of this "feature". The difference in sound quality between the MC outboard pre and the MM stage is vanishingly small. I'm just floored by this discovery . . .

I've read this entire thread, and I will be replacing the smaller caps, having taken Chris's sage advice to heart and ignoring the filter caps, which look and work fine as-is.

[cosmo181]

I have a Cyrus II. Not sure which version PCB, however last night resistors R95 and R96 blew. Does anyone know the vlues of these resitors and possible cause (other than age) of why they would blow?

[anatech]

Hi soldersmoker,
The phono sections in these are extremely good. Your report is no surprise to me, and I just received another email earlier on today where the owner of a unit I repaired was very happy with the unit's phono section.

Hi Rad,
Never, never, never use anything abrasive on switch or relay contacts - ever! The plating is not that thick, and once you're down to base metal the switch is perma-toast.

What you should have done was disassemble that switch (may as well do the other also) and worked a business card soaked in contract cleaner back and forth. That will clean up these contacts like new. Not much in the way of wear to shorten the life of the switch. Once you're done, use a non-residue cleaner to wash the contacts out. Then you can apply a small amount of cleaner on those contacts to slow down the aging process.

You're not done yet! Apply some "white grease" along the contact areas with the plastic contact holder. You can use some oil on the shaft bearings (single weight, no additive, light machine oil) and also on the detent mechanism, or a little heavier grease if you'd rather. Now you can carefully reassemble the switch and crimp the base back on. If you aren't careful when crimping, you can break a lead off, or cause the case to become a trapezoid. That won't be helpful, so stay alert.

Hi cosmo181,
Sounds like you blew up a channel there. Better check your speaker cables.

-Chris

[soldersmoker]

Thanks for piping up, Chris! I haven't done a thing to "improve" my Cyrus since I've been so satisfied with how it's sounding, a real testament to the little integrated. I'm waiting for a QUAD 33 to finally get here, in addition to a Bottlehead Quickie, either one of which will be acting as the preamp for my favorite amp, a Sure Tripath. But the Cyrus One has kept me very happy in the meantime. I'm surprised and pleased at how cool the amp remains, as does the voltage converter, but that is probably in part a function of my efficient 97dB speakers, which allow the amp and converter to coast.

One fly in the ointment: the RCA jacks seem to be a bit flaky on a couple of settings (AUX and CD have intermittent dropouts), so I may just replace all the jacks in the future. Using DeoxIT and Caig Gold contact cleaner didn't remedy the problem. But I'm satisfied, thus lazy. Besides, I listen to vinyl most of the time, and those jacks are fine.

--Alan