I have now two units. Cyrus One v.TOG and Cyrus Two v.07. Soundwise these are very different. Cyrus Two has significantly more treble, almost too bright and somewhat fatiguing and bass could be better pronounced. One has beautiful clean and soft bass, but highs are dull and lacking - no spark.
Is this normal for these units or cap replacement has affected the sound?
C One has only 470uf ROE caps replaced(by me), C Two has full cap work done(by previous owner).
Is this normal for these units or cap replacement has affected the sound?
C One has only 470uf ROE caps replaced(by me), C Two has full cap work done(by previous owner).
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You need to be clear about the condition of these amplifiers, since they are quite old and many faults apart from capacitors are likely. Certainly, original ROE moulded case electrolytic caps are trouble. Replace them all, observing correct polarity, with your favourite grade/brand including current ROE aluminium cased types but use original values - don't increase capacitance in the hope of making general improvements because capacitance affects frequency response to some degree, in most applications within the actual amplifier circuits and changing them significantly, won't help with tracing persistent faults either.
Also, check what work has obviously been done already - this is likely where the problems are and probably why the amplifiers were sold in bad condition. Check the power transistors for original types, shorts or messy work. They often failed, taking out drivers too and there are many threads here already which discuss the problem of replacements for BUV28 and how to refit them properly with suitable insulating pad material, to the diecast metal case models. i.e. Cyrus 2 and later. Note that they are switching power transistors, not linear audio types and some "mr fixits" get it wrong.
Also, check what work has obviously been done already - this is likely where the problems are and probably why the amplifiers were sold in bad condition. Check the power transistors for original types, shorts or messy work. They often failed, taking out drivers too and there are many threads here already which discuss the problem of replacements for BUV28 and how to refit them properly with suitable insulating pad material, to the diecast metal case models. i.e. Cyrus 2 and later. Note that they are switching power transistors, not linear audio types and some "mr fixits" get it wrong.
Many years ago now, I couldn't get parts for the cyrus one. They sent substitutes, but the magic was all gone
Yes, I am very cautious to replacing anything in C ONE. Specially in the Phono preamp.
Thank you for the advise of checking the caps that are replaced in C TWO.
Thank you for the advise of checking the caps that are replaced in C TWO.
Two values has been replaced with higher values: C67/68 470uf to 1000uf and c53-56 100uf to 220uf. The C67/68 are at the regulated power supply that feeds Phono preamp only so we could forget these? What do you think which caps could affect the sound the most?
A 2:1 increase in power supply smoothing is unlikely to cause trouble but cumulatively, as in increasing all capacitors on principle, or matching the physical size instead, so they look original or more impressive in pics, is going to be risky. I couldn't predict where the problems would be worst, without direct experience of trying the many possible combinations of caps, their values and types, myself.
I'm sure there are some types/brands of electrolytic caps that could be be increased without problems but I don't like the idea of messing about with successful designs on the presumption that more of something is better. By the same logic, would not larger resistors sound better too?
Electrolytics have a complex mix of materials and electrical qualities that make them a difficult proposition to match from one brand, grade and format to another and manufacturers will simply stop making those you are familiar with and introduce another, for any cost and size reasons which will enable them to remain competitive - not necessarily to improve their performance for particular groups of audiophiles. All a professional repairer wants to do is restore something old to its former glory, not to create something different that may sound impressive or interesting for a while and then become tedious as some differences begin to annoy more than enhance our listening pleasure. Oversizing caps isn't inherently wrong unless it stresses other components but its not a smart way to hear the original sound quality approved by the designer and manufacturer. That is the sound quality that built their reputation - not something imaginary, like thinking if something is good, more of it must be better.
Another important factor is resale. Nobody wants an amplifier that has already been modified in some way and is now up for sale - kind of admitting a failure, I think. What buyers usually want is something original to listen to as designed, then do any mods themselves. Same outcome though, another Ebay wreck.
To start any repair that is going to need new, larger caps, look at ESR or just for the main power supply caps, the ripple current rating. ESR should be low and ripple current rating high, compared to cheap caps for general purpose applications. The actual values will depend on the amplifier's power rating and bear in mind that smaller caps will have several types of use, including signal coupling, which all have different needs but fortunately, there are more or less universal types like Panasonic FC and its alternatives like FR and FM, that are hard to beat for good, long life sound and electrical performance all round. Boutique brands and types are all very well for those who believe in them and are happy to spend a small fortune on components. Even the idea of hand-made caps at three figure prices just depresses me though.
