Danger of running hot receiver (Kyocera)?

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 ??o??:

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.

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:

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)

weird heatsink in that thing:

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

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

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.

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 ??o??:

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.

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

**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:

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)

**You need to measure to be certain.

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

--
Trevor Wilson
www.rageaudio.com.au

I got curious and dug up a sample of a heat pipe (Noren Products

) 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.

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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

On Thu, 01 Jul 2010 22:20:16 +0000, Cydrome Leader ??o??:

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.