Cyrus 2 eBay purchase

I recently purchased a Cyrus 2 early version with red led logo. I have been lent a PSX from a friend to use on it. Whilst opening the Cyrus 2 to remove the 4.0a fuses to enable PSX and air blasting what looked like a mouse sized fluff ball off the heatsinks I noticed bubbling on one of the components. The amp sounds excellent, I have read about getting electrolytics replaced etc from a specialist online but I would prefer not to spend over £100 on when its working perfectly. I don't really know what I'm doing but will use my free time to hopefully get the skills to sort. [IMGDEAD]http://i68.tinypic.com/mijdiv.jpg[/IMGDEAD]
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
First, get the "tinypic" link right or confirm that the bubbles are on a component such as an electrolytic capacitor. Look at the label on an electrolytic to find the essential identifying capacitance in microfarads (μF) and its voltage rating (V).

Replace it and any similar parts with similar or more modern grade caps, since amplifiers this old will be full of dying caps. They may work fine at the polite volume levels many people have to use, but just like old batteries - how well and for how much longer?
 
First, get the "tinypic" link right or confirm that the bubbles are on a component such as an electrolytic capacitor. Look at the label on an electrolytic to find the essential identifying capacitance in microfarads (μF) and its voltage rating (V).

Replace it and any similar parts with similar or more modern grade caps, since amplifiers this old will be full of dying caps. They may work fine at the polite volume levels many people have to use, but just like old batteries - how well and for how much longer?

Thanks for the input. I have searched for the values and found another Cyrus 2 post. They are apparently phono stage capacitors. I dont plan on using the phono however I will be getting a soldering station and having a go in the near future.
 
Hi, agree with everything Ian said. You should be get a 470, 680uF or 1000uF 63V or 80V DC rating capacitor that will be half the size as originals. The capacitors are for the regulated supply of the RIAA phono pre-amp. In case you didn't know, if you use a Cyrus PSX with the Cyrus II (its fuses F1/F2 4A correctly removed) the Cyrus II RIAA pre-amp circuit is unpowered when the IEC power lead is plugged into the Cyrus PSX only. So if you are not using a turntable, there will be no issue with these capacitors. Normally, when you are using a turntable, you need to connect the IEC power lead to BOTH the Cyrus II and the Cyrus PSX. I have repaired quite a few of these lovely amps, let me know if you need more help.
 
The 470uF 50V capacitors look like glue or some such has made the plastic cover warp. Probably not worth worrying about.
If you wish to change them, it probably will have no effect unless you have 100HZ hum on the phono stage. RS components are probably the safest supplier of quality components.
| RS Pro 470μF 50 V dc Aluminium Electrolytic Capacitor 2000h 10 Dia. x 20mm | £3.00 +VAT for 10 or
MAL213651471E3 | Vishay 470μF 50 V dc Aluminium Electrolytic Capacitor, 136 Series 8000h 12.5 Dia. x 25mm | Vishay £6.50 + VAT for 5 if you push the boat out.
Don't pay silly money from the 'experts' that say a good price is £5 or more each. You are being ripped off by them!
 
Hi, agree with everything Ian said. You should be get a 470, 680uF or 1000uF 63V or 80V DC rating capacitor that will be half the size as originals. The capacitors are for the regulated supply of the RIAA phono pre-amp. In case you didn't know, if you use a Cyrus PSX with the Cyrus II (its fuses F1/F2 4A correctly removed) the Cyrus II RIAA pre-amp circuit is unpowered when the IEC power lead is plugged into the Cyrus PSX only. So if you are not using a turntable, there will be no issue with these capacitors. Normally, when you are using a turntable, you need to connect the IEC power lead to BOTH the Cyrus II and the Cyrus PSX. I have repaired quite a few of these lovely amps, let me know if you need more help.

Thankyou very much for your kind offer. The amp is paired with PSX currently and its sonically amazing. My friend upgraded from this to a Cyrus 8a and I really think this combo is as good. His Cyrus 2 has a very low left channel hence his upgrade and my psx windfall. Just need to get some Tannoy DC6T currently on a mega deal at £299 for bargain hifi of the century.
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
For interest, the bubbles you see under the capacitor's yellow coloured plastic sleeve, are signs of heavy corrosion of the aluminium case. If nothing else, that means the electrolyte has leaked and/or evaporated so it's effectively dead. Strip the plastic away and you will be left with a spongy mess of white powder encrusting the remains of the can. Better still, just bin it, period.
 

jean-paul

diyAudio Moderator Emeritus
2002-09-20 7:20 am
Germany
Standard practice and common knowledge: amps of 20+ years need ALL electrolytic caps to be replaced or you have a serious risk of losing your speakers. Even in an unused phone stage as otherwise you'll see that if you omit those you will forget and one day you'll be trying out that recently obtained turntable and ...poof... Those old ROE caps often leak and that is not a shame after all those years.

Make a list of what caps you need. If the current ones with the same ratings are way smaller you may up the voltage rating. So an old 2200 µF 25V may be replaced by a 2200 µF 50V is that one fits on the board. In some cases it won't hurt to up the value itself but this depends on the function it has. The large filter caps for instance may be upped to have lower ripple but do make sure the diode bridge is rated for higher inrush currents (or replace those too for nice high current audiophile politburo approved diodes). For instance the 7000 µF filter caps may be 10.000 µF versions or even 15.000 µf if they fit physically.

