Hi Guys
A grounded-bridge amp is a specific amplifier type that provides a single-ended output, i.e.e one signal line and one ground to the speaker.
In the circuit, two output stages are used, and these are driven out of phase. If you imagine each to be just complimentery EFs buffers, then both buffers are tied to the split-rail supplies as usual: NPN collectors to V+ and PNP collectors to V-. The unusal feature is that the power supply is not tied to to ground and floats. It is "positioned" by the negative-phase output stage while the positive-phase output stage drives the speaker. This has the overall effect of allowing the whole supply voltage to be swung across the speaker in either direction. The front-end of this amp is identical to a standard amp except that it drives two output stages instead of one.
A grounded-bridge amplifier can be considered the same as any standard amplifier and can be bridged with any other amplifier.
A bridged amplifier wiring uses two separate and independent power amps to drive the ends of the speaker from each end. The PAs are driven out of phase so one output goes positive while the other goes negative. If the amplifiers are identical, then the effect of bridged wiring and drive is to allow the full supply to be swung across the speaker in either direction.
Where a grounded-bridge amplifier is considered to be a single amplifier, bridged wiring of two amplifiers requires two amplifiers. If the supply voltage in all the amps is the same, then the bridged-amp will have the same output power as the two bridged amplifiers.
Have fun
A grounded-bridge amp is a specific amplifier type that provides a single-ended output, i.e.e one signal line and one ground to the speaker.
In the circuit, two output stages are used, and these are driven out of phase. If you imagine each to be just complimentery EFs buffers, then both buffers are tied to the split-rail supplies as usual: NPN collectors to V+ and PNP collectors to V-. The unusal feature is that the power supply is not tied to to ground and floats. It is "positioned" by the negative-phase output stage while the positive-phase output stage drives the speaker. This has the overall effect of allowing the whole supply voltage to be swung across the speaker in either direction. The front-end of this amp is identical to a standard amp except that it drives two output stages instead of one.
A grounded-bridge amplifier can be considered the same as any standard amplifier and can be bridged with any other amplifier.
A bridged amplifier wiring uses two separate and independent power amps to drive the ends of the speaker from each end. The PAs are driven out of phase so one output goes positive while the other goes negative. If the amplifiers are identical, then the effect of bridged wiring and drive is to allow the full supply to be swung across the speaker in either direction.
Where a grounded-bridge amplifier is considered to be a single amplifier, bridged wiring of two amplifiers requires two amplifiers. If the supply voltage in all the amps is the same, then the bridged-amp will have the same output power as the two bridged amplifiers.
Have fun
Ground bridge amplifier have two separate power supply.
Transistor output on ground bridge amplifier's has single power supply, non of them is grounded. The input power supply is dual (center tap) and separate from transistor output power supply. Ground was taken from input power supply.
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Some indonesian diyers making crown grounded bridge amps
Some indonesian diyers making crown grounded bridge amps
yes sir ...
yes sir,,, so what is the answer of the more powerful one ??? btl or ground bridge
Ground bridge is BTL with single supply on output transistor. If single supply Ground bridge, example 100V and split supply BTL, example +50V 0 -50V, the power is same.
P = V x V / R
P = power
V = Voltage
R = Impedance or resistance
You can not break this law
There is absolutely no theoretical reason why one is superior to the other. Practical considerations favor the grounded bridge. The fact that signal ground is not tied to the power supply at all means there is no possibility of signal ground contamination, a significant source of distortion. These distortion mechanisms don't show up in a simulation unless the entire layout is simulated - including real resistances and reactances of wires, PCB tracks, and busses. The power supply itself will likely be higher performing (at equivalent cost and weight) because it doesn't need two capacitors in series. The power supply layout can be more optimum (for low ESR/ESL) as well because you don't have to worry about signal ground routing into/out of it. The more wattage you're dealing with, the more all of this matters.
Hi Guys
Power-wise, there is no difference to the limit of output for either the grounded-bridge or the bridged amp pair.
However, wg_ski is incorrect about the ground contamination. The bridged amp pair is free from ground contamination by the speaker currents but the grounded-bridge is not. The signal drive to the speaker is single-ended for the grounded bridge where it is differential or floating for the bridged amp pair.
