Hi,

Just bought on flea-Bay a nice looking Cyrus One Integrated Amplifier. Back in the old days (late 80's) I remember it being a Nait-1 competitor and some of my customers loved it!

Cyrus One comments are welcomed!!!

I'm not planning to sell my gear! Just setting up a 2nd system for my bedroom...

Vic

Hi Vicdiaz:

I used one for 10 years or so. Bullet proof little amp and the later versions offer very good value for money. Mine was the grey “Nextel” coated one with the fully cast aluminium case (the last and best version of the Cyrus One model). I always thought its strengths were speed and detail but it could sound a little too thin if you partner it with the wrong speakers and the Image was a little 2 dimensional and shut in.

Steer away from speakers that have a bright and forward presentation and you should be OK. Probably one of the larger stand mounted book shelf type speakers. You could even match it up with some of those more euphonic and slightly coloured models like the Audionote Snell copies for a bit of musical fun rather than accuracy:D . Under no circumstances put it any where near a pair of Linn Kans or Naim IBLS:o .

LPSPinner.

Wot LPSpinner said.

The later the version, the better the sound.
If you want to try a Cyrus with Kans, get a late Cyrus 2 - it works.

"Back in the old days (late 80's) I remember it being a Nait-1 competitor"

To be fair that's not exactly how I remember it - nice amp though.

"Bullet proof little amp"

This isn't exactly how I remember it either.

I've still got a "1", down in the basement. I tried it against my Nait 3 a few months back and I couldn't honestly say there was a great deal of difference.

I bought one to replace my stolen NAD 302. Preferred the NAD I'm afraid.

I've still got a "1", down in the basement. I tried it against my Nait 3 a few months back and I couldn't honestly say there was a great deal of difference.

Then it is not that bad!!! ;-)

NO ! Far from it. I keep thinking I should sell it, but if I want a second system it will be ideal. (TBH it would be pretty good as a replacement for my Nait!)

Full set of schematics here for future reference;

http://www.tcaas.btinternet.co.uk/index-4.htm

Well, finally I bought a pair of Rega Kytes and connected them to the Cyrus One with Linn's K20 cable. Not bad at all!!!

One quirk... the rectangular power switch on the Cyrus One is stuck on the on-position. Any one with a spare or tps on how to fix it???

Well, finally I bought a pair of Rega Kytes and connected them to the Cyrus One with Linn's K20 cable. Not bad at all!!!

One quirk... the rectangular power switch on the Cyrus One is stuck on the on-position. Any one with a spare or tps on how to fix it???

You've got to take the front off and free up the red lever! Carefully pull the knobs off their splines, making note of their position. The front can then be unscrewed (two or three underneath and one each side on the plastic ones).

Speaking of Rega, they had a dealer conference over a weekend around 89-90 and when there, they compared their amp(s) to a Cyrus 1 and left opinion open.

The Cyrus 1 had been measured by Rega and, apparently, it starts to oscillate or ring slightly over 5 Watts output, this giving a sense of tension and excitement. I certainly found that it wouldn't go loud before hardness set in! Other trendy amp makers did this too for a while back then and What HiFi LOVED it......................

The Cyrus 2 was a FAR better behaved animal, although today it MUST have the PSX (if you can find one) to even begin to be competitive, otherwise it sounds thin..

A Cyrus 1 was my first "serious" amp in the mid 1980's. That sample sounded detailed but "thin", and needed fixing quite early on in its life. I once borrowed a Cyrus 3 quite a few years later (belonging to bor, IIRC) and though much better, there was a similarity in presentation from what I remember thinking at the time. However I must admit to prefering the presentation of earlier Naits.

The Cyrus 1 had been measured by Rega and, apparently, it starts to oscillate or ring slightly over 5 Watts output, this giving a sense of tension and excitement. I certainly found that it wouldn't go loud before hardness set in! Other trendy amp makers did this too for a while back then and What HiFi LOVED it......................



Hmm....I suspect old Gandy & Bateman were pulling your plonker there David. I'd be interested to know how Cyrus pulled off this trick if true. It would have been suicide to engineer such a fault into an amp as the likes of Colloms, Atkinson & Miller would be splashing nasty looking plots across the mags. Cyrus amps have always produced superb lab results.

The C1 & C2 were nice stable little amps and the equal of any small Naim IMO.

I've got an original Cyrus 1 in plastic case, and a Cyrus 2 with PSX. They both make a pleasing noise to me, and have done various jobs over the years. The 2 is destined to drive some ATH9000 headphones for the missus, whilst the 1 is used in my study to drive some small monitors.

Cesare

Hmm....I suspect old Gandy & Bateman were pulling your plonker there David. I'd be interested to know how Cyrus pulled off this trick if true. It would have been suicide to engineer such a fault into an amp as the likes of Colloms, Atkinson & Miller would be splashing nasty looking plots across the mags. Cyrus amps have always produced superb lab results.

