Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

Question: does anyone know what kind of overcurrent or overtemperature
protection this unit has? User is concerned about "ruining" it if it is
in fact overheating (which I can't determine at this distance). They're
running it with 4-ohm speakers at not-very-high levels; I also suggested
trying it with 8-ohm speakers and seeing if the smell lessens.

Not much info to go on, I know, but I really would like to know more
about any protection circuitry in this piece of gear.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

Hi!

I'm guessing this is of a similar vintage to something like my Kyocera
DA-610 CD player (1985)?

If it is, I'd expect that you'll find it is Incredibly Overbuilt
inside. Kyocera absolutely was *not* cheap-skating on these things.

Even so, the DA-610 I found had some problems and needed some simple
R&R before it was at its best. Most of it was just age-related wear
and tear. The electronics themselves have never needed a thing, but
then again, they're not under the stress that an audio amplifier would
be.

I would at least clean the thing.

William

On Tue, 29 Jun 2010 12:54:13 -0700, David Nebenzahl �ʇoɹ�:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

Question: does anyone know what kind of overcurrent or overtemperature
protection this unit has? User is concerned about "ruining" it if it is
in fact overheating (which I can't determine at this distance). They're
running it with 4-ohm speakers at not-very-high levels; I also suggested
trying it with 8-ohm speakers and seeing if the smell lessens.

Not much info to go on, I know, but I really would like to know more
about any protection circuitry in this piece of gear.

If it smells of burning electronics I would strongly suggests the person
unplug the unit and get it somewhere to be looked at. Smoking the outputs
in a DC coupled amp can cascade back through driver and current control
stages in the blink of an eye and cause a catastrophic amount of damage.

On Jun 29, 12:54*pm, David Nebenzahl wrote:
Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; *I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

Question: does anyone know what kind of overcurrent or overtemperature
protection this unit has? User is concerned about "ruining" it if it is
in fact overheating (which I can't determine at this distance). They're
running it with 4-ohm speakers at not-very-high levels; I also suggested
trying it with 8-ohm speakers and seeing if the smell lessens.

Not much info to go on, I know, but I really would like to know more
about any protection circuitry in this piece of gear.

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

A bit of a reach... A 35 degree rise above ambient in a room at 68 F
feels warm to the touch, but when you run the same amp in a hot
location, room temp 90F that absolute temperature is now 125F and you
feel burnt touching it. Just like its summer here the room temp there
could be high, perhaps there is something overheating and outgassing,
for a while.

My gut feeling is that the owner is simply smelling "burning dust". But he
should stop using it immediately, and have someone look it over. It might
need only a thorough vacuuming.

On 6/29/2010 4:15 PM Robert Macy spake thus:

On Jun 29, 12:54 pm, David Nebenzahl wrote:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

Question: does anyone know what kind of overcurrent or overtemperature
protection this unit has? User is concerned about "ruining" it if it is
in fact overheating (which I can't determine at this distance). They're
running it with 4-ohm speakers at not-very-high levels; I also suggested
trying it with 8-ohm speakers and seeing if the smell lessens.

Not much info to go on, I know, but I really would like to know more
about any protection circuitry in this piece of gear.

A bit of a reach... A 35 degree rise above ambient in a room at 68 F
feels warm to the touch, but when you run the same amp in a hot
location, room temp 90F that absolute temperature is now 125F and you
feel burnt touching it. Just like its summer here the room temp there
could be high, perhaps there is something overheating and outgassing,
for a while.

That's along the lines of what I was thinking too.

I used to use this receiver, which ran fine for years with no noticeable
odors whatsoever. It *is* incredibly overbuilt, as someone else
mentioned here, so I'm not particularly worried about an impending
catastrophic failure.

Still would be nice to find out specifically what kinds of protection
circuits it has from someone who actually knows ...


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

David Nebenzahl wrote:
Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

On Wed, 30 Jun 2010 00:52:12 +0000, Cydrome Leader �ʇoɹ�:

David Nebenzahl wrote:
Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

I've seen many of those in different pro power amps.

On Tue, 29 Jun 2010 12:54:13 -0700, David Nebenzahl
wrote:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

Question: does anyone know what kind of overcurrent or overtemperature
protection this unit has? User is concerned about "ruining" it if it is
in fact overheating (which I can't determine at this distance). They're
running it with 4-ohm speakers at not-very-high levels; I also suggested
trying it with 8-ohm speakers and seeing if the smell lessens.

Not much info to go on, I know, but I really would like to know more
about any protection circuitry in this piece of gear.


This unit doesn't have thermal protection but it has a DC offset
protection. This model was extremely reliable but I repaired one that
had both amplifiers completely wiped out. Even though I told the
customer I wouldn't void his warranty if he told me how he managed to
accomplish this feat, he wouldn't divulge what he did.

