I would certainly endorse all those who have recommended Crown power amps. In my experience they put sound quality, power output and reliability all at the top of their design list. I have used 4 DC 300's conservatively rated at 150 watts per channel in to 8 ohms (can be easily bridged for greater output)
for the last 25 years, they were bought secondhand. You can still find them on eBay and the like, but they now fetch a premium price. If you can stretch to it listen to the latest Crowns, they're a sound investment, pardon the pun, not a fashion purchase.
Hmm, interesting you mention that! I couldn't find any PS400's, least not two or four like I wanted to try based on a member's suggestion. However, I did stumble upon two MA-2402's:
MA-2402-Manual-127240 (3).pdf
These dudes are supposed to be ~500wpc into 8 ohms so they should provide all the headroom the XPL200's I have need! Although most say they are magical for bass and impressive everywhere else, some say the mids & highs are fatiguing. No better way to confirm or deny that than try some personally! They are currently enroute, hopefully they'll show up. The other Carver TFM55x I bought was destroyed in shipping so that's why I just hit the trigger on the Crown gear. You happen to have any experience with the MA series??
Thank you for the detailed response, Titanium Dome!! Really, I appreciate it. Especially considering that you tried all this gear through your XPL's. I think I stumbled upon your thread where you talked with GT about the XPL200. Something about replacing the midbass unit too.. Did you ever try that? Anyway, the DX-1 is unobtanium and those who have them and are willing to sell seem to do so with a schiit eating smile on their face as they gouge you.. I've heard good things about Ashly crossovers with these and so that's what I'm using, an XR1000. Might be something wrong with my XPL's or amps or the crossover as the left seems to play hotter than the right, so I have to attenuate with the Ashly. Could also be I've got diminished hearing in my right ear.. Had that tested and they said it was fine though.. Anyway, I've got my crossover set up at 200hz with a 12db slope, seems to be the best. I've tried the same slope with 300 and the midbass was just too boomy and muddy, least it was when the level was set the same as the level for the highs. So I'm running something like input at "5" (12 o'clock pos.), high at "5" and low at "7" with pretty satisfactory results. But like you mentioned, I just need more from that 12" woofer. My L150A's are apart again, so I can't compare, but I already mentioned somewhere else that I love the bass I got from them, much much better than the XPL's. Tighter, more dynamic, clear and articulate, especially the midbass and kick- you feel that in your chest. The XPL's just seem bloated and muddy by comparison. And I am vertically biamping right now with two Adcom GFA 555 II's.
Thank you also for the comments about Carver preamps. Your thoughts and the stuff I read is what lead me to stay away from them. As an update to that Adcom GFP 555, I decided to keep it, have it fixed and replace all the caps on it. Heard they really come alive when that is done. I was impressed with the bass and the articulation, so I'm going to roll the dice on it, hopefully it'll relax and warm up in the mid and treble departments.
So should I look into the Citation 5.0 and some Hafler SR2300's?
I used to have some MA2402 amps.
You may want to open it up and check for dust build up.
Also it may come with a 30amp or 20 amp plug on it depepending
on age and if anyone has changed it out overtime.
There is also a hidden three position switch inside the PIP module slot that sets the input
level of the amp, you take out the PIP module and it's on the inside top through a
hole.
Forward is 1.4 volt, the middle is 26db about 5 volt and all the way back is .77 volt.
I still use MA3600vlz amps on my subs.
Mike Caldwell
www.mikecaldwellaudioproductions.com
Thanks Mike!
Definitely, I at least try to peek under the skirt of every piece I get before powering it on. I was really impressed with the inside of that GFP 555..
What did you think of the sound of the 2402? What would you compare it to and what would you say it's better than? Also, which setting would be suitable for the preamp I'm using? (Marantz 3600)
Funny, I've been watching an MA3600VZ but those seem like overkill for what I'm doing and I bet I'd trip a breaker with one. Probably might with two 2402's, pretty sure I will have to swap the plug out. I did check the user manual, a 2402 is compatible with 120v 15A circuit. Mine might be 20A, not sure..
