PDA

View Full Version : Feedback on Crown DC300A as LF amp



oldr&b
02-05-2004, 01:33 PM
Help me with this, please.

IMO, a decent used not abused $300 Crown DC300A connected bridged mono represents the best value in a low frequency specific power amplifier. I'm talking minimum 500 RMS 8 ohm bombproof watts @ .05% THD down to 1 Hertz. Please tell me what gives more bang for the buck in this specific application.

Also, I believe it's the KING OF SPARES. The amp to keep around for when the ship hits the sand.

4313B
02-05-2004, 02:08 PM
I just picked up yet another Citation 22 for $300. It's Consumer Crap though, so people on this forum might retch if not using balanced gear. :rotfl:

*****

Anyway, I've done the Crown D-150A and DC-300A with 4315B's, 4333B's, 4343B's, 4430's and 4435's and they both work well enough. I think the Citation 19 and Citation 22 are a bit better, the Citation 19 should probably be limited to just LF even after being modified with poly bypass caps. One could say the Citation 22 is a bit grungy on the top end and should also be limited to the LF but it's certainly a bit better than either Crown full range, or the Citation 16A or Citation 19 for that matter. Adcom GFA-545 and GFA-555 aren't bad either, although I don't know what they are going for these days - they too should be in the $150 to $300 range. Any of them should probably satisfy modest home LF requirements.

PaulB
02-05-2004, 02:42 PM
I'm overall very very happy with my Crown gear and agree they give damn good bang for the buck and have been nearly indestructable in my experience (I've owned most of mine since new, approx. '78). If you want a great laugh you have to read the original service manuals, (I have them if they are helpful to anyone). Whoever wrote them had a damn good sense of humor and among other things they describe their potential as welding power sources...

Tom Loizeaux
02-05-2004, 03:29 PM
Hey, I'm a Crown amp fan, but remember that DC means direct current, so I've been told. It WILL put out 1 Hz! I've known these DC Crown amps to fry speakers when over driven. If you use these, you should use some sub-sonic filtering in your signal path.
I use the Crown PS series amps partly because they have a 10Hz roll-off and a sub-sonic detector circuit.

Tom

PaulB
02-05-2004, 03:36 PM
:eek: well, knock on wood...

oldr&b
02-05-2004, 03:44 PM
Tom, you're certainly right. With DC300s if DC gets in, then DC goes out! Not for nothing, as our colleague noted above, could they conceivably be used for WELDING! Caveat emptor. Keep the input clean.

For another fascinating use of the wonderful DC300, check this out: www.sl-prokeys.com/prokeys/power.htm

oldr&b
02-05-2004, 04:06 PM
By the way, I readily acknowledge the DC300s main shortcoming and it's significant. They don't sound good enough to be used as a full range amplifier (except in emergencies!). However, IMO, if you want a tight, stone reliable LF amp, they're better than anything else.

4313B
02-05-2004, 04:42 PM
Well, that's you're opinion :)

I've owned both and even A/B'd them on several occassions. I still own the Citation 22's and don't hesitate to snag them when they show up for the stupid price of only $300. If you have the Crowns then use them for sure but don't cry if you can't find any for $300 because an Adcom GFA or Citation 22 will bust them up on the bottom end and you should be able to pick them up for $300 as well.

Whatever floats your boat. :smthsail:

*****

"I'm talking minimum 500 RMS 8 ohm bombproof watts @ .05% THD down to 1 Hertz."
Well, if one is into reading specs:

Crown DC-300A (FTC)
250 watts/channel into 4 ohms from 1 Hz to 20 kHz at 0.05% THD
155 watts/channel into 8 ohms from 1 Hz to 20 kHz at 0.05% THD
500 watts mono into 8 ohms from 1 Hz to 20 kHz at 0.05% THD
310 watts mono into 16 ohms from 1 Hz to 20 kHz at 0.05% THD
8 volts per microsecond slew rate (stereo)
16 volts per microsecond slew rate (mono)
Frequency Response is DC to 100 kHz +- 0.1 dB

