Hifi amps with true 75Watt RMS

[Andrewjvt]

I have never heard an Abrahamson, but if it's anything like his silly god he can keep his amplifiers.

OK, I looked them (Abrahamsen) up. Made in China stuff, looks pretty so will automatically 'sound' good in sighted testing. Unfortunately they also market foo wire, a major negative in terms of credibility IMO. I have never heard any, but then I only ever hear stuff that goes faulty.

Abrahamsen amplifiers are all made in Sweden and it is unlikely that you will ever hear an Abrahamsen amp in that case .

The technical spec is far beyond anything  near the price with a 1000va transformer , 100 amps of peak current delivery and transient power measured in kilowatts.

http://www.iqspeakers.co.uk/#!abrahamsen/ckbj

?

Hi,

Is that 100amps per channel, or from the power supply? I examined the Web site and it seems that there are 3 power transistors per positive or negative swing of the waveform. I am not sure each could withstand 33.3amps each, even as a transient.

Regards, Shadders.

There are a total of 12 output transistors .

Hi,

there are 6 transistors per channel, where only 3 conduct at one time per channel. Assuming each channel is on the positive swing then each transistor will have to conduct 16.65amps each to achieve the 100amps quoted.

From the website picture, the transistors are Toshiba 2SC3421 which have a peak continuous current capability of 1amp, and not 16.65amps. Pulse capability is 2 amps maximum, and safe operating is 3 amps for a one off pulse. This equates to 5 times less than shared 100amps/6=16.65amps.?

i believe that numbers quoted by people or manufacturers need to be reviewed and understood.  The 100amps quoted sounds very impressive, yet the output relay has a maximum capability of 16amps.

One channel has a maximum peak output of 9 amps (based on transistors) as a single non repeatable transient.

Or 6amps as a repeated pulse on the output.

Or 3amps continuous per channel, which is 6amps continuous per amplifier (both channels).

Much less than the quoted 100amps.

Regards,?

Shadders.

 Hi Shadders, also if you have time, could you have a look how the roksan k3 compares. Thank you.

?

I take it the k3 is n improvement so would like to hear it. The abe wont go as loud as your k3 but may deal better with demanding speakers at higher volume. As long as your happy thats the main thing.

K3 Gets great reviews also and looks very well made

 You are correct here. I recently did a side by side audition of the k3 and abrahamsen, and one thing did surprise me was that the k3 was quite a bit louder/had more power. Written experience to follow soon, when I get some down time  

Well dont know where you live but once ive got my atc scm40s you are welcome to come over to mine and test them with your amp and have a listen to mine. Believe me they sound much better in the home than in the shop.

 

[iQ Speakers]

Correct Vlad !

 

[radiorog]

I have never heard an Abrahamson, but if it's anything like his silly god he can keep his amplifiers.

OK, I looked them (Abrahamsen) up. Made in China stuff, looks pretty so will automatically 'sound' good in sighted testing. Unfortunately they also market foo wire, a major negative in terms of credibility IMO. I have never heard any, but then I only ever hear stuff that goes faulty.

Abrahamsen amplifiers are all made in Sweden and it is unlikely that you will ever hear an Abrahamsen amp in that case .

The technical spec is far beyond anything near the price with a 1000va transformer , 100 amps of peak current delivery and transient power measured in kilowatts.

http://www.iqspeakers.co.uk/#!abrahamsen/ckbj

Hi,

Is that 100amps per channel, or from the power supply? I examined the Web site and it seems that there are 3 power transistors per positive or negative swing of the waveform. I am not sure each could withstand 33.3amps each, even as a transient.

Regards, Shadders.

There are a total of 12 output transistors .

Hi,

there are 6 transistors per channel, where only 3 conduct at one time per channel. Assuming each channel is on the positive swing then each transistor will have to conduct 16.65amps each to achieve the 100amps quoted.

From the website picture, the transistors are Toshiba 2SC3421 which have a peak continuous current capability of 1amp, and not 16.65amps. Pulse capability is 2 amps maximum, and safe operating is 3 amps for a one off pulse. This equates to 5 times less than shared 100amps/6=16.65amps.

i believe that numbers quoted by people or manufacturers need to be reviewed and understood. The 100amps quoted sounds very impressive, yet the output relay has a maximum capability of 16amps.

One channel has a maximum peak output of 9 amps (based on transistors) as a single non repeatable transient.

Or 6amps as a repeated pulse on the output.

Or 3amps continuous per channel, which is 6amps continuous per amplifier (both channels).

Much less than the quoted 100amps.

Regards,

Shadders.

Hi Shadders, also if you have time, could you have a look how the roksan k3 compares. Thank you.