The C1 & C2 were nice stable little amps and the equal of any small Naim IMO.

Should I mention some Arcam models too way back when. Even some early Naims were set *just* this side of stability.

It's not really a *fault* anyway, but it's amazing how many products were made to be *exciting* and then were smoothed out the following year.

I can't obviously prove it, but this phenomena was observed in certain products as I recall. Not major oscillation, just a little ringing, enough to put some added tension into the music.

And yes, these early Cyrus amps were very reliable indeed, apart from the odd phono stage power supply cap going home after a few years, causing a terminal BUZZ on the disc input...

A silly question, but was the Cyrus 1 ever given a serious technical evaluation? I seem to remember the 2 being given a warm recommendation...........

When I meant that it's stuck in the "on" position is that if you press the red button it moves freele and "clicks" accoirdingly either on the "off" or "on" positon but it never powers-off in the "off" position.

Even the red LED stays lit up in the "off" position.

Cyrus One - no need to say by now it is a great amp.

How much did you get it for? I have an early one unused and it would be good to sell on flea-bay. :)

Earlier ones were better I was told as made in the UK, at some point production was moved to far east and audio quality wasn't as good. Don't know what year that happened. Somewhere here might.

Ah, the joys of buying used, eh Vic?

I'm thinking that the Cyrus One and Two power switch might actually be a low voltage trigger for a relay that turns on the power amplifier section - the pre-amp section being always on with these plugged into the mains.

I'd try unplugging the amp and letting it sit for a while before reconnecting to the mains and operating the press switch (making sure that said switch is in the off position when plugging back in).

HTH,

Craig

Warren Day wrote:
...Earlier ones were better I was told as made in the UK, at some point production was moved to far east and audio quality wasn't as good. Don't know what year that happened. Somewhere here might.

Every Cyrus One and Cyrus Two amplifier ever made came out of Huntingdon, and I would disagree about the earlier versions being better. The final version of Cyrus one, the one that was housed in a cast aluminium case and without the headphone socket was the best version for both build quality and sound The earlier versions had a pressed aluminium case, a less substantial heat sink and a top cover that just didn’t feel as substantial as the cast aluminium case of the later models. I’m not saying the earlier ones were bad but the late ones just had a slight edge on sound quality, measured performance and from what I remember they also developed a little more power as well.

Craig B Wrote:
…I'm thinking that the Cyrus One and Two power switch might actually be a low voltage trigger for a relay that turns on the power amplifier section - the pre-amp section being always on with these plugged into the mains…

No, both the Cyrus One and Two used a hard-wired switch that disconnected the secondary side of the transformer that supplied the power amplification stages. You were right about the Preamp section being active from when the unit was connected to the mains. In truth though, the preamp section is the phono section only as all the line level inputs were fed directly to a 10K pot and then onto the input of the power amplifier section.

Another spot of trivia is that the Cyrus One and Two shared the same Printed circuit board and therefore the same circuit. The only difference on the line level inputs was that the Cyrus Two used bigger output transistors (or multiple paralleled transistors in the earlier Cyrus Two) and higher voltage secondary on the transformer which allowed the Two to develop more power. Unfortunately the half width casing was just not big enough to house a power transformer big enough for a 50 Watt amplifier and the actual amplifier circuitry as well. This is why mission had to skimp on the Two’s internal power supply and then offer the PSX out-board power supply for the Cyrus Two. The Cyrus Two’s internal Power supply was enough to get you going but that’s about all. Adding the PSX allowed you to split the power supply duties, the internal phono preamp ran off the Two’s internal transformer and the Two’s Power amp section could build up a good head of steam with a competent external PSU.

The other difference between the One and Two was with the Phono stage’s Moving coil head amplifier. The Cyrus One just shunted the first NE5534’s feed back loop so as to up the gain for the Moving coil section without varying the input loading, as a result the Cyrus One was a little noisy with moving coils cartridges, although I still enjoyed my Cyrus one with Ortofon MC10 Super II for a good 12 years. The Cyrus Two used a proper moving coil head amp based around a super matched low noise input pair and extra OpAmp gain stage. Again since both amplifiers share the same PCB any body who knew the part values could convert the Cyrus One’s phono input into a Cyrus two phono input.

In short the Cyrus One and Two amplifiers were nice little pieces of engineering for its day, and I kind of regret selling my little Cyrus One. It is also interesting to note that that the One’s second hand price when compared to the Two has narrowed a little, suggesting that although the Two was the better of the two amplifiers the One has become the more collectable. In its day the Cyrus One was considered exceptional value for money and usually got a “Best Buy” sticker where as the Cyrus Two usually had to put up with a recommended tag. As for the Cyrus One and Two being unstable into difficult loads, I remember seeing several results of capacitive loading tests and both the Cyrus One and Two showed no signs of ringing or instability, and both gave a very clean ultrasonic spurious output up to 100 KHz. I actually had my Cyrus One driving a pair of Quad ELS for a short time and it handled it quite comfortably. The only difficulty I encountered was that I had to return the Quads back to their original owner :(.

