Dirtyk777, I ment the amp will do just fine with solvent-based paint.
I know powder coating is a very strong paint surface application.
My post was more like a joke 😀
Referring to heat as class D amps don't get hot at all - powder coatings being better heat resistant and all...😉
I know powder coating is a very strong paint surface application.
My post was more like a joke 😀
Referring to heat as class D amps don't get hot at all - powder coatings being better heat resistant and all...😉
DirtyK777, Imix500 & V-Bro ...
I was merely suggesting that there is a need short run powder coating. Here in Northern California there are only high production powder coating operations, so getting two or three chassis parts done up pretty can be a real snipe hunt ...
Maybe I should just DIY do it myself and start another small business ... my taxes are getting high again and that's the best way to deal with that ... 😀
I was merely suggesting that there is a need short run powder coating. Here in Northern California there are only high production powder coating operations, so getting two or three chassis parts done up pretty can be a real snipe hunt ...
Maybe I should just DIY do it myself and start another small business ... my taxes are getting high again and that's the best way to deal with that ... 😀
And what i was merely saying, if you want quality work, you can't do small jobs and operate with a profit. Cost would run you out of business quick.
That short order gun imix, won't cut it in my opinion...My Sata Jet paint guns cost more than that kit.
That short order gun imix, won't cut it in my opinion...My Sata Jet paint guns cost more than that kit.
Good try though. But i think just normal mettalic automotive painting style would be an easier start for a diy'er. Just email me for instructions or im sure their are forums everywhere for it.
" ... if you want quality work, you can't do small jobs and operate with a profit. ..."
" ... i think just normal mettalic automotive painting style would be an easier start for a diy'er. Just email me for instructions or im sure their are forums everywhere for it. ..."
Dirtyk777:
Looks like this would qualify as another thread ... a DIY thread on painting or coating technics. (I'll be happy to email, but I would rather respond to another thread. My email address is relatively public knowledge if you prefer.)
FYI: http://www.diyaudio.com/forums/showthread.php?s=&threadid=87587&highlight= ... which is a quite recent thread on the subject. (I have not read it all, but looks promising.)
" ... i think just normal mettalic automotive painting style would be an easier start for a diy'er. Just email me for instructions or im sure their are forums everywhere for it. ..."
Dirtyk777:
Looks like this would qualify as another thread ... a DIY thread on painting or coating technics. (I'll be happy to email, but I would rather respond to another thread. My email address is relatively public knowledge if you prefer.)
FYI: http://www.diyaudio.com/forums/showthread.php?s=&threadid=87587&highlight= ... which is a quite recent thread on the subject. (I have not read it all, but looks promising.)
New update on the subject at hand(my amp).
While deconstructing the amp for the readily new Class D amplifiers, I come across four missing cap's on each channel. Is it just me, or could this be our problem. I feel like a dumb....im better than cussing so i need to stop.
While deconstructing the amp for the readily new Class D amplifiers, I come across four missing cap's on each channel. Is it just me, or could this be our problem. I feel like a dumb....im better than cussing so i need to stop.
Is the board silk-screened? This way you could look up the caps in a schematic and reason whether you need them. (maybe it's a board with options belonging to other Crown amps...)
Sorry sorry sorry sorry sorry...Not caps...Four are NPN power transisters missing, and Four are PNP transistors.
Yes i did look at the schematic...and apparently the way its on teh board, it is an optional extra transistor...what would these do to the amp? Because the board is set up just like where the other transistors are in place.
Maybe they're just extra feedback stages or a class A option, what are the Txxx numbers in the schematic? Were they clearly soldered-out or are the holes in the board clean copper (never soldered)?
They were definitely gunked up with some type of electrical tape and glue...and ill go ahead and give props for Bear listing this as the thing i should check out because this actually might be where my problem lies....i don't have a meter to check these transistors...how can this be done?
CPN numbers for NPN -
c 4571-1
for PNP
C 6492-0
which apparently is stock for these bad boys....but this amp has definitely been worked on before from what i can tell.
CPN numbers for NPN -
c 4571-1
for PNP
C 6492-0
which apparently is stock for these bad boys....but this amp has definitely been worked on before from what i can tell.
Seems to me -for the same reason as Bear stated they should be matched transistors- like a difficult repair..
And probably too expensive if you need to replace all transistors in order to have them "matched"...🙁
And probably too expensive if you need to replace all transistors in order to have them "matched"...🙁
yea it looks hard just to get those transistors out of the board without burning something near by...
Use soldering wick, solder the paws loose with large intervals in order to let them cool inbetween. And very important to mark where they came from!!!!
You can test them with an ohms- meter (no short should be measured) or better with a signal and scope....
But I'm sure Bear can help you out a lot better on this repair, his knowledge probably exceeds mine by far....
You can test them with an ohms- meter (no short should be measured) or better with a signal and scope....
But I'm sure Bear can help you out a lot better on this repair, his knowledge probably exceeds mine by far....
bear said:Dirtyk777,
And see if you find a non-functional transistor.
You can start with a simple ohms test too... if you find a dead short then you know something is NG. But pulling the transistors works best. Anyhow these are pretty good high power complementary matched sets (keep them together - or mark them with a marker so you know which came with which!!) that can be used to build an amp - you need a new driver board, of course to do that.
A blown transistor will tell you something about the failure. IF you find one or more, then you need to look at the driver transistors (also on the heatsink) and if they are blown, I'd say the amp is ready to be junked for parts... it will cost more to repair at that point than buying one on ebay - or darn close in time & parts... ok?
_-_-bear
Or go for the class D aproach afterall...
Empty spots on the heatsink are because the same heatsink is used for a higher power version of the amp...
