Danger of running hot receiver (Kyocera)?
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From: Cydrome Leader on 30 Jun 2010 12:11 Meat Plow <mhywatt(a)yahoo.com> wrote: > On Wed, 30 Jun 2010 00:52:12 +0000, Cydrome Leader ??o??: > >> David Nebenzahl <nobody(a)but.us.chickens> 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/showthread.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?
From: Meat Plow on 30 Jun 2010 15:30 On Wed, 30 Jun 2010 16:11:12 +0000, Cydrome Leader ǝʇoɹʍ: > Meat Plow <mhywatt(a)yahoo.com> wrote: >> On Wed, 30 Jun 2010 00:52:12 +0000, Cydrome Leader ??o??: >> >>> David Nebenzahl <nobody(a)but.us.chickens> 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/showthread.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 Matsushita 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.
From: Chuck on 1 Jul 2010 09:23 On Wed, 30 Jun 2010 16:11:12 +0000 (UTC), Cydrome Leader <presence(a)MUNGEpanix.com> wrote: >Meat Plow <mhywatt(a)yahoo.com> wrote: >> On Wed, 30 Jun 2010 00:52:12 +0000, Cydrome Leader ??o??: >> >>> David Nebenzahl <nobody(a)but.us.chickens> 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/showthread.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
From: Trevor Wilson on 1 Jul 2010 17:16 "Cydrome Leader" <presence(a)MUNGEpanix.com> wrote in message news:i0e4fs$apf$1(a)reader1.panix.com... > David Nebenzahl <nobody(a)but.us.chickens> wrote: >> Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say >> "smells like something's burning". Don't have more specific information >> than that; I'm assuming no magic smoke is visible. I'm advising them >> that perhaps something (dust, etc.) is in the heat sink that's getting >> heated and smelling. Apparently the output stages (MOSFET) of these >> beasts tend to run on the hot side. > > weird heatsink in that thing: > > http://www.audiokarma.org/forums/showthread.php?t=246095 **Ah, heat pipes. Quite common in the late 1970s, early 1980s. If the fluid has leaked, there can be problems. A quick way to test is to power up and ensure that heat travels rapidly (less than 10 seconds) from the hot devices to the other end of the heat pipe. If it doesn't then it is possible that the fluid is gone from inside the pipe. -- Trevor Wilson www.rageaudio.com.au
From: David Nebenzahl on 1 Jul 2010 17:24 On 7/1/2010 2:16 PM Trevor Wilson spake thus: > "Cydrome Leader" <presence(a)MUNGEpanix.com> wrote in message > news:i0e4fs$apf$1(a)reader1.panix.com... > >> David Nebenzahl <nobody(a)but.us.chickens> 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/showthread.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)
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