The Cyrus amps are not powerful without their PSX booster units, so they don't need massive capacitance in the power supplies and any decent quality, Japanese brands such as Rubycon, which are currently popular plus traditional types from Nichicon, Elna etc will be fine, assuming the grade is currently available and suitable, as per datasheets and application notes. Datasheets and tables are easy to view online at the manufacturer's website. Take care with where you buy the caps though, there are plenty of very convincing fake caps at cheap and attractive prices online too.
I'm sure there are some types/brands of electrolytic caps that could be be increased without problems but I don't like the idea of messing about with successful designs on the presumption that more of something is better. By the same logic, would not larger resistors sound better too?
Electrolytics have a complex mix of materials and electrical qualities that make them a difficult proposition to match from one brand, grade and format to another and manufacturers will simply stop making those you are familiar with and introduce another, for any cost and size reasons which will enable them to remain competitive - not necessarily to improve their performance for particular groups of audiophiles. All a professional repairer wants to do is restore something old to its former glory, not to create something different that may sound impressive or interesting for a while and then become tedious as some differences begin to annoy more than enhance our listening pleasure. Oversizing caps isn't inherently wrong unless it stresses other components but its not a smart way to hear the original sound quality approved by the designer and manufacturer. That is the sound quality that built their reputation - not something imaginary, like thinking if something is good, more of it must be better.
Another important factor is resale. Nobody wants an amplifier that has already been modified in some way and is now up for sale - kind of admitting a failure, I think. What buyers usually want is something original to listen to as designed, then do any mods themselves. Same outcome though, another Ebay wreck.
To start any repair that is going to need new, larger caps, look at ESR or just for the main power supply caps, the ripple current rating. ESR should be low and ripple current rating high, compared to cheap caps for general purpose applications. The actual values will depend on the amplifier's power rating and bear in mind that smaller caps will have several types of use, including signal coupling, which all have different needs but fortunately, there are more or less universal types like Panasonic FC and its alternatives like FR and FM, that are hard to beat for good, long life sound and electrical performance all round. Boutique brands and types are all very well for those who believe in them and are happy to spend a small fortune on components. Even the idea of hand-made caps at three figure prices just depresses me though.
The Cyrus amps are not powerful without their PSX booster units, so they don't need massive capacitance in the power supplies and any decent quality, Japanese brands such as Rubycon, which are currently popular plus traditional types from Nichicon, Elna etc will be fine, assuming the grade is currently available and suitable, as per datasheets and application notes. Datasheets and tables are easy to view online at the manufacturer's website. Take care with where you buy the caps though, there are plenty of very convincing fake caps at cheap and attractive prices online too.
Thanks!
The recap was done with Nichicon Muse BP's and CE FM's. The work is done very professionally so before I start redoing anything I want to make sure it would make sense. I have ELNA RFS SILMIC II 100uf to replace CE 220uf's(C53-56).
Other thought is that maybe the amp has been sitting for some time and needs a break-in.
The recap was done with Nichicon Muse BP's and CE FM's. The work is done very professionally so before I start redoing anything I want to make sure it would make sense. I have ELNA RFS SILMIC II 100uf to replace CE 220uf's(C53-56).
Other thought is that maybe the amp has been sitting for some time and needs a break-in.
A break-in? Maybe that term is used in your region but very old capacitors can require "re-forming" which involves applying a reduced forward voltage to gently polarize the cap and charge it slowly to test and verify that it holds a useful amount of charge before full voltage is applied. This usually applies to equipment that has lain unused for a decade or more (i.e. dire circumstances) and I assume that wouldn't apply here.
In practice, powering the amp with a "Dim bulb tester" or DBT, Lightbulb limiter etc. is a good and simple way to do this and fairly safe, compared to hitting the parts with full supply voltage and inrush current.
In practice, powering the amp with a "Dim bulb tester" or DBT, Lightbulb limiter etc. is a good and simple way to do this and fairly safe, compared to hitting the parts with full supply voltage and inrush current.