Citation 22 (FTC)
200 watts/channel into 4 ohms from 20 Hz to 20kHz at 0.08% THD
200 watts/channel into 8 ohms from 20 Hz to 20kHz at 0.08% THD
400 watts/channel into 8 ohms from 20 Hz to 20kHz at 0.12% THD
160 volts per microsecond slew rate
Power Bandwidth is 10 Hz to 100 kHz
Frequency Response is 0.1 Hz to 250 kHz - 3 dB
Negative Feedback is 12 dB
Instantaneous Current Capability is +- 120 amps
Dymanic Power
High Voltage/High Current Mode
300 watts 8 ohms
500 watts 4 ohms
800 watts 2 ohms
High Current Mode
300 watts 4 ohms
500 watts 2 ohms
Bridged-mono Mode
600 watts 8 ohms
1000 watts 4 ohms

Anyway, that about does it for me and talking "amps" and "specs". One would really need to A/B them to get a feel for what they preferred. I've owned both and didn't cry about owning either one :p

I just react when I hear KING and bombproof and stuff :rotfl:

oldr&b
02-05-2004, 04:55 PM
Point taken, Giskard. I'm sure I've never heard a system that would let me appreciate the difference in a LF A-B shoot out. I'm splitting hairs for sure. Thanks for bearing with me. Opinions are like noses, yadda yadda yadda.:p

House de Kris
02-05-2004, 05:19 PM
For PA work, I have no trouble using Crown gear. I too use(d) a DC300A for subwoofer duty. In addition, a D150II for the woofer, a D-40 for the mids/tweets, and D-60 for monitors. Still looking for a D-75. Interestingly, all of these amps in the "D" series sound very similar, except the D-40 in my opinion. The little one is actually pretty nice. Perhaps I'm crazy, dunno. Oh, and I spent only two hunnerd smackers on my DC300A at the local swapshop.

Recently I picked up a Peavey DECA-528 (I think that's the number) for about $170. 250WPC@4ohm 1U high deep box amp. I've only listened to it for a short time, and the highs and mids are gawd-awful. The test will be the durability of this amp.

My biggest issue with the DC300A is its sheer weight. I admire brute-force designs, and love heavy amps in the home. But after lugging the rack with the DC300A and D150II in it around, I opted for a more powerful and lighter QSC amp.

In general, I've never heard any of these amps in bridged mode, so can't give comments on your specific needs. But my feelings thus far is that just about any rugged powerful amp should give you good results on a sub. Then finding the best bang for the buck is merely how lucky you are in shopping.

I could be wrong, what do the experts say?

oldr&b
02-05-2004, 06:13 PM
Kris, I guess I'm an old tin-eared rock & roll PA worshiping throwback and Crown is my link to that "olds'cool" stuff.

Maybe I'm wishing my Crown stuff had more "value" than it really does. I hate self-delusion but maybe that's what's coloring my judgement!

"They say confession's good for the soul..."

SteveLeigh
02-05-2004, 11:10 PM
Originally posted by oldr&b

For another fascinating use of the wonderful DC300, check this out: www.sl-prokeys.com/prokeys/power.htm [/B]

This act of insanity was forced upon me (us). I traveled to Europe with a very hot band, we tried a voltage converter, but the Hammond requires 60Hz to synchronize. 50 Hz get you flat, well below pitch. It became a frantic event to get the damn Hammond to play.

The solution was right under our noses, but it took a week to see it. If I recall properly, we sent 60Hz to the input, slowly cranked the output, and found 115vac on the terminals. 60 seconds later, the output was connected to a normal wall outlet, and during that and subsequent tours, we never had a drop of trouble with line freq synchronization.

FWIW - the Hammond is the only motor driven instrument on stage. Everything else can get away with 56 HZ or 62 Hz.

Side note: I bought my first JBL 4320s in 1971. Then bought a 2nd pair. Still have 'em, still love 'em. And here's the kick: they're guaranteed for LIFE.

