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View Full Version : Silent fan on Crown MA3600VZ



baldrick
03-21-2009, 08:12 AM
I've just bought a Crown Macro Tech 3600VZ, the sound is great but the fan makes way too much noise so that it can not be used in a hifi setup.

Is there a way too shutoff the fan (and keep an eye on the temp) or replace it with a more quiet fan? I was hopeing it was a normal "PC fan" that I could just unplug, but this fan is nothing like the ordinary PC fan, and I guess that explains the noise it makes :)

jeenie67
03-21-2009, 12:10 PM
...I replaced all the fans in my Crowns with whisper fans bought online for about $4 a crack. Search the sites. All you need to know is the metric outside dimensions, the bolt hole spread, and depth. The re-wiring a chimpanzee could do! I found exact replacements that are 100% silent! Jeenie.

baldrick
03-21-2009, 12:40 PM
Did you have the same amp? It only seams to have one big fan (apox 4")and it's not the same type as I've seen before in other amps. Before I took a look I was hopeing I could replace it with a silent PC fan, but this fan seems to be somthing totally different tha the usual 12v fan.

the best would ofcourse be to replace it with a silent fan, the other option is to unplug it if I find a way :)

Here's a picture of the amp (and fan) inside:

http://i64.servimg.com/u/f64/11/64/98/33/dsc01410.jpg

baldrick
03-21-2009, 01:56 PM
I've just found out how this thing is wired, there are 3 smaller wires that goes to the printcard, they look very much the same as normal PC fan wires/plug. But when I disconnect that, nothing changes. I then realsed that there are one wire to each powersupply, I unpluged thoes and everything was quiet... VERY quiet, the amp didn't power up at all :( So it seems that to get the amp turned on I need to have the fan installed. Maybe I could shortcut the wire but this I don't dear until someone tells me it's good.

Any advice how I can turn of/bypass the fan :(

jeenie67
03-21-2009, 02:31 PM
Hi again. Crown buys most of it's fans from outside sources. Try and disconnect it from it's mounting. On the fan there should be all the data you would need to replace it with a quieter unit. The ones I pulled were made in...where else...China! Xinruilian brushless DC fans...12 Volts DC.. 0.17 amps. 4 hole mounting....kinda' tough to get at! Jeenie.

SMKSoundPro
03-21-2009, 03:16 PM
NO!!!

a Crown MacroTech 3600 NEEDS THE FAN!!! to create the low voltage to power the "preamp" circuits!!!

YOU cannot unwire the fan, unless you create a low voltage power supply in its place.

If you look at the schematic for a Macro Tech 2400, you will see the "Motor Transformer" which creates voltage for the low voltage circuitry.

This is why it is SO important to keep the fan filters clean. When this fan fails, the "preamp" stuffs does not turn on, and nothing else works.

These amps were designed for Pro sound install and touring rigs. Not for home home hi-fi.

Scotty.

jeenie67
03-21-2009, 03:29 PM
A fan is a fan....a motor is a motor. The unit does not know the difference. It is different from what I replaced, but....just replace the fan motor with an identical voltage and amperage unit. There are only two wires, hot and neutral. The rest stays original. The noise is all in the manufacturers choice of bearings and fan blade angle. CFM should remain close to the original, but a little less is OK. For home use the unit can handle it. For Pro-Sound I would not recommend it.

baldrick
03-21-2009, 03:31 PM
Hi again. Crown buys most of it's fans from outside sources. Try and disconnect it from it's mounting. On the fan there should be all the data you would need to replace it with a quieter unit. The ones I pulled were made in...where else...China! Xinruilian brushless DC fans...12 Volts DC.. 0.17 amps. 4 hole mounting....kinda' tough to get at! Jeenie.

Unfortunately you are wrong, you are talking about the normal kind of fans, not the kind that is on my amp


NO!!!

a Crown MacroTech 3600 NEEDS THE FAN!!! to create the low voltage to power the "preamp" circuits!!!

YOU cannot unwire the fan, unless you create a low voltage power supply in its place.

What are you thinking?

Scotty.

Sound like you know what you are talking about. I've tried unwire the fan and it doesn't hurt because the amp will not power up! But I agree that I probably need a low voltage power supply in instead of the fan, do you have any idea how I can fix this? Or is it just a stuipd idea to try and just sell the amp instead. Like it is now I have no use for it since it's WAY to noisy :(

SMKSoundPro
03-21-2009, 03:49 PM
Sound like you know what you are talking about. I've tried unwire the fan and it doesn't hurt because the amp will not power up! But I agree that I probably need a low voltage power supply in instead of the fan, do you have any idea how I can fix this? Or is it just a stuipd idea to try and just sell the amp instead. Like it is now I have no use for it since it's WAY to noisy :(
Dear Baldrick,

I know of no way to take the fan out of circuit, unless you create a +15 & -15vac power supply to take the motor transformer's place.

