Cyrus 2 amplifier

[ftpols]

Check what voltage is actually powering the amp. Put black probe on black speaker output socket and red probe on the end of D5 with the white line, note the voltage reading. Now move the red probe to the end of D7 opposite the white line, note the voltage reading.

Hi, Richie.

I followed your advice and read +38.2v at D5 and -19v at D7

 

[richie00boy]

38.2 is an expected measurement. It seems that you have something pulling the negative rail voltage down.

 

[ftpols]

38.2 is an expected measurement. It seems that you have something pulling the negative rail voltage down.

Hi, Richie.

Thanks for the feedback. I will start testing the circuit after I finish the re-cap, and hope you can help me agin when I get stuck.

Cheers!

 

[ftpols]

Hi, Richie.

Thanks for the feedback. I will start testing the circuit after I finish the re-cap, and hope you can help me again when I get stuck.

Cheers!

Hi, Ritchie.

After recapping, I still read -19v at D7 and VR1 output reads -37.9VDC instead of -18V. I replaced the VR1 LM337 and recapped C70 (22mf 25V), which was blown. R119 and D12 (resistor) are now running hot.

Can you or any other Cyrus experts kindly direct me to probable source of the problem? Many thanks!

 

[Igor Fritzenstein]

I have the same problem,
i power up the amplifier and the conus form my speaker move up and down.
And i got an buzzing sound like an earthloop since 2 days ago.

 

[naveen francis]

Hello sir,

I m from India, Kindly help me to solve my Cyrus amplifier 2. the issue is while switching off after few seconds some kind of discharging noise through both speakers.if you could give me a hint which section i need to check or which component i need to replace ,,,,,kindly help me .

 

[Mark Whitney]

Hi Naveen, my Cyrus 2 does the same. It has done this sinds it was new. I don't think that there is anything broken.

 

[naveen francis]

Hi...Mark

Thank you for your immediate reply to my mail....is there any chance to rectify this issue .i have changed the main capacitors, few 22 mfd 50v, 100 mfd 50v, but this issue is only once we switched off the amplifier after few minutes or few hours. kindly help me mark...also i suspect the 470 mfd 6v bipolar under the ribbon cable but the same is not available here in india.

 

[Mark Whitney]

I know what you mean. I don't think anything is broken as my amp has always done this. You could connect a relay at the outputs of the amp to disconnect the speakers after the amp is switched off. I have never found it a problem.

 

[naveen francis]

good morning Mark...

When i checked the Dc voltages in both speaker out ...Power on reading 0. and immediate power off reading shows 0.12 and decreasing ...other voltages seems perfect...can you please guide me which is the test point for checking idling current...

 

[Beppe Starnazza]

Ciao Sorry for the automatic translation .....But I'm Italian from Venice....I recently bought a pair of Mission Cyrus two + PSX I noticed that in the cyrus two inside the R 121 section there are 2 resistors instead of one only as I usually see on sites where this amplifier is mentioned and I saw that the pair of F4 fuses have not been removed to couple the PSX, is my question normal? From the videos he sent me during the purchase, the old owner can be seen that he had both 2 frames (Cyrus + PSX) with the power LEDs on, so he used the internal power supply of the Cyrus, again I ask is this normal or yes ruin if you don't remove the F4 fuses inside the Cyrus using it in pair Cyrus + PSX thanks I hope someone will help me Merry Christmas everyone