I don't know.
What I do know is that MC2 amps happily drive four 8 ohm woofers in parallel at full rated power.
Are we buying a commercial amp, or building a DIY amp??
Regardless, the prerequisite is a boatload of output devices in parallel (given the present technology). One could build up any number of amplifiers (driver boards) and with the proper chassis and power supply come up with a fine "2 ohm amplifier".
One idea is to make a relatively low voltage pure Class A amplifier (take a look at the classic ML-2 amplifier as an example). Of course if it is set up for Class A into say 4 ohms, it will still drive 2 ohms but run into class AB, which is still ok, since unless ur playing rather loud music, you'll not see the transition except on peaks.
I would not try to build an ML-2, it's just an example of a high current, low voltage, pure class A amp that would drive the pants off just about anything it was connected to.
Or, you could do a tube amp with a specially wound output transformer too!
_-_-bear
Regardless, the prerequisite is a boatload of output devices in parallel (given the present technology). One could build up any number of amplifiers (driver boards) and with the proper chassis and power supply come up with a fine "2 ohm amplifier".
One idea is to make a relatively low voltage pure Class A amplifier (take a look at the classic ML-2 amplifier as an example). Of course if it is set up for Class A into say 4 ohms, it will still drive 2 ohms but run into class AB, which is still ok, since unless ur playing rather loud music, you'll not see the transition except on peaks.
I would not try to build an ML-2, it's just an example of a high current, low voltage, pure class A amp that would drive the pants off just about anything it was connected to.
Or, you could do a tube amp with a specially wound output transformer too!
_-_-bear
Alesis RA500, power amplifier rated 125 W@8; 250@4;500@2 use 3 couple of 230V 15 A capable transistors for channel and a ...HUGE 500W trasformer!
This is hardware needed for do the job!
This is hardware needed for do the job!
Maybe a better idea it's use two bridged amplifier; you should drive 2 ohms load in class A without switch in class AB? Or am I wrong?
Bridging doesn't increase the available class A power. It takes more quescient current to do that.
Bridging amplifiers
Of course! I mean bridging 2 class A power amplifier deliver more power on the load (both resting in class A). Alternative is a single class A amplifier (with a rendiment of 25% of class A mean a 100W delivering 25W on 8 Ohm with relative moltiplication decreasing the load). For don't switch in class AB you should have a monstrous amplifier with an idle current similar at the current requested by load) try a simple math. Please excuse my poor english language!
Of course! I mean bridging 2 class A power amplifier deliver more power on the load (both resting in class A). Alternative is a single class A amplifier (with a rendiment of 25% of class A mean a 100W delivering 25W on 8 Ohm with relative moltiplication decreasing the load). For don't switch in class AB you should have a monstrous amplifier with an idle current similar at the current requested by load) try a simple math. Please excuse my poor english language!
Using your example of a high bias class AB amplifier making 100wpc stereo into 8 ohms the first 25wpc of which is class A. If you bridge that amplifier ideally you end up with 400w mono Class AB into 8ohms but still 25w Class A into 8 ohms.
No, i mean a truly 25W un class A. You Know a 25W dissipate 75W in heat form, so you must design a 100W amplifier. You could increase idle current on the same amplifier for deliver 30W in class A on the same load, now you must design a 120W amplifier, 30W in load and 90w in heat dissipation) and so on. If you halve load you double current but (resting in class A) your power request increase in consequence:
Hi,
Bridging into low impedance loads is completely wrong.
Each amplifier will see a 1 ohm load for a 2 ohm speaker.
Paralleling via 0.2R resistors makes a lot more sense.
rgds, sreten.
Bridging into low impedance loads is completely wrong.
Each amplifier will see a 1 ohm load for a 2 ohm speaker.
Paralleling via 0.2R resistors makes a lot more sense.
rgds, sreten.
