The last set for step response w/wo capacitive load
as well as hard clipping behviour for the DX amp,
Leach amp , JLH10W and Pass F5.
The latter is the only one which is tested with capacitive
load without zobel and LR network.
A graph adding these networks is also provided.
All the other amps have a 1R//1uH in serial with
the output for capacitive loading test.
The JLH is tested with and without zobel network,
but in both graphs with the LR serial circuit.
Step response with pure resistive load is made
without this filter for all amps.
as well as hard clipping behviour for the DX amp,
Leach amp , JLH10W and Pass F5.
The latter is the only one which is tested with capacitive
load without zobel and LR network.
A graph adding these networks is also provided.
All the other amps have a 1R//1uH in serial with
the output for capacitive loading test.
The JLH is tested with and without zobel network,
but in both graphs with the LR serial circuit.
Step response with pure resistive load is made
without this filter for all amps.
Good job done! I am already built from this list Leach and F5 - and both sound great!
I think about next my DIY project - on the one hand - de - lite amp from master Pass, on the other - watching the results there (OK its just theory - lot of the parameters depend on PCB , layout, installation ...) and think about symasym or Ostripper amp....
I think about next my DIY project - on the one hand - de - lite amp from master Pass, on the other - watching the results there (OK its just theory - lot of the parameters depend on PCB , layout, installation ...) and think about symasym or Ostripper amp....
Hi , Apex
It s one where you have corrected the rail sticking
that occured in the first version..
Good work btw, so i think that it s the final version.
regards
I share overcompesated shematics for diyers, I use lower caps value, look post #321 in my thread:
http://www.diyaudio.com/forums/solid-state/164093-100w-ultimate-fidelity-amplifier-33.html
At the end posts: #1, #20 and #48 in same thread, and I don't think that my AX14 amp is popular.
Regards
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That s the good one...
Reducing the 47pF lead cap increase high range THD.
As for overcompensating your amps, did you have
to deal with musicians ?..
As for being a famed amp, well, there s not a lot of designs
by there these times, so in a way, it s popular..
regards
Before 20years I made only High-End amplifiers, and then I go to PA amplifiers, but many people want my amps for Hi-Fi... I still not made Amp perfect for myself, do you made some for yourself? 🙂
Regards
Well, i recently unmounted my 25 years old daily usage amp
to downgrade its power from 2x100W to 2X20W...🙂
regards
Hi a.wayne,
Let's try and remain on topic here people. Focus on what wahab is doing rather than what you think the value of the exercise is. These are tools for those who understand how to use them.
BTW, I don't know any amplifier designers that fail to listen to a prototype as part of the design process. I can't see anyone releasing a product to production without listening tests of some type.
-Chris
Please keep in mind that the entire purpose of this thread is to introduce simulation as a tool and to compare the results from this to real, operating amplifiers. Looking at the items you brought up is clearly beyond the intended scope of what wahab is doing here.
Let's try and remain on topic here people. Focus on what wahab is doing rather than what you think the value of the exercise is. These are tools for those who understand how to use them.
BTW, I don't know any amplifier designers that fail to listen to a prototype as part of the design process. I can't see anyone releasing a product to production without listening tests of some type.
-Chris
Hi SY,
The only one of those two I do know is Jan.
Jan designs, then freezes the design without listening? Really? Okay, that I didn't expect to hear.
My main point is that the bulk of designers listen to the design before accepting that the design is complete.
-Chris 🙂
The only one of those two I do know is Jan.
Jan designs, then freezes the design without listening? Really? Okay, that I didn't expect to hear.
My main point is that the bulk of designers listen to the design before accepting that the design is complete.
-Chris 🙂
I'm not sure, but I think Doug Self also. As for the designers who create the majority of amplifiers sold (mostly Asian), I don't know, but I doubt they do any extensive listening during the design process.
I didn't know Peter Walker but I wish I had.
I didn't know Peter Walker but I wish I had.
Hi SY,
Well, experienced designers already have an idea what the amp will sound like when they design it. Therefore they know what they are listening for and it doesn't take very long. Extensive listening wasn't the point though. The point was that most designers do have a listen before the design is committed. It doesn't have to be an extensive listening test.
Those prepackaged designs you are talking about are evaluated as well. The firm that supplies the parts normally does have recommended (reference) designs that perform the best they can make them. After all, Sanyo (for example) published the reference designs for everything from the 2 watt chips to the STK complete amp and even for the STK voltage amp / discrete transistor design. As a servicer of audio products, a look in the Sanyo catalog (or National or TI or Motorola ....) for the IC was sufficiently accurate to service those circuits properly. In fact, they often pointed the cause out that explained why a certain model had a tendency to fail some times. So while the actual "built as" circuit may not have had a critical ear applied, the reference design did. They even had suggested PCB layouts to avoid that entire problem.
I've corresponded with Doug in the past. Although it didn't come up, he understands enough of the details and pitfalls in amplifier design that I doubt he would release anything without a listen first. Remember too that his reputation is on the line with each design he releases. If I had to guess, he listens.