Break-in term is widely used among audio enthusiasts. From Phono styli to speaker cables😉 I just want to find out why two very similar amps sound so much different and what I can do to remedy this. Since Cyrus One has more pleasant sound to start with but lacks crisp highs I would try to improve that one first. Cyrus Two has ALL el. caps replaced - possibly 10000uf power caps as well.
So listened these two again. C2 sure has problem with treble specially with Phono. CD is OK but Phono definitely has unpleasant kind of piercing quality. And I get a feeling that the whole sound spectrum has shifted towards high frequencies on Phono.
I have gone through many discussions about these two amps and somewhere was suggestion that oscillation may occure, moreover it has been used to brighten the highs in some amps. So maybe that is what I hear.
If so where I should look for - maybe regulated power supply caps? There was a suggestion to bridge these with 0,1uf Wimas.
Also would it be good to replace the LM317/337 with something more robust. These are always on and run pretty hot. Maybe fixed +-18V regulators?
BTW I listen in very low volume - there are notches attached to the vol. pot - 1-2 steps, 3 at the max.
I have gone through many discussions about these two amps and somewhere was suggestion that oscillation may occure, moreover it has been used to brighten the highs in some amps. So maybe that is what I hear.
If so where I should look for - maybe regulated power supply caps? There was a suggestion to bridge these with 0,1uf Wimas.
Also would it be good to replace the LM317/337 with something more robust. These are always on and run pretty hot. Maybe fixed +-18V regulators?
BTW I listen in very low volume - there are notches attached to the vol. pot - 1-2 steps, 3 at the max.
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Unless the circuits themselves have been altered by a previous tinker, its unlikely that you'll hear such high frequency emphasis from the original product. When an untrained owner tries to follow bad or unclear advice in an effort to "improve" a circuit, anything can go wrong and will be much more difficult to identify and repair, since nobody knows yet, what was changed for what or perhaps damaged in the process.
I suggest you make a photocopy of the schematic for the model, inspect each PCB from the solder side and highlight on the schematic, any traces or component pads that have obviously been hand soldered. I don't recall any PCB copper trace diagram in the Mission Cyrus service manuals that might aid you there. Still, the schematic alone should help to realise what has been done in the past and the likely circuits affected. Most tinkering with any amplifier is done on flaky or simply bad advice, starting with the notion that even though it was very successful product, the designer was wrong - too conservative to risk operating a commercial product at the edge of instability or with increased distortion, in order to enhance some particular sound effect.
It's likely a previous owner(s) who caused or perhaps botched up repairing a fault or tinkering with circuit modifications, making errors hard to identify. Locate any rework and you should be half way to restoring the amp. I'd add a comment that you definitely don't need more robust regulator IC's when the loads will only be around 10% of capacity. If they feel hot, its due to power dissipated in the reg, not the load of only a few opamps, so small TO220 heatsinks will soon fix that, bearing in mind that the metal tabs are at either +30VDC input or -18VDC output potential so the tabs and sinks will accordingly be live.
I suggest you make a photocopy of the schematic for the model, inspect each PCB from the solder side and highlight on the schematic, any traces or component pads that have obviously been hand soldered. I don't recall any PCB copper trace diagram in the Mission Cyrus service manuals that might aid you there. Still, the schematic alone should help to realise what has been done in the past and the likely circuits affected. Most tinkering with any amplifier is done on flaky or simply bad advice, starting with the notion that even though it was very successful product, the designer was wrong - too conservative to risk operating a commercial product at the edge of instability or with increased distortion, in order to enhance some particular sound effect.
It's likely a previous owner(s) who caused or perhaps botched up repairing a fault or tinkering with circuit modifications, making errors hard to identify. Locate any rework and you should be half way to restoring the amp. I'd add a comment that you definitely don't need more robust regulator IC's when the loads will only be around 10% of capacity. If they feel hot, its due to power dissipated in the reg, not the load of only a few opamps, so small TO220 heatsinks will soon fix that, bearing in mind that the metal tabs are at either +30VDC input or -18VDC output potential so the tabs and sinks will accordingly be live.
