Cyrus III power amp schematic here, but schematics of the later models wanted

[anatech]

Hi Barry,
I didn't show up "to have another go at you".

I haven't been that well medically, and this is a chance to go through replies and clean up loose ends. Since these threads to show up in search engines, I care that the record be set straight. I felt that some of your comments do not reflect the truth with regard to the quality of both the design and manufacture of this brand.

What amazes me Barry, is that the Cyrus brand equipment one of the most technologically advanced and reliable of British built products. You really ought to have been impressed with both the design (but I haven't checked to see if the supplied schematics are correct or not) and build quality. Cyrus is in fact one of the most reliable products I have seen, certainly in the top number in that class. That and it is entirely a British design and build, instead of a bought design from an Asian design house. That is the truth behind many British brand names in this day.

I have done work on other brands, some you mentioned by name. I can say as fact that Cyrus is a better design than, say Naim. That is a design that I'm not impressed with at all, many short comings there.

What I saw in your posts was an upset, disgruntled person, lashing out because he couldn't get what he wanted. That is not the position that will provide an unbiased opinion, and it is clearly not fair to make comments that damage the reputation of a brand, on an older, discontinued product that you may not have properly repaired and set up.

BTW, those insulators for the output transistors are special gap-gilling types (take note tiefbassuebertr) that are available to the general public. They just cost more. I will say that I'm not happy with the rough finish either, and I do resurface some. The answer to that is the surface, using the gap filling insulators, has a normal thermal resistance. Surfacing those areas would increase the end cost to the consumer for no benefit that I can see. If a technician does work on these, and does not use the proper insulator, or resurface the mounting areas, it is the fault of the technician alone.

Now Barry, this final comment you made earlier is completely unfair ...

I just have a Cyrus Power now that blows fuses and I can't seem able to fix. I would never buy a new Cyrus knowing that after a year you are stuffed.

You did not purchase any of these new, or warranty would have covered them. So your comment is a complete distortion of what a potential buyer might experience. Truth be told, the failure rate is extremely low, lower than most brands. On top of that, service rates are in the normal range for consumer products, and the final testing each repair gets is at the level that it had to pass when brand new. That is well above the normal standards (in practice) that all but a few brands enforce.

My guess is that you are use to the average piece of equipment, and this design is beyond your experience. No shame in that. But you failed to acknowledge that many more brand name equipment refuse to release any information, and that many of these are poorly designed, and / or constructed. I know, because I've signed many NDA's over the years. So the fact that service information is not released is not abnormal, but in this case they have good reasons to have this policy. This decision was pretty much forced on them through the actions of many poor service people over the years. It intent is to protect consumers from having their equipment destroyed.

Keep in mind too, Cyrus can and will service most of their old products except for some extremely old ones (for lack of parts). Some of these are over 20 years old now. How many manufacturers or distributors can say that? I'll break the suspense - not very many.

Finally, I am not attacking you. I am setting the record straight to agree with the facts. In fact, if you go back through my various posts over the years, you will see I help where I can, within the guidelines I am bound to keep. Where I decline assistance, it is because the person is asking for things I can not provide, or I'm convinced they do not possess the skills, knowledge or equipment needed to reasonable complete the task they set out to accomplish.

Now Barry, I don't think you even asked for help here. You simply barged in with complaints and a bad attitude. You didn't give anyone the opportunity to assist you really. Do you find that you don't get much help with problems in life? This could be one reason why.

-Chris

[barry.childs]

sorry

[anatech]

Hi Andrew,

an offensive remark that is also personal, fails to meet Forum rules on at least two counts.

I'm sorry, which remarks are you referring to? If one is ...

until some bone head with an iron gets loose inside.

That was a comment made in a general sense to describe the less capable "technicians" we all have to clean up after. It was not directed at Barry since I do not know what his skill level actually is. Believe me when I say that I had stronger words in mind as I thought back over some of the destroyed equipment I have seen.

Hi tiefbassuebertr,
I know you have an insatiable appetite for circuit diagrams, and really rail against any obstacles to that quest. But, what you are asking for here ...

From the model III and IIIi the schematic of the preamp section and the MCU section I need, also the firmware (custom made software) of the MCU I want to have.
Additional service manual of "8 XP" (8XP) needed, at least the schematic.

The firmware you are asking for is theft, very clearly laid out in the law. Study other examples for the processor you are interested in (the manufacturer of the micro controller supplies them for free download) and go from there. There are only so many ways to make it do what you want, and one of them will be a close match. Provide for the IR signals, and the MC buss as well.

You are well aware that the manufacturer does not release this information. I've told you that more than once. So, although the designs are advanced and interesting (they are cool!), you will have to wait until they come out in the fullness of time. Pressuring someone to break the internal company policy is not an admirable trait.

I will add that you need more than the preamp section of the IIIi. The amp section is a total redesign I think. I should check that instead of going off memory, but I do know that circuit changes are made during the model production runs, and they are signified with a different rev number on the various PCBs. It's not just a software change. Could be layout or circuit and layout. Both the III and IIIi have more than one version, but they are close enough to retain the same model number. Typically, a new model number signifies many basic changes.

I think you'd be really interested in the Pre X and later preamp information. Much more advanced beyond what you are considering now. Then you also have the pick of some excellent designs that have been posted here too.

-Chris

[anatech]

Hi Barry,
Hey, no problem. From the type of work you do, I understand where you're coming from.

I see that you offer new products and modifications as well. Therefore you do have a good idea how the basic amp should work. This Power model amplifier, if you ever are interested to examine it, is fundamentally different in design from what you would normally see. It borrows some general design elements from the Nakamichi 620 and Marantz 170DC / 300DC. Similar, but not nearly close enough to call a copy. Look at the current amplifier section and take another look at the Power PCB. I think they are using smt dual transistors in there. Complimentary -HINT!-

Best, Chris

[antonof]

Hi, all!
I am new here so maybe not even in right section but I need some help here.
I recently bought old Cyrus 3 integrated amp and Cyrus Power. I would like to connect them in a Bi-amp setup but I am not sure how to do it and don't want to make a fatal misteku. So would please you if you can help me with it.
If you have any scheme even better.
Thanks!
Andrej