Would you happen to have any experience with Crown K2 amps? Just found out about these after of course purchasing 2402's. I like that the K2's don't have fans, but people seem to prefer the 2402 to a K2. Interested in your feedback or others who have tried them. Here's some food for thought on 'em from a different forum:
"
If you like the Macrotechs, try the K2, IMO, it's the best sounding amp Crown ever put out and I really like the Macrotechs...
I have since bought another K2 and it beats my Bryston 4B hands down in power and clarity... It took letting go of a K2 to realize that 3-4 times the money couldn't touch it..
Only bad thing about the K2 is that it's one of the ugliest amplifier ever built.. Does not impress with it's looks..
"
I'm going to say if your really whomping on a pair of MA2402's both on a single 20 amp circuit the breaker will be tripping.
The K2's were good amps, I put a few in some installations that are still going strong.
The K series output section is what became Crown's I class used later in the I Tech series amps.
The K series used a conventional power supply with a really big toroidal power transformer,
the I Tech series amps use a switching mode power supply.
For some reason for a time Crown offered the K series amps in about half a dozen different color choices!
So if you find one that is red, yellow, green, blue and I think there was a purple and a chrome version those
are legit amps!
Mike Caldwell
www.mikecaldwellaudioproductions.com
Guess I'll find out just how hard I drive stuff! I uh, just got a K2 from eBay last night, black. Jeez, I never thought I'd have so much gear. This is highly addictive, yet fun. If only I could get paid to do this stuff..
I actually came across posts from you and BMWCCA while trying to find stuff out about the K2 & 2402, small world.
Anyway, what are your thoughts about the sound quality between the two? Do you think the K2 is better all around or are there somethings the K2 doesn't do as good as a 2402? From a power standpoint, it might be better if I run two K2's. I was able to find a technical manual for the 2402 which shows how much current one of those pulls, along with it's THD & signal to noise ratio but nothing like that for the K2..
Unfortunately I never had the chance to do a side by side listening test between a K2 and MacroTech.
Where I used the K2's they did sound very tight and fast, yes I know those are vague terms!
They are still one of the higher powered convection cooled amps, no so much for massive heat sinks all around the amp but the amp output stage design.
A sealed convection cooled amp made it a great choice for installs where no one ever cleans
the filters on a fan cooled amp!
If they had a higher power version available back then I would have looked into them for subs.
Mike Caldwell
www.mikecaldwellaudioproductions.com
Mike Caldwell
www.mikecaldwellaudioproductions.com
I got all three amplifiers in over the weekend. Two 2402's and the one K2. Couldn't get the K2 apart but did pop the hood on the 2402's. DUSTY! I also was expecting two giant caps but these appear to be using just 7500uF per channel. Transformers are F'n huge, and these things seem to be a dual mono block amp. And good god dham are they all heavy lol. I used to think amps couldn't get much heavier than the 510M but I was wrong. Anyway, all of them power on but I will confirm that the fans on the 2402 are pretty loud. The K2 is DEAD silent. Sure, it doesn't have a fan but there isn't even much transformer hum, least none I could hear. The stock setting of 0.775v for sensitivity was far too low, so while it was easy to switch on the K2, I'll have to pull the 2402's apart to change that setting as well as dust them off and disconnect the fan. If I like these things enough to keep them, I'm not sure what the long term solution will be to the fan noise. A resistor or thermal switch like the Marantz 510M has would be nice, but I'm no electrician..
Sound test will commence tonight
Also, I checked DC volts at the output terminals. The 2402's were both at 0.00, but the K2 measured something like -0.157 volts. Is this cause for concern? Should I ship the amp back? They're all eBay specials..
Lastly, the settings on the 2402 for sensitivity range from the factory position of 0.775v to 1.4v to 26 or 28dB, whatever that means. Which would best suit the Marantz 3600 preamp? I couldn't hear much of anything using 0.775 on the K2, 26 or 28dB seemed to grainy but 1.4v seemed fine. I would just like to confirm with you fine folks before putting the pedal down on these things..