In practical terms, it is easier to build the bridged amp pair than the grounded bridge. Crown's circuits for grounded-bridge are overly complex because of the "analog computer" they incorporate for protection. Were one to strip away all of that, you are still left with a balaned-output circuit that requires some extra bits to keep it balaned compared to simply having two identical power amps with a front-end circuit added to have paraphase drive. Overall, the latter system works much better if if low-THD is the goal and all of the "super amps" for hifi are built this way.
If you merely want high power and it is just for subwoofers, then the amplifiers can be built in a very basic but functional way to be reliable. A response to 160Hz is no big deal and anything you podge together will function. Even class-H will have good performance at these frequencies and provide reasonable efficiency.
Have fun
Power-wise, there is no difference to the limit of output for either the grounded-bridge or the bridged amp pair.
However, wg_ski is incorrect about the ground contamination. The bridged amp pair is free from ground contamination by the speaker currents but the grounded-bridge is not. The signal drive to the speaker is single-ended for the grounded bridge where it is differential or floating for the bridged amp pair.
In practical terms, it is easier to build the bridged amp pair than the grounded bridge. Crown's circuits for grounded-bridge are overly complex because of the "analog computer" they incorporate for protection. Were one to strip away all of that, you are still left with a balaned-output circuit that requires some extra bits to keep it balaned compared to simply having two identical power amps with a front-end circuit added to have paraphase drive. Overall, the latter system works much better if if low-THD is the goal and all of the "super amps" for hifi are built this way.
If you merely want high power and it is just for subwoofers, then the amplifiers can be built in a very basic but functional way to be reliable. A response to 160Hz is no big deal and anything you podge together will function. Even class-H will have good performance at these frequencies and provide reasonable efficiency.
Have fun
Ground contamination from speaker currents is not the issue. Ground contamination from power supply currents is. Speaker currents are linear, which is tolerable while power supply currents are half-sine which is not. Break the connection to the supply and there is no way for those half sines to get in except through induction. Twist the + and - suply wires together (and keep them short, which is easier to do it you don't need to connect an input ground and try to keep it clean) and even that goes away.
Hi Guys
Yes, the halfwave nature of the supply currents in a split-rail amp is a significant source of noise, THD and ground contamination, easily mitigated as you described. The ground from the main filters should NOT be twisted with the negative and positive supply wires. One may note in the photos of D.Self's own builds that the twisting is very light; in other high-performance amps there is no twisting whatsoever, which I find surprising.
The heavy speaker currents must be well isolated from the input signal reference ground to avoid oscillation and for lowest THD. This is relatively easy to do but having a load that does not have a "ground current" makes things even simpler and performance is improved. This happens even with low-power circuits such as headphone drivers. Significant and audible improvement of sound quality is the happy result of bridged drive.
The floating supply of the grounded-bridge (also used in the Transnova amps and Crest PAs) is of concern to some designers. Best to leave the PT out of the audio path. Filter caps are of course a part of the signal path in every amp. Ideally one uses distributed capacitance to further isolate the clean and dirty currents.
Have fun
Yes, the halfwave nature of the supply currents in a split-rail amp is a significant source of noise, THD and ground contamination, easily mitigated as you described. The ground from the main filters should NOT be twisted with the negative and positive supply wires. One may note in the photos of D.Self's own builds that the twisting is very light; in other high-performance amps there is no twisting whatsoever, which I find surprising.
The heavy speaker currents must be well isolated from the input signal reference ground to avoid oscillation and for lowest THD. This is relatively easy to do but having a load that does not have a "ground current" makes things even simpler and performance is improved. This happens even with low-power circuits such as headphone drivers. Significant and audible improvement of sound quality is the happy result of bridged drive.
The floating supply of the grounded-bridge (also used in the Transnova amps and Crest PAs) is of concern to some designers. Best to leave the PT out of the audio path. Filter caps are of course a part of the signal path in every amp. Ideally one uses distributed capacitance to further isolate the clean and dirty currents.
Have fun
Yes, only the + and - supply wires. In a grounded bridge that's all there are and they don't need to be routed anywhere near the inputs or feedback. The currents are half sine in each, and the total is a full sine. When twisted, the far field radiation is relatively free of 2nd HD. Each one by itself is full of it.
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