D'Agostino Momentum amp melts down


The latest issue of Stereophile tests the Momentum amplifier and amp number 1 melts down during the precondition test. Atkinson is afraid to subject amp number 2 to the same test and only runs it for 1/2 as long as the standard test.

Parasound, Bryston, and others pass this test but the Momentum can't? Then they act like it's no big deal like it melted down. So, if that's the case, why perform the test?

The manufacturer response doesn't remark on the melt down. I would think Dan would be duly embarrassed but what the heck, those copper heat sinks sure look great.

Would a prospective buyer (not me) be hesitant to power an inefficient speaker to loud levels with this amp?

rhljazz
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A quick internet search shows that the following amps did not, or could not pass the Stereophile administered 1/3 power test: Bryston 14BB-SST, Arcam Alpha 10P, McIntosh Mc1201 and Pass X1000. I can only imagine that a thorough search would turn up many more examples.

Not passing this test doesn't mean an amplifier is bad. It could mean underspecified heat sinking, very high bias settings or very conservatively set protection circuitry. In the case of the D'Agostino I suspect the copper heat things are an attempt to keep the amps weight manageable. Remember, the 1/3 power test does not reflect real world operating conditions. It's designed to stress a solid state amplifier in order to then measure distortion components.

Rhljazz, what exactly is your agenda in starting this thread? Nowhere in the Stereophile article does it say anything about a melt down. The amp stopped working. It didn't melt, catch fire or explode, yet you keep using language suggesting some Chernobyl style event. You actually seem to take pleasure in the amp's malfunction. The German language has a multisyllabic word for what you're exhibiting.
It is what it is. You don't have to ignore the fact that it exploded under test conditions. It did not in the other two reviews I read. It was not even hot when I listened to it. I'm sure at $40k it has a hefty warranty.
When you audition at the store push it hard and see what happens.