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Cyrus 1

Stereo Integrated Amplifier (1984-92)

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Cyrus 1


Power output: 25 watts per channel into 8Ω (stereo)

Frequency response: 1Hz to 50kHz

Total harmonic distortion: 0.005%

Damping factor: 100

Input sensitivity: 0.4mV (MC), 4mV (MM), 65mV (line)

Signal to noise ratio: 67dB (MC), 84dB (MM), 86dB (line)

Dimensions: 85 x 215 x 345mm

Weight: 4.5kg

Finish: black / grey

Price: GBP £230 (1991)


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Reviewed Oct 11th, 2019 by Seaworker

Hello I have a Cyrus one and love it.. It has recently been serviced and repaired and is as good as new. I had all the electrolytics replaced plus various other repairs its such a good amplifier I felt it was worth the cost!! I noticed one of your members was asking about the high cost the Mission Service centre charge.
I used ARS (Amplifier repair service) I cannot recommend them enough it might be worth googling there website or dropping them a note at amprepairservices@btinternet.com. A Basic fixed price service was £139 .
Great site and lots of information big thanks

Reviewed Jul 09th, 2019 by ronderful

I just got mine at Craigslist; the very 1st generation I think. 3 knob, plastic body with no balance and no LED light. It says at the back Consumption 100 watts. I connected it to a Control4 Music Bridge, Thiel TM3 speakers, WireWorld Power Cable, Furman Power Conditioner and played music through Bluetooth via Pioneer DAP on FLAC. Streamed Amazon Music and Pandora via AirPlay on an iPhone 5s.

It's jaw dropping, very clean, a lot of fine detail with a very good dynamic-range. I noticed it don't like inter-phase like a Cambridge DacMagic. It sound best straight Belden RCA and it will pin you to the couch.

The audio quality is competing par or better than my Sansui AU-X701 streaming on an Arcam rPlay... at a size of a large car-stereo. It is HiFi and audiophile.

Reviewed Jul 18th, 2017 by DrGizmoBAB

Scored a mint condition Cyrus 1 on ebay in hopes of finding something to properly drive a pair of Tannoy Eaton loudspeakers. The electronics reside in a half wide chassis with minimalist controls. Volume, Balance, Source & Record rotary switches, and a headphone jack ... That's it. Yup, Not very exciting. The Balance control varies the right vs. left image by +/- 5dB. You cannot get right or left alone. Weirdest Balance control concept ever ... until you actually use it to get the sonic image centered in your listening room. Absolutely brilliant! Then comes the chassis construction ... It's heavy cast aluminum. The cover is not bent, spot welded steel ... It's also cast aluminum. The wrap test makes a muffled thunk sound. No resonance at all. You then start to realize that this little integrated amplifier is a different beast all together. All design elements are focused on performance, nothing else. Connecting the Cyrus 1 to the Tannoy's create a symbiotic relationship that's hard to fathom in that it's phenominally good. Bass? Solid! Mids! Etheric. Highs? Crystaline without being clinical. It's the best match so far ... beating more expensive amplification regardless of tube or solid state topology. The best source is Analog in that it presents slightly fuller bass than digital. A truly magical experience. That said, two drawbacks exist with this amplifier ... 1) A low-ish 25 Watts per channel output into 8 ohms. 4 or 5dB more output would have added a half point to the score, and 2) this unit was made for use in the UK (240V operation), thus requiring the use of a Step Up Transformer to get 220VAC from 110VAC used here in North America. This drawback subtracts another half point, albeit strictly convenience based. In summary, how somthing that's unassumingly small and relatively inexpensive (I paid ~ $300) can optimally drive top-notch speakers that now cost an order of magnitude more is no small feat. The Cyrus 1 may look sparce and dated by today's standards, but perfomance wise, it's Spot On!

Reviewed Jan 24th, 2017 by randombeliefs

I was servicing this for my brother and hadn't heard one since the 90's.
Crikey, what a little belter it is ! Knocked a few well regarded cheap amps i had lying around for 6. In a different league to the rotel840bx , Marantz pm40se and pioneer A400 I compared it to. While those amps sound pretty good *for what they cost me* the Cyrus simply sounds good , full stop.

Reviewed Dec 04th, 2016 by haja

Cyrus one is a great amplifier, I am using it since 1986.
I don't want to upgrade for a bit better amplifier. The Cyrus one produce 3 dimensional sound. some time I have to look around to find that unique sound but it is coming from the speaker. I was trick many time.

Reviewed Jan 04th, 2015 by vinyl_solution

As with Cyrus 2, love the Cyrus 1... Fabulous sound which never ceases to amaze but sadly my OAP amps now need phono-stage repair (failed capacitors) any advice, schematic etc would be most welcome please as, Cyrus Electronics (who now own Mission) want 240GBP for each repair! Zoinks!

Reviewed Apr 09th, 2012 by daniele mattei

A little gem!

Reviewed Jan 26th, 2012 by JaS

A bit brighter sounding than the Cyrus 2, but partnered with the right equipment it's a dynamic performer. A good phono stage built in too.



Cyrus One (1990)

Thank you for sharing the manuals.

I've been using this remarkable amplifier since 1990 and have served me without any hiccups except for burnt fuses now and again. I have yet to send the amp for a major service but I think I would do it myself with the help of your shared manuals.

IMO this amp although coming into its 22 years still sounds the same as and when I bought it back in 1990 in Brighton, England. I also bought the Cyrus 780, Marantz CD62 and finally the Linn Basik Akito/K9 t-table. This setup is still with me here in Malaysia. The best combination.

re: Cyrus One (1990)

Hi Jumpstat,

I too have been using my Cyrus 1 since the early 90's and I have just found myself in the situation where I need to use it with headphones. Plugging in my 'phones doesn't cut out the speaker output (apparently by design). Do you happen to know whether it's safe to run the amp without the speakers being plugged in? I know that my guitar amp shouldn't be used without speakers. Is it the same for the Cyrus?

Thanks in advance for any help or advice that you could offer,



muchas gracias por el manual,y el esfuerzo

Cyrus one

thanks a lot for Your help but I am looking for a service manual or circuit diagram for cyrus one TUNER. Can You help me?


Service manual for Cyrus one tuner


Looking for such manual too. Did you finally find it?
Have some burned components to identify (IC9 - erasable EEprom - on main board and T33 on display circuit board).



re: Service manual for Cyrus one tuner

I have the same tuner standing here:
T33 is a PNP transistor BC212L.
IC9 is a 256x8 bit eeprom PCF8582A.

Could you please identify capacitor C19 on the mainboard for me?

Onno Tromop

service manual

Thanks very much for service manual , a really useful site , much appreciated.

Dave Pentin.

Mission Cyrus One

Thanks for the manual - cheers!

service manual cyrus 1 and 2

Hi there,
Thanks a lot for the service manual I was able two download for my cyrus one.
I did alos look for the service manual for the cyrus two but wasn't able to find that one on your side. Do you by any chance have that one as well?

Thanks again!!


Thanks a lots...

Thanks a lots...

Thanks a lot!!!

Thanks a lot!!!

Cyrus One

Ancora grazie

This website is not affiliated with or sponsored by Cyrus. To purchase 1 spares or accessories, please contact the company via their website or visit an authorised retailer.