I have many Macro tech amp's here in my nightclub, and LOVE THEM!!! They are the deal for me.

I know of many other amps that are home hi-fi oriented or even Pro amps that are good for your application. This Crown 3600 is NOT one of them!

Scotty.

baldrick
03-21-2009, 04:15 PM
I'm beging to realise that it was not a good idea to buy this amp, I thought it would be the perfect match for a pair of 2245, but I did never thought about this problem. I have a Crown Studio Reference powering my 250s and I can hardly hear the fan on that, so I thought the MA3600 would be something similiar, buy boy I was wrong :)

robertbartsch
03-21-2009, 04:34 PM
I have a few Crown XLS 802s with VERY noisy fans. I'm experimenting with a few options. One option is cutting the fan wire and using a pancake fan instead. Another is to use no fans.

I also think there are variations in the thermal curcuits in these amps as one does not turn off without a fan. Another, however with no fans turns off when driven to moderate levels.


Anyway, I will sort this issue out eventually. I will be intersted in knowing how folks resolve the issue inthis thread.

jeenie67
03-21-2009, 04:57 PM
Hola....somewhere in all these posts someone substituted a resistor in the fan circuit to slow it down...this would be for that style of cooling fan....for the Macro....good luck! Looking at it's picture it wouldn't be impossible, but hard to substitute just the fans motor with something else...leaving the existing circuitry the same. Anything CAN be done!

subwoof
03-22-2009, 02:11 PM
do not change anything on the 3600's fan circuit.

That model has the highest "heat" density of any of their pro amps and needs a substantial airflow EVEN at idle to maintain it's cooling. By contrast the macro reference has a chassis with twice the internal space, a VERY VERY good low noise ball bearing fan but uses the SAME main board and output section...:)

And yes that is special type called a "fanformer" where the low voltage AC is created for the +/- 15 volt supplies. you cannot lower it's voltage with a resistor.

If it bothers you that much remote the amp or buy a different model. Just how much power are you looking for? How many channels?

I fix and own a lot of crowns and when one of those cooks it's a costly repair.

sub

baldrick
03-22-2009, 02:19 PM
I've just found a way so that I can use my new amp, I drilled a hole threw to the wall to the room next door and placed the amp there :) It's not ideal but it works.

For what you are saying I just got an idea, could I use the fan of the MacroReference if I can get one?

Since you are mentioning the MacroReference, do you know the difference/simmilarity between it and the StudioReference?

subwoof
03-22-2009, 02:46 PM
do not change the fan, period.

There are many differences and I cannot type that much. look at crowns website and you can download all the manuals / schematics and see.

http://www.crownaudio.com/gen_htm/legacy/legacamp.htm

ALL the older MA/MI/PB/PT/MR/SR/CSL/CT type grounded bridge amplifiers use the same design basics but differ in size, power, blinky lights, interfaces/jacks and of course, cost.

Like you would take a MG on a road rally and a van with kids to a soccer ( sorry - football ) game the reverse is not recommended BUT can be accomplished.

It's just not what the designers had in mind for the target group that uses / buys them.

SKOL :cheers:

baldrick
03-22-2009, 03:00 PM
:hmm: :coolness:

If it's doable maybe I'll give it a try :D

I know it's ideal solution, but than again, I will not be running it on full power for hours like it was meant, I will only be useing it for my subwoofers at moderate levels. Maybe you will ask why I bought it then... the reason is quite simple, I was looking for a K2 but there are not many for sale in Norway, so when I found the 3600 I went for that instead :)

I've checked and it seems like MacroReference and CT1600 share the same fan, so maybe that is what I should try IF I will try replaceing it :bouncy: On the other hand, maybe I will just keep it in the next door room ;)

subwoof
03-22-2009, 03:16 PM
it also will NOT FIT - they are different size frames.

No means no. I know what I am talking about here...:)

here are pics of *just* a few of the crowns that are here - the 2K and 10K monoblocks along with all of the "D" series are not yet inventoried.

baldrick
03-22-2009, 03:35 PM
it also will NOT FIT - they are different size frames.

No means no. I know what I am talking about here...:)


OK then :applaud: I thougt you meant you wouldn't advice it but it was doable :) Looks like you have quite some experince with Crown so I guess I'll just have to trust you on this one even if I don't like it ;)

subwoof
03-22-2009, 04:13 PM
*if* it was one of the less jampacked PB or PT amps I would say to get a small 40VCT 250ma transformer and use it to run the LV reg section and put a 600 ohm 10 watt resistor in series with the fanformer and that would work.

BUT BUT the 2400 and larger macrotech amps are just to busy inside and the 3600 has problems with heat even with NO signal / load so you are SOL.