The foam surrounds on the 2215 LFs have disintegrated from components in the ozone *FOUR TIMES*. Complete rebild cost absolutley zero. A call to Northridge, I selected a quality recone shop locally, JBL shipped complete rebuild kits out for all 4 2215s, and replacement = no charge. Amazing for speakers originally sold in 1971.

Plenty of interesting recording data at my site:

www.sl-prokeys.com

Best,
Steve

Oldmics
02-05-2004, 11:55 PM
Man,I been in Pro hell for many a year now and that is the first time that I have ever heard of of stablizing a Leslie by using an amplifer.Pretty slick trick. A sincere thanks for that tip.


Best regards,Oldmics

oldr&b
02-06-2004, 06:41 AM
Steve Leigh, small world! I've added your sweet and super web site to my list of favorites. I admire your item I listed here not only for the keen technical aspect but for scintillating writing style. Thank you and I'm truly sorry for your profound loss.

Ian Mackenzie
02-06-2004, 10:05 PM
Love that Pa experience.....if only we could turn back the clock.

Have a look at some of the newer mostfet pro power amps, they are surprisingly cheap these days and can really dump some current into low impediance loads.

Ian

PSS AUDIO
02-07-2004, 02:49 AM
Originally posted by Ian Mackenzie
Have a look at some of the newer mostfet pro power amps, they are surprisingly cheap these days and can really dump some current into low impediance loads.

Ian

Good morning!

But how do they sound?

That IS the question, do they sound good or do they sound bad?

What is the use spending little money for an awful sound?

About DC and Crown DC300 amplifiers letting DC in and out, the best thing is not placing a filter in the audio circuitry as you will loose the benefit of DC sound, one must place, as I do, at the output of the amplifier a DC detector and when there is more than 2V, then the output relay disconnects the speaker from the amplifier.

The trick is done and you can have all the benefit of those very low frequencies one cannot hear but one can feel!

Alex Lancaster
02-07-2004, 07:35 AM
Loved that trick of using an amp to get 60Hz!!; Now You can buy not too expensive solid state phase inverters in all sizes, but they use to be horribly expensive, specially the motor-generator type.

Alex.

asta
09-11-2010, 07:14 PM
This act of insanity was forced upon me (us). I traveled to Europe with a very hot band, we tried a voltage converter, but the Hammond requires 60Hz to synchronize. 50 Hz get you flat, well below pitch. It became a frantic event to get the damn Hammond to play.

The solution was right under our noses, but it took a week to see it. If I recall properly, we sent 60Hz to the input, slowly cranked the output, and found 115vac on the terminals. 60 seconds later, the output was connected to a normal wall outlet, and during that and subsequent tours, we never had a drop of trouble with line freq synchronization.

FWIW - the Hammond is the only motor driven instrument on stage. Everything else can get away with 56 HZ or 62 Hz.

Side note: I bought my first JBL 4320s in 1971. Then bought a 2nd pair. Still have 'em, still love 'em. And here's the kick: they're guaranteed for LIFE.

The foam surrounds on the 2215 LFs have disintegrated from components in the ozone *FOUR TIMES*. Complete rebild cost absolutley zero. A call to Northridge, I selected a quality recone shop locally, JBL shipped complete rebuild kits out for all 4 2215s, and replacement = no charge. Amazing for speakers originally sold in 1971.

Plenty of interesting recording data at my site:

[/URL]

Best,
Steve "Looney" Leigh

I tried to buy an organ from this guy, but this guy is a not job. The used organs that he had left out in the yard were worthless and overpriced. When I refused to buy one from him; I started receiving crank phone calls late at night. Then I find these two sites about him. http://www.jsbigdog.blogbus.com (http://www.sl-prokeys.com) and [url]http://www.greatauntirma.wordpress.com He has been charged and convicted of making harassing phone calls against someone.

He claims to be some sort of famous musician, so he has given up his right to privacy. He is also violent. He has a restraining order from his ex-wife from when he was beating her.

