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Post by Don't use on Nov 6, 2019 2:58:17 GMT -5
Does anyone here know the specific class bias for the DR amps, or even the XPA Gen3 amps? I'm curious to know when they start to transition to class b operation.
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Post by routlaw on Nov 6, 2019 12:09:54 GMT -5
I've been wondering the same thing, thanks for asking. Surprised no one has answered this yet though.
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Post by benbvan on Nov 6, 2019 18:32:00 GMT -5
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Post by knucklehead on Nov 6, 2019 22:40:20 GMT -5
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Post by benbvan on Nov 6, 2019 22:46:09 GMT -5
Thank you. No, not what I meant. Class A/B modules but what is the bias, meaning how much class A to class B? Where does it transition to class B?
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Post by knucklehead on Nov 6, 2019 23:10:39 GMT -5
Read the link I posted above, it'll clear it all up for you.
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Post by benbvan on Nov 6, 2019 23:23:21 GMT -5
Read the link I posted above, it'll clear it all up for you. Yes I've read that. I understand it has a class H power supply, and Class A/B amplifier modules. But all class A/B amplifiers are a combination of both Class A and Class B designs, making them more efficient and cooler running than Class A and sound better than Class B alone. That also means at some point the amp acts like class A more than class B at lower output levels, and a Class B more than Class A at higher output levels. Sounding it's best at 5 watts on some A/B amps, and 50 watts on other A/B amps. At some output level maybe 5-10 watts, or as high as maybe 50-100 watts the amp transitions to more class B operation. I own an XPA2 G3, same design, just one amp module vs 2 amp modules for the DR units.
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Post by knucklehead on Nov 7, 2019 0:13:20 GMT -5
Read the link I posted above, it'll clear it all up for you. Yes I've read that. I understand it has a class H power supply, and Class A/B amplifier modules. But all class A/B amplifiers are a combination of both Class A and Class B designs, making them more efficient and cooler running than Class A and sound better than Class B alone. That also means at some point the amp acts like class A more than class B at lower output levels, and a Class B more than Class A at higher output levels. Sounding it's best at 5 watts on some A/B amps, and 50 watts on other A/B amps. At some output level maybe 5-10 watts, or as high as maybe 50-100 watts the amp transitions to more class B operation. I own an XPA2 G3, same design, just one amp module vs 2 amp modules for the DR units. Email or call Emotiva and ask Lonnie Vaughn, he'll know, he probably designed it. I read the full description and it does not mention where the cutoff is for class a to b. Maybe there isn't one? The amp design is rather unique.
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Post by benbvan on Nov 7, 2019 0:17:04 GMT -5
Yes I've read that. I understand it has a class H power supply, and Class A/B amplifier modules. But all class A/B amplifiers are a combination of both Class A and Class B designs, making them more efficient and cooler running than Class A and sound better than Class B alone. That also means at some point the amp acts like class A more than class B at lower output levels, and a Class B more than Class A at higher output levels. Sounding it's best at 5 watts on some A/B amps, and 50 watts on other A/B amps. At some output level maybe 5-10 watts, or as high as maybe 50-100 watts the amp transitions to more class B operation. I own an XPA2 G3, same design, just one amp module vs 2 amp modules for the DR units. Email or call Emotiva and ask Lonnie Vaughn, he'll know, he probably designed it. I read the full description and it does not mention where the cutoff is for class a to b. Maybe there isn't one? The amp design is rather unique. Yes, good idea. I see Dan and Keith in here at times, but not Lonnie really. I know he had told someone that the G2 units transitioned at about 5 watts but now with more powerful amps and smps I'm wondering if that has been raised.
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Post by mgbpuff on Nov 8, 2019 9:47:13 GMT -5
The Gen 1 mono amps had a minimum Class A range of roughly 2 to 5 watts. The Gen 2 1L mono had a Class A range of about 30 watts. The Gen 2 mono was based on the 1L operation (but about 60 watts) but had a class A - Class A/B toggle switch. I don't think that any of the DR series have appreciable Class A operating ranges, just the minimum to reduce cross over distortion. There are no Class A / Class A/B switches and the switching ps may not be as forgiving as the old linear ps on Gen 2 series. Also, the DR series is based on 2 XPR amp module in bridge mode - I am pretty sure that high Class A was never designed for these, probably because of the massive heat dissipation capability that would be required. I am stating this off the top of my head so I expect many pile ons and perhaps Emotiva corrections (which is good)!
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Post by benbvan on Nov 8, 2019 13:54:30 GMT -5
The Gen 1 mono amps had a minimum Class A range of roughly 2 to 5 watts. The Gen 2 1L mono had a Class A range of about 30 watts. The Gen 2 mono was based on the 1L operation (but about 60 watts) but had a class A - Class A/B toggle switch. I don't think that any of the DR series have appreciable Class A operating ranges, just the minimum to reduce cross over distortion. There are no Class A / Class A/B switches and the switching ps may not be as forgiving as the old linear ps on Gen 2 series. Also, the DR series is based on 2 XPR amp module in bridge mode - I am pretty sure that high Class A was never designed for these, probably because of the massive heat dissipation capability that would be required. I am stating this off the top of my head so I expect many pile ons and perhaps Emotiva corrections (which is good)! Yes, I was thinking a lot of the same things also. I'm also wondering if the amps are more class a than b or vice versa.
