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**tthurman** · 09-07-2012, 03:57 PM

If you go this route, I'm certainly interested in your results.

My experience with sound reinforcement amps, and it's admittedly not super extensive, is they are built like tanks, and hold up quite well over time. On the other hand, they are generally aimed at live performances, and so aren't the cleanest sounding amps, if that makes any sense at all. I haven't messed with any of these in years, but when I did Crown and the CS series from Peavey where the models I most often was around.

**dane** · 09-09-2012, 12:33 PM

Yes, it makes sense, and I agree-- To really tell I'll need to take it home and listen to it, but I wanted to know if anybody had any experience with this or any other Crate amps.. A/B'ing between my Marantz SR8001's internal amp and this one wouldn't be TOO difficult, and in the end that's what I'll need to do. That will be testing full-range rather than just subs, but that's okay. If it sounds acceptable full-range, then I extrapolate that it will sound acceptable for sub-use. I doubt it's going to be on par with some of the uber-fancy amps that are out there, but I also think sub-only use is a *little* more forgiving than for mains.. And there's a good chance that I can get this 1kW/ch amp for under $200. That's a big incentive right there..

I will be sure to keep this thread posted with my progress. That said, if anyone does read this with experience with Crate (or like tthurman, other Pro amps), please feel free to chime in..

I've also posted on AVSforum, and am preparing for either an onslaught or crickets.. :)

thanks!
..dane

**dane** · 09-25-2012, 12:44 AM

Back from my trip and picked up the Crate SPA-2000 amp today (1kW/ch @ 4ohm, [email protected]), but I want to take it through some paces before hooking it up to my home theater subs.. missing a few screws and nuts here and there, but nothing I can't replace. It's dinged up pretty good (after all, it was a loaner+demo unit for a pro-audio shop it's entire life), but it's going in an equipment rack so I really don't care what it LOOKS like.. :)

I took the cover off tonight and it's fairly clean inside. I've not yet found any obvious signs of abuse (rips, tears, heat/scorch marks, repairs) but will continue looking in the coming days. After blowing out what little dust was in there, I got out my meter and turned it on. After about ten minutes I measured around 9mV and 2mV DC offset. After 45 minutes at the lowest gain setting the DC offsets are still sitting about 8.5mV and 1.9mV. (!) I have checked them multiple times over the past hour in disbelief. It's not a terribly old amp, but it's a pro-audio amp, and I'm just surprised that the offset is THAT low.. I keep thinking "surely I'm doing something wrong!" :) (and maybe I'll yet find that I was!)

Oddly, about 30-40 seconds after turn-on, the protect circuits clicked on, and about ten seconds later clicked back off. While I can understand this at first power-on, that late into the game suprised me. They haven't come on again since, however. I plan to look into this a little more over the coming days/weeks.

I have emailed Crate Amps (best I could find, seem to have the same font in "Crate" on their website as my amp) to see if they have schematics and/or service manuals for this amp. A quick cursory glance I do not see DC Offset adjust OR bias adjust pots, but will be taking a closer look in the coming days.

The fans are pretty loud too-- I will need to find some much quieter ones if I want them in my home theater equipment rack.. I'm assuming a class AB design with as many heatsinks (and fans) that this thing has. Looks like a dual mono style design with a shared power supply (and a pretty massive torroid).

I'd like to have this thing hooked up and running my subs ASAP, but I'm going to take my time and investigate the protect circuits and fans.. Later this week I'll let it idle for a good hour and get some IR measurements on the heatsink blocks too.. not the ideal way to measure bias currents, but at least it can give me an idea if the two channels are running comparably to each other (both equal temperature). Doesn't really answer bias currents at all, but matching bias currents will have closely matching idle heatsink dissipation..

If anyone has any experience with this amp with any helpful tips on checking bias, (or quieter fans), I'd appreciate the guidance. :)

For now though, here are some early pictures..

cheers,
..dane

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What do you know about the Crate SPA-2000 power amp?

What do you know about the Crate SPA-2000 power amp?

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