Series resistance
With current drive you don't need any series resistance, so all the power is delivered to the driver. And you can manipulate the Q value actively or passively, as e.g. in Pass' FIRST WATT F1, where a resistor in parallel with the amplifier output does the job.
With current drive you don't need any series resistance, so all the power is delivered to the driver. And you can manipulate the Q value actively or passively, as e.g. in Pass' FIRST WATT F1, where a resistor in parallel with the amplifier output does the job.
I have run into this observation more than once - Jon ver
Halen has commented that series resistance "sucks the life
out" as an example.
And yet Thevenin equivalency is clear that there is no
difference between a perfect voltage source in series with
a resistor and a perfect current source in parallel with the
same resistor. If there is a difference then we have to
presume that there is either a failure in the perfection of
the cs and/or vs or a flaw in the test / listener.
Sorry, I didn't post carefully enough. Wanted to say "I also don't think series are bad per se. But that too high values "suck out life" is true. The character of this driver before was a bit what a naim lover calls "energy", I don't like that kind of sound. I didn't make such experiments with other drivers, but with this driver +/- 0.3 Ohm was clearly audible (in the midrange, I don't speak about bass response). Are there different paper mixes that demand weaker/stronger motors?
Knuts the new seas will be in the 125$ range....
http://www.diyaudio.com/forums/pass-labs/148620-papa-watts-next-9.html#post2359532
http://www.diyaudio.com/forums/pass-labs/148620-papa-watts-next-9.html#post2359532
"In theory, there is no difference between theory and practice. But, in practice, there is." -Yogi Berra
By the way, I noticed that even simple L/R circuits that are used in series with the fullrange speaker in order to 'correct' their frequency response degrade the sound. Theoretically, they should be just shelving frequencies above the certain point, but...they suck some life out the music. That's why I prefer current source amps, and I (again) removed the feedback resistors (and CCS modulation) from my Zen V9.
Equalization
Have you tried active equalization instead of simple L/R circuits? What kind of speakers do you use, and how would you describe the difference between current drive and voltage drive?
"In theory, there is no difference between theory and practice. But, in practice, there is." -Yogi Berra
By the way, I noticed that even simple L/R circuits that are used in series with the fullrange speaker in order to 'correct' their frequency response degrade the sound. Theoretically, they should be just shelving frequencies above the certain point, but...they suck some life out the music. That's why I prefer current source amps, and I (again) removed the feedback resistors (and CCS modulation) from my Zen V9.
Have you tried active equalization instead of simple L/R circuits? What kind of speakers do you use, and how would you describe the difference between current drive and voltage drive?
Yes, I tried equalization instead of simple L/R circuits. They do work, but any such circuits would require to be "sandwiched" between two buffer blocks for the best effect, which works well if you use J-fet (or even tube) buffers (I do not prefer opamps). My Open baffle (120x50cm-flat baffle) consists of The Eminence Beta 15 for the bass and Visaton B200 for the highs. It is biamped, so that the the Beta is driven by a voltage source amp (Sony TA-N511) while Visaton is driven by Zen V9 without feedback, i.e. current amp. The whole thing is now actively crossed over, though during the last two years I have been playing with various crossover combination (slopes, frequencies, active, passive, hybrid). The difference, V/I: Current drive changes the damping (hence bass) and the tonal character of the driver, often for the better. In my case, only the fullrange (above 150 Hz) is driven with the current amp, so no effect on the bass here, but some nice things happen in the upper registers as well. Somehow it sounds more musical, there is more "air', it just sounds more natural and less strident. Also, there is a bit of compensation here as well, in order to correct for fullrange nasties. There is Zobel (C+R) in parallell with speaker terminal (B200) to correct for its rising response.
On the paper, you would see that Zen V9 without feedback has actually more distortion than with feedback. However, at normal volumes I do not find it distracting. To me, connecting the feedback (this making it a conventional voltage amp) makes it sound more 'solid' and loose that 'breath of air that makes some instruments sound so lively....
I know it's all subjective, but...
On the paper, you would see that Zen V9 without feedback has actually more distortion than with feedback. However, at normal volumes I do not find it distracting. To me, connecting the feedback (this making it a conventional voltage amp) makes it sound more 'solid' and loose that 'breath of air that makes some instruments sound so lively....
I know it's all subjective, but...
I have TB-W8-1808 in 24 inch wide OB without any kind of filter.
My amp is a factory (kitchen) buildt F4.
The low end is taken care of with a pair of Klipsch RSW-10d subwoofers.
It sounds fantastic. But after reading the article about fullrange¤t source i was curious.
Mr Pass. Do you reccomend a particulary filter here?
Hans Erik
My amp is a factory (kitchen) buildt F4.
The low end is taken care of with a pair of Klipsch RSW-10d subwoofers.
It sounds fantastic. But after reading the article about fullrange¤t source i was curious.
Mr Pass. Do you reccomend a particulary filter here?
Hans Erik
I have not played with it enough to recommend a specific
for the F4 or similar. Most likely you will want to consider
taking some of the edge off the upper mid with a small
coil in parallel with a resistor, this in series with the driver.
Thanks
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Joined 2009
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Wow, I had some thoughts along these lines last summer, a speaker that looks like a jet engine - any drawings etc ?
Don't think about filter circuits, go active equalization. Because you have to correct the response not only at the lowest frequencies. I have a lack of time to post more things on Home, but there is some comparison between OB fullrange current drive system vs Proac response 2.5 clones. Sound difference is big. I don't listen the Proac clones if OB system is in that room.
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