@gpapag: Symmetrical amps have "balance slew rate".
So if music signal is asym-signal, Symmetrical can be redundant .
I think that Asym amp will increase "asymmetry of music signal"
To me, it's easier to have a low distortion amp with symmetrical topology than asym-topology
I'm using a Symmetrical amp, I don't have to use any Curren Mirror
So if music signal is asym-signal, Symmetrical can be redundant .
I think that Asym amp will increase "asymmetry of music signal"
To me, it's easier to have a low distortion amp with symmetrical topology than asym-topology
I'm using a Symmetrical amp, I don't have to use any Curren Mirror
I don't think tolology symmetry is required for low distortion or distortion cancellation.thanh said:@gpapag: Symmetrical amps have "balance slew rate".
So if music signal is asym-signal, Symmetrical can be redundant .
I think that Asym amp will increase "asymmetry of music signal"
To me, it's easier to have a low distortion amp with symmetrical topology than asym-topology
I'm using a Symmetrical amp, I don't have to use any Curren Mirror
Look at D.Self's design for asymmetrical topology and low distortion. A far as I can recall he only makes the output stage (driver and output device) from symmetrical complementary pairs, all else is single ended.
wds said:
International Rectifier has an interesting paper on their website -- a tip for further enhancements http://www.irf.com/technical-info/appnotes/an-957.pdf
Nelson Pass had a paper in AudioXpress on a "do everything" test --
As I have mentioned before, it is regrettable that National Instruments has abandoned Softwire -- with its ramp generator function, array functions, dump to Excel it was really useful -- but it was also a bit clunky -- I am probably upgrading to Measurement Studio. It is also too bad that you can't access the microprocessor or some RAM in their USB units --
infinia said:
It wasn't deliberate but we didn't print those limits...I guess we got used to reading the graphs and forgot.
Presently, the CT100 USB Curve Tracer will test up to 22ma with 0 to 15V sweeps. We have tested a board hack that can improve the present design to near 50ma. For now, we have decided to keep the 22ma version while we work on a new board design. Our goal is 100-125ma with USB power only. Unfortunately, the price of components goes up as you squeeze something reliable from USB at those levels, and there lies the tradeoff of price/performance.
We may decide to support the board hack with some software adjustments for those who would like to get a little more performance out of the CT100. The board performs very well for a large number of available semiconductor components, as is. It's a very convenient and useful lab and bench tool with great easy-to-read graphics.
@AndrewT:
I really don't understand you!
D.Sefl uses current mirror. This technique can only decrease distortion. It can not cancel distortion. My amp is too! Like my words
Now I prefer Symmetrical amp. I don't mean a Bridge amp. I also viewed Leach's amp. Leach doesn't use differential VAS but I do .
Bye!
I really don't understand you!
D.Sefl uses current mirror. This technique can only decrease distortion. It can not cancel distortion. My amp is too! Like my words
Before I also love current mirror. I built a version of Blameless amp. I found that the amp will become worst after using for a long time. Perhaps input transistors are not matched longer.
Now I prefer Symmetrical amp. I don't mean a Bridge amp. I also viewed Leach's amp. Leach doesn't use differential VAS but I do .
Bye!
Hi Thanh,
I threw up Leach and Krell as examples of symetrical.
It is precisely because they are symetrical that neither can use Mirror loading for the input LTP. They must use resistor loading to define the current in the VAS or change to an alternative Topology.
Now back to D.Self. He achieves something of the order of 0.0006% distortion (<-104db) in a very conventional topology without using any tricks. He does it by optimising each stage for minimum distortion.
I did not say that Leach used a differential VAS.
I threw up Leach and Krell as examples of symetrical.
It is precisely because they are symetrical that neither can use Mirror loading for the input LTP. They must use resistor loading to define the current in the VAS or change to an alternative Topology.
Now back to D.Self. He achieves something of the order of 0.0006% distortion (<-104db) in a very conventional topology without using any tricks. He does it by optimising each stage for minimum distortion.
jackinnj said:
Maybe you were just yanking his chain, but...
Without wanting to induce any flames or ongoing topic derailment, I am compelled to remind you that XML, a parsed text format, is by far the most popular [current] data interchange standard, and has shown no signs of abating. CSV into excel isn't an unduly onerous solution for that particular application in my mind. 'nuff said on that (I hope
)...Todd
Hi wds,
I would be interested in an add on unit that could be used with external supplies. With that you may be able to test high power transistors or even tubes. Think of two add on modules. The USB power draw would of course drop.
You have my attention (not in a bad way either). This will allow you to leverage your current offering or future improvements to that basic unit.
I am in the unenviable position of being interested in both add-ons as well as the basic unit. Are your new ones shipping now?
One concern. The Windose platform often shifts it's compatibility. I have devices and programs that do not run past windose 98, the XP version I currently need forces me to run two computers. The newly released version may complicate that further. Is there any thought of releasing Linux drivers? Believe it or not, I still run OS/2 for other things. It is stable as a system, I have to say that.
-Chris
I would be interested in an add on unit that could be used with external supplies. With that you may be able to test high power transistors or even tubes. Think of two add on modules. The USB power draw would of course drop.
You have my attention (not in a bad way either). This will allow you to leverage your current offering or future improvements to that basic unit.
I am in the unenviable position of being interested in both add-ons as well as the basic unit. Are your new ones shipping now?
One concern. The Windose platform often shifts it's compatibility. I have devices and programs that do not run past windose 98, the XP version I currently need forces me to run two computers. The newly released version may complicate that further. Is there any thought of releasing Linux drivers? Believe it or not, I still run OS/2 for other things. It is stable as a system, I have to say that.
-Chris
anatech,
We are testing new circuit designs that will push USB to it's spec limits and provide decent V and I to test a good number of common semiconductors.
We will also approach any new designs so that an external power supply will be possible using the same USB board, thus extending the overall power capabilites. It is our intention to create a cost-effective solution for many engineers and DIY'ers.
As it stands right now, the CT100 is a lot of bang for the buck, although it is somewhat limited in the number of curves that can be displayed for high current devices without going over-range.
OS compatibility is generally not a problem as long as it's Win98 SE and newer, and has USB 2.0. Our programming uses the Windows functions directly for its built-in USB capabilities, so it requres no special drivers.
We are testing new circuit designs that will push USB to it's spec limits and provide decent V and I to test a good number of common semiconductors.
We will also approach any new designs so that an external power supply will be possible using the same USB board, thus extending the overall power capabilites. It is our intention to create a cost-effective solution for many engineers and DIY'ers.
As it stands right now, the CT100 is a lot of bang for the buck, although it is somewhat limited in the number of curves that can be displayed for high current devices without going over-range.
OS compatibility is generally not a problem as long as it's Win98 SE and newer, and has USB 2.0. Our programming uses the Windows functions directly for its built-in USB capabilities, so it requres no special drivers.
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