JeffW
09-11-2010, 07:30 PM
Luckily, it looks to be some 6 years since he's graced this site with his presence.

jbl_daddy
09-12-2010, 09:33 AM
I used a DC300 ll running two B380's in my theater and replaced it with a crown k2. Much more distinction on the sub. I still use one in mono for a single B380 in my family room and am very happy.

louped garouv
09-15-2010, 07:44 AM
I used a DC300 ll running two B380's in my theater and replaced it with a crown k2. Much more distinction on the sub. I still use one in mono for a single B380 in my family room and am very happy.


do you think it's the additional power you are liking?

jbl_daddy
09-15-2010, 06:45 PM
Yes, I immediately noticed the difference. I am a huge fan of the DC300 so please do not think i am bashing them. Ps. I own 4 DC300's and would never part with them.
Mark

Doc Mark
01-06-2014, 10:44 AM
Greetings, All,

I still have my first Crown DC300, which I got in a trade from our keyboard player, back around 1980. Our band used to use it for PA use, and once, up in Minneapolis, the Crown passed DC to our crappy Bose 802 copies, and friend all those little speakers!! Got the amp fixed at a Crown dealer, and it went into storage. I got it when looking for a big amp, and my friend offered to trade it to me for a VW Fastback with a blown engine! I snapped up the trade, and have used that old amp for many happy years since then, with no problems, at all!

OK, enough reminiscing, here is my question: What are the differences/upgrades from the Crown DC300, to the DC300A, to the DC300A II, and then the PS 400? I have that old DC300, plus two DC300A's, and recently scored a D150AII and D45A, and want to use the lot of them in an all active system. As a side note, my old friend from whom I traded my VW for the DC300, recently gifted me a huge Peavey CS1200X amp, which is a real brute!! As a subwoofer amp, that one might have some use..... But, an all-Crown system rather calls to me, too.....!! Thanks for any thoughts, or comments, on the differences between the old Crown big amps. Take care, and God Bless!

Every Good Wish,
Doc

PaulB
01-06-2014, 11:26 AM
Someone may well be more knowledgeable than I on this, but my rather vague recollection is that the A had "IOC", input output comparison, essentially clipping indicators. I seem to recall that there was even an upgrade kit available at one time. As to the II series, I'm afraid I don't know as that was after my time. Hope that's of some help!

bill8888
01-06-2014, 11:50 AM
I don't know much about the DC300A except that it's rather industrial looking and most wives wouldn't want it sitting in the living room. To appease the wife I put my DC300A in a nice walnut Phase Linear case...It fit perfectly without any modification. The only issue is the walnut case can cost nearly as much as a used DC300A.:)

Doc Mark
01-06-2014, 11:56 AM
Hey, Paul and Bill,

Thanks, very much. Bill that old Crown looks great in it's new home. Nicely done. I'm lucky in that Sweet Bride knows that musicians needs their "stuff about them", and she has no problem with Crown amps, or just about any other musical gear, in the living room, as long as it's arranged nicely. If this Crown amp project comes to fruition, I'll have to change my Hi-Fi cabinet, as the current one, which I built back in 1983, is chock-full, and there is not more room. I'd like the Crowns to be rack-mounted, as they are easier to hook up, and maintain, that way. At least for me..... Thanks, again, for your comments, and I look forward to hearing more comparisons from other members, too. Take care, and God Bless!

Every Good Wish,
Doc

subwoof
01-06-2014, 04:23 PM
there were at least 9 versions of this amp - and I have used / serviced /still own one of each vintage in my collection.

The very first 2 gens ( DC300 as used at woodstock ) were different ( no opamps. hysteresis switch ) and they are the only ones that have a continuous front panel with fuses - all the "A" subsequent versions had ears that could be removed but no "end bars" were ever made available like the other "D" amps so they did not sell as well as the 150 or 60/75's that could.

sub

martin2395
01-06-2014, 04:39 PM
Is this the oldest version of the DC300?

