I have a Curtis Mathes integrated stereo amplifier mod. # KA270 and I would like to find out what the maximum wattage output is, it does not say anywhere on the amp itself. This amp can be viewed at http://members.aol.com/jeepisheap/pics/ebay This amp really cranks, and I have always been curious of the power output. Thank you for reading this inquiry!

Hi Jim, I don't know your amp but hopefully someone can answer your question. If you don't get an answer I can estimate it's power for you if you can supply some information. If it's a tube amp list the tubes used. If it's a solid state amp list the putput transistors or power IC's (they'll be mounted on the large finned heatsink) and measure the supply voltage. It may be a single supply line or a positive and negative line depending on design. Also the speaker impedance, proboly 8 ohms.
Good Luck, Don Black.

: I have a Curtis Mathes integrated stereo amplifier mod. # KA270 and I would like to find out what the maximum wattage output is, it does not say anywhere on the amp itself. This amp can be viewed at http://members.aol.com/jeepisheap/pics/ebay This amp really cranks, and I have always been curious of the power output. Thank you for reading this inquiry!

No tubes in that one. Hybrid IC power Amps only.

I am not current on where the "average" home amps average for power output these days.

Curtis Mathes was not really well known for high power units, and I suspect that 27 watts may be the true output. Certainly no more 50 Watts per channel. If you look through the cooling holes in the cabinet, you should see a pair of heatsinks, witht he hybrid either as part of them, or attached to the side of them. Chances are that the modules will be only about 3/8 inch thick, and about 2 inch by 3 inch. This isze is consistent with about 50 watts peak power, and about 30 watts continuous maximum.

What is the power rating on the "boilerplate" where it refers to power consumption? Figure the peak to be approximately slightly better than 1/5 the consumption ratings.

Otherwise, the only other clue will be the part number of the hybrid itself.

The "loudness" of an amp can be decieving due to a number of variables involved. Efficiency of the speakers is the foremost determining factor. I have a pair of super eficient speakers that filled a large open and reflective room with loud clear sound on 50 watts. In the home, I can get similar loudness with about 8 watts from a pair of 6V6's.

In contrast, I have a pair of speakers that are not efficient, and require the 50 watt amp to power them adequately.

Another factor in loudness is the amount of gain within the preamp and phase inverter stages.

The good news is that the amount of power for normal listening is only about 5 watts peak. The resistance curve of "audio taper" pots is parabolic when graphed out, and that is why volume controls on modern stereo equipment are at mid-point when the power meter is registering only 3-5 watts.

Don't sweat the "noise specs" either. There are two types of noise in an amp; as a rule. "Noise Floor" is what you hear when you turn the volume way up with zero signal. THD (Total Harmonic Distortion) is actually a measurement of the noise "resonating" within the circuit itself. Harmonic distortion is not all bad; Most tube amp designs are quite high with second order harmonics.
Harmonics are also what make the difference between bagpipes sounding like reedy bagpipes and bagpipes sounding like someone running a "Midi" stream.

: Hi Jim, I don't know your amp but hopefully someone can answer your question. If you don't get an answer I can estimate it's power for you if you can supply some information. If it's a tube amp list the tubes used. If it's a solid state amp list the putput transistors or power IC's (they'll be mounted on the large finned heatsink) and measure the supply voltage. It may be a single supply line or a positive and negative line depending on design. Also the speaker impedance, proboly 8 ohms.
: Good Luck, Don Black.

: : I have a Curtis Mathes integrated stereo amplifier mod. # KA270 and I would like to find out what the maximum wattage output is, it does not say anywhere on the amp itself. This amp can be viewed at http://members.aol.com/jeepisheap/pics/ebay This amp really cranks, and I have always been curious of the power output. Thank you for reading this inquiry!

