..... 20mA output stage bias ??
I just dont understand why some think its hard to match smd transistors, its exactly the same as matching through hole ones except the smd is tiny, so what exactly is the problem ???
Anyway a reason that cyrus doesnt like to publish schematics is because they are very close, basically copies of other high end amps. For instance this cyrus 3 is very very closely related to a myrayd amp, I have to wonder about the others..........
Barry how is the sound compaired to your DIY builds ?
Anyway a reason that cyrus doesnt like to publish schematics is because they are very close, basically copies of other high end amps. For instance this cyrus 3 is very very closely related to a myrayd amp, I have to wonder about the others..........
Barry how is the sound compaired to your DIY builds ?
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Because the enclosure with integrated heatsink function is "aluminium die cast" the mounting surface for the power devices isn't perfect smooth. This means, that through the insulating washers occurs unwanted resistances/shorts between the collectors of the power devices and the mounting surfaces.
Perhaps this is in your case also the reason for blowed fuses.
In general I would first try to operate without the power devices; if the resistors for the driver stage isn't connect to the output line (i. e. only one resistor from emitter to emitter) remove this resistor and replace it through two resistors (each 330R) in serial connection. The cross point of this two resistors you must connect with the output line. In this mode you will get only very low levels, but you can clearly say, whether an operation possible in the right way or whether one or more errors present. Make your DC measuring without signal level (i. e. volume control: minimum).
I replaced the o/p transistors and drivers for a second time and turned on without using heatsinks. Fuses blew immediately, I suspect other transistors down the line. I need a transformer for my next project, so I will strip it of what I need and the case can go on ebay so not all is lost. Thank you for your help and advice.
Service manuals of all integrated amplifiers about
Cyrus | Amplifiers
still wanted, except the models "ONE" and "TWO".
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.
An additional question: Who knows, how many devices were made at whole of each of the models about
Cyrus | Amplifiers
Cyrus | Amplifiers
still wanted, except the models "ONE" and "TWO".
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.
An additional question: Who knows, how many devices were made at whole of each of the models about
Cyrus | Amplifiers
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Hi Barry,
Good lord!
So you can't properly repair a Cyrus product and so they aren't any good? There is a very low failure rate with them - until some bone head with an iron gets loose inside.
Honestly!
This is precisely why they don't release service information. As I said before, most TV type shops who do the bulk of repair business are not technically capable of even understanding bias current and what is reasonable. Most don't even touch that adjustment (just as well).
Look, you may call me a supporter, but I am contractually not permitted to release service information. It's that simple. In fact, I have helped those who know what they are doing at no charge. I'm greedy?
I'm not being hard headed about this at all. Most servicing dealers destroy these units while servicing them. Not very many technicians (sadly) actually spend the time to learn how each amplifier type really works, nor do they take the time to do a neat job on them.
Sell the Power before you trash it. I have two in here that were messed up by another "technician". What a mess! This one from a well known shop in our area (Toronto) who I will not name.
Sorry, but your comments and conclusions show me that you would never be fair to a brand you do not understand.
-Chris
Good lord!
So you can't properly repair a Cyrus product and so they aren't any good? There is a very low failure rate with them - until some bone head with an iron gets loose inside.
Honestly!
This is precisely why they don't release service information. As I said before, most TV type shops who do the bulk of repair business are not technically capable of even understanding bias current and what is reasonable. Most don't even touch that adjustment (just as well).
Look, you may call me a supporter, but I am contractually not permitted to release service information. It's that simple. In fact, I have helped those who know what they are doing at no charge. I'm greedy?
Possibly because it wasn't operating properly? I know, it's just your opinion, but I'd like to point out that it is entirely possible that the unit was not repaired as it should have been.
I'm not being hard headed about this at all. Most servicing dealers destroy these units while servicing them. Not very many technicians (sadly) actually spend the time to learn how each amplifier type really works, nor do they take the time to do a neat job on them.
Sell the Power before you trash it. I have two in here that were messed up by another "technician". What a mess! This one from a well known shop in our area (Toronto) who I will not name.
Sorry, but your comments and conclusions show me that you would never be fair to a brand you do not understand.
-Chris
Hi homemodder,
I've posted one possible jig for this, there are others made by various members.
This is something I can say from personal experience, the design occurred in-house and is not a copy from anything else. Having said that, I think it is impossible to design anything these days that will not be similar in some way to a design that came before.
Hi analog_sa,
I am currently assisting two others in troubleshooting their own units, and since I am in Canada, "my market" does not include Cornwall and other areas such as the USA. For all the help I give free of charge, that comment offends me to some degree.
-Chris
Well, you've hit the nail squarely on the head. That's if the person in question knows how to properly match TO-92 parts to begin with. Smt parts are a pain to match, trust me. Keeping the terminals in contact with the test pads takes some thought. If you sneeze half way through, you'll want to lay down and cry - trust me on that as well. Using the various hFE testers is only a pre-selection. Once you have them sorted into gain ranges (even with the same beta readings), you're ready to use a jig and put them into actual matched pairs, or quads if you are so inclined. This is the same whether you're talking about J-Fets or BJTs, except the J-Fet will be sorted for Idss groups first.
I've posted one possible jig for this, there are others made by various members.
Get real! Look at the Cyrus one and two. They are not copies of anything to the best of my knowledge. If anything, some others may have copied Cyrus from way back when they were called Mission. As for the III, it's an extension of their earlier designs, the IIIi is completely new. The engineers were designing the Power when I was in the factory in 2004, and I was talking with them at that point. Some of the design is very close to something I was working on by myself at the time. Anyway, other people may obviously have come up with something similar, as I had. But the work they were doing was original, and the engineers I was talking with were actively developing the circuit from scratch. It was at that time that I pre-ordered a pair of Mono X amplifiers. Not even a prototype existed yet, but I knew what the design was going to be. Having been designing something very close, I also knew what it would sound like. Guess what? I was correct, they sound as I imagined they would. Close to my own prototypes, but very different in some areas.
This is something I can say from personal experience, the design occurred in-house and is not a copy from anything else. Having said that, I think it is impossible to design anything these days that will not be similar in some way to a design that came before.
Hi analog_sa,
You know that's not true in my case - or you should. You are aware I have shared as much as I can over the years. That comment taken seriously isn't a nice one, but I suspect you were maybe making a slight joke?
I am currently assisting two others in troubleshooting their own units, and since I am in Canada, "my market" does not include Cornwall and other areas such as the USA. For all the help I give free of charge, that comment offends me to some degree.
-Chris