61078

BMWCCA
01-06-2014, 06:54 PM
What are the differences/upgrades from the Crown DC300, to the DC300A, to the DC300A II, and then the PS 400? I have that old DC300, plus two DC300A's, and recently scored a D150AII and D45A, and want to use the lot of them in an all active system.

Yes, the DC300A added IOC lights. The -II was all black with the front knobs all on the right side and the back was a flipped version of the previous model. The PS-400 added a bit more power, new circuitry, the ability to use balanced XLRs through an adapter, more enclosure over the electronics hanging out the back, as well as turn-on delays, monitor jack, signal-presence lamps, and other upgrades. The PS-series was intended to replace the D-series but the increase in price helped to maintain the D-series popularity and kept those in production nearly as long as the P-series.

Doc Mark
01-06-2014, 07:14 PM
Evening Sub, and BMWCC,

Much appreciated, Gentlemen. The little D45 arrived today, and I only wish ALL my amps were in the nice condition of this little amp! I'll test it, and the D150AII, in the next few days, when I drag out some speakers, about which I don't care much, so I don't damage my good speaks. Thanks, again, and God Bless!

Every Good Wish,
Doc

subwoof
01-06-2014, 07:24 PM
the PS200 is the same as the D150 and the 400 the same as the 300A - the only diff is packaging and the additional chip that allows delay turn-on and display board revisions. Same power transformers, number of outputs, etc etc, Just a much better frame for multi-amp commercial installs. Power specs tend to change with marketing people so take it with a grain of salt.

The PL3+4 are versions with more blinky lights ( oh yeah - we NEED them )..

if any of you guys are looking for some serious sub action, I have a large number of the 2KW mono block amps of different vintages / features.. M600/7560/DO2000/etc... AND I can do a simple rewire of the front panel card slot so the standard PIP cards will work..

I also have some 10KW and 36KW amps.

sub

BMWCCA
01-06-2014, 09:14 PM
the PS200 is the same as the D150 and the 400 the same as the 300A - the only diff is packaging and the additional chip that allows delay turn-on and display board revisions. Same power transformers, number of outputs, etc etc, Just a much better frame for multi-amp commercial installs. Power specs tend to change with marketing people so take it with a grain of salt.

Scott Fitlin frequently mentioned differences between the PS-series an the D-series. He used them both but seemed to prefer the PS. This was but one of his comments on the subject:


The PS and Powerline series are basically the same. The PS was the pro variant, and the Power Line was Crowns attempt, in the `80,s at the consumer/home audio market.

I have them all, they are all good, the PS and Power Line series uses what Crown called Multi-Mode circuitry, which allowed the amps pre driver stage to run in Class A fir the first couple of watts, and then, as the amp gets pushed, it switches over to AB+B. I happen to like the Power Line series, and the PS series, I also happen to like the older and original D series, as in D-150A,s and DC-300,s and the D-75.

Since I`ve used them all, I do notice slight differences between the different series and generations of amps, but only slight, nothing major. If you use them properly, you should get great sound out of any of them. I particualrly like the highs using Crown Power Line 2,s mid 80,s, and I like a crown D-150A, white face circa 1978 or so for my mid horns. The slight differences in sound are due to the circuit refinements and possibly the newer generation of output transistors. And there are some who say the older D series was the Best Crown ever made.

I did notice an improvement in the higher frequencies when I switched from DC300A-II and D150A-II to PS-200 and 400 in the biamped 4345 system.

There's also some interesting related info on the smaller D-series amps from Subwoof in this old thread: http://www.audioheritage.org/vbulletin/showthread.php?18825-WTB-jbl-urei-6215-amp-or-similar&p=190556#post190556

subwoof
01-07-2014, 08:52 AM
Well the original "D" series amplifier design dates to 1967 and over the years better quality caps, resistors, chips and (finally) reliable output transistors meant that the sound would improve overall to a small degree.

