Adcom cooling fan noise

[Charles Packer]

The cooling fans in my Adcom GFA5800 are noisier than
they were last year at similar ambient temeprature levels.
I learned from a search of related postings here that
there is a fan for each channel. Does anybody know if
it's practical to replace them? I bought this unit used
over 10 years ago and it's served me well. I queried
Adcom about this but they never replied.

--
Charles Packer
http://cpacker.org/whatnews
mailboxATcpacker.org

[Audio Empire]

On Sat, 27 Mar 2010 06:31:53 -0700, Charles Packer wrote
(in article >):

> The cooling fans in my Adcom GFA5800 are noisier than
> they were last year at similar ambient temeprature levels.
> I learned from a search of related postings here that
> there is a fan for each channel. Does anybody know if
> it's practical to replace them? I bought this unit used
> over 10 years ago and it's served me well. I queried
> Adcom about this but they never replied.
>
> --
> Charles Packer
> http://cpacker.org/whatnews
> mailboxATcpacker.org

Electronic cooling fans are commodity items and are made and sold by a myriad
of manufacturers and distributors. The first thing you need to know is the
size and physical configuration of the fan (diameter, size of the housing,
mounting hole spacing, etc.) then you need to know the electrical
requirements (AC or DC, and voltage). Often, you can get a manufacturer's
name and model number off of the fan itself. This makes finding a replacement
very easy. If it's a standard fan, then other manufacturers will likely
cross-reference it. If the fans name and model number aren't on the fan, then
more investigation is required. Most fans for equipment designed for domestic
household applications run off of mains current (the power that comes out of
the wall in your house). That means for the USA, that would be 120 V, 60Hz.
But this isn't necessarily the case. Some run off of the DC power supply for
the amplifier or off of low-voltage AC from a separate winding on the
amplifier's power transformer. This is advantageous for the amp manufacturer
because it allows them to use the same fans for all markets, regardless of
that market's mains supply voltage. In other words, if the fans run on mains
power, the manufacturer, when configuring their amp for say, the European
market would not only have to wire the amplifier's power transformer for
220/240 volts 50 Hz, but use fans for that voltage level as well. By
designing-in fans that run off of either a lower AC voltage from a secondary
winding on the transformer, or a DC fan which was powered by the amp's power
supply, the same fans can be used for all models in all markets because these
voltages at these points in the circuit do not change from market to market.
This means that only one fan model needs to be stocked, and fitted, thus
reducing material cost and labor.

So it is important to find out what the fan's voltage is and whether its a DC
or an AC fan before looking for replacements on-line. Once you know what the
fans are, it should be a simple matter to order them and replace them
yourself. Most likely they run on house current, but you never know....

[Bill Noble[_2_]]

you don't say what kind of noise - sometimes the fans pick up a lot of crud
and cleaning the blades can help - if it's bearing noise, try oiling the
bearings, if it's a bushing type fan, check for free play, if there is much,
replace fans

"Charles Packer" > wrote in message
...
> The cooling fans in my Adcom GFA5800 are noisier than
> they were last year at similar ambient temeprature levels.
> I learned from a search of related postings here that
> there is a fan for each channel. Does anybody know if
> it's practical to replace them? I bought this unit used
> over 10 years ago and it's served me well. I queried
> Adcom about this but they never replied.
>
> --
> Charles Packer
> http://cpacker.org/whatnews
> mailboxATcpacker.org

[Charles Packer]

On Mar 28, 12:40 am, "Bill Noble" > wrote:
> you don't say what kind of noise - sometimes the fans pick up a lot of crud

The hum is louder than it has ever been before. The amp
is quiet when first turned on, but as it warms up, and
depending on the volume level of the program material, the
hum of the fans emerge. I assume this is because the fans
are thermostatically controlled. Oddly enough, the
frequency of the hum is constant as it gets louder. If
the fans' speed increased, I would expect the sound
to increase in frequency as well, but they sound the same
tone, which I'm guessing is 120 Hz. Anyway, on a recent
warm evening after playing a symphony, the fan sound
was irritatingly evident.

--
Charles Packer
http://cpacker.org/whatnews
mailboxATcpacker.org

[Ken[_8_]]

On 28 Mar 2010 18:11:03 GMT, Charles Packer > wrote:

> > you don't say what kind of noise - sometimes the fans pick up a lot of crud
>
> The hum is louder than it has ever been before. The amp
> is quiet when first turned on, but as it warms up, and
> depending on the volume level of the program material, the
> hum of the fans emerge. I assume this is because the fans
> are thermostatically controlled. Oddly enough, the
> frequency of the hum is constant as it gets louder. If
> the fans' speed increased, I would expect the sound
> to increase in frequency as well, but they sound the same
> tone, which I'm guessing is 120 Hz. Anyway, on a recent
> warm evening after playing a symphony, the fan sound
> was irritatingly evident.

