Reply to thread

Message

<blockquote data-quote="John Roberts" data-source="post: 67068" data-attributes="member: 126">Re: Crest repair center neededIndeed this is more stressful, but for years Crest has earned a reputation for high current output, and all amp designs for about the last 15+ years have anticipated 2 ohm operation by customers, and all professional amps should even tolerate dead short circuits. That said power amps do fail from time to time for random reasons. They are all (most) designed to be cost effectively repaired. One obvious exception to design for repair, was the early CE1000/2000 amps that used undersized emitter degeneration resistors, so when those amps lost a power device, the undersized emitter resistor often burned a hole in the PCB. I don&#039;t think this was a cognizant design decision to not make a repairable amplifier but an oversight by an inexperienced mechanical designer who just repackaged an old amp schematic into new SMD technology.&nbsp; As others have stated the Crest PCB should not be a throw away. ASSuming it uses SMD, in the early days of SMD many were intimidated by board level repairs, but it isn&#039;t as hard, as figuring out &quot;what&quot; to replace, and there probably aren&#039;t any 0201s on a big dog power amp PCB. JRPS: Regarding &quot;pay me now, or pay me later&quot; for cost associated with ease of repair, I recall some 20-30 years ago when CS800 series amps were famous for ease of repair, and the design engineers put a lot of effort and some extra cost into that. Since then the consumers drove the trend for more power for less dollars, by rewarding cheaper amp models and brands that were less repair friendly. I notice that since I left the power amp game, the amps have gotten even cheaper, so good luck with repairing them. I&#039;m so old I recall when $1/watt was a cheap amp. <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":-)" title="Smile&nbsp; &nbsp; :-)"&nbsp; data-smilie="1"data-shortname=":-)" /></blockquote>

[QUOTE="John Roberts, post: 67068, member: 126"] Re: Crest repair center needed Indeed this is more stressful, but for years Crest has earned a reputation for high current output, and all amp designs for about the last 15+ years have anticipated 2 ohm operation by customers, and all professional amps should even tolerate dead short circuits. That said power amps do fail from time to time for random reasons. They are all (most) designed to be cost effectively repaired. One obvious exception to design for repair, was the early CE1000/2000 amps that used undersized emitter degeneration resistors, so when those amps lost a power device, the undersized emitter resistor often burned a hole in the PCB. I don't think this was a cognizant design decision to not make a repairable amplifier but an oversight by an inexperienced mechanical designer who just repackaged an old amp schematic into new SMD technology. As others have stated the Crest PCB should not be a throw away. ASSuming it uses SMD, in the early days of SMD many were intimidated by board level repairs, but it isn't as hard, as figuring out "what" to replace, and there probably aren't any 0201s on a big dog power amp PCB. JR PS: Regarding "pay me now, or pay me later" for cost associated with ease of repair, I recall some 20-30 years ago when CS800 series amps were famous for ease of repair, and the design engineers put a lot of effort and some extra cost into that. Since then the consumers drove the trend for more power for less dollars, by rewarding cheaper amp models and brands that were less repair friendly. I notice that since I left the power amp game, the amps have gotten even cheaper, so good luck with repairing them. I'm so old I recall when $1/watt was a cheap amp. :-) [/QUOTE]

Verification