http://www.diyaudio.com/forums/solid-state/252809-dynacord-l2400-output-board-schematic.html
I have seen the above amp performing and its just breath taking superb in dynamics and very effortless driving 4 x 18 inch B&C subwoofers per channel and they were literally shaking the walls of the buildings on a live event.
I was just checking the schematics of the above amp that what class is it or what really made that amp to do that job. I have seen labgruppen, crown but none of them came close to such an extreme effortless dynamic sound. sledge hammer tight and absolutely no stint.
Just gone through the schematic and found shocking that there are about 9 x 2200/160V psu caps ( gone mad after seeing this )
saw another thing that the rails are at +/-68V and got shocked again..
how come something could deliver that performance with just such low voltage? is the amp bridged?
just want to know which class is this amplifier? and how come it could deliver such a tremendous dynamics with just less than 20000uf caps?
I have seen the above amp performing and its just breath taking superb in dynamics and very effortless driving 4 x 18 inch B&C subwoofers per channel and they were literally shaking the walls of the buildings on a live event.
I was just checking the schematics of the above amp that what class is it or what really made that amp to do that job. I have seen labgruppen, crown but none of them came close to such an extreme effortless dynamic sound. sledge hammer tight and absolutely no stint.
Just gone through the schematic and found shocking that there are about 9 x 2200/160V psu caps ( gone mad after seeing this )
saw another thing that the rails are at +/-68V and got shocked again..
how come something could deliver that performance with just such low voltage? is the amp bridged?
just want to know which class is this amplifier? and how come it could deliver such a tremendous dynamics with just less than 20000uf caps?
I don't know what schematic you were looking at but the one you refer to has 136VDC rails hence the 160VDC capacitors in the supply. But if you notice the PS for the output stage is floating, why would that be? And why does each channel appear to have two output sections? Why is one of the output sections grounded? Go do some research at the Crown site for the answers. I think you'll find it interesting if you can understand it. They call it Grounded Bridge.
Craig
To speed things up download the Crown Power Base 1 service manual and read the theory.
Craig
To speed things up download the Crown Power Base 1 service manual and read the theory.
Last edited:
I was looking at this schematic.. http://www.diyaudio.com/forums/atta...acord-l2400-output-board-schematic-84157e.pdf
is it grounded bridged amplifier?
is it grounded bridged amplifier?
Looks like it kinda runs BTL with a floating supply. Not sure how exactly that setup works (one half of the amp would seem to be pulling the floating pair of supplies up and down), but if the schematic says the thing can do 69.3 V into 4 ohms (which is 1200 watts) I'll believe that. The circuit gives the impression of having been competently designed.
9x 2200 µF / 160 V might seem modest to you but
a) PA amps generally aren't designed with as much dynamic headroom to begin with and
b) it's not as little as you think if you look at things from an energy storage perspective.
These 9 2200 µF caps at ~140 V store as much energy as 2x9 2200 µF caps on ~100 V, so they're about the equivalent of 2x 20000 µF with +/- 100 V supplies.
I'm not exactly sure why they chose this supply setup, but my hunch is that this one allows the outputs to be run in BTL while still being friendlier in terms of SOA compared to a +/- 100V supply.
Oh, and this looks like your average AB class amplifier, though fully balanced.
EDIT: Looks like I was a little too slow... Anyway...
9x 2200 µF / 160 V might seem modest to you but
a) PA amps generally aren't designed with as much dynamic headroom to begin with and
b) it's not as little as you think if you look at things from an energy storage perspective.
These 9 2200 µF caps at ~140 V store as much energy as 2x9 2200 µF caps on ~100 V, so they're about the equivalent of 2x 20000 µF with +/- 100 V supplies.
I'm not exactly sure why they chose this supply setup, but my hunch is that this one allows the outputs to be run in BTL while still being friendlier in terms of SOA compared to a +/- 100V supply.
Oh, and this looks like your average AB class amplifier, though fully balanced.
EDIT: Looks like I was a little too slow... Anyway...
Licensed? Patent's run out?
Last edited:
sgrossklass you are correct, the left side of that schematic pulls either side of the power supply towards ground depending on the signal. A positive signal would pull the negative side towards ground and vice versa. Seems overly complicated to me but what do I know?
Craig
Craig
can we do ground bridge with lme49810s? if so what is the inverter circuit to be used the one which flips the input signal to operate in grounded bridge operation? an inverting opamp?
EV P3000 vs Dynacord L2400 vs Crown Mac's & Mic's
I know this is an old thread, but for those needing the information...
The EV P2000 & P3000 and the Dynacord L2400 are grounded bridge amplifiers. The main output rails are at +- 72VDC (approx) and the supply for those is floating. Basically, when one side is pulling the + output low, the other is pulling the other side (grounded side) high, thus 'imposing' most of the 144 volts (72 +72) across the speaker output and vice-versa.
EV does it a bit differently than Crown. The Crowns use a 'voltage translation' circuitry to affect the high side driver (+ output). This translates the lower ground referenced input voltages up to where the high side drivers have to run.
EV, on the other hand, uses driver circuits that run off of a +- 135 volt ground referenced supply to keep the drive voltages where they need to be to run BOTH the high and low side drivers during the entire signal cycle.
IMHO, the EV's are easier to work on because everything is normalized to a ground reference, rather than the Crown voltage translation system. I've worked on a lot of both and learned a lot in the process. Each animal has its own set of peculiarities...
I know this is an old thread, but for those needing the information...
The EV P2000 & P3000 and the Dynacord L2400 are grounded bridge amplifiers. The main output rails are at +- 72VDC (approx) and the supply for those is floating. Basically, when one side is pulling the + output low, the other is pulling the other side (grounded side) high, thus 'imposing' most of the 144 volts (72 +72) across the speaker output and vice-versa.
EV does it a bit differently than Crown. The Crowns use a 'voltage translation' circuitry to affect the high side driver (+ output). This translates the lower ground referenced input voltages up to where the high side drivers have to run.
EV, on the other hand, uses driver circuits that run off of a +- 135 volt ground referenced supply to keep the drive voltages where they need to be to run BOTH the high and low side drivers during the entire signal cycle.
IMHO, the EV's are easier to work on because everything is normalized to a ground reference, rather than the Crown voltage translation system. I've worked on a lot of both and learned a lot in the process. Each animal has its own set of peculiarities...
- Status
- Not open for further replies.