Crown sold a series called geodyne in europe - one is a 750 watt/ch at 4 ohm that you CAN easily do this trick. It's a barebones MT2400 with one power transformer instead of 2

Or do a search for a techron or tecron 7560 / 7570 / etc. it is an industrial monoblock amp that is about 2K into a 2 ohm. It's fans are 2 speed and it's a great sub amp. Check with liquidators, machinery auction places or medical equipment recyclers.

sub

timc
03-23-2009, 03:12 AM
Thats a large amount of Crown power :applaud:

subwoof
03-23-2009, 06:14 AM
This is.

Each of the smaller ones are 10K, the larger ( dissasembled for now ) are 15K. A pair of the larger ones have enough power to blow the fusible link on the power companies transformer down the street.

but they would get mad.

They are also great spot welders for the precious metals industry and my favorite, worm shocking.

Put 4 ground rods in the side yard, connect to the amp and give it a 5 to 3000hz sweep at full power right after a rainstorm. Everything underground is in for a ride esp if you put a little salt on top of the mole runs.

Mole Fricasse

:cheers:

louped garouv
03-23-2009, 08:27 AM
SUBterranean signal experiments?
:D


Put 4 ground rods in the side yard, connect to the amp and give it a 5 to 3000hz sweep at full power

hjames
03-23-2009, 08:45 AM
Be very careful - thats how you call the Sand Worms of Arrakis (http://en.wikipedia.org/wiki/Sandworm_%28Dune%29)-
you are certainly no Muad'Dib (http://en.wikipedia.org/wiki/Muad%27Dib), my friend ...



Put 4 ground rods in the side yard, connect to the amp and give it a 5 to 3000hz sweep at full power right after a rainstorm. Everything underground is in for a ride esp if you put a little salt on top of the mole runs.

Mole Fricasse

:cheers:

subwoof
03-23-2009, 08:55 AM
I am more worried about the iron 6" water main that is right in the middle. it's possible to induce a voltage or current powerful enough to send signal to the neighbors houses.

So If I can make their water heaters into receivers, what should I say?

"meter man"
"here kitty kitty"
"knock three times"
"I..buried..paul"
"take me to your leader"
"we all live in a yellow submarine"
( need to send at 6 hz carrier though )

it could get real fun and nobody would be the wiser.

bad thoughts bad thoughts.

SMKSoundPro
03-23-2009, 01:15 PM
Wasn't this one of Tesla's patents? Ground current tranformation.

robertbartsch
03-24-2009, 12:27 PM
SMK:
I heard there are a few volcanos going off in Alaska.

...stay safe!

SMKSoundPro
03-24-2009, 02:09 PM
SMK:
I heard there are a few volcanos going off in Alaska.

...stay safe!
Thanks Robert! We're safe. There are volcanos always going off in Alaska. We are the most active earthquake zone on the planet. But no one notices because no one live out there on the "ring of fire."

A little ash from our volcano across Cook Inlet from downtown Anchorage. No big deal.

boputnam
03-24-2009, 10:58 PM
NO!!!

a Crown MacroTech 3600 NEEDS THE FAN!!! to create the low voltage to power the "preamp" circuits!!!Scotty, this is a really great post. Informed and informative.

Raising the bar... :)

hjames
03-25-2009, 04:58 AM
Yep - I just wonder how this will play with our members who seem intent on redesigning Crown amps to work outside their original design parameters.

Subwoof excepted, of course.
He's an EE and specially skilled at such stuff!
(He's good, I've seen his Ungar workin'!)



Scotty, this is a really great post. Informed and informative.

Raising the bar... :)

subwoof
03-25-2009, 09:42 AM
Just wait until summer...and you thought an amplifier with 8
outputs had thump. wait until there's 88...

And the original parameters were 0 to 100Khz down to .25 ohm
running on 3 phase so I am playing *inside* those parameters.

I plan on a fully adjustable DSP inside the chassis with a single phase supply.

And only 3K or so into 8 ohms.

And yes, quiet fans. very quiet.

sub

ps: note the speaker lugs. Banana that...:)

jeenie67
03-25-2009, 10:05 AM
...Jeez, do those worms glow? After you Zap em'? This could be a new industry! :hmm:

1audiohack
03-25-2009, 10:33 AM
Damn you subwoof!!!

I can't help myself, I must have one! 220V single phase please. I will supply my own welding cable.

I don't have a problem, I can quit any time I want... Yeah right.

SMKSoundPro
03-25-2009, 11:41 AM
Buzz box lincoln welder with crown faceplate!

I really want to fly to your shop and play. You have some really fun stuff!!!

subwoof
03-25-2009, 02:20 PM
I am aiming for the several small species of furry creatures ( that gathered together in a cave and are grooving with a pict ) that tunnel and destroy the grass.

