Cyrus Two | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine
if you download the service manual (en) from the above link, it clearly states what you should do..... and how to proceed.
edit: page 10
if you download the service manual (en) from the above link, it clearly states what you should do..... and how to proceed.
edit: page 10
hi richie,
yes i have done this and they are both reading 39v and same on the other channel.
I have also checked
d17 d18 they are reading 1.1 m ohms, and rising slowley
d19 d20 they are reading 450.k ohms, and rising quite fast
these are the same should these not read the same..
Its driving me bonkers! But i love it!!
yes i have done this and they are both reading 39v and same on the other channel.
I have also checked
d17 d18 they are reading 1.1 m ohms, and rising slowley
d19 d20 they are reading 450.k ohms, and rising quite fast
these are the same should these not read the same..
Its driving me bonkers! But i love it!!
Another check that you can do with the amplifier tuner off is to read the resistance of the Vr2 + and the Vr1- to ground. Both resistance should read close. Ii you have a low resistance in the VR2+ means something it is loading it. If both are close then you may have a bad voltage regulator.
Hi,
Simple tests re phono stages.
Plugged into the mains, the power supplies are always powered up. The power amp rails are connected by the "On" switch but the preamp supply bypasses the switch and is always working.
With the power amp switched off any loading effects on the regulator should still be present and you can test for heat by touching the body with a moistened finger. If needed try the NE devices and 394 to see if any is hot. IC's can go short circuit while caps can short out or cause problems through drying out.
If you don't use phono sources a simple cure for any problems would be cutting the live end of the rectifier leads for the phono section - or desoldering these if surgery is too rough.
The main amplifier switch and/or the snubbing capacitors across these have the job of connecting simultaneously the already charged positive and negative rails noiselessly to the amplifier. These switches have to pass a lot of current and may not be as good as new.
Michael Jonassen
Simple tests re phono stages.
Plugged into the mains, the power supplies are always powered up. The power amp rails are connected by the "On" switch but the preamp supply bypasses the switch and is always working.
With the power amp switched off any loading effects on the regulator should still be present and you can test for heat by touching the body with a moistened finger. If needed try the NE devices and 394 to see if any is hot. IC's can go short circuit while caps can short out or cause problems through drying out.
If you don't use phono sources a simple cure for any problems would be cutting the live end of the rectifier leads for the phono section - or desoldering these if surgery is too rough.
The main amplifier switch and/or the snubbing capacitors across these have the job of connecting simultaneously the already charged positive and negative rails noiselessly to the amplifier. These switches have to pass a lot of current and may not be as good as new.
Michael Jonassen
When the Cyrus PSX (outboard power supply) is used and the Cyrus 2 amplifier is disconnected from the mains, the phono stage is completely unpowered.
could you rewrite that statement to avoid ambiguity?
I know that the phono section continues to operate when the PSX has been added to the modified amplifier.
The phono section cannot be "completely unpowered".
I think that it is possible that the +18 volts it is loading the +rail side causing an unbalance. Both are connected to the transformer but the PSX it is already connected. You need to find out what it is loading the +18 volt to read 7 volts. You already proved that by removing the PSX the problem goes away. Like I said before check the resistance for both +/- 18 volts to ground they should read close. Low resistance in the +18 means that something it is loading it.
Maybe I have not read this thread clearly but do you use your Cyrus2 only with PSX? If yes then the ground connection resistor is probably broken. This is a small (10Ohm or 15 as far as I remember) inside the PSX to isolate the ground to avoid ground loops. If the PSX is used seperately for whatever reason this resistor burns and the voltages are floating. This may explain some of the symptoms here.
(I repaired this fault at least once way back in the eighties so please pardon me if my memory fails here.)
(I repaired this fault at least once way back in the eighties so please pardon me if my memory fails here.)
And of course you have not forget to remove the fuses in your Cyrus 2 when connecting the PSX, have you? When used with an PSX the original psu from the amp powers the phono section alone - so of course you can switch off the amp when phono is not in use. But the mains cables must left plugged in.
Hi Andrew, I hope you are well and yes I'll try to clarify.
As I understand it, when the PSX is properly connected to the Cyrus 2, the PSX powers the amplifier and the Cyrus 2's own supply powers the phono stage and power indicator L.E.D.
By properly connected, I mean with the correct fuses removed from the Cyrus 2 as prescribed in the service manual.
The extract below is taken from the service manual:
Having quoted the service manual, I believe that there is an error in the above text and the PSX does not supply the main reservoir caps in the Cyrus 2. The PSX has it's own main reservoir caps and the Cyrus 2's are used for the phono stage alone when the fuses FS1 and FS2 are removed for PSX operation.