I've seen you listen to what you design SY. The importance of doing that isn't lost on you either. I know that I have a decent idea what something will sound like, although I do get disappointed from time to time.
Peter Walker would have been interesting to know, as would many other people. Many even members here on this forum.
-Chris
Well, experienced designers already have an idea what the amp will sound like when they design it. Therefore they know what they are listening for and it doesn't take very long. Extensive listening wasn't the point though. The point was that most designers do have a listen before the design is committed. It doesn't have to be an extensive listening test.
Those prepackaged designs you are talking about are evaluated as well. The firm that supplies the parts normally does have recommended (reference) designs that perform the best they can make them. After all, Sanyo (for example) published the reference designs for everything from the 2 watt chips to the STK complete amp and even for the STK voltage amp / discrete transistor design. As a servicer of audio products, a look in the Sanyo catalog (or National or TI or Motorola ....) for the IC was sufficiently accurate to service those circuits properly. In fact, they often pointed the cause out that explained why a certain model had a tendency to fail some times. So while the actual "built as" circuit may not have had a critical ear applied, the reference design did. They even had suggested PCB layouts to avoid that entire problem.
I've corresponded with Doug in the past. Although it didn't come up, he understands enough of the details and pitfalls in amplifier design that I doubt he would release anything without a listen first. Remember too that his reputation is on the line with each design he releases. If I had to guess, he listens.
I've seen you listen to what you design SY. The importance of doing that isn't lost on you either. I know that I have a decent idea what something will sound like, although I do get disappointed from time to time.
Peter Walker would have been interesting to know, as would many other people. Many even members here on this forum.
-Chris
Hi, Anatech
Agree...
Surely that listening to an amp is a necessary step on a design
process, but it s even more sure that building something
that doesn t provide full satisfaction in simulations is somewhat
discarding the fundamental step of the said process.
If it doesn t simulate well, it wont sound well.
Saying otherwise is denying the laws of physics...
cheers
I would have thought listening to your design is important.
After all, that's what the customer does. It should have good specs AND sound good.
Interesting......
After all, that's what the customer does. It should have good specs AND sound good.
Interesting......
Hello Chris ,
I'm not disagreeing or against simulations, in fact i'm for it and view sims essential and necessary part of designing ..... PART !!!
My original point was that Wahab had started to comment negatively on certain designs based on his sim, when others have said otherwise and spoken positively to the designs test criteria and sound. Finding the correlation between the 2 is what i seek, a poor design will sound and sim poorly, that is academic and if not?
We now have a ton of simulated results, ( thanks Wahab) .......... Conclusions ?
OS... Agree +10 !!!!
.
I'm not disagreeing or against simulations, in fact i'm for it and view sims essential and necessary part of designing ..... PART !!!
My original point was that Wahab had started to comment negatively on certain designs based on his sim, when others have said otherwise and spoken positively to the designs test criteria and sound. Finding the correlation between the 2 is what i seek, a poor design will sound and sim poorly, that is academic and if not?
We now have a ton of simulated results, ( thanks Wahab) .......... Conclusions ?
OS... Agree +10 !!!!
.
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Conclusion: There are three criteria by which modern amp designs are judged.
#1 Measured THD et al
#2 Simulated THD et al
#3 Subjective listening.
Since #3 is unreliable, it is downplayed.
But #1 and #2 don't always correlate well with the listening experience.
What to do?
#1 Measured THD et al
#2 Simulated THD et al
#3 Subjective listening.
Since #3 is unreliable, it is downplayed.
But #1 and #2 don't always correlate well with the listening experience.
What to do?
Design and simulate seeking for a specific distortion profile and level according to your experience and knowledge, then build the amplifier and listen to it, tune it till you like the sound, simulate and measure again then, you might be able to find some correlation between the new simulation results and the measurements a well we as the listening experience. This is what I can conclude for my self.
So then we will know when we look at a simulation, if the amplifier does sound good or not, because we started to know that this distortion profile and level and this simulation do correspond to a good sounding amplifier. Why do we always have to say that this specific very low distortion amplifier sounds good all the time, are not there any irregularities to your physics laws Wahab? May be the very low distortion amplifier Wahab likes, sounds dead to others, so how can we we judge later on, simulations are the very first step, no one can deny that, but which distortion level, and which distortion profile?
I can't believe that the laws of physics say that the best sounding amplifiers have extremely low distortion whether simulations or measurements, do they really sound good for all music colors and for all people?
So then we will know when we look at a simulation, if the amplifier does sound good or not, because we started to know that this distortion profile and level and this simulation do correspond to a good sounding amplifier. Why do we always have to say that this specific very low distortion amplifier sounds good all the time, are not there any irregularities to your physics laws Wahab? May be the very low distortion amplifier Wahab likes, sounds dead to others, so how can we we judge later on, simulations are the very first step, no one can deny that, but which distortion level, and which distortion profile?
I can't believe that the laws of physics say that the best sounding amplifiers have extremely low distortion whether simulations or measurements, do they really sound good for all music colors and for all people?
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