Hi John and Jim, I looked at the pictures after I posted my comments and thought when I saw them it was likely to use Hybrid IC's. It probably uses a split power supply (+ & - supply rails) and I agree with Johns comments. When judging power on listening tests it's necessary to pick the distortion level. As soon as it hits distortion it will sound much louder, look at those transistor radios with 1/4 watt that sound ear piercing when run hard into distortion. It should be capable of good results. If you can find the supply voltages (total from positive to negative) you can calculate the approximate power by squaring the voltage (multiply it by itself) and devide it by 10 times the speaker impedance. That will give a close RMS power rating. If you can't measure the voltage, read the voltage rating on the electrolytic filter capacitor(s), probably two of them about 4700 mfd at 35 or 50 volts. Assume the supply is about 85% of this (probably double if there are two capacitors, + &-) and use this in the calculation. It's only rough, since the voltage is squared any error is magnified, but it will be a ball park figure. I think 30 to 50 watts is about right. One other thing, when you see 30 to 50 watts that seems tiny compared to some of the advertised power outputs. That's largely due to the advertisers getting loose. They double it for the two channels, then double it again for the peak power, then double it again for "music power" and if the one down the road looks better on paper they increase it again. Some of the tiny computer amp/speakers are rated up to 300 watts and they'd be lucky to make 3 watts a channel. Just sit back and enjoy the music. Don Black.

: No tubes in that one. Hybrid IC power Amps only.

: I am not current on where the "average" home amps average for power output these days.

: Curtis Mathes was not really well known for high power units, and I suspect that 27 watts may be the true output. Certainly no more 50 Watts per channel. If you look through the cooling holes in the cabinet, you should see a pair of heatsinks, witht he hybrid either as part of them, or attached to the side of them. Chances are that the modules will be only about 3/8 inch thick, and about 2 inch by 3 inch. This isze is consistent with about 50 watts peak power, and about 30 watts continuous maximum.

: What is the power rating on the "boilerplate" where it refers to power consumption? Figure the peak to be approximately slightly better than 1/5 the consumption ratings.

: Otherwise, the only other clue will be the part number of the hybrid itself.

: The "loudness" of an amp can be decieving due to a number of variables involved. Efficiency of the speakers is the foremost determining factor. I have a pair of super eficient speakers that filled a large open and reflective room with loud clear sound on 50 watts. In the home, I can get similar loudness with about 8 watts from a pair of 6V6's.

: In contrast, I have a pair of speakers that are not efficient, and require the 50 watt amp to power them adequately.

: Another factor in loudness is the amount of gain within the preamp and phase inverter stages.

: The good news is that the amount of power for normal listening is only about 5 watts peak. The resistance curve of "audio taper" pots is parabolic when graphed out, and that is why volume controls on modern stereo equipment are at mid-point when the power meter is registering only 3-5 watts.

: Don't sweat the "noise specs" either. There are two types of noise in an amp; as a rule. "Noise Floor" is what you hear when you turn the volume way up with zero signal. THD (Total Harmonic Distortion) is actually a measurement of the noise "resonating" within the circuit itself. Harmonic distortion is not all bad; Most tube amp designs are quite high with second order harmonics.
: Harmonics are also what make the difference between bagpipes sounding like reedy bagpipes and bagpipes sounding like someone running a "Midi" stream.

:
: : Hi Jim, I don't know your amp but hopefully someone can answer your question. If you don't get an answer I can estimate it's power for you if you can supply some information. If it's a tube amp list the tubes used. If it's a solid state amp list the putput transistors or power IC's (they'll be mounted on the large finned heatsink) and measure the supply voltage. It may be a single supply line or a positive and negative line depending on design. Also the speaker impedance, proboly 8 ohms.
: : Good Luck, Don Black.

: : : I have a Curtis Mathes integrated stereo amplifier mod. # KA270 and I would like to find out what the maximum wattage output is, it does not say anywhere on the amp itself. This amp can be viewed at http://members.aol.com/jeepisheap/pics/ebay This amp really cranks, and I have always been curious of the power output. Thank you for reading this inquiry!

: I have a Curtis Mathes integrated stereo amplifier mod. # KA270 and I would like to find out what the maximum wattage output is, it does not say anywhere on the amp itself. This amp can be viewed at http://members.aol.com/jeepisheap/pics/ebay This amp really cranks, and I have always been curious of the power output.

Well being a tech for CM for 14 years, it's power out is 70 per channel. It was made by technics or panasonic. If the transformer ever go forget it. the part is nolonger made.