Bridging via resistor
Bridging on 2Ohm, each amplifier see a 1 Ohm load; and this it's OK. You would add a 0,2 ohm resistence paralleled to 1 Ohm load? this will result in 0,16 Ohm load with an higher current dissipated in 0.2 Ohm resistor. Other solution proposed it's the 0,2 Ohm resistor in series with the load; each amplifier see a 1,2 Ohm load and 0,2 resistor is traversed by the same current value of the load (with relative power dissipated in form of heat).
I can't understand the meaning of 0,2 resistors or, maybe, have I misinterpreted your words?
Bridging on 2Ohm, each amplifier see a 1 Ohm load; and this it's OK. You would add a 0,2 ohm resistence paralleled to 1 Ohm load? this will result in 0,16 Ohm load with an higher current dissipated in 0.2 Ohm resistor. Other solution proposed it's the 0,2 Ohm resistor in series with the load; each amplifier see a 1,2 Ohm load and 0,2 resistor is traversed by the same current value of the load (with relative power dissipated in form of heat).
I can't understand the meaning of 0,2 resistors or, maybe, have I misinterpreted your words?
Sreten is talking about paralleling the two stereo channels and using a .2 ohm resistor from each half of the amp to the load to force current sharing between the two. This would greatly increase the current capacity and Class A power by 4x.
Hi,
You don't seem to understand bridging is a very bad idea into 2
ohms for all practical circuits and typical practical amplifiers.
(And will cause less power and more blown amplifiers.)
When paralleling you add output series resistors to take care
of any dc offset and gain differences between the two channels.
(0.2R is ball park, nominally 0.1R output impedance.)
For a parallel amplifier into 2 ohms, each channel is 4 ohms.
rgds, sreten.
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Bridges & parallels
OK, now I understand where is the problem. You was talking about resistor for equalize and balance currents (otherwise an amplifier become the load of the other despite the TRUE low impedance. You talk about PARALLELING and not bridging. There are many type of bridging, (in phase or in contro phase (maybe anti phase in USA jargon?), floating or not. With load bridged or not etc etc. You talk about a conventional Class AB amplifier (with a little part working in class A), i talk about a properly designed class A amplifier wich MUST work in class A and bridged, obviously if it exceeds it's current limit it will work in class AB, I consider this dissipated power.
Ciao
OK, now I understand where is the problem. You was talking about resistor for equalize and balance currents (otherwise an amplifier become the load of the other despite the TRUE low impedance. You talk about PARALLELING and not bridging. There are many type of bridging, (in phase or in contro phase (maybe anti phase in USA jargon?), floating or not. With load bridged or not etc etc. You talk about a conventional Class AB amplifier (with a little part working in class A), i talk about a properly designed class A amplifier wich MUST work in class A and bridged, obviously if it exceeds it's current limit it will work in class AB, I consider this dissipated power.
Ciao
I designed a class d amp that worked into 2 ohms.
Just used 2 pairs of IRFB4227.
Worked very well.
IRUADAMP7 is worth looking at with 2 pairs of output transistors.
Just used 2 pairs of IRFB4227.
Worked very well.
IRUADAMP7 is worth looking at with 2 pairs of output transistors.
Solution?
This is, maybe, the better solution of the problem; neat, simple & economically logical!
Ciao🙂
This is, maybe, the better solution of the problem; neat, simple & economically logical!
Ciao🙂
Well, since the OP is silent, the discussion becomes meaningless...
...and it is strange that IF the OP actually owned $15k speakers that he/she does not have an appropriate amplifier (per the manufacturer's suggestion, etc.) to run them.
So, draw your own conclusions.
...and it is strange that IF the OP actually owned $15k speakers that he/she does not have an appropriate amplifier (per the manufacturer's suggestion, etc.) to run them.
So, draw your own conclusions.
Hi,
You just don't get bridging a class A amplifier is bad news.
They don't all enter class B on request and generally there
is no point to bridging any class A amplifier unless you
have a high impedance load, certainly not circa 2 ohm.
Your talking advanced nonsense about the subject,
and don't understand any of the real issues involved.
Show me an example of bridged class A, they don't exist.
rgds, sreten.
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