iloveitloud
Active Member
Specifically a KENWOOD super Eleven. I have an Eleven III, and am just wondering what a high speed DC reciever has over mine, or any other regular reciever?
What is a high speed DC reciever?
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whoaru99
Epic Member
A fancier-sounding name.
Supposedly they used faster-switching transistors.
Ohifio
Aesthetic Oxymoron
I believe in the case of the "KENWOOD" brand that "High Speed" is the technology that was carried out of the Lab Series amps(L-05M, L-07M, L-07MII..etc) and put into the general line-up of consumer gear. The receivers and amps like the KA-907 on down got the "High Speed" moniker.
I have a set of L-05M's and they are very detailed sounding. It has something to do with slew rate performance and waveform duplication as measured comparing input signal and output signal on a O-scope. Not just that though it also includes damping factor and the fact that the "High Speed" Lab Series amps are essentially ultra high frequency (by sonic standards) oscillators that are controlled by circuitry NOT to oscillate. I'm not sure I've described all that exactly right though.
As far as "High Speed" receivers, I have a Kenwood 7050 "High Speed DC" receiver and it is no match for the L-05M mono-block Kennies. I'm sure the "High Speed" is meaningful in the KA-907 integrated and some of it's smaller brethren. Many extoll the virtues of this line of Kenwood amps.
Hope this answers your question.
I have a set of L-05M's and they are very detailed sounding. It has something to do with slew rate performance and waveform duplication as measured comparing input signal and output signal on a O-scope. Not just that though it also includes damping factor and the fact that the "High Speed" Lab Series amps are essentially ultra high frequency (by sonic standards) oscillators that are controlled by circuitry NOT to oscillate. I'm not sure I've described all that exactly right though.
As far as "High Speed" receivers, I have a Kenwood 7050 "High Speed DC" receiver and it is no match for the L-05M mono-block Kennies. I'm sure the "High Speed" is meaningful in the KA-907 integrated and some of it's smaller brethren. Many extoll the virtues of this line of Kenwood amps.
Hope this answers your question.
zenith2134
Lunatic Member
On a lot of the old gear I've encountered, it is similar to the manufacturer tagging "SOLID STATE" on the front somewhere; i.e., they were proud of their DC coupled amplifier designs early on.
I think all SS amps should be DC coupled and ICL but be careful about DC offsets in your source gear.
I think all SS amps should be DC coupled and ICL but be careful about DC offsets in your source gear.
In the case of Kenwood, the "High Speed" amps and receivers came in around 1980. My KR-720 has the same markings.
JBL GUY
Addicted Member
Yep Sam nailed it...
Back in the day..."Slew Rate" and Transient Response" ...The faster the better.
And made possible by faster-switching transistors...better circuit design and direct coupling...or so the story goes...
hardrock94
Super Member
I own a KR-9400-1974, KR-9600-1976,also a KR-7050 High Speed DC,can't tell any difference.:nono:
Fred Longworth
audio fanatic
The engineering term is "slew rate" measured in volts/microsecond. It answers this question: how fast can the output stage move?
The "pro" argument -- and it is a valid one -- is that if an amplifier has a fast slew rate, it will have a wide bandwidth, and therefore the phase shift at all audio frequencies will be negligible.
The "con" argument is that wide-bandwidth amplifiers, such as the Kenwood Super Eleven, are always attempting to turn into oscillators at frequencies like 500kHz. Sadly, as amplifiers age, component tolerances drift, and the circuit board itself may acquire a lumped reactance. A great many machines are no longer unconditionally stable. They may "blow up" during power up, or when hooked into a load with a "difficult" reactance, such as electrostatic speakers.
This problem is exacerbated by the unavailability of many original parts, and the necessity that substitute parts be used for power amp repairs, thus making the amplifier even more susceptible to instability.
Fred
The "pro" argument -- and it is a valid one -- is that if an amplifier has a fast slew rate, it will have a wide bandwidth, and therefore the phase shift at all audio frequencies will be negligible.
The "con" argument is that wide-bandwidth amplifiers, such as the Kenwood Super Eleven, are always attempting to turn into oscillators at frequencies like 500kHz. Sadly, as amplifiers age, component tolerances drift, and the circuit board itself may acquire a lumped reactance. A great many machines are no longer unconditionally stable. They may "blow up" during power up, or when hooked into a load with a "difficult" reactance, such as electrostatic speakers.
This problem is exacerbated by the unavailability of many original parts, and the necessity that substitute parts be used for power amp repairs, thus making the amplifier even more susceptible to instability.
Fred