I take it the k3 is n improvement so would like to hear it. The abe wont go as loud as your k3 but may deal better with demanding speakers at higher volume. As long as your happy thats the main thing.

K3 Gets great reviews also and looks very well made

You are correct here. I recently did a side by side audition of the k3 and abrahamsen, and one thing did surprise me was that the k3 was quite a bit louder/had more power. Written experience to follow soon, when I get some down time

Well dont know where you live but once ive got my atc scm40s you are welcome to come over to mine and test them with your amp and have a listen to mine. Believe me they sound much better in the home than in the shop.

Very kind sir! I'm up in Edinburgh, might be a bit of a trek for me.?

 

[TrevC]

[

With such a large power supply, I am not sure why only 70watts,

Regards,

Shadders.

It's limited mainly by the voltage present on the supply rails, which you haven't mentioned so far.

 

[TrevC]

Who do you think you are? Behave yourself please its only hifi Or at least have a little respect

You can't win against TrevC, as he deals in facts; whereas we mere mortals have to make do with our opinions, which can simply be dismissed.

Was this a joke?

It's a fact that all amplifier of similar spec sound the same, even tho they clearly don't? And he said he hasn't even heard the abrahmsen.

And it's a fact the story of Jesus was a joke? I'm sorry, but I thought there was no concrete proof either way. He was basing his statement on his opinion. Now that's a fact!

I always stick to the facts. It isn't possible that two amplifiers with identical specs can sound different, and it isn't possible that, 2000 years ago, a child can be born of a virgin, get killed and then spring back to life as a zombie god thingy.

 

[shadders]

[

With such a large power supply, I am not sure why only 70watts,

Regards,

Shadders.

It's limited mainly by the voltage present on the supply rails, which you haven't mentioned so far.

Hi,

Yes, I was not able to determine the transformer voltages. The quoted 100amps power supply capability indicated that the amplifier was very underrated.

Regards,

Shadders.

 

[shadders]

Correct Vlad !

Hi,

Thanks, so the bank of 12 transistors are the drivers for the ON Semiconductors as pictured, where each channel has a single pair (NPN/PNP).

Regards,

Shadders.

 

[gasolin]

My Nad C326BEE has a max,power current of more then 20 amp 1ms in 1 ohm

Does that make it at bad amp sice it can't it's not as wild as lets say a HK 980 with 80 amps?

 

[TrevC]

My Nad C326BEE has a max,power current of more then 20 amp 1ms in 1 ohm

Does that make it at bad amp sice it can't it's not as wild as lets say a HK 980 with 80 amps?

Nope, it's fine, maximum current capabilty is only relevant on the limit. Like maximum speed is of little concern in a car normally driven at the speed limits.

 

[Electro]

If you want to see an extreme version of the Abrahamsen / Otala/ Lohstroh design philosophy .

then look at this sadly now discontinued Abrahamsen SA1.

40 wpc

40 amps continuous current output

200 amps peak current output .

 

[iQ Speakers]

No idea! Shadders unfortunatly I did not design it. Vlad will probably answer. As in Electro's very good graph , it controls the bass drivers very well starting and stoping them, which gives room for other notes to be heard. When I took the amp to SteveR750 we both concluded there was very little difference in SQ compared to his Hegel H160 driving his lovely ATC SCM40's.

 

[TrevC]

If you want to see an extreme version of the Abrahamsen / Otala/ Lohstroh design philosophy .

then look at this sadly now discontinued Abrahamsen SA1.

40 wpc

40 amps continuous current output

200 amps peak current output .

Kind of meaningless in a 40W amp really.

 

[CnoEvil]

Kind of meaningless in a 40W amp really. 

Surely it would only be meaningless if speakers remained at one impedance.

Since an amp like that will likely double its output as impedance halves and modern speakers often have impedance that plummets to nearly 3 Ohms, it will, in real world conditions, produce far more than the quoted 40W....and that doesn't take into account its huge reserves of current that will effortlessly cope with sudden dynamic shifts.

 

[Vladimir]

If you want to see an extreme version of the Abrahamsen / Otala/ Lohstroh design philosophy .

then look at this sadly now discontinued Abrahamsen SA1.

40 wpc

40 amps continuous current output

200 amps peak current output .

Kind of meaningless in a 40W amp really.

