You should call it the Hotrod Kampala ACA!
yes we call it Super Kampana ACA.....
55% refers to the 16 Ohm numbers with reference to the 8 Ohm numbers. The numbers I question are in the middle two columns. If the 8 Ohm power is 15W, the 16 Ohm power should be about 8W.
Below is attached a graph of ACA v1.6 bridged to 8 Ohms with balanced and SE drive. I didn't try bridged into 4 Ohms.
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Tony, is it always this simple? Or is it different when you half the impedance?
If I look at the table of FirstWatt amps here:
FIRST WATT PRODUCTS
I, being a noob, do not understand why F5 gives 25W into 8 ohms and 40W into 4 ohms, but Aleph J gives 25W into 8 ohms but only 13W into 4 ohms. Both are like regular voltage source amplifiers.
Could anyone be so kind to explain this?
-Alvis
F5 being able to make Klunk!!, while J not able of same
read http://www.firstwatt.com/pdf/art_leave_classa.pdf , then http://www.firstwatt.com/pdf/art_leaving_class_a_2019_redux.pdf
generally, entire page worth investing some time : FIRST WATT
read http://www.firstwatt.com/pdf/art_leave_classa.pdf , then http://www.firstwatt.com/pdf/art_leaving_class_a_2019_redux.pdf
generally, entire page worth investing some time : FIRST WATT
The difference is because the amplifiers have definite limits on current delivery as well as voltage output.
If an amplifier can deliver 25w/8 ohm but this then falls to 40w/4 ohm then it is simply that the amplifier can not supply the current the lower load impedance demands.
So it all depends on the current delivery available.
If an amplifier can deliver 25w/8 ohm but this then falls to 40w/4 ohm then it is simply that the amplifier can not supply the current the lower load impedance demands.
So it all depends on the current delivery available.
assumptions being resistor load and sine waves.....with music, all bets are of, since a so called 8ohms speaker is not really 8 ohms at all frequencies...
also the psu stiffness comes into play, traffo regulation for one, the terminal voltage decreased as the current draw increased with load...
that is why i stopped counting watts a long time ago....
we need watts to dimension components, once we have that and playing music, then another play.....
I have just built an Amp Camp Amp and the left channel is very faint compared to the right. I notice when turning on the amp I hear the caps on the right but not the left charge up. Both channels bias at 24.3v and my inspection shows same build. I checked values of all resistors at installation and were in spec. I could not check caps because I do not have the equipment to do so. I suspect one of the caps. Any ideas would be helpful.
Thanks in advance,
Herb
Thanks in advance,
Herb
With the amp off start by measuring the resistance between the Red and Black speaker terminals. It should read somewhere in the 500 to 1000 ohms range. Compare to the good side.
Do the same with the input RCA sockets, from the outside ring to the centre pin should read about 50K ohms.
'Bias' is 12 volts by the way not 24 volts, that is the power supply voltage. Have you measured the correct place?
Then post some good pictures of your build. Poor quality or dry solder joints are 80%+ of faults. Faulty components are very rare.
Alan
Do the same with the input RCA sockets, from the outside ring to the centre pin should read about 50K ohms.
'Bias' is 12 volts by the way not 24 volts, that is the power supply voltage. Have you measured the correct place?
Then post some good pictures of your build. Poor quality or dry solder joints are 80%+ of faults. Faulty components are very rare.
Alan
Power output into load impedance
Power into a given impedance is a function of the output impedance of the amplifier, as is damping factor. A perfect amp for voltage transfer would have a 0 ohm output impedance, and would double power each time you half the load impedance. When you see an amp that is 100WPC into 8ohm, and 200WPC into 4ohm, it has an impedance that is <<1ohm.
Optimum power transfer happens when the output impedance is the same as the load impedance. An amp with a 4ohm output impedance would have the highest power rating into 4 ohms and less power into either 2ohm or 8 ohm load.
It sounds like the F5 has an output impedance close to 4ohms, and the Aleph J output impedance is around 8ohms.
Power into a given impedance is a function of the output impedance of the amplifier, as is damping factor. A perfect amp for voltage transfer would have a 0 ohm output impedance, and would double power each time you half the load impedance. When you see an amp that is 100WPC into 8ohm, and 200WPC into 4ohm, it has an impedance that is <<1ohm.
Optimum power transfer happens when the output impedance is the same as the load impedance. An amp with a 4ohm output impedance would have the highest power rating into 4 ohms and less power into either 2ohm or 8 ohm load.
It sounds like the F5 has an output impedance close to 4ohms, and the Aleph J output impedance is around 8ohms.
did you calibrate the outputs to 1/2 the b+? say 12vdc with a 24v supply, mesured at the +side of hte output capcitor...a leaky 10ufd cap or wrong values of 10k68k resistors can be a cause...
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power supply for amp camp
I'm considering buying one or 2 amp camp kits.
To limit custom fees, I would like to find the Meanwell block within EU, if it's possible.
I will need the exact reference for this.
Many thanks for your help
I'm not an absolute DIY beginner but my previous attempts (20w Hiraga Amp, Nemesis Amp), were extremely "painful". Since then, I'm at least able to solder components relatively properly.
I'm technically quite illiterate.
This little amp will be used on TAD2001 drivers, I think of using a capacitor to limit possible DC problems.
Yves
I'm considering buying one or 2 amp camp kits.
To limit custom fees, I would like to find the Meanwell block within EU, if it's possible.
I will need the exact reference for this.
Many thanks for your help
I'm not an absolute DIY beginner but my previous attempts (20w Hiraga Amp, Nemesis Amp), were extremely "painful". Since then, I'm at least able to solder components relatively properly.
I'm technically quite illiterate.
This little amp will be used on TAD2001 drivers, I think of using a capacitor to limit possible DC problems.
Yves
According to the store page
Meanwell 24V 5A power supply and power cord (PRE-ORDER NOW, SHIPPING J – diyAudio Store
the power supply is a Meanwell GST120A24-P1M. It's available, for example,
at Digikey and Mouser.
Meanwell 24V 5A power supply and power cord (PRE-ORDER NOW, SHIPPING J – diyAudio Store
the power supply is a Meanwell GST120A24-P1M. It's available, for example,
at Digikey and Mouser.
Cannot help with the Meanwell, but the ACA is capacitor coupled to the speakers already.
Have a look at the schematic in step 1 of the build guide, it is C1.
Amp Camp Amp V1.6 Build Guide - diyAudio Guides
Thanks, it's good to know.
I'm in a very preliminary exploration, there are other simple amps on my short list.
For ecological reasons, class A amps have a slight handicap ... But should we have to sacrifice everything we particularly appreciate ?
Yves