Couple things here......
First you CAN NOT disconnect the Fan on the MA2402.
The fan in those is a one of kind fan, they actually call it a "fanformer" the windings on the motor assembly
are also the low voltage power supply transformer.
Were the blades coated in dust on the fan.
On a Crown MA I'm not sure how long you could run it even at moderate power till it would start to over heat with out the fan even running.
How are you connecting to the amp inputs, XLR or 1/4 inch, balanced or unbalanced?
The input sensitivity voltage selections indicate the needed input voltage for the amp to produce
full output power. The 26 db gain setting will be around a 4 volt input sensitivity.
With the same input level (start out with the amp turned down) the .775 should be the loudest, 1.4 lower by about 3db and the 26db much lower by about 8db.
The K2 DC off set is not an issue.
I would not use the speaker switching connections on the pre-amp with either of those amps.
Mike Caldwell
www.mikecaldwellaudioproductions.com
Thanks for your input Mike, much appreciated.
Oh, I did not know that about the fans. Yes, each fan was caked with dust. Although perhaps "caked" is too hard, they're just worse than I expected, like someone ran these things for quite a while without the front filters. Guess if I can't do anything about the fan noise ( would be nice just to reduce it's speed by half..) I'll still try and test the sound quality and then either sell both or keep one for the garage.
Here's a pic of one of the MA2402's with the hood popped, guess they don't look too bad:
I didn't get around to listening to any of the amps last night, but when I did my preliminary testing, I used the 1/4" inputs. Using output II of the 3600, RCA to 1/4" on the amps. Funny thing is, I'm having issues with the right side output, not getting any signal. Haven't figured out if that's because of the amps, the connections or what, but I'm pretty sure each amp (Channel II) works just fine.. Going to see what happens when I switch to balanced XLR. The Ashly XR1000 will enable me to run the amps that way, before I was just going straight from the preamp to each amp.
Hmm, that's the opposite of what I experienced, what gives? Seems like at 0.775v, everything was too low and the sound quality was poor. I had the preamp at half (12 o'clock on the knob) but had to run each of the gain knobs at 0dB (Max) on the amps just to hear anything, which really sounded like the amps were being bypassed.. When I switched to 1.4v, it got much better, turned the gain dials back to about 3o'clock. 26dB sounded fuzzy like 0.775v. I think I need to revisit this.
Glad to hear that about the DC offset of the K2.
Noted. Come to think of it, I've never used them. Not a big fan of those cheap looking push style speaker connections..
As for the left right issue what happens when you swap the cables at the input to the amp?
Mike Caldwell
www.mikecaldwellaudioproductions.com
Turns out one of the switches wasn't fully engaged in a position. Once I cycled those a few times on the K2, all was well. You were right about the sensitivity settings, I don't know what I was doing before but the MA2402's worked really well last night as did the K2. But of course, the K2 only has 1.4v and 26dB available so I had to make due with 1.4.
More testing to follow, but both amps are really good! I don't know why the stigma of "You can't/shouldn't use a pro amp for home use" exists. My ears seem to prefer the K2 everywhere. That unit seems more authoritative on bass duties and is clear/dry/sterile/open up top. The 2402 seems slightly veiled in the upper registers. Everything is there, but slightly obscured/blurred, if that makes any sense. That's why I prefer the K2, it seems more accurate & less colored. Nothing I'd even notice if I didn't have another amp to compare it against. I had both 2402's running without any issues electrically. Isn't easy to see when the 2402s are clipping though, as the green IOC light or whatever always flashes dim and then sometimes flashes brightly. These amps are too much for the XPL200's though, the woofer ends up bottoming out a little before I see any clipping.
More testing to follow. Will compare against incumbent Adcom stuff and then pair the K2 with my Carver TFM 55x and see how that goes. Pretty sure the 2402's will end up for sale...
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