This unit doesn't have thermal protection but it has a DC offset
protection. This model was extremely reliable but I repaired one that
had both amplifiers completely wiped out. Even though I told the
customer I wouldn't void his warranty if he told me how he managed to
accomplish this feat, he wouldn't divulge what he did.

Plugged the speaker outputs into an AC wall socket?

I had an amplifier with DC offset protection, in which the amplifier failed,
and the protection failed, at the same time, an incredibly unlikely
coincidence. The DC damaged one of my speakers.

Meat Plow wrote:
On Wed, 30 Jun 2010 00:52:12 +0000, Cydrome Leader ??o??:

David Nebenzahl wrote:
Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

I've seen many of those in different pro power amps.

It's a first for me. I can't say I've ever seen a kyocera amp in the US
either.

Do those heatpipes ever leak or break after being decades old?

On Wed, 30 Jun 2010 16:11:12 +0000, Cydrome Leader �ʇoɹ�:

Meat Plow wrote:
On Wed, 30 Jun 2010 00:52:12 +0000, Cydrome Leader ??o??:

David Nebenzahl wrote:
Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific
information than that; I'm assuming no magic smoke is visible. I'm
advising them that perhaps something (dust, etc.) is in the heat sink
that's getting heated and smelling. Apparently the output stages
(MOSFET) of these beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

I've seen many of those in different pro power amps.

It's a first for me. I can't say I've ever seen a kyocera amp in the US
either.

Do those heatpipes ever leak or break after being decades old?

Yep they sure do. I worked for a warranty station that did a ton of
Matsu****a enterprise offshoots and saw the heat pipe mainly in condensed
units (consumer grade) so they really didn't have to design the rest of
the thing around the amplifier. They could put the final section where
they wanted it with minimal heat sinking and run a tube bent to fit
wherever there was enough space for some finning. Don't ask me what goes
on the inside of the pipe I suppose it depends on the designer. But I
have received tech bullets and shipment of replacements just in case we
got a run of units that had defective pipes. Having replaced a few I
can't recall seeing anything that 'leaked' out so again I have no idea
what was inside but it probably was an inert gas, I doubt if it had any
of the properties of a freon refrigerant. Maybe someone could expound who
actually knows for certain. I have one old SCS (Sound Code Systems) MOSFET
pro power amp that uses a finned heat pipe with the MOSFETS mounted on
the end. This amp has got to be 3o years old, uses the Hitachi K135/J40
FETS long discontinued. It's 350 per side into 4 ohm. Used it for a few
years as part of my bass guitar rig until I came across a non-working
Crown Mico-Tech 1000. It needed a diode block bridge and has worked
flawlessly since 1993.

On Wed, 30 Jun 2010 16:11:12 +0000 (UTC), Cydrome Leader
wrote:

Meat Plow wrote:
On Wed, 30 Jun 2010 00:52:12 +0000, Cydrome Leader ??o??:

David Nebenzahl wrote:
Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

I've seen many of those in different pro power amps.

It's a first for me. I can't say I've ever seen a kyocera amp in the US
either.

Do those heatpipes ever leak or break after being decades old?

Kyocera was sold by high end audio salons in the U.S., during the mid
80s, as an entry level line. The products were very well built and
reliable. One of their cd players was sold under the ADC brand name
at a very low price. It was probably the best cd player buy in its
day. Chuck

"Cydrome Leader" wrote in message
...
David Nebenzahl wrote:
Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

**Ah, heat pipes. Quite common in the late 1970s, early 1980s. If the fluid
has leaked, there can be problems. A quick way to test is to power up and
ensure that heat travels rapidly (less than 10 seconds) from the hot devices
to the other end of the heat pipe. If it doesn't then it is possible that
the fluid is gone from inside the pipe.


--
Trevor Wilson
www.rageaudio.com.au

On 7/1/2010 2:16 PM Trevor Wilson spake thus:

"Cydrome Leader" wrote in message
...

David Nebenzahl wrote:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

**Ah, heat pipes. Quite common in the late 1970s, early 1980s. If the fluid
has leaked, there can be problems. A quick way to test is to power up and
ensure that heat travels rapidly (less than 10 seconds) from the hot devices
to the other end of the heat pipe. If it doesn't then it is possible that
the fluid is gone from inside the pipe.

Having been inside this unit before, I'm fairly certain the heat pipe is
intact.

Any idea what the fluid is?


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

"David Nebenzahl" wrote in message
.com...
On 7/1/2010 2:16 PM Trevor Wilson spake thus:

"Cydrome Leader" wrote in message
...

David Nebenzahl wrote:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

**Ah, heat pipes. Quite common in the late 1970s, early 1980s. If the
fluid has leaked, there can be problems. A quick way to test is to power
up and ensure that heat travels rapidly (less than 10 seconds) from the
hot devices to the other end of the heat pipe. If it doesn't then it is
possible that the fluid is gone from inside the pipe.

Having been inside this unit before, I'm fairly certain the heat pipe is
intact.