Many of the earlier configurations had issues with oscillations depending on what opamp and what driver or output was used so that also was corrected. This also meant many were sold that were NOT updated so they had a certain "sound" with certain loads...and that era had studio monitor crossovers with just TWO caps and Lpads...jus sayin'

I still think the PSA2 / SA2 with the motorola dual-die outputs tweaked with the showco mod is the overall best home amplifier.. Takes a bit of work to update and such but it's quite punchy. The first stage is a precision diff transistor pair just like the very high end mixing console mic preamps.

Think of it as an older muscle car with a large V8 but newer computer ignition/carb control...

sub
ps - still haven't got the knob boxes sorted yet phil..:)

big2bird
01-11-2014, 05:44 AM
Well the original "D" series amplifier design dates to 1967 and over the years better quality caps, resistors, chips and (finally) reliable output transistors meant that the sound would improve overall to a small degree.

Many of the earlier configurations had issues with oscillations depending on what opamp and what driver or output was used so that also was corrected. This also meant many were sold that were NOT updated so they had a certain "sound" with certain loads...and that era had studio monitor crossovers with just TWO caps and Lpads...jus sayin'

I still think the PSA2 / SA2 with the motorola dual-die outputs tweaked with the showco mod is the overall best home amplifier.. Takes a bit of work to update and such but it's quite punchy. The first stage is a precision diff transistor pair just like the very high end mixing console mic preamps.

Think of it as an older muscle car with a large V8 but newer computer ignition/carb control...

sub
ps - still haven't got the knob boxes sorted yet phil..:)

I have 2 of those PSA-2 amps. What is the showco mod?

Hoodoo Haus
01-11-2014, 09:55 AM
I have 2 of those PSA-2 amps. What is the showco mod?

Check out the PSA-2xh variant, it was the ShowCo mod institutionalized...
From my understanding

subwoof
01-11-2014, 03:18 PM
I've posted this before so take a poke around the site with the search function.

In essence the showco mod was a re-tapped power transformer ( one each channel ) and a bias mod. This raised the DC voltage to +/- 95v from the stock 73 (?) so the 8 ohm power is around 420 and 4 is close to 700..:)

Because there were ONLY 8 outputs per channel, and the main caps rated at 100V, it was a "right on the edge" mod that pushed the limit...the new dual dies are almost 400 watts *each* dissipation and I install 125V caps so...

thump.

I also mod the balanced module's filters so it is HP/LP at 125/25 so it is a dedicated subwoofer amp with limiters.

Couldn't make it any lighter though.

Doc Mark
01-12-2014, 02:30 PM
Greetings, All,

In addition to the big Peavey amp I was recently gifted, I got to test the two Crown amps, too. Both the D150AII, and the D45 worked perfectly. Clean, smooth, sweet, and concise, I am totally happy with this pair of older Crown amps!! The Peavey, too, did very well, and is very powerful, clean, and tight, but it's top end is not as sweet as either of the Crowns, and most certainly not as sweet as my H/K amps. All in all, a happy and satisfactory day of amp testing, and musical listening!! Thanks to one and all for your comments and suggestions on the older Crowns! MUCH appreciated! Take care, and God Bless!

Every Good Wish,
Doc

maxserg
01-13-2014, 01:59 PM
I've posted this before so take a poke around the site with the search function. In essence the showco mod was a re-tapped power transformer ( one each channel ) and a bias mod. This raised the DC voltage to +/- 95v from the stock 73 (?) so the 8 ohm power is around 420 and 4 is close to 700..:) Because there were ONLY 8 outputs per channel, and the main caps rated at 100V, it was a "right on the edge" mod that pushed the limit...the new dual dies are almost 400 watts *each* dissipation and I install 125V caps so...thump. I also mod the balanced module's filters so it is HP/LP at 125/25 so it is a dedicated subwoofer amp with limiters.Couldn't make it any lighter though.Did that with the DC-300 to. Change primary tap from 120v to 100v and that gave 210w/ch/8 Ohms instead of 170w/ch. Never had any problem with these.