Hi. NEEEEED HElp!
The rather odd design (for me at least) is puzzleing me - can't figure out precisely how it works - AND - i have a channel that doesn't work as it is supposed to. It says a little - but even low signal causes the amp to sound distorted and the clip LED flashes in rythm with the SIG LED and (as a result thereof) in sync with the music that is fed into the amp.
Do anyone have a schematic!? Please do help!
Thanks in advance
Regards
Hans-Henning Terp-Hansen, Denmark
The rather odd design (for me at least) is puzzleing me - can't figure out precisely how it works - AND - i have a channel that doesn't work as it is supposed to. It says a little - but even low signal causes the amp to sound distorted and the clip LED flashes in rythm with the SIG LED and (as a result thereof) in sync with the music that is fed into the amp.
Do anyone have a schematic!? Please do help!
Thanks in advance
Regards
Hans-Henning Terp-Hansen, Denmark
Copy or not
Hi there
Fact is that the component markings (R5 C7 etc) are exactly the same. So is the connector numbering.
The Silkscreen markings matches the schematic as well.
Weather Behringer is copying or it is an OEM common product i do not know.
One could say that Behringer some years ago went through a lawsuit. They were acused for copying Mackie designs. From what I know Mackie either won the case or they made an "agreement".
If Behringer is copying again, I guess they prove to be stupid.
So I think, without being able to support it with anything, that Behringer has some sort of agreement.
Regards
Hans-Henning, Denmark
Hi there
Fact is that the component markings (R5 C7 etc) are exactly the same. So is the connector numbering.
The Silkscreen markings matches the schematic as well.
Weather Behringer is copying or it is an OEM common product i do not know.
One could say that Behringer some years ago went through a lawsuit. They were acused for copying Mackie designs. From what I know Mackie either won the case or they made an "agreement".
If Behringer is copying again, I guess they prove to be stupid.
So I think, without being able to support it with anything, that Behringer has some sort of agreement.
Regards
Hans-Henning, Denmark
Re: Copy or not
Sounds like it's an OEM common product to me?, it's very common these days, many different companies buy OEM products made cheaply in China or elsewhere - I see no reason why QSC wouldn't?, and certainly none why Behringer wouldn't?.
From what I recall (and there's been a LOT about it on Usenet), Mackie lost the case as the Behringer mixer wasn't a copy at all, and only had a similar visual appearance.
They much more recently had to recall and redesign their new range of effect pedals, as they looked too much like Boss ones! - you had to look at the name to tell the difference!.
Personally I like the Behringer gear, it's keenly priced, performs well, and has proved reliable.
How do the QSC prices compare with the Behringer prices?, for the same unit manufactured in the same factory?.
BTW, I have a Behringer PMH880S and BX1200, does anyone have circuits for them?, or links to a 'similar' unit - certainly the BX1200 is a visual 'copy' of a Hartke model.
freedom said:
Sounds like it's an OEM common product to me?, it's very common these days, many different companies buy OEM products made cheaply in China or elsewhere - I see no reason why QSC wouldn't?, and certainly none why Behringer wouldn't?.
From what I recall (and there's been a LOT about it on Usenet), Mackie lost the case as the Behringer mixer wasn't a copy at all, and only had a similar visual appearance.
They much more recently had to recall and redesign their new range of effect pedals, as they looked too much like Boss ones! - you had to look at the name to tell the difference!.
Personally I like the Behringer gear, it's keenly priced, performs well, and has proved reliable.
How do the QSC prices compare with the Behringer prices?, for the same unit manufactured in the same factory?.
BTW, I have a Behringer PMH880S and BX1200, does anyone have circuits for them?, or links to a 'similar' unit - certainly the BX1200 is a visual 'copy' of a Hartke model.
While I agree at first blush that the Behringer looks a lot like the QSC circuitry (haven't verified components and numbering is the same yet) I assure you that the EP1500 is NOT the same unit as the RMX 1450.
Behringer may have nic'd the design from QSC in terms of schematic and components, but the build quality is very different. The QSC does not contain any surface mount components (no power amp should ever contain surface mount components on the same board with power devices that are mounted to the main heat sink for mechanical stress reasons). The QSC is cooled by an industral grade AC fan while the Behringer is cooled by a cheesy plastic frame DC fan like the one in your computer power supply. Everything about the Behringer is cheap and light-duty.
Don't get me wrong; It's not that I don't like Behringer; I like some of their processors and recording gear, but I don't like their power amplifiers and I don't like using their stuff in a live sound environment because it fails too often at a critical moment. They make some products that are great bang for the buck! I love my Autocom 1400 compressors and my UCA202 U-control interface.