**You need to measure to be certain.


Any idea what the fluid is?

**Not really. Some kind of refrigerant. It could be FreonT, ammonia, alcohol
or a number of others.


--
Trevor Wilson
www.rageaudio.com.au

Trevor Wilson wrote:

"David Nebenzahl" wrote in message
.com...
On 7/1/2010 2:16 PM Trevor Wilson spake thus:

"Cydrome Leader" wrote in message
...

David Nebenzahl wrote:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

**Ah, heat pipes. Quite common in the late 1970s, early 1980s. If the
fluid has leaked, there can be problems. A quick way to test is to power
up and ensure that heat travels rapidly (less than 10 seconds) from the
hot devices to the other end of the heat pipe. If it doesn't then it is
possible that the fluid is gone from inside the pipe.

Having been inside this unit before, I'm fairly certain the heat pipe is
intact.

**You need to measure to be certain.


Any idea what the fluid is?

**Not really. Some kind of refrigerant. It could be FreonT, ammonia, alcohol
or a number of others.

I got curious and dug up a sample of a heat pipe (Noren Products
http://www.norenproducts.com ) from a trade show, and it seems they can
even be filled with distilled water depending on the use.

It's still interesting to me that anybody bothered to use these in
amplifiers, products where nobody cares about size and complains about it
being made too sturdy and too heavy.

I have an ATI amp where it's not clear if the heatsinks or tranformer
weigh more.

On Jul 1, 2:24*pm, David Nebenzahl wrote:
On 7/1/2010 2:16 PM Trevor Wilson spake thus:







"Cydrome Leader" wrote in message
...

David Nebenzahl wrote:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; *I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

**Ah, heat pipes. Quite common in the late 1970s, early 1980s. If the fluid
has leaked, there can be problems. A quick way to test is to power up and
ensure that heat travels rapidly (less than 10 seconds) from the hot devices
to the other end of the heat pipe. If it doesn't then it is possible that
the fluid is gone from inside the pipe.

Having been inside this unit before, I'm fairly certain the heat pipe is
intact.

Any idea what the fluid is?

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

At a show a heat pipe/heat sink company took a straight normal looking
tube at room temperature and plunging it into ice water transferred
ice water temp to your hand NOW! The speed of the heat flow was
impressive. a simple copper pipe was no where near as fast.

Old issues of ?? Electronics Design?? described the heat pipe and its
operation in great detail. Should be at Wiki, or someplace, too.

I think this is the right firm for heat pipes. I munged his email
address a bit.

Amir Tahsini, Regional Sales Manager
Radian Heatsinks an Intricast Div.
2160 Walsh Avenue
Santa Clara, CA 95050
Phone: 408-988-6200 ext. 224
Fax: 408-988-0683
Email: atahsini
@?radianheatsinks .?com

http://www.radianheatsinks.com

On Thu, 01 Jul 2010 22:20:16 +0000, Cydrome Leader �ʇoɹ�:

Trevor Wilson wrote:

"David Nebenzahl" wrote in message
.com...
On 7/1/2010 2:16 PM Trevor Wilson spake thus:

"Cydrome Leader" wrote in message
...

David Nebenzahl wrote:

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they
say "smells like something's burning". Don't have more specific
information than that; I'm assuming no magic smoke is visible. I'm
advising them that perhaps something (dust, etc.) is in the heat
sink that's getting heated and smelling. Apparently the output
stages (MOSFET) of these beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/sho...d.php?t=246095

**Ah, heat pipes. Quite common in the late 1970s, early 1980s. If the
fluid has leaked, there can be problems. A quick way to test is to
power up and ensure that heat travels rapidly (less than 10 seconds)
from the hot devices to the other end of the heat pipe. If it doesn't
then it is possible that the fluid is gone from inside the pipe.

Having been inside this unit before, I'm fairly certain the heat pipe
is intact.

**You need to measure to be certain.


Any idea what the fluid is?

**Not really. Some kind of refrigerant. It could be FreonT, ammonia,
alcohol or a number of others.

I got curious and dug up a sample of a heat pipe (Noren Products
http://www.norenproducts.com ) from a trade show, and it seems they can
even be filled with distilled water depending on the use.

It's still interesting to me that anybody bothered to use these in
amplifiers, products where nobody cares about size and complains about
it being made too sturdy and too heavy.

I have an ATI amp where it's not clear if the heatsinks or tranformer
weigh more.

The whole heatpipe/heat sink/mosfet mount block assembly on my SCS
350x350 WRMS rackmount amp probably weighs 2 pounds minus the 12 fets.
The actual heat sink looks like a round bristled aluminum brush through
which an infinitely speed controlled fan blows through from back to
front. SCS is not in business now, hasn't been for a long time but I
really like this amp. Low THD for a pro audio amp easily usable for a big
home system. Makes no noise unless you're pushing it then the noise
doesn't really matter.