cyrus 2

[atomised]

hi
is the capacitor i have linked to below the required type
http://www.maplin.co.uk/Module.aspx?...itors&doy=18m5
just to make sure i have the right one.

I have a pic of the underside attached and as you said there is a + sign so side closest to edge is positive.

Thanks for the help

[richie00boy]

The track breaking points to another fault as well as the cap. Really you need to trace where the track connects to. This is where the schematic comes in handy. If you tell me if you have issue 6 design (pushbutton mains switch), or issue 7 (toggle mains switch) I can put the appropriate schematic up.

Can't really coment on the cap, need to check the pin spacing.

[atomised]

hi
the unit is powered on by a push button on front panel ( with led lighting the cyrus2 letters on front panel ).
thanks

[Geoff]

Originally posted by atomised
hi
is the capacitor i have linked to below the required type
http://www.maplin.co.uk/Module.aspx?...itors&doy=18m5
just to make sure i have the right one.

No, far too large! 4700uF rather than the required 470uF.

Try this page instead:

http://www.maplin.co.uk/Module.aspx?...ce=14&doy=18m5

You will probably need to go for the 470uF 100V to get the right lead pitch.

[richie00boy]

Has the output stage got a pair of TO220 devices per rail (total 8 devices), or a single TO247 per rail (total 4 devices)?

[anatech]

Hi atomised,
I've seen that trace go on other Cyrus 1 products.

Please check for a shorted diode, that would explain the exploded cap as well. A 63 V capacitor should be close enough in pin spacing. That is the value I use for replacement. Use a piece of insulated wire to replace the burned track, cut away all the loose trace.

Any short in the supply from that capacitor could also cause the burned trace. Do not fail to replace the 22 uF caps (I thought they were 10 uF - sorry) and replacement of the regulators may not be a bad idea. I know they were running hot (they all do).

That should put you back in fighting trim.

-Chris

[AndrewT]

Hi Anatech,
I went daft with Ebay a year or two back and now have a lot of secondhand nearly modern Cyrus gear. I'll not list it, but I have a couple of eights and no Xs.

[anatech]

Hi Andrew,
So, what do you think of the sound?

-Chris

[Geoff]

Originally posted by anatech
A 63 V capacitor should be close enough in pin spacing.

Chris

Sorry to disagree with you but modern 50V and 63V 470uF capacitors have a lead pitch of 5mm. The older 16mm dia cans used in the Cyrus 1/2 have a lead pitch of 7.5mm which is why I suggested atomised went for a 470uF 100V which also has a lead pitch of 7.5mm.

That is of course assuming that one wishes to match the lead pitch rather than splaying the leads and mounting the capacitors further off the board.

Geoff

[lohk]

The burned broken track routs both caps to the star ground (which is between the main power caps), so it is very likely one of the diodes (close to the cap) broken also. The orientation of the cap is - maybe already mentioned - with plus outwards. Both caps should be changed, that is pretty obvious.

An Cyrus 1 from this bunch (small transistors) can easy be changed into a Cyrus 2 (power amp only) by adding another 4 output transistors, adding another 4 drivers (ZTX753/653), all other parts are on the board already. I forgot the infos about the bigger transformer.
I did not remember a sensational big difference in sound to a Cyrus 1, but I only have one Cyrus 1 left in my collection.