LPSPinner

PS: As to the Cyrus one Vs a Naim Nait Two. I auditioned an olive Nait two against my Cyrus One. I decided there and then I didn’t like the Naim sound at all. I spent the money on an LP12 instead.

My only complaint about my (final generation) Cyrus 1 was that having used it as Phono only for 5 years, when I finally added a CD player, it became apparent that the input selector switch was full of crud! Thus, it never worked reliably as a multi-source amp... Anyone know if it's possible to dismantle and clean it because it's still up in the roof somewhere...

I have a very nice late version C2 tucked away.
The case is mint but sadly Mr postman was a little careless and the selector took a direct hit causing damage to the part. I have a spare switch and one day soon I'll get round to fixing it.

The tranny inside the C2 looks around 200VA so fine for driving 4 ohms to rated spec.
Think NAP140 size and you'd be about right. A PSX does add grunt if you push it hard into low impedance loads and more importantly improves the sound of LP as the phono stage gets the internal supply all to itself.

Some nice parts in there too.
Holden & Fisher tranny, poly caps in the signal path and DNM slit foils for the PSU. Add in the beautiful alloy castings and these are little stormers for what they go for these days.

No, both the Cyrus One and Two used a hard-wired switch that disconnected the secondary side of the transformer that supplied the power amplification stages.
Thanks for clarifying LPSpinner.

So, good news for Vic that his faulty switch appears to prefer to remain in the on position - hopefully until such time as he gets round to sourcing/installing a new one.

On that last note, based upon my own recent experience, the nice folks at Cyrus Audio (service@cyrusaudio.com) will be only too glad to help.

Craig

Norwich John, get some contact spray (Maplin or similar) and take the cover off (power lead unplugged!) Ensure it's all cooled down, you don't want a shock off the caps so ensure it's been unplugged for 30 min, then use the contact spray on the vol pot, balance, and selector switch. OPerate the controls a few times. Let it dry, reassemble it, job done.

Here's a pic of what to expect under the neatly vented hood John...

http://k53.pbase.com/o4/52/449952/1/55341610._D2H2054.jpg

You won't have to remove the front panel, as this fellow did, unless you wish to visually inspect the two black power supply filter caps for bulging and/or leaking below the PCB (always a good idea after this many years).

Best to do a bit of dusting round before using the contact cleaner spray. I use a combination of compressed air in a can and a clean dry artists brush.

Notice that the volume and balance controls (LH side) are 'ganged' - so two pots to clean there. These will have one or two access indentations in the rear edge of each of the two cylindrical metal housings (the front being balance and the rear being volume) through which the spray can be injected at 45 degree angles via the extension straw that comes with the contact cleaner.

The record and listen rotary switches are identical and appear to be of the sliding type - i.e. the knob is rotated, but the contacts actually slide fore/aft beneath the less shiny metal cover that is located aft of the switch gear proper.

After all these years, I'd also pop out the two output protection fuses, polish their end caps, and, clean and tighten the housing clips before snapping the fuses back in.

Craig

Thanks for clarifying LPSpinner.

So, good news for Vic that his faulty switch appears to prefer to remain in the on position - hopefully until such time as he gets round to sourcing/installing a new one.

On that last note, based upon my own recent experience, the nice folks at Cyrus Audio (service@cyrusaudio.com) will be only too glad to help.

Craig

Thanks for the tip! I just sent an e-mail to the above address to check if they can source it!

My first proper hi fi amp is the Cyrus one in 1986, driving a pair of Tannoy Mercury and the source was a Dual CS505-II. My Cyrus One was the first edition, the plastic sticker strip at the lower fascia always came off! The case was plastic.

The Cyrus One's sound was more upfront than the Rotel RA820BX. The Rotel made a loud bang when switched on, my electronic engineering student friend told me that it was the transformer making such a noise so I changed it to the Cyrus One.

Norwich John, get some contact spray (Maplin or similar) and take the cover off (power lead unplugged!) Ensure it's all cooled down, you don't want a shock off the caps so ensure it's been unplugged for 30 min, then use the contact spray on the vol pot, balance, and selector switch. OPerate the controls a few times. Let it dry, reassemble it, job done.

Steve67 / CraigB - Thanks! I'll give it a go. I've often wondered what it'd sound like through my big Tannoys (loud, probably..)

Another vote for the Cyrus one. I'm using one now in my classroom. I use it for the sound system for the data projector, driving Mordaunt Short 05s. It makes watching French films and internet radio a very pleasant experience. These kids don't know how lucky they are!

