Crown PS-400

Still looking to replace my ailing subwoofer amp and am tired of the excessive noise associated with "PA" amps with SNR ~100 (which is only 70-80 at 1 watt) and can have audible fans.

The PS-400 presents a nice alternative, extremely good specs and no fan, though it could use a little more power. I am willing to give up 2 dB of volume to get better specs elsewhere and not put up with the excessive noise.

My dellema is that while I typically run my sub (W15GTI) at 12 ohms, I sometimes run it at 4.8 ohms (W15GTI in parallel with 2235) and in bridged mono, the amp is only recommended to 8 ohms. I recognize that a quality amp should not have deleterious effects when pushed to a lower impedience, other than it gets hot and limits the current, or shuts down, if pushed to excessive volumes, that I'm probably not going to incur sitting in my living room 15 feet away.

Has anyone used this amp and do you have any comments? Can it reliably push a 4.8 ohm load to a reasonable level without frying either itself, or my JBLs?

Thanks

Specs on Crown:

http://www.crownaudio.com/pdf/amps/k1073-4.pdf

the crown k1 or k2 should work for you with whatever you need it to do. the best part is no fan. the ps-400 should do a 4 ohm load as do all crowns i have ever used. i havent had much experience with that amp at all so i cant honestly say but i figured i would recommend the k1 or k2

Quote:

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Originally Posted by pelly3s

the crown k1 or k2 should work for you with whatever you need it to do. the best part is no fan. the ps-400 should do a 4 ohm load as do all crowns i have ever used. i havent had much experience with that amp at all so i cant honestly say but i figured i would recommend the k1 or k2

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Big $$$ difference though.

I have PS200's that I have run bridged. You can't run a PS400 bridged with a 4 ohm load. If you bridge an amp tyically you double the lowest rated load so in stereo they are rated for 4 ohms and up, bridged is 8 and up.

http://www.crownaudio.com/pdf/amps/k1073-4.pdf

Rob:)

You shouldnt really run the PS-400 bridge mono 4 ohms, thats equivalent to 2 ohms stereo and the amp will thermal. However, it will do the load, and work, but youll need a fan, a sizeable one, to keep that amp cool. We used to do this with DC-300A,s years ago, until they came out with the PSA-2.

So, yes, with some effort, you actually can do it, but, it isnt the optimum solution. The optimum solution? An amp with enough power and the sound you want, and the ability to run in stereo.

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Originally Posted by toddalin

Big $$$ difference though.

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I don't know what a PS-400 goes for, but I bought a K2 off ebay for about $800. I use it to power two sub1500s and it could easily power four of them.

I love the Crown PS-400. I run mine at 8 ohms and would be concerned about 4 ohms/bridged.
Why not run it in dual mode, letting each channel drive and 8 or 4 ohm load?
Want to run your dual driver set-up in stereo?...get two PS-400s!

Tom

Quote:

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Originally Posted by Tom Loizeaux

I love the Crown PS-400. I run mine at 8 ohms and would be concerned about 4 ohms/bridged.
Why not run it in dual mode, letting each channel drive and 8 or 4 ohm load?
Want to run your dual driver set-up in stereo?...get two PS-400s!

Tom

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98+% percent of the time it runs a 12 ohm load. It only has to push 4.8 ohms on rare occasion. I could actually put a fan on it and turn it on for those rare occasions. Hardly pays to buy two PS-400s to let one sit idle 98% of the time. And, would be a real pain to rewire the system every time for the 2% of the time it would be use.

For those that have experience with these, how do you operate one in bridge mode?

I am under the impression you flip the switch on the back to "Bridged", turn CH2's input knob full CCW and then use CH1's input and then CH1's speaker Positive as positive and CH2's Positive as negative when connecting a speaker. Then only CH1's IOC light will pulse green in relation to the signal strength. From there you're supposed to enjoy ~3x the power output, double the slew rate and the other good stuff I'm after.

However, I went to do that with all four of my PS amps and only the PS-200's are behaving that way. When the 400's are turned on and in use, both IOC's illuminate equally in relation to signal strength. Is that normal for a 400? I can find service manuals and tech sheets, but not an owner's manual for a PS-400.

Other weirdness:

-The PS-400 driving my left sub actually turned off and then turned back on.
-The PS-400 driving the right sub also adds a considerable amount of ground loop hum to the system as well as itself, but most noticeably with the speakers being driven by the PS-200's. When turned off, the speakers being driven by the 200's are virtually silent.

Other notes:
-All of my PS amps were working just fine when last used. Two were already deployed in my system running stereo, including the PS-400 which is now adding noise to the system and itself.
-The spare PS-400 has a wonky 1/4" input jack on CH2. CH2 isn't used for Bridge-mono mode so I don't see this as an issue. This is the amp which turned off and then turned back on.
-Speakers being driven by the PS-200's are UREI 813C's.
-Speakers being driven by the PS-400's are JBL 2245H's.
-Everything is plugged into a Furman M8-S switcher, which is now plugged into a dedicated 20A outlet.
-For grins, I plugged all amps (minus signal input and not connected to speakers) straight into the two new dedicated 20A outlets I had installed. No hum from any of the amps. I suspect the Furminator is the culprit with my hum. It is being eliminated in favor of three Pyle PDBC70's- one for the 200's, one for the 400's and one for the accessories. Three of those because I don't have the funds for a single 20A switcher and those will cheaply allow me to use both 20A outlets, one for the 200's and one for the 400's.

Hi Derek;

Have you found this?

http://www.aetechron.com/pdf/service...7540Manual.pdf

Barry.

I've never bridged any of my Crowns, but then I also use a Studio Reference-II, so not much need.

But I do own a PS-400 Owner's Manual and these are the appropriate pages for your questions:

https://live.staticflickr.com/65535/...643ef529_k.jpg

https://live.staticflickr.com/65535/...5b01c56b_k.jpg

And this is as close as I see to it in Crown's archives: https://www.crownaudio.com/en-US/sit...ctional-manual

Oh wow, just what I was looking for! Thank you, BMWCCA!!

Looks like I've got my amps wired and set correctly, then.. I'll dig through the manual in just a moment, maybe there's a word about the IOC lights and how they operate in bridge-mono mode.

Thank you, Barry! I have a manual similar to that from Crown, but not Techron. I'll dig through it a bit. As for the Crown manual and as a laymen, I didn't get much out of it other than how to set DC offset. If you're available for a call later today, that would be fabulous. :bouncy: