Steve Dunlap said:
In fact .01Hz is perfectly acceptible, or should I say this number is meaningless. This viewpoint is ONLY held in the "audiophile" community.
andy_c said:
I have posted some of my designs. Not that one yet. Most here seem to be content with 50 to 100W.
It would be somewhat OT to post it here anyway as this is (was) a preamp thread.
Steve Dunlap said:
Okay. I've seen the Krill, and its front end was a feedback amp as I recall. Are you talking about something like that, and calling it open loop?
Feel free to post the schematic in any relevant thread. A link will do fine.
Not bagging the design, but the non-switching OPS of the Krill will not do 0.005%.
You won't even get that with full class A bias.
Lets be realistic.
You won't even get that with full class A bias.
Lets be realistic.
scott wurcer said:
Are you saying that only an "audiophile" would bother to design a circuit with a little bandwidth before the application of feedback?
G.Kleinschmidt said:
I know what you're saying. Seeing Steve's past posts leads me to believe he's completely on the level - but his claim stretches credulity.
Steve Dunlap said:
In the non-audiophile world, only the gain-bandwidth product is important, and the open-loop bandwidth is irrelevant.
G.Kleinschmidt said:
Sorry, that wasn't my opinion. That was what it measured. Not just one sample either.
andy_c said:
If you have followed the Krill thread, which you have no reason to have done, you would see that I make no claim to the posted voltage gain stage. I was trying to present the evolution of the amp in a teaching manner. I started near the beginning of the design process and had planned to progress onward. The information I have posted so far is pretty old. In fact, those "impossible" specs are over 12 years old.
It turns out most people don't want to learn. They either already know everything, or they only want the finished product handed to them.
Yikes, I would completely redesign that one.
.0005% at 400w/w out NFB , you should be designing ALL the linear circuits for the "big boys". .05% is more realistic, giving
.0003% after NFB. Come on' ..at least divulge the topology for
this magic amp..words are cheap.
(I know it is not the "krill")
OS
Steve Dunlap said:
If your claim is true, then I have a lot to learn from you. But so far you haven't provided any evidence for your claim. Big difference there.
I,ve simulated the OPS of the krill (no global NFB)using known .003% or below
VAS's And it does not add any (.001% or less) to whatever
you "plug" into it , so .. maybe he refers to this ??
OS
VAS's And it does not add any (.001% or less) to whatever
you "plug" into it , so .. maybe he refers to this ??
OS
OS, I seem to recall you do most of your sims at 1 kHz, but Steve is claiming this measurement at 20 kHz - which is a lot harder to do.
Maybe he's right? If so, I'd be very interested in finding out more.
Edit: OS, is that sim up on your site? I'll grab it if so.
Maybe he's right? If so, I'd be very interested in finding out more.
Edit: OS, is that sim up on your site? I'll grab it if so.
No , andy.. the krill drove me crazy. I wanted one but did not
want to hijack his design. I was/am still amazed by its performance given it's udder simplicity. (envy)
It is very easy to do on LT (5 minutes) and with the best models
works as advertised.
edit: I do 1k- 10k -20K now ,both at medium and pre clip power.
OS
want to hijack his design. I was/am still amazed by its performance given it's udder simplicity. (envy)
It is very easy to do on LT (5 minutes) and with the best models
works as advertised.
edit: I do 1k- 10k -20K now ,both at medium and pre clip power.
OS
Hi Steve (Dunlap),
Focus on those who want to learn.
-Chris
I've been real short of time as of late. Did you post those designs here? I didn't read your Krill thread yet, but you have peaked my interest. I didn't care much for the sound of early Krell product. I haven't heard any later ones.
I'll agree with you there. Most commercial designs I've seen over the last number of years have been in that power range. If you increased the power level up to 200 watts, I'm pretty sure you would have 90 % of amps out there covered. In fact, I built some SymAsym amplifiers because they were about 40 ~ 50 watts.
I'm sure there is ample interest in this topic, so start a thread when you have the time.
I guess that may seem true. However I do know many members are all about learning, as am I. So I am looking forward to reading your thread now (Krill).
That has been an increasing trend I think. Too bad because there is nothing cooler than designing and building something and it works. Sometimes it even works well. A finished project is always nice so you can learn by comparing what you come up with against the project. But I have to give some credit to those who make the boards and stuff them. That's a far cry from just buying one done, or buying modules and wiring them up.
Focus on those who want to learn.
-Chris
Steve Dunlap said:
No, what really maters anywhere but in the GE world is a strange two headed cross-breeded animal called "gain-bandwidth product".
Good opinion, I have found the "blowtorch" , but would not build it. (maybe use the general topology with modifications)
Maybe my thought process "bucks the trend", but I
would much rather "bastardize" the original design and learn
the hard way. (reverse engineer)
3 outcomes are possible.. 1. you realize the original design was the best/ most feasible. (Krill)
2. You realize that a few modifications/ better devices really improve things and as a added benefit you can call it your own.
3. use all or parts of the design as a "building block" to create
something unique to share (make available for criticism) 😀
I have found lately the lines between op-amp's , preamps, and
power amps blur as I find useful techniques that are common
to all of them. ( I am listening to a baby leach triple op headphone amp with a holman input stage 😎 24v rails )
Maybe a "blowtorch poweramp" is due.. 🙂 an amp is a
amp
.OS
Hi ostripper,
You also have an amplifier I want to study. I am wayyy behind these days.
One thing I was starting to do in 2005 was design the output stage and voltage amp stage by themselves. There is a great deal of freedom doing things that way. Your design also ends up being more modular. By doing this, you can upgrade each bit as you improve things, or even just want to play "what-if".
-Chris
You also have an amplifier I want to study. I am wayyy behind these days.
You aren't bucking the trend that much. Playing with a design is the best way to learn about it. You can then revisit the design choices that were made and even go in a different direction.
One thing I was starting to do in 2005 was design the output stage and voltage amp stage by themselves. There is a great deal of freedom doing things that way. Your design also ends up being more modular. By doing this, you can upgrade each bit as you improve things, or even just want to play "what-if".
-Chris
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