Isn't it like a diesel engine theres no point in having so much torch with so little horsepower? ;-)

Abrahamsen is just like a diesel engine it doesn't have so much horsepwer,it has alot of torch , that's why it can control any speakers without losing control up to the watt limited of the amp (top speed)

70W in 8 ohms

140W in 4 ohms

280W in 2 ohms

560W in 1 ohm

Now, if you had speakers that dip down very low, the Abe will have a lot more watts in large transient peaks than a 150Wpc in 8 ohms amplifier that has a PSU that can't handle going under 6ohms (sagging voltage rails). Considering that 99% of the time we listen using no more than 10W, this is a smart concept IMO. Again depends on application - the speakers, loudness preference, type of music, digital or analogue (dynamic range) and the room. It's all relevant.

 

[Vladimir]

Correct Vlad !

Hi,

Thanks, so the bank of 12 transistors are the drivers for the ON Semiconductors as pictured, where each channel has a single pair (NPN/PNP).

Regards,

Shadders.

Cascode amplifier stage, these are wide bandwith BJT amplifiers. When you want more info on Abrahamsen feel free to look at Electrocompaniet (which are less obscure) since they are essentially the same amplifiers, circuit design wise.

I calculated the PSU to be 320 joules on the 70Wpc V2.0UP model. Jokingly we noticed that is the size of a large defibrillator. Within few milisecond bursts it can chuck out 100A no problem, not that you would need so much, but it's there.

I wish I could go on more about these great amps but I'm merely parroting what I learn online and I'm not an EE or a service tech.

 

[CnoEvil]

70W in 8 ohms

140W in 4 ohms

280W in 2 ohms

560W in 1 ohm

Now, if you had speakers that dip down very low, the Abe will have a lot more watts in large transient peaks than a 150Wpc in 8 ohms amplifier that has a PSU that can't handle going under 6ohms (sagging voltage rails). Considering that 99% of the time we listen using no more than 10W, this is a smart concept IMO. Again depends on application - the speakers, loudness preference, type of music, digital or analogue (dynamic range) and the room. It's all relevant. 

Exactly so.

 

[TrevC]

Kind of meaningless in a 40W amp really.

Surely it would only be meaningless if speakers remained at one impedance.

Since an amp like that will likely double its output as impedance halves and modern speakers often have impedance that plummets to nearly 3 Ohms, it will, in real world conditions, produce far more than the quoted 40W....and that doesn't take into account its huge reserves of current that will effortlessly cope with sudden dynamic shifts.

Presuming the rated output power of 40W is at 8 ohms (which is a voltage output of around 18 volts), in order to take the quoted peak current of 200A the impedance of the speaker would need to dip to below 0.1 ohm resulting in a power output of around 3600W.

Which is why I said it was kind of meaningless.

 

[CnoEvil]

Presuming the rated output power of 40W is at 8 ohms (which is a voltage output of around 18 volts), in order to take the quoted peak current of 200A the impedance of the speaker would need to dip to below 0.1 ohm resulting in a power output of around 3600W.?

Which is why I said it was kind of meaningless.

 

Thank you for clarifying. I thought you were saying that producing an amp with 40W was pointless.

FWIW. I think that you have to hear what an amp like this can do, before writing it off as meaningless.

 

[TrevC]

70W in 8 ohms

140W in 4 ohms

280W in 2 ohms

560W in 1 ohm

Now, if you had speakers that dip down very low, the Abe will have a lot more watts in large transient peaks than a 150Wpc in 8 ohms amplifier that has a PSU that can't handle going under 6ohms (sagging voltage rails). Considering that 99% of the time we listen using no more than 10W, this is a smart concept IMO. Again depends on application - the speakers, loudness preference, type of music, digital or analogue (dynamic range) and the room. It's all relevant.

Exactly so.

While too much sag in a power supply is undesirable you aren't really going to notice it unless you play music so loud you make your amp clip. Transient peaks can be catered for with large capacitance. You would be just as well off with an amplifier with higher voltage rails and a less substantial power supply.

 

[Vladimir]

Kind of meaningless in a 40W amp really.

Surely it would only be meaningless if speakers remained at one impedance.

Since an amp like that will likely double its output as impedance halves and modern speakers often have impedance that plummets to nearly 3 Ohms, it will, in real world conditions, produce far more than the quoted 40W....and that doesn't take into account its huge reserves of current that will effortlessly cope with sudden dynamic shifts.

Presuming the rated output power of 40W is at 8 ohms (which is a voltage output of around 18 volts), in order to take the quoted peak current of 200A the impedance of the speaker would need to dip to below 0.1 ohm resulting in a power output of around 3600W.

Which is why I said it was kind of meaningless.

Agreed. An overikill, but not completely meaningless.

 

[gasolin]

If you want to see an extreme version of the Abrahamsen / Otala/ Lohstroh design philosophy .

then look at this sadly now discontinued Abrahamsen SA1.

40 wpc

40 amps continuous current output

200 amps peak current output .