You can use good industrial caps like Panasonic FC/FM or Silmic II if you want them to be "audio grade" and to have non ferro lead wires.

If you wait long enough till it breaks it will cost you some woofers, some power transistors AND the caps which is quite uneconomical. When you decide to make the wise choice, please clean the PCB where the old caps were to remove the acidic stuff that may damage the PCB. It likes to eat copper.

http://ftbw.de/xp/amplifier-xp/cyrus-2-v3.html

http://www.amprepairservices.co.uk/repair-blog/4559566775/Mission-Cyrus-Two/1181028
 
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For interest, the bubbles you see under the capacitor's yellow coloured plastic sleeve, are signs of heavy corrosion of the aluminium case. If nothing else, that means the electrolyte has leaked and/or evaporated so it's effectively dead. Strip the plastic away and you will be left with a spongy mess of white powder encrusting the remains of the can. Better still, just bin it, period.

Thanks for that.
 
I have ordered some Panasonic electrolytics as I read that these are most used by one of the main repairers of Cyrus amps at the moment.
5 X Panasonic Ultra Low ESR 105 Degrees FR Range Radial Electrolytic Capacitors
EEUFR1H471 470uf 50V Panasonic Panasonic FR Series 12.5mm x 20.0mm x 5.0mm x 0.6mm 0.020Ω 10000 Hours
My friend is lending me his soldering kit as he has repaired his old Pioneer amp in a similar way. I would also like to change all the rest of the electrolytics in the hope their will be some sonic due to them being so old.
 
Standard practice and common knowledge: amps of 20+ years need ALL electrolytic caps to be replaced or you have a serious risk of losing your speakers. Even in an unused phone stage as otherwise you'll see that if you omit those you will forget and one day you'll be trying out that recently obtained turntable and ...poof... Those old ROE caps often leak and that is not a shame after all those years.

Make a list of what caps you need. If the current ones with the same ratings are way smaller you may up the voltage rating. So an old 2200 µF 25V may be replaced by a 2200 µF 50V is that one fits on the board. In some cases it won't hurt to up the value itself but this depends on the function it has. The large filter caps for instance may be upped to have lower ripple but do make sure the diode bridge is rated for higher inrush currents (or replace those too for nice high current audiophile politburo approved diodes). For instance the 7000 µF filter caps may be 10.000 µF versions or even 15.000 µf if they fit physically.

You can use good industrial caps like Panasonic FC/FM or Silmic II if you want them to be "audio grade" and to have non ferro lead wires.

If you wait long enough till it breaks it will cost you some woofers, some power transistors AND the caps which is quite uneconomical. When you decide to make the wise choice, please clean the PCB where the old caps were to remove the acidic stuff that may damage the PCB. It likes to eat copper.

Freie Ton- und Bildwerkstatt: Mission Cyrus II Variante 3 - ca. 1989

Mission Cyrus Two

Thanks for the help.
 
Well I have just been quite surprised by my soldering abilities. I managed to remove the offending electrolytics and replace with Panasonic FC 63v 470uf as I have read elsewhere on here that its a good move to go up on the voltage. The old ones had not leaked at all fortunately.

The amp is fantastic.

Would anyone be able to recommend the best brand and type for the rest of the amp, I dont mind changing the Panasonics again if it makes any improvements?
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
The short answer is that there is no "best brand" capacitor any more than there are best brand amplifiers, speakers or cables. The greatest improvement you will make is to fit new capacitors. Industry standards like Panasonic, Nichicon, Elna, Rubycon, Nippon Chemicon all have their avid supporters. Then there are "for audio" caps with special construction features that you seldom see on sale anywhere other than as expensive spares held by service companies.

If you like splashing out, there are also audiophile boutique brands where the prices are stratospheric and some people pay them too! Have a look at the prices of caps sold for tube amplifiers and you'll be staggered. Here are some higher-end products: Duelund Capacitors | Hifi Collective
All Brands Electrolytic Capacitors

I think you can get good results from the right grade of cap, rather than brand. There is no best, just the appropriate one and that will vary from application to application.

See what member Eric Juaneda had to say in some interesting subjective comparisons. Note that some grades are now obsolete or superseded since the article was written. Blackgates BTW, was a unique and popular Rubycon brand but often unreliable, now withdrawn. High End Audio - Electrolytic capacitors
 
Just to underline what jean-paul and others have said about 20 year old electrolytics, pictures of blown/leaking Elna Duorex capacitors from a repaired Sony x33es CD player. The player was cheap on eBay so I couldn't resist:). I didn't expect it to work but surprisingly, perfect audio via optical output but only distorted, low volume sound from one analogue channel. The capacitors had failed and the electrolyte leaked onto the PCB underside, dissolving several tracks. After a complete capacitor replacement and some delicate PCB surgery, all good and the Sony lives to fight another day:D
 

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jean-paul

diyAudio Moderator Emeritus
2002-09-20 7:20 am
Germany
Oh no, now Elna caps failing. First time I see these caps leaking but they are relatively rarely found in devices so that does not say too much. Good job you replaced them all at once as it really is the best way of solving capacitor problems.
 
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