Krill - The little amp that might...

[Joshua_G]

Well said, Chris.

jkeny, arrogance is something we aren't lacking here …

 

[MJL21193]

I'm also dumbfounded by MJL statement that his circuit is close enough - I hope it was a joke otherwise - Jeez the arrogance!

Edit: I see you just posted - yes MJL explain how the circuit works!

I pretty much knew that this would happen.

You and your new best friend Joshua can team up and build it the correct way, with the correct devices and values. You can post your results for criticism.
While your at it, you guys can explain how it works. Having read some of Joshua's comment over in the blowtorch, this should be interesting...

 

[MJL21193]

Re: Okay! Enough bickering!

I guess we may have to split some stuff out, and trash the noise. My first inclination would be to split the sim stuff out, but I'm open to suggestions here. To that end, what do you people want to have stay, and what should be in a different thread?
-Chris

I vote for leaving it all in here. I'm not good with censorship...

Hi John,
Thank you for building that up. You are welcome by if you want to. We can measure THD and run it through the Spectrum Analyzer. That would give the answers you are looking for I think.

Hi Chris,
30 minutes out of my life to build it (incorrectly ) is no big deal. I will tack a frontend on it a get some rudimentary measurements with RMAA, but it will be for my own satisfaction/information, not to post here.
Good results they love you, bad results you're public enemy #1 again...

 

[stinius]

Re: Okay! Enough bickering!

I guess we may have to split some stuff out, and trash the noise. My first inclination would be to split the sim stuff out,
-Chris

BTW, I'm a "build it guy", I don't know enough to simulate a circuit.

-Chris

Interesting, indeed very interesting, and you are a moderator?

Have fun

 

[megajocke]

John

I think this is one of the latest scematics by Steve.

Cheers
Stinius

When did R29/R30 (56.2 ohms) in the collectors of the bias transistors appear? They weren't there in the earlier schematics.

Were they used in the circuit with the claimed low distortion?

The difference in circuit operation is non-neglible.

 

[anatech]

Hi stinius,

Interesting, indeed very interesting, and you are a moderator?

That's what the label says.

I can see that if you put those two comments together you get a totally different picture. Thank you for pointing that out.

So, why would I consider pulling the sim stuff? Simple. It was pointed out to me that that was part of the problem. The "sim people" attacking what appears to be a stable, working design. However, you will notice that I did ask for input on this, I didn't just go ahead and do anything. Don't I get any points for trying to do what our members want?

As for my last comment "BTW, I'm a "build it guy", I don't know enough to simulate a circuit.", it's a statement of truth. I stated publicly, and clearly, that I do not have the knowledge or training to be able to simulate any circuit, not even a simple resistor and power source. It is a statement that shows my own shortcomings and how I deal with the problem.

Honesty, it'll kill ya every time I tell ya!

-Chris

 

[jkeny]

I retract my hats off to you MJL - you're a detriment to the whole idea of scientific experiment & repeatability - do you even know the concept? Please don't post your results here and pollute the thread

Edit: Chris, I vote for hiving off these sim discussions - to where is immaterial. (Texas). I've nothing against sims except when used in the manner shown here by ******

 

[anatech]

Hey John,
If you want, I'll post the measured performance. It can't be held as the performance of Steve's amplifier, but it will stand for your quick build.

If you spend the time to build this, I can spend the time to measure it if you want. You could bring along some other things as well, making the trip more worthwhile. I have no problems doing this.

Has anyone else built up this output stage and measured it? To be honest with you, the design intrigues me. I'd like to build a real one some time.

-Chris

 

[stinius]

When did R29/R30 (56.2 ohms) in the collectors of the bias transistors appear? They weren't there in the earlier schematics.

Were they used in the circuit with the claimed low distortion?

The difference in circuit operation is non-neglible.

It seem like we are not allowed to talk about simulation anymore in this thread, but I used these resistors in my simulation, and they make a difference.

Cheers
Stinius

 

[jkeny]

Chris,
Please don't post the MJL measurements it will further pollute the thread with misleading information - after all he has admitted that it isn't the Krill circuit (close enough!!!!!!!!!). I believe it would do the circuit a disservice to post these measurements - let's wait for somebody to build it who cares about the process

 

[MJL21193]

I retract my hats off to you MJL - you're a detriment to the whole idea of scientific experiment & repeatability - do you even know the concept? Please don't post your results here and pollute the thread

Your true colours are showing now.
I'll do whatever I want, within the confines of rules and procedures of this forum.
I'm done with you.

 

[megajocke]

It seem like we are not allowed to talk about simulation anymore in this thread, but I used these resistors in my simulation, and they make a difference.

Cheers
Stinius

I'd expect them to improve performance. What did they do in the simulator?

MJL21193, did you use those resistors in your (very nice looking ) build?

 

[anatech]

Hi Stinius,

It seem like we are not allowed to talk about simulation anymore in this thread, but I used these resistors in my simulation, and they make a difference.

Sure you are. It's just that sims have been used to beat people over the head before. Keep in mind I don't know the entire story as yet, and that the votes so far are to leave the sim stuff in. That's fine by me, just don't beat Steve Dunlap up with sim results where they do not agree with his running amplifier performance.

