I'm hoping someone can help me find a service manual or schematics for the Crown K2 amplifier.
I have two dead ones that I want to repair. One has an intermittant fault, and the other one is completely dead. They look reasonably modular so I think I should be able to trace the faults given a set of schematics to work from.
I'm willing to pay for copies if anyone has a set of schematics they could duplicate, or hopefully a service manual.
Thanks everyone,
Len.
I have two dead ones that I want to repair. One has an intermittant fault, and the other one is completely dead. They look reasonably modular so I think I should be able to trace the faults given a set of schematics to work from.
I'm willing to pay for copies if anyone has a set of schematics they could duplicate, or hopefully a service manual.
Thanks everyone,
Len.
Thanks for the offer Alan,
Talk about crazy timing... I just bought a set of crown service manuals off a trader on ebay!!
So thanks again, but I now have all the information I need to get these repaired.. I should have posted something here but I thought the thread had gone cold.
Now here's hoping for a few hours free time to get these repaired. One of these will be going into service as my next sub amp when TC Sounds release their new Neo driver.
- Len.
Talk about crazy timing... I just bought a set of crown service manuals off a trader on ebay!!
So thanks again, but I now have all the information I need to get these repaired.. I should have posted something here but I thought the thread had gone cold.
Now here's hoping for a few hours free time to get these repaired. One of these will be going into service as my next sub amp when TC Sounds release their new Neo driver.
- Len.
I appreciate if you are kind enough to send me a copy by email...Anyone?
I was able to get one of these that I'm working on to power up by unplugging one of the amplifier boards.
Since I have 3 of them, I'm hoping to combine parts to make at least one of them work. But I would much rather find the schematics and fix them all.
How would one of these compare to a Nady XA-900 in terms of sound quality?
I was able to get one of these that I'm working on to power up by unplugging one of the amplifier boards.
Since I have 3 of them, I'm hoping to combine parts to make at least one of them work. But I would much rather find the schematics and fix them all.
How would one of these compare to a Nady XA-900 in terms of sound quality?
me too Allan please send me a copy. here is my email ad jade_808a@yahoo.com, thank you very much. Happy New Year everyone 
Got one working so far... There are many small caps that go bad on the large bottom board which cause it not to power up. Mainly the 100uf 25v caps at C6, C9, C23, C24, the 33uf 160v cap at C11, and the 470uf 16v cap at C15.
And almost all of the 2.2uf bipolar caps were bad as well.
I decided to completely recap these amps (with exception of the large filter caps) with high grade caps from Panasonic and United Chemi-con.
And watch the filter caps on the output boards. They hold a charge forever and have over 100 volts across them. I discharged them through a resistor several times and still got a good shock off them after they sat for a few minutes. And it's a pain to remove the output boards, they get stuck to the thermal pad pretty good
Also had to swap out one of the output boards, I'll take a look at that shortly.
I could really use the schematics though. Kinda hard doing this without them.
And almost all of the 2.2uf bipolar caps were bad as well.
I decided to completely recap these amps (with exception of the large filter caps) with high grade caps from Panasonic and United Chemi-con.
And watch the filter caps on the output boards. They hold a charge forever and have over 100 volts across them. I discharged them through a resistor several times and still got a good shock off them after they sat for a few minutes. And it's a pain to remove the output boards, they get stuck to the thermal pad pretty good
Also had to swap out one of the output boards, I'll take a look at that shortly.
I could really use the schematics though. Kinda hard doing this without them.
I'm still having trouble figuring out how to fix the output boards, I have little understanding of how they work. I have one good amp to use as a test jig, but these things are fragile and I hate to kill the one good amp I have. Anyone know what the HP2601 and HP2611 IC's are? I found a datasheet for the MC34151P, but not the other chips.
Maxxarcade said:
lumanauw said:
Hi Maxxarcade
The HCPL2601//2611 ARE optocouplers... http://www.alldatasheet.com/datasheet-pdf/pdf/64581/HP/HCPL2601.html
I don’t know the physical aspect of the K2 output board, but reading the schematics, the circuit is very simple.
They are some parts of the circuit you must check.
First thing is confirm if power mosfets and diodes are ok.
If you are not sure, simply take it of the circuit and confirm all the remaining parts as follow:
A- The left part (on schematics) of output board has their own local floating power supply. You must first check if it works.
Is the transformer T01, diodes D01 and D02, voltage regulator U01 and associated passive components. This power supply provides 5V for the HCPL2611 optocoupler (U02) and you could check it with a voltmeter on pins 5 and 8 of U02; must read about 5Volt.
The right side (of schematics) is supplied from somewhere else but has also the regulator for the U52 optocoupler and you must check it also.
B- You must check also if the MC34151 driver is properly supplied with about 12V on pins 6 and 3.
Please follow the steps above and come back to tell us the results…
I presume you have the schematics …?
Thanks Len and Toino!
Making good progress here... Gotta order the FETs and a couple other things and I can start the repairs on the other two amps.
Digikey is going to love me this week, I've already placed 3 separate orders for parts, because I keep finding more things I need.
At least these amps have some resale value if I need to get back some of my investment. We got 3 of them (nonworking) in a package deal with some old EAW FR-153 speakers for $500.
From what I hear, the original MSRP on these amps was ~$2800, and Musician's Friend still sells them for $1,249 last I checked.
Also FYI, the caps I used to replace the old ones are low impedance, 105c high temp caps, I used Panasonic FC and FM series, and United Chemicon KY series. I also upgraded the voltages a step. Only drawback is the 100uf 35v caps I used were a slightly larger diameter, so they were a tight fit in a couple places. Kind of detracted from the "perfect" look I was going for on the board repairs. I'm a bit of a perfectionist when it comes to replacing caps
While I'm at it, maybe I'll use one of these amps to test the Cerwin Vega 152W 15" woofer that I picked out of the trash a while back, I'm replacing the foam this weekend, and hoping to use it and build a subwoofer to match my other CV speakers in my home theater
Making good progress here... Gotta order the FETs and a couple other things and I can start the repairs on the other two amps.
Digikey is going to love me this week, I've already placed 3 separate orders for parts, because I keep finding more things I need.
At least these amps have some resale value if I need to get back some of my investment. We got 3 of them (nonworking) in a package deal with some old EAW FR-153 speakers for $500.
From what I hear, the original MSRP on these amps was ~$2800, and Musician's Friend still sells them for $1,249 last I checked.
Also FYI, the caps I used to replace the old ones are low impedance, 105c high temp caps, I used Panasonic FC and FM series, and United Chemicon KY series. I also upgraded the voltages a step. Only drawback is the 100uf 35v caps I used were a slightly larger diameter, so they were a tight fit in a couple places. Kind of detracted from the "perfect" look I was going for on the board repairs. I'm a bit of a perfectionist when it comes to replacing caps
While I'm at it, maybe I'll use one of these amps to test the Cerwin Vega 152W 15" woofer that I picked out of the trash a while back, I'm replacing the foam this weekend, and hoping to use it and build a subwoofer to match my other CV speakers in my home theater
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