Well the worms come up all right but sometimes don't live too long.

When I was a kid my father had an old hand crank generator and at 4AM on the golf course it was not fun. If you didn't get enough worms, *you* didn't live long either.

And that's why I could care less about fishing. My great-great grandfather did it with dynamite in the mohawk river in the 30's.

My father would be downstream with a net to catch one of 3 species:

Large mouth Bass
Small mouth Bass

And for the lucky few near the boom, No mouth Bass.

chummy..:)

jeenie67
03-25-2009, 04:58 PM
.... An' ere' We GOoooo......!!!
Nuttin' like fishin' wit gwo wurms!
An' lisnen' tu good moosik!!!!

Hail Thee' Pos Monuos on High! .....
Nuttin' like Massive Crowns and the Throne!
Kneel .. before me Plebe ! and answer to me .. NOW!
And put your ear to the dirt and tell me......
...What's your favorite color? ..What's your mother's maiden nickname? What's the psycho-socio-pleametomic background of ego-consciousness, in an autonomic and independently controlled subconscience ego complex , exhibited in the behaviors within partial personalities in unity of conscience, with an extent to the" Father Complex" ??? What Db is exhibited?
Answer swiftly commoner !!!

:blink:
:screwy:

:blink:

subwoof
03-25-2009, 06:44 PM
:blink:

JBL 4645
03-25-2009, 11:03 PM
Wouldn’t they be best suited in another room isolated from the listening room/home cinema what ever?

jeenie67
03-26-2009, 01:08 AM
.....ARF! .. HE SED! :blink:

Mike Caldwell
03-28-2009, 09:33 AM
Let me jump in here kind of late to say again....do not alter the fan in the MA3600 amp. The MA series indeed has a power transformer winding as part of the fan motor. I use MA3600's in my system and have an extra small fan on each rack helping draw the air out of the rack.

I was at the Crown service department a few years ago and they have big something model Tecron amps as a power supply on the benches. I guess it's fed with a 60hz sine wave and adjusted for the voltage output they need.

Mike Caldwell

gwar
03-28-2009, 02:06 PM
sorry for the title, I had to, lol
but seriously, unplug the fan!?! you bump your head or something, I own two crown cL-1 amps with the three stage fans which are used for my outdoor system. I have them in the pumphouse and yes, they can be a bit loud, but then, the music is outside, and secondly, the music is usually loud enough that you wouldnt hear the fans, yes TWO OF THEM anyways. lol.
And on another note, might your warranty be in jeapordy after opening the case? Not that Im suggesting you dont know what your doin in there but thats usually a standard warranty clause.
Oh yeah, hello to all, Im new here! And Im starting to ramble, so Ill end this now,:blah:

jeenie67
03-28-2009, 04:44 PM
Boy! Thanks for that bit of info...about the integrated fan motor. Nothings simple these days....everything is compacted, does three jobs using the same sub-structure....made in Asia-pa Kua toy Nou Tei, Instanistan... Stanly's Stan! ....who knows what they're (the production people and assemblers) there for, and ....my opinion, ....everything's gone to hell for the sake of $$. I've owned so many Crown amps (DC300's, IC 150's DC 150/90's, AC 9500's, DNF 75's, LST 10,000's; float me to a new battlefront-gig-home stereo stress relief 42's posture and whatever said Crown! ...I bought it without question. Like my tube amps...I want things simple, well laid out, and like a fine specimen of auto racing machinery....serviceable-modificational' on the fly, and ready available replacement or upgrade parts available now! I highly regard Crown even though they have been Corporated...and stand by without question their products but!!!

I have to add this....I don't need a warranty with a "Crown" Amp....It does it's job....always....almost forever! I will never buy the newer plug it in online or to my gigabox...looks like a space station inside..I don't need all those watts or gigidy do-dads! use efficient speakers and let a few watts cruise!

Mike Caldwell
03-28-2009, 07:18 PM
The Macro's were / are all made in good ole Indiana in the USA. The XLS series amps are imports. When they were introduced the MA 3600's were the big boys on the block for a two rack space amp size.


Mike Caldwell

robertbartsch
04-14-2009, 01:31 AM
This has been my solution to Crown fan noise which has worked well for several weeks in a home setting.

The fan has a variable speed selector that can be adjusted based on how hard you are driving the amp. One indicator is placing your hand on the box to feel any heat. The XLS units assembled in Communist China run very cool with no heat at all at moderate levels, however.

robertbartsch
04-14-2009, 01:40 AM
...another shot...


Anyway, I have three of the XLS 802s and only one unit seems to be thermally challenged with no fans.

I also saw some extra quiet computer fans on the Net that were the same dementions as stock and were mentioned above as possible candidates for replacement of the factory fans.