They should be symmetrical and the same from channel to channel.
Same number and position of transistors on each heatsink.
The numbers are house numbers.
They are actually Motorola devices.
Easy enough to find and replace.
Mark the transistors.
I use a paint marker, but you can get away with just a "magic marker" or nail polish, etc... use dots. The same number of dots per transistors on a heatsink. The transistors on a given heatsink should be all the same, doesn't matter where they go in the holes.
(unless one of them is used as a driver - I don't remember if they do that - other mfrs do... the schematic will show that)
To unsolder, you remove the screws (2) per transistor.
heat the pins (after the bottom panel is removed, of course), use a solder sucker or wick to remove the solder. Grab the transistor from the top side with a locking forceps or needle nose through the mounting holes, pull lightly, heat the pins (if all the solder isn't all gone already) if needed and remove the transistor.
There should be two large "can" capacitors mounted next to the fan on the top side - and two bridge rectifiers... 4 small plastic transistors on the heatsinks... the rest of the business end is underneath...
Check ur transistors... a scope will tell you quickly what the amp is doing, and if both channels are blown the same way.
Two things that often happen:
blow the outputs &/or driver transistors
or
blow the input devices
or both... etc...
If the thing works, it will work nicely enough.
If it has bad outputs or drivers, the amp will not work or not work properly.
_-_-bear
PS. keep in mind that it will "work" without matched devices, and it will actually work with just a pair of transistors (one per rail) in the output, although I wouldn't try to drive a lot of power like that...
OH - if it LIGHTS UP and shows the "health lights" as good, you may just have not put the signal in properly!?!!
They should be symmetrical and the same from channel to channel.
Same number and position of transistors on each heatsink.
The numbers are house numbers.
They are actually Motorola devices.
Easy enough to find and replace.
Mark the transistors.
I use a paint marker, but you can get away with just a "magic marker" or nail polish, etc... use dots. The same number of dots per transistors on a heatsink. The transistors on a given heatsink should be all the same, doesn't matter where they go in the holes.
(unless one of them is used as a driver - I don't remember if they do that - other mfrs do... the schematic will show that)
To unsolder, you remove the screws (2) per transistor.
heat the pins (after the bottom panel is removed, of course), use a solder sucker or wick to remove the solder. Grab the transistor from the top side with a locking forceps or needle nose through the mounting holes, pull lightly, heat the pins (if all the solder isn't all gone already) if needed and remove the transistor.
There should be two large "can" capacitors mounted next to the fan on the top side - and two bridge rectifiers... 4 small plastic transistors on the heatsinks... the rest of the business end is underneath...
Check ur transistors... a scope will tell you quickly what the amp is doing, and if both channels are blown the same way.
Two things that often happen:
blow the outputs &/or driver transistors
or
blow the input devices
or both... etc...
If the thing works, it will work nicely enough.
If it has bad outputs or drivers, the amp will not work or not work properly.
_-_-bear
PS. keep in mind that it will "work" without matched devices, and it will actually work with just a pair of transistors (one per rail) in the output, although I wouldn't try to drive a lot of power like that...
OH - if it LIGHTS UP and shows the "health lights" as good, you may just have not put the signal in properly!?!!
"and it will actually work with just a pair of transistors (one per rail) in the output, "
Of course he actually means four outputs per channel, two NPN and two PNP.
One heatsink per side is at + potential, the other at - potential. There are two NPNs on the + heatsink, the two PNPs are on the - heatsink.
There are several Crown amps in the series that use the same basic chassis/heatsink/board layout. For reference I will call them 1,2,3. The 1 uses one pair of outputs per half of the bridge (two per sink), the 2 uses two pair, the 3 uses three pair. The circuit boards are the same, they just stuff the extra parts on the bigger models, and use more transformer.
The 1 blows up driving less than 8 ohms. It's really quite simple. The outputs are only rated at 15A continuous and the Beta is only rated at 5 at 10A DC, and of course is lower at AC. With the amp driving a short duration peak at 4 ohms, it is trying to drive 160V peak-to-peak, or 20A. Of course it will never get that high, the Beta drops like a rock and the driver transistors blow up, and then the whole channel lets the smoke out.
The MacroTech 600 hangs together at 4 ohms because they doubled up on the outputs (like the 2).
If you want to drive bass, I suggest that you stuff up at least the same number of outputs (four pair per channel).
I will sell sets of four pair from the same date code batch for $20, or eight pair (two channels worth) for $32.
Of course he actually means four outputs per channel, two NPN and two PNP.
One heatsink per side is at + potential, the other at - potential. There are two NPNs on the + heatsink, the two PNPs are on the - heatsink.
There are several Crown amps in the series that use the same basic chassis/heatsink/board layout. For reference I will call them 1,2,3. The 1 uses one pair of outputs per half of the bridge (two per sink), the 2 uses two pair, the 3 uses three pair. The circuit boards are the same, they just stuff the extra parts on the bigger models, and use more transformer.
The 1 blows up driving less than 8 ohms. It's really quite simple. The outputs are only rated at 15A continuous and the Beta is only rated at 5 at 10A DC, and of course is lower at AC. With the amp driving a short duration peak at 4 ohms, it is trying to drive 160V peak-to-peak, or 20A. Of course it will never get that high, the Beta drops like a rock and the driver transistors blow up, and then the whole channel lets the smoke out.
The MacroTech 600 hangs together at 4 ohms because they doubled up on the outputs (like the 2).
If you want to drive bass, I suggest that you stuff up at least the same number of outputs (four pair per channel).
I will sell sets of four pair from the same date code batch for $20, or eight pair (two channels worth) for $32.
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