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Post by Gary Cook on Nov 8, 2019 15:33:31 GMT -5
My guess, it's so low that it isn't worth Emotiva mentioning it.
Cheers Gary
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Post by benbvan on Nov 8, 2019 16:29:41 GMT -5
My guess, it's so low that it isn't worth Emotiva mentioning it. Cheers Gary Most likely so sir.
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KeithL
Administrator
Posts: 9,902
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Post by KeithL on Nov 8, 2019 17:22:58 GMT -5
The XPA and XPA-DR amps operate in Class A for the first few watts of operation.
We don't specify the transition point because it will vary slightly depending on things like exactly how warmed-up the amp is. As with all Class A/B amplifiers, the reason for this region of Class A operation is primarily to avoid distortion at the zero crossing point, so how far it extends is not considered to be especially important.
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Post by benbvan on Nov 8, 2019 17:27:18 GMT -5
The XPA and XPA-DR amps operate in Class A for the first few watts of operation.
We don't specify the transition point because it will vary slightly depending on things like exactly how warmed-up the amp is. As with all Class A/B amplifiers, the reason for this region of Class A operation is primarily to avoid distortion at the zero crossing point, so how far it extends is not considered to be especially important.
Thank you Keith. Are they more bias towards class A than B? Or is that not a thing. I though that it was.
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Post by AudioHTIT on Nov 8, 2019 20:18:36 GMT -5
The XPA and XPA-DR amps operate in Class A for the first few watts of operation.
We don't specify the transition point because it will vary slightly depending on things like exactly how warmed-up the amp is. As with all Class A/B amplifiers, the reason for this region of Class A operation is primarily to avoid distortion at the zero crossing point, so how far it extends is not considered to be especially important.
Thank you Keith. Are they more bias towards class A than B? Or is that not a thing. I though that it was. That’s really not a thing, they are biased Class A to a certain point at which point they’re not. In the case of the XPA-1G2 and XPA-1L they have enough Class A wattage where you are mostly running there, and maybe you could say they’re biased ‘toward’ class A, but I’d just say they have significant Class A power. I’d call the DR’s high average.
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Post by benbvan on Nov 8, 2019 21:12:26 GMT -5
Thank you Keith. Are they more bias towards class A than B? Or is that not a thing. I though that it was. That’s really not a thing, they are biased Class A to a certain point at which point they’re not. In the case of the XPA-1G2 and XPA-1L they have enough Class A wattage where you are mostly running there, and maybe you could say they’re biased ‘toward’ class A, but I’d just say they have significant Class A power. I’d call the DR’s high average. Isn't that exactly the same thing? Lol
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Post by AudioHTIT on Nov 8, 2019 22:31:34 GMT -5
That’s really not a thing, they are biased Class A to a certain point at which point they’re not. In the case of the XPA-1G2 and XPA-1L they have enough Class A wattage where you are mostly running there, and maybe you could say they’re biased ‘toward’ class A, but I’d just say they have significant Class A power. I’d call the DR’s high average. Isn't that exactly the same thing? Lol If that means something to you then great, go with it. What’s important (for this discussion) is how much of the time your speakers in your room at your listening levels, a given amp spends in Class A (presuming the more the better). Your original question, which implied you want to know at what wattage it transitioned from A to B, was useful, a quantifiable value you could use to determine how your speakers/room/habits might interact. An opinion about whether they’re “more bias towards class A than B” is not. If you find that funny, ok.
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Post by garbulky on Nov 8, 2019 23:38:01 GMT -5
The XPA and XPA-DR amps operate in Class A for the first few watts of operation.
We don't specify the transition point because it will vary slightly depending on things like exactly how warmed-up the amp is. As with all Class A/B amplifiers, the reason for this region of Class A operation is primarily to avoid distortion at the zero crossing point, so how far it extends is not considered to be especially important [/b]. [/div] [/quote] But... what about the XPA-1 gen 2 and its class A capabilities (60 watts!). I would say it was quite important at least in design consideration how to vent all that heat. (Love my class A!)
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Post by benbvan on Nov 8, 2019 23:44:59 GMT -5
Isn't that exactly the same thing? Lol If that means something to you then great, go with it. What’s important (for this discussion) is how much of the time your speakers in your room at your listening levels, a given amp spends in Class A (presuming the more the better). Your original question, which implied you want to know at what wattage it transitioned from A to B, was useful, a quantifiable value you could use to determine how your speakers/room/habits might interact. An opinion about whether they’re “more bias towards class A than B” is not. If you find that funny, ok. What I meant to ask is, at some point do class a/b amplifiers act more like a class b amplifier than a class a or a/b design when pushed hard or do they not?
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