I have had to work on too many EP1500 that have strange intermittent problems or just plain quit, but my ~20 year old QSC amplifiers ( 2 x MX1500 + 2 x 1400 series one) just keep working every time I turn them on. My amps spend most of their time reproducing progressive house and drum'n'bass at warehouse partys, very demanding music both in terms of power and duration (shows typically last 8 hours) and I would trust my old QSC's over a whole stack of EP1500s or 2500s under any circumstances.
If you want a good amplifier for home use or studio use where it isn't mission critical, then go for the Behringer. If you are in a live sound situation and it is mission critical, go QSC or Crown or maybe even Crest; but stay away from Behringer, Mackie, and Peavey!
Behringer may have nic'd the design from QSC in terms of schematic and components, but the build quality is very different. The QSC does not contain any surface mount components (no power amp should ever contain surface mount components on the same board with power devices that are mounted to the main heat sink for mechanical stress reasons). The QSC is cooled by an industral grade AC fan while the Behringer is cooled by a cheesy plastic frame DC fan like the one in your computer power supply. Everything about the Behringer is cheap and light-duty.
Don't get me wrong; It's not that I don't like Behringer; I like some of their processors and recording gear, but I don't like their power amplifiers and I don't like using their stuff in a live sound environment because it fails too often at a critical moment. They make some products that are great bang for the buck! I love my Autocom 1400 compressors and my UCA202 U-control interface.
I have had to work on too many EP1500 that have strange intermittent problems or just plain quit, but my ~20 year old QSC amplifiers ( 2 x MX1500 + 2 x 1400 series one) just keep working every time I turn them on. My amps spend most of their time reproducing progressive house and drum'n'bass at warehouse partys, very demanding music both in terms of power and duration (shows typically last 8 hours) and I would trust my old QSC's over a whole stack of EP1500s or 2500s under any circumstances.
If you want a good amplifier for home use or studio use where it isn't mission critical, then go for the Behringer. If you are in a live sound situation and it is mission critical, go QSC or Crown or maybe even Crest; but stay away from Behringer, Mackie, and Peavey!
Pictures of the inside of both. They may be the same circuit, but definitely not the same design. I'd agree with dj_ee. Behringer is about quality to a price-point, while QSC is more about quality.
I did get page one of the Behringer EP2500 schema once, but it's not much good without the other pages...
I did get page one of the Behringer EP2500 schema once, but it's not much good without the other pages...
QSC / Behringer similarity.
Upon further investigation I have found that the circuits are very similar, even to the point of saying that Behringer maybe did copy most of the QSC design. I must also admit that the RMX1450 does have some surface mount components in it as well, much to my surprise. If they did copy the circuit they at least went to the trouble of updating some of the parts and re-arranging the connector and component numbers.
The components on the underside of your behringer EP1500 circuit board are the input buffer circuitry, LED driver, and driver opamps; there are three ICs and handfull of resistors and small capacitors; not as much circuitry as expected.
So far I have seen mostly connector problems with the EP1500s and 2500s; channels will intermittently quit or you won't be able to completely attenuate one channels audio, or the LEDs won't work. All I have done so far is to burnish the connector pins and use DeOxit D5 cleaner on them and it has worked, but amps like this shouldn't be having these annoying kind of problems. At least the connector failure isn't causing smoke leaks (yet!).
Upon further investigation I have found that the circuits are very similar, even to the point of saying that Behringer maybe did copy most of the QSC design. I must also admit that the RMX1450 does have some surface mount components in it as well, much to my surprise. If they did copy the circuit they at least went to the trouble of updating some of the parts and re-arranging the connector and component numbers.
The components on the underside of your behringer EP1500 circuit board are the input buffer circuitry, LED driver, and driver opamps; there are three ICs and handfull of resistors and small capacitors; not as much circuitry as expected.
So far I have seen mostly connector problems with the EP1500s and 2500s; channels will intermittently quit or you won't be able to completely attenuate one channels audio, or the LEDs won't work. All I have done so far is to burnish the connector pins and use DeOxit D5 cleaner on them and it has worked, but amps like this shouldn't be having these annoying kind of problems. At least the connector failure isn't causing smoke leaks (yet!).
i had a behringer in here for repair a while back...... probably a 1500...... one of the most annoying things is that all of your positive rail voltages are fed with identical red wires (as well as the negative rails feeding from identical black wires)....... if you remove the board to work on it MARK your wires..... i didn't, and let the magic smoke out of one of the filter caps (surprisingly, didn't damage the amp circuitry though) you have a +55v rail and a +110v rail, and putting the +110v rail across a 65v cap isn't pretty......... you may complain about peavey, but at least they color code their rail voltages.........
Class G or H? Why does this seem backwards?
Hmm... As I understand it, class G has two power rails, and it switches to the higher rail momentarily during peaks. Class H, on the other hand, uses a switching power supply to track the signal, so the output devices have a constant low voltage drop across them. This looks more like a class G to me, but I could be wrong.
The QSC schematic shows a 28 V DC fan.
Even disregarding the class G/H issue, no one has mentioned the "rather odd design". I've seen this once before and it confuses me quite a bit. It looks as if the node that would normally be an output is actually ground, so that the output devices are pulling the entire power supply (floated by the transformer) up or down around that ground point, and the center tap of the amp's transformer ("CT_A") becomes the actual output. Is there a name for this type of amp design? What is the benefit of this (unintuitive) configuration? Would this also explain why they aren't using regulators to generate the 15 V for the op-amps?
4fun said:
Hmm... As I understand it, class G has two power rails, and it switches to the higher rail momentarily during peaks. Class H, on the other hand, uses a switching power supply to track the signal, so the output devices have a constant low voltage drop across them. This looks more like a class G to me, but I could be wrong.
dj_double_e said:
The QSC schematic shows a 28 V DC fan.
Even disregarding the class G/H issue, no one has mentioned the "rather odd design". I've seen this once before and it confuses me quite a bit. It looks as if the node that would normally be an output is actually ground, so that the output devices are pulling the entire power supply (floated by the transformer) up or down around that ground point, and the center tap of the amp's transformer ("CT_A") becomes the actual output. Is there a name for this type of amp design? What is the benefit of this (unintuitive) configuration? Would this also explain why they aren't using regulators to generate the 15 V for the op-amps?
Failure on EP1500 and EP2500?
Hi There.
I have been told, also on this forum, that the EP1500 and EP2500 fails often and are not suitable for live PA...
I cannot say that I agree on this. The reason is that I am running 6 Behringer amps in a dual rack setup. They are bumped in and out of cars, trailers and venues and keep rocking everytime I turn them on.
Check this link for pics.
http://www.largerthanlife.dk/cms/?Forst%E6rkerrack
note: The website is in danish however the pics speaks any language.
Cheers, Hans-Henning, Denmark.
Hi There.
I have been told, also on this forum, that the EP1500 and EP2500 fails often and are not suitable for live PA...
I cannot say that I agree on this. The reason is that I am running 6 Behringer amps in a dual rack setup. They are bumped in and out of cars, trailers and venues and keep rocking everytime I turn them on.
Check this link for pics.
http://www.largerthanlife.dk/cms/?Forst%E6rkerrack
note: The website is in danish however the pics speaks any language.
Cheers, Hans-Henning, Denmark.
guys.....
lets face it ....same factory that produces qsc boards works also for behringer buat also for some electrovoice amps and also for a lot of phonic amps ......
in the past i was dealing a lot for service in adcom products and that was in the turning point when adcom decided to have the boards manufactured in taiwan
yes ok the quality was almost the same but the things they missed and the mods made after the board produced and especially in brand new models was something else......
huge adcom amp with gozzilion of mosfet inside kept fruing eggs while in almost idle cause the used not matched mosfets !!!!!!! it was so obvious cause at the time all mosfet from adcom had a hand writing about matching on them ...well not in the particular product......
replace them with original matched set and all was just fine ....
our small chimnese products.........
lets face it ....same factory that produces qsc boards works also for behringer buat also for some electrovoice amps and also for a lot of phonic amps ......
in the past i was dealing a lot for service in adcom products and that was in the turning point when adcom decided to have the boards manufactured in taiwan
yes ok the quality was almost the same but the things they missed and the mods made after the board produced and especially in brand new models was something else......
huge adcom amp with gozzilion of mosfet inside kept fruing eggs while in almost idle cause the used not matched mosfets !!!!!!! it was so obvious cause at the time all mosfet from adcom had a hand writing about matching on them ...well not in the particular product......
replace them with original matched set and all was just fine ....
our small chimnese products.........
Re: Class G or H? Why does this seem backwards?
I thing the main reason to use such a configuration is a better cooling for the old TO2 final's capsules because those could be mounted directly to the radiator, with no izolation. But with the new plastic capsules for finals its not a big point anymore.
JoelM81 said:
I thing the main reason to use such a configuration is a better cooling for the old TO2 final's capsules because those could be mounted directly to the radiator, with no izolation. But with the new plastic capsules for finals its not a big point anymore.
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