The Cyrus One and Two are pretty much identical circuitry wise.. the main difference is the Two has two pairs of output transistors instead of the one pair that the One has
Only issue v.06(8 PT7's) - V.07 and TOG have two pairs, but beefier PT77's.
So sonically these shouldn't be too different.
Dear Vanakaru:
I'm in the middle of a process to buy a Cyrus One and upgrade its bipolar capacitors - like you did.
Please let me know your opinion.
Does it deserve the 250 euros requested by the seller, or is it a waste of money, considering that it is a very old equipment?
Do you know the Audiolab 8000A? Will it sound better than Cyrus One?
Many thanks for you attention,
Antonio
I'm in the middle of a process to buy a Cyrus One and upgrade its bipolar capacitors - like you did.
Please let me know your opinion.
Does it deserve the 250 euros requested by the seller, or is it a waste of money, considering that it is a very old equipment?
Do you know the Audiolab 8000A? Will it sound better than Cyrus One?
Many thanks for you attention,
Antonio
I got all 3 of mine from eBay also about 250 with shipping. My reason to get Cyrus was the compact form at the first place and it had good reviews about Phono stage. I find the reviews rather accurate comparing to some Marantz, Denon, Yamaha, Luxman integrated amps. My Cyrus is very capable driving my odd vintage speakers at very low vol. producing good bass and pleasant soundstage.
So if your Cyrus is fully functional and has not butchered before the price is about right. When you start replacing el. caps the best advise I got was to do it one section at the time and listen that you have not altered the sound to the worse. First caps to go are the 470uf 6V ROE's under the ribbon cable, then 22uf caps and 470uf caps at the regulated power section. I would be thinking twice to do anything to Phono preamp unless there is something wrong with it.
So if your Cyrus is fully functional and has not butchered before the price is about right. When you start replacing el. caps the best advise I got was to do it one section at the time and listen that you have not altered the sound to the worse. First caps to go are the 470uf 6V ROE's under the ribbon cable, then 22uf caps and 470uf caps at the regulated power section. I would be thinking twice to do anything to Phono preamp unless there is something wrong with it.
OK. Thank you so much for your kind advice.
I put the Audiolab 8000A in the question because, just now, I´m able to get one for the same amount of price (about 250 euros) and it is also famous for is phono section.
I also prefer the shape of Cyrus because they are very compact.
Have fun and best regards!
I put the Audiolab 8000A in the question because, just now, I´m able to get one for the same amount of price (about 250 euros) and it is also famous for is phono section.
I also prefer the shape of Cyrus because they are very compact.
Have fun and best regards!
So I put 0,1uf Wimas across Phono section power supply el. caps both sides of voltage regulators and it seems to have tamed the harshness of trebles. Well at least couple of records I played tonight. But C ONE would need some better highs. But it is really hard to tell by listening and I think I shall leave it like that.
They have different gains, the One and Two - R65/66 is 1K in the one, 750R in the two - which does affect the sound a little. Plus some other differences in compensation capacitor values between one and two and different versions.
I did clone the circuit/PCB and had a play a few years ago. Also have original TOG and Issue 06 Ones to play with, they sound different. Using different types of capacitors and equivalent replacement transistors can make the amp very harsh, and pushing to towards unstable and noisy. More fussy on the input/VAS stage, less so with the output transistors, the original output transistors being switching parts not audio transistors... Panasonic FC capacitors work well for most electrolytic parts where possible, for me at least.
I did clone the circuit/PCB and had a play a few years ago. Also have original TOG and Issue 06 Ones to play with, they sound different. Using different types of capacitors and equivalent replacement transistors can make the amp very harsh, and pushing to towards unstable and noisy. More fussy on the input/VAS stage, less so with the output transistors, the original output transistors being switching parts not audio transistors... Panasonic FC capacitors work well for most electrolytic parts where possible, for me at least.
I had both amps. One, which I updated to the Two. I also personally upgrade all the caps that were in these amplifiers (except for the large ones) at Nichicon Muse es/kz. so if we talk about the differences, then I would say that both amplifiers benefited from this. They became cleaner, more detailed, larger and louder. I didn’t notice any sharpness or any problems other than presentation nuances. the first is faster, the second is large-scale and powerful. Both are excellent amplifiers, so look for problems in other components, especially in the power cables, or IC, etc.