Bad capacitors in the power supply?

[Arny Krueger]

"Ken" > wrote in message

> On 28 Mar 2010 18:11:03 GMT, Charles Packer
> > wrote:
>
>>> you don't say what kind of noise - sometimes the fans
>>> pick up a lot of crud
>>
>> The hum is louder than it has ever been before. The amp
>> is quiet when first turned on, but as it warms up, and
>> depending on the volume level of the program material,
>> the hum of the fans emerge. I assume this is because the
>> fans are thermostatically controlled. Oddly enough, the
>> frequency of the hum is constant as it gets louder. If
>> the fans' speed increased, I would expect the sound
>> to increase in frequency as well, but they sound the same
>> tone, which I'm guessing is 120 Hz. Anyway, on a recent
>> warm evening after playing a symphony, the fan sound
>> was irritatingly evident.

> Bad capacitors in the power supply?

Bias setting shifting, and current drain growing?

There is a failure mode in fans where the bearing friction increases, and
the current draw goes way up. Waaay up! I've seen a 12v CPU fan motor take
out the 12 volt supply on a desktop PC. I saw this happen last week. Most
of those PC power supplies can put out 12 amps or more at 12 volts.

[Charles Packer]

On Mar 29, 6:57 pm, "Arny Krueger" > wrote:
> Bias setting shifting, and current drain growing?
>
> There is a failure mode in fans where the bearing friction increases, and
> the current draw goes way up. Waaay up! I've seen a 12v CPU fan motor take
> out the 12 volt supply on a desktop PC. I saw this happen last week. Most
> of those PC power supplies can put out 12 amps or more at 12 volts.

Yikes, this would call for immediate investigation.
I hope the fans are reasonably accessible when I
lift out the 50-pound behemoth from its shelf and
take off the covers.

--
Charles Packer
http://cpacker.org/whatnews
mailboxATcpacker.org

[Arny Krueger]

"Charles Packer" > wrote in message

> On Mar 29, 6:57 pm, "Arny Krueger" >
> wrote:
>> Bias setting shifting, and current drain growing?
>>
>> There is a failure mode in fans where the bearing
>> friction increases, and the current draw goes way up.
>> Waaay up! I've seen a 12v CPU fan motor take out the
>> 12 volt supply on a desktop PC. I saw this happen last
>> week. Most of those PC power supplies can put out 12
>> amps or more at 12 volts.
>
> Yikes, this would call for immediate investigation.
> I hope the fans are reasonably accessible when I
> lift out the 50-pound behemoth from its shelf and
> take off the covers.

If the existing fans run on 12 volts DC, the larger PC parts retailers like
Newegg have many options for attractive prices.

[Charles Packer]

On Mar 27, 9:31 am, Charles Packer > wrote:
> The cooling fans in my Adcom GFA5800 are noisier than
> they were last year at similar ambient temeprature levels.

After I removed the top plate and front panel, I could see
that it would be too difficult to replace the noisy
right-channel fan in the time I had at my disposal, so I
went to put it all back together to wait until next weekend.
But first I vacuumed out 10 years worth of dust bunnies
clinging to the fan housings. That did it! Now I can barely
hear the fans purring.

--
Charles Packer
http://cpacker.org/whatnews
mailboxATcpacker.org

[bxboy3191]

;904725']you don't say what kind of noise - sometimes the fans pick up a lot of crud
and cleaning the blades can help - if it's bearing noise, try oiling the
bearings, if it's a bushing type fan, check for free play, if there is much,
replace fans

"Charles Packer" > wrote in message
...
> The cooling fans in my Adcom GFA5800 are noisier than
> they were last year at similar ambient temeprature levels.
> I learned from a search of related postings here that
> there is a fan for each channel. Does anybody know if
> it's practical to replace them? I bought this unit used
> over 10 years ago and it's served me well. I queried
> Adcom about this but they never replied.
>
> --
> Charles Packer
> http://cpacker.org/whatnews
> mailboxATcpacker.org

I also had a cooling problemw/ my Yamaha rx-v665 to the point it was clipping. I tried a fan from coolerguys.com but after a while I noticed a stain on the fan and hoped it wasn't any lubericating oil. Nothing leaked and I changed my rack so the avr gets the best air