I have no plans to remove the simulation stuff if most of you wish to retain them. The only personal stake I have in this is that I know Mr. Dunlap is not well and that some members are not treating him very nicely. That is my concern. Whether simulation stays or not really depends on how everyone feels about those posts, and that they are not used to contradict the results of measurements on a working amplifier.

Hi jkeny,

I retract my hats off to you MJL - you're a detriment to the whole idea of scientific experiment & repeatability - do you even know the concept? Please don't post your results here and pollute the thread

Comments like that are not at all helpful to anyone. All you have done is insulted another member, but you have not provided any helpful information here what so ever. If you want to be helpful, why not share what your problem is with MJL's idea. There is such a thing as a conceptual design. Steve himself presented his output stage with a rather stock, "make it go" voltage amplification stage. MJL has simply done a similar thing, so I really do not see your point. Help me out here, what is wrong with what MJL is doing.

-Chris

 

[KLe]

Re: Re: Okay! Enough bickering!

IT is a shame, that ... Because of all this bickering BS , we could never see the more advanced version.
I see mr. dunlops point , as the more advanced version would bring about more advanced bickering BS..
I am glad someone else prototyped it ...

Yes, absolutely correct ... (but, I hope your wrong ...)

... It really ticks me off to see behavior like this.

Originally posted by c2cthomas Thanks Chris!

Thanks Chris ...

Edit: Chris, an idea ... perhaps there could be 2 threads. This one for constructor discussions and improvements as indicated by Steve, and another one for discussions called 'Krill - The little amp that might ... Discussion'. Just a thought ...

 

[jkeny]

Your true colours are showing now.
I'll do whatever I want, within the confines of rules and procedures of this forum.
I'm done with you.

It's a pity you're not done with the whole thread - what are you trying to prove? Is your circuit an honest attempt at testing/measuring the Krill OPS? Or is it some bodged effort at god knows what? Please explain!

 

[jkeny]

Chris I already pointed out to MJL where his circuit differed to the Krill OPS here http://www.diyaudio.com/forums/showthread.php?postid=1762689#post1762689 so I think I've clarified what my position/objections are to MJL's circuit

Edit: Yes Steve said use any VGS you like - the whole unique/interesting element is the OPS - so this part isn't a do it as you like stage! i.e "close enough" is not the OPS

 

[MJL21193]

I'd expect them to improve performance. What did they do in the simulator?

MJL21193, did you use those resistors in your (very nice looking ) build?

Hi Mega,
I posted the schematic that I worked from and no, I didn't include the resistors. Steve's original schematic doesn't use them and I gather he included them in the latest to accommodate the re-purposed boards he's been sending out.
FWIW in my SIM the resistors slightly worsened performance. This is neither here nor there for my real world test, as I built that to look (mainly) for stability and gross distortion. Seeing both of these are in order, I am fulfilled.

 

[anatech]

Hi jkeny,

Please don't post the MJL measurements it will further pollute the thread with misleading information - after all he has admitted that it isn't the Krill circuit (close enough!!!!!!!!!). I believe it would do the circuit a disservice to post these measurements - let's wait for somebody to build it who cares about the process

It's not often I quote an entire post.
I don't see how posting the results with proper notifications of it's design will hurt. It may actually serve to point out what is important with this design.

I would love to build one of these, then I will post the results. How close they are would depend on whether I use original boards or not.

I see your reasoning for requesting this, and this thread is too wild right now. My goal? I want to settle things down, and I want to defuse all this personal garbage back and forth. We as a group should be concentrating on the design while we retain a respectful and professional bearing.

So, I really don't want to pick any fights here, although some of you might be upset with me right now. That is one of the perks of being a moderator. Some members will resent you because of the job.

Can we post results of similar or exact circuits as long as the circuit is close to the original, and the schematic and picture is posted? My belief is that this information would be instructive. It is, after all, the same thing as simulating a changed circuit with it's predicted performance.

-Chris

 

[ostripper]

It seem like we are not allowed to talk about simulation anymore in this thread, but I used these resistors in my simulation, and they make a difference.

Those resistors R29/30
"trim" the gain of the diamond to reduce offset
in a open loop config. In a closed loop config you do not
need them.


Andy C. "corrected" my sim (embarrassed) and his should not
go to texas. As far as the simulations go, The krill is not a
standard EF stage, one can not just sub out one part
without making changes to the other parts.
(diamond gain vs. CCS/bias gen current vs. OP gain)
The simulator makes this possible in minutes..
To get it right with the devices you have
available , you have to understand it.

Some in the 3rd world (or even the 1st world) might not
have the devices specified in steve's pdf.. so, to get the
basic values (currents) right and avoid simulate
then build...

OS

 

[jkeny]

Part of the problem is that there were a number of schematics posted which had different errors on them - this was as a result of Steve's condition and I'm sure we can all empathise with him on this so it behoves us to make sure we use the latest schematic when we build/sim this circuit & not just the first one posted.

As Joshua? posted recently here is the latest 50W schematic

Edit: I hope this is the correct one - please check it out for me all who care!