Jeez!!! No reply from Cyrus Audio yet...

Talk about service...

How is it that someone cannot hear the difference between one of the best integrateds of its era and one of the worst?

Nait vs Cyrus? FFS!!

Heavy advertising budget = biased positive review = deluded public.

An amazing combination of lack of finesse , tune , rhythm or indeed any musical attribute.

And unreliable to boot.

An amazing combination of lack of finesse , tune , rhythm or indeed any musical attribute.

And unreliable to boot.

I agree about the sound..............but a Nait should be pretty reliable

Paul.

Nait vs Cyrus? FFS!!

Heavy advertising budget = biased positive review = deluded public.

An amazing combination of lack of finesse , tune , rhythm or indeed any musical attribute.



You forgot the biased flat earth press which gave it a lift but you are being a little unfair IMO. The Nait does indeed sound as you describe into inefficient, current hungry speakers but it sounds quite passable into moderate loads at low volume.

Pretty competent little box but the second hand values are rather silly as it should really sit in A&R A60 territory, ie £40-£75 tops.

Well,

I would gladly get my hands on a NAIT-1 but they're not common and not cheap!!!! Seen a few go for more than $400 USD.

Pretty competent little box but the second hand values are rather silly as it should really sit in A&R A60 territory, ie £40-£75 tops.[/QUOTE]

Market forces !!! Look at the s/hand price of the LS3/5a.

Here's a pic of what to expect under the neatly vented hood John...

http://k53.pbase.com/o4/52/449952/1/55341610._D2H2054.jpg

You won't have to remove the front panel, as this fellow did, unless you wish to visually inspect the two black power supply filter caps for bulging and/or leaking below the PCB (always a good idea after this many years).

Best to do a bit of dusting round before using the contact cleaner spray. I use a combination of compressed air in a can and a clean dry artists brush.

Notice that the volume and balance controls (LH side) are 'ganged' - so two pots to clean there. These will have one or two access indentations in the rear edge of each of the two cylindrical metal housings (the front being balance and the rear being volume) through which the spray can be injected at 45 degree angles via the extension straw that comes with the contact cleaner.

The record and listen rotary switches are identical and appear to be of the sliding type - i.e. the knob is rotated, but the contacts actually slide fore/aft beneath the less shiny metal cover that is located aft of the switch gear proper.

After all these years, I'd also pop out the two output protection fuses, polish their end caps, and, clean and tighten the housing clips before snapping the fuses back in.

Craig

Craig - I hope you aren't squeamish, because I finally opened up the Cyrus 1 this morning.... and this is what I found....oh the shame.

http://www.flickr.com/photos/8539385@N03/2242236720/

I've cleaned it up now. Hopefuly I can get the pots clean!

Grab a Cyrus 2 before the prices start to climb (Naits are being bumped up far higher than they deserve - musical yes, but gutless soft clippers nonetheless).

We sold a lot of Cyrus twenty years ago, although I think the annual Skiing holiday promised to our then Sales Director rather forced the issue sometimes :D, although I liked the Cyrus 2. The ONLY problem we ever had with either of them was the phono stage reservior caps, which were changed to a higher voltage version made, I think, by Rubicon. This completely sorted them out.

P.S. to Robert - I don't have the HFC lab review on the "2" and I'm sure there was one done, but the original 778 came out quite well in an earlyish eighties HFC group test, although the internal supply was criticised for being a bit weedy for the job, hence the PSX option...

I can confirm some of the points made above...the very last version of the cyrus one is the best(nextel grey no headphone socket) and is the version I currently own. There are significant differences between earlier versions and later ones. In fact I have an original hifi news magazone with a test of the then improved cyrus one (refererred to as mark two) and they conclude that the performance of the mark two cyrus One is as good as a mark one cyrus Two. The mark two cyrus one is also more powerful and better driving difficult loads than the earlier version.

But as for comparing it to a Nait One...well I did a lot of comparisons (I owned a red led early nait one for years too) and I have to say that the cyrus one is warmer in tone and more cloudy but still drives to loud volumes in easy loads (it is only supposed to be used into 8ohm speakers or higher). The nait one has more current and a clenaer, crisper sound, greyer in tone but is in my opinion a superior amp. It ought to be, IFRC the nait was £250 ish? and even the final version of the cyrus one was only around £150. Perhaps a better comparison would be the nait one with the cyrus two, they were more evenly priced. Interestingly I tried my ESL57s with the nait one and the cyrus one. The cyrus was ok, a bit muddy and congested, whereas the nait is a good match and far more capable (if you like no tonal colour!).

Take care John, it looks as though there could be a small Balrog nesting.

Craig

A good vax-ing and some servisol later...

http://farm3.static.flickr.com/2318/2246759117_e4338438bb_o.jpg

Not quite like new, but not bad for the vintage