Kind of meaningless in a 40W amp really.

Isn't it like a diesel engine theres no point in having so much torch with so little horsepower? ;-)

Abrahamsen is just like a diesel engine it doesn't have so much horsepwer,it has alot of torch , that's why it can control any speaker load without losing control up to the watt limited of the amp (top speed)

 

[gasolin]

If you want to see an extreme version of the Abrahamsen / Otala/ Lohstroh design philosophy .

then look at this sadly now discontinued Abrahamsen SA1.

40 wpc

40 amps continuous current output

200 amps peak current output .

Kind of meaningless in a 40W amp really.

Isn't it like a diesel engine theres no point in having so much torch with so little horsepower? ;-)

Abrahamsen is just like a diesel engine it doesn't have so much horsepwer,it has alot of torch , that's why it can control any speakers without losing control up to the watt limited of the amp (top speed)

70W in 8 ohms

140W in 4 ohms

280W in 2 ohms

560W in 1 ohm

Now, if you had speakers that dip down very low, the Abe will have a lot more watts in large transient peaks than a 150Wpc in 8 ohms amplifier that has a PSU that can't handle going under 6ohms (sagging voltage rails). Considering that 99% of the time we listen using no more than 10W, this is a smart concept IMO. Again depends on application - the speakers, loudness preference, type of music, digital or analogue (dynamic range) and the room. It's all relevant.

I'd like to see an amp that actually can double the wattage (within the margain of error "few" watt ) as the ohm drops 50%

 

[TrevC]

Presuming the rated output power of 40W is at 8 ohms (which is a voltage output of around 18 volts), in order to take the quoted peak current of 200A the impedance of the speaker would need to dip to below 0.1 ohm resulting in a power output of around 3600W.

Which is why I said it was kind of meaningless.

Thank you for clarifying. I thought you were saying that producing an amp with 40W was pointless.

FWIW. I think that you have to hear what an amp like this can do, before writing it off as meaningless.

Where did I say the amp was meaningless?

 

[TrevC]

If you want to see an extreme version of the Abrahamsen / Otala/ Lohstroh design philosophy .

then look at this sadly now discontinued Abrahamsen SA1.

40 wpc

40 amps continuous current output

200 amps peak current output .

Kind of meaningless in a 40W amp really.

Isn't it like a diesel engine theres no point in having so much torch with so little horsepower? ;-)

Abrahamsen is just like a diesel engine it doesn't have so much horsepwer,it has alot of torch , that's why it can control any speakers without losing control up to the watt limited of the amp (top speed)

70W in 8 ohms

140W in 4 ohms

280W in 2 ohms

560W in 1 ohm

Now, if you had speakers that dip down very low, the Abe will have a lot more watts in large transient peaks than a 150Wpc in 8 ohms amplifier that has a PSU that can't handle going under 6ohms (sagging voltage rails). Considering that 99% of the time we listen using no more than 10W, this is a smart concept IMO. Again depends on application - the speakers, loudness preference, type of music, digital or analogue (dynamic range) and the room. It's all relevant.

I'd like to see an amp that actually can double the wattage (within the margain of error "few" watt ) as the ohm drops 50%

This one probably comes closer than most, but would you be able to tell by listening at normal volumes? Unlikely.

 

[Vladimir]

If you want to see an extreme version of the Abrahamsen / Otala/ Lohstroh design philosophy .

then look at this sadly now discontinued Abrahamsen SA1.

40 wpc

40 amps continuous current output

200 amps peak current output .

Kind of meaningless in a 40W amp really.

Isn't it like a diesel engine theres no point in having so much torch with so little horsepower? ;-)

Abrahamsen is just like a diesel engine it doesn't have so much horsepwer,it has alot of torch , that's why it can control any speakers without losing control up to the watt limited of the amp (top speed)

70W in 8 ohms

140W in 4 ohms

280W in 2 ohms

560W in 1 ohm

Now, if you had speakers that dip down very low, the Abe will have a lot more watts in large transient peaks than a 150Wpc in 8 ohms amplifier that has a PSU that can't handle going under 6ohms (sagging voltage rails). Considering that 99% of the time we listen using no more than 10W, this is a smart concept IMO. Again depends on application - the speakers, loudness preference, type of music, digital or analogue (dynamic range) and the room. It's all relevant.

I'd like to see an amp that actually can double the wattage (within the margain of error "few" watt ) as the ohm drops 50%

Would this be less impressive?

78W in 8ohms

144W in 4ohms

282W in 2ohms

560W in 1 ohm

The way you get perfect doubling down of watts in half the load is by rounding up the number by substracting few watts (by trade regulation laws you can't add, but you can declare less power).