Well... I have the schematics kindly offered by another member but have not the complete service manual.
If you have it complete with Pcb drawings I will appreciate.
What I really need is the Crown Itech service manual. It seems that is impossible to found in this corner of the planet.
Your K2 is already repaired?
It is amazing how they do the amplifier without short circuit protection!
If you have it complete with Pcb drawings I will appreciate.
What I really need is the Crown Itech service manual. It seems that is impossible to found in this corner of the planet.
Your K2 is already repaired?
It is amazing how they do the amplifier without short circuit protection!
V
Vek
TOINO said:It is amazing how they do the amplifier without short circuit protection!
Really, do they? I can't imagine a professional amplifier (namely from crown) out in the wild without at least this kind of protection! But since I have never seen the circuit diagram I'm not in the position to call this into question ... It just sounds weird to me.
But now to something completely different:
These amps seem to have an auto-standby function, switching the amp off when there is no (better: insufficient) signal and back on when there is sufficient signal. At low listening levels this feature becomes really annoying, the amp switches off at still audible levels.
Does anybody of you know the trick to disable this, perhaps a jumper somewhere inside the amp?
The manual don't even mention this feature! (AFAIR)
Any hints from the service manual owners?
Cheers, Ralf
Hi Vek
It is not completely unprotected but it is near the same. They have a kind of “current Limiter” after the power stage.
The output power stage is not directly and real-time protected as it should be.
About the “self stand-by” feature I have not adequate amount of information to help you. Sorry…
It is not completely unprotected but it is near the same. They have a kind of “current Limiter” after the power stage.
The output power stage is not directly and real-time protected as it should be.
About the “self stand-by” feature I have not adequate amount of information to help you. Sorry…
I can send the service manual... Anyone who wants it, let me know your email.
Also I believe Crown will soon be posting the manuals on their site, since they discontinued the K series this past Summer.
And yes, you can disable the standby, but i don't recommend that. You can change R15 on the input module to 845K and you will get 56 seconds of delay instead of 6 seconds.
The next issue I'm up against is getting some replacement FETs. The Fairchild FQP16N25C is what I ordered, hopefully it will work. Crown matches the transistors for gain and other specs, but they want over $6.00 each for them. That would be over $50 for one output module worth of transistors that I risk blowing up again if something else is wrong.
Also I believe Crown will soon be posting the manuals on their site, since they discontinued the K series this past Summer.
And yes, you can disable the standby, but i don't recommend that. You can change R15 on the input module to 845K and you will get 56 seconds of delay instead of 6 seconds.
The next issue I'm up against is getting some replacement FETs. The Fairchild FQP16N25C is what I ordered, hopefully it will work. Crown matches the transistors for gain and other specs, but they want over $6.00 each for them. That would be over $50 for one output module worth of transistors that I risk blowing up again if something else is wrong.
V
Vek
Maxxarcade said:
I'm very interested, perhaps I can find some clues to solve my little issue there!
Please mail to: ral.sim@web.de
Thanks very much!
V
Vek
V
Vek
Maxxarcade said:
I fear my limit is 4MB per email at this account, feel free to use ralf.simon@retroton.com instead. This one should work! I didn't expect such a big file ...
Thanks
lumanauw said:
AFAIK Crown I-Tech Series http://www.crownaudio.com/amp_htm/itech.htm
Not a direkt replacement, but similar technology, this time combined with switching power supply, DSP...
V
Vek
Vek said:
Why you don't recommend this modification?Please elaborate a little bit more ...
The amp will draw over 150 watts at idle and decrease the life of components due to heat. Of course if you're using these at home, where continuous use will not happen, this may be ok.
Also, for anyone replacing the output FETs with Fairchild FQP16N25C parts, there are some components that need changing on the main board if you have an older amp. Let me know if you need it and I will send.
Vek, I'm sending the manuals now, and I included the instructions for using newer FETs as well.
V
Vek
mrx23 said:
You've got mail
Maxxarcade said:
Thanx for sending a second time, everything arrived in good condition
Sorry, I have no ad hoc access to webspace ...
But as I sent the stuff over to mrx23 hopefully he can do it! (took me two trials, then i splitted the file like in good old floppydisc days, email is not made for something big like this)
Fet Changes...
Maxx,
Would you mind posting the changes necessary when replacing fets here so everyone has access to them?
I also have one of these amps and knew about the resistor change to increase the auto standby time. However, I don't know about other required changes if I ever need to fix mine.
I would also second the request that someone post the service manuals somewhere so we have a resource for repair if we ever need it.
Thanks,
Maxx,
Would you mind posting the changes necessary when replacing fets here so everyone has access to them?
I also have one of these amps and knew about the resistor change to increase the auto standby time. However, I don't know about other required changes if I ever need to fix mine.
I would also second the request that someone post the service manuals somewhere so we have a resource for repair if we ever need it.
Thanks,
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