You see dear Ostry.... i hate to have wrong images from people into my head
reason why i use to ask pictures from my dear friends.
I have some image in my mind that certainly does not match the real world image about you.
Yeah... this bothers me a lot.
You know, since 2008 i could see you producing some amplifiers already made, as Symassym you have made it different, a new version...no problem..this is fair...and Michael Bittner have never complained about..so..it is fair.
Also some amplifiers that looks alike Aksa published schematic and my own Aksa clone...the Dx amplifier (worst than Aksa..have not Aksa secrets on it).
As i am watching you producing some "legal" copies.... say... development into this or that amplifier...or "another point of view about Leach or something alike"....or.... "Ostry style into XYZ amplifier"...well..all that stuff, and from someone that has born into the copyrigth protection country, the wonderfull USA, them i feel strange having wrong image about some folks.
Could you be kind and send an image from yourself to uncle Charlie (I am older than you 18 years i think...i have age to be your dearest uncle) and this way i will be able to delete from my mind the strange images comes when i met you into the forum.
The picture is just for kidding purposes..you see how crazy can be our imagination.... that pirate does not make any sense as you know....just my wrong and delirating imagination
about you.
Uncle Charlie mail adress is:
panzertoo@yahoo.com
Always opened to you...and you can call me "bull", that's the name friends callls me because my behavior...you are welcome there into my mail box..just do not copy my e mail adress by accident or just for a kidding purpose to be laughing together your dearest uncle.
You see... the annoying effect when we have wrong image about people...send me a picture man!.. this way we gonna be more close.
ahahahahahh!
regards,
Carlos
reason why i use to ask pictures from my dear friends.
I have some image in my mind that certainly does not match the real world image about you.
Yeah... this bothers me a lot.
You know, since 2008 i could see you producing some amplifiers already made, as Symassym you have made it different, a new version...no problem..this is fair...and Michael Bittner have never complained about..so..it is fair.
Also some amplifiers that looks alike Aksa published schematic and my own Aksa clone...the Dx amplifier (worst than Aksa..have not Aksa secrets on it).
As i am watching you producing some "legal" copies.... say... development into this or that amplifier...or "another point of view about Leach or something alike"....or.... "Ostry style into XYZ amplifier"...well..all that stuff, and from someone that has born into the copyrigth protection country, the wonderfull USA, them i feel strange having wrong image about some folks.
Could you be kind and send an image from yourself to uncle Charlie (I am older than you 18 years i think...i have age to be your dearest uncle) and this way i will be able to delete from my mind the strange images comes when i met you into the forum.
The picture is just for kidding purposes..you see how crazy can be our imagination.... that pirate does not make any sense as you know....just my wrong and delirating imagination
about you.
Uncle Charlie mail adress is:
panzertoo@yahoo.com
Always opened to you...and you can call me "bull", that's the name friends callls me because my behavior...you are welcome there into my mail box..just do not copy my e mail adress by accident or just for a kidding purpose to be laughing together your dearest uncle.
You see... the annoying effect when we have wrong image about people...send me a picture man!.. this way we gonna be more close.
ahahahahahh!
regards,
Carlos
Attachments
Why not to try a different sonics Ostripper, just change the output
style and sonics will be very different..this way you gonna offer another sound amplifier, with different characteristics, to forum folks to build.
And for sure many guys will build and you gonna be happy with that.
Using transistors, not Ibgts..... you can produce a different sound, topologie will change.
With minor decisions into currents and some surrouding sub circuits you may have small differences that will not change the amplifier sonic "character"...but the output, in this style, sounds much better into the treble, and have the controlled bass people loves ( i do not love that).
This is the suggestion, or you gonna offer the same old song to forum..nothing new, just the same sound.... small modifications in currents (resistances) will change a little, will be within the bootstrapp characteristic sonics... try something different for a while.
Same sound now a days...Aksa offered to forum schematic published... mine Dx Amplifier, Bigun TGM and sligtly different, but not too much sonically different (more trebles too and more distortion) to the MJl21193 transistorized folk.
Of course i can provide complete schematic of this one..by mail, as this may have copyrigth with the Italian Fratellos
What about to have something new?
regards,
Carlos
style and sonics will be very different..this way you gonna offer another sound amplifier, with different characteristics, to forum folks to build.
And for sure many guys will build and you gonna be happy with that.
Using transistors, not Ibgts..... you can produce a different sound, topologie will change.
With minor decisions into currents and some surrouding sub circuits you may have small differences that will not change the amplifier sonic "character"...but the output, in this style, sounds much better into the treble, and have the controlled bass people loves ( i do not love that).
This is the suggestion, or you gonna offer the same old song to forum..nothing new, just the same sound.... small modifications in currents (resistances) will change a little, will be within the bootstrapp characteristic sonics... try something different for a while.
Same sound now a days...Aksa offered to forum schematic published... mine Dx Amplifier, Bigun TGM and sligtly different, but not too much sonically different (more trebles too and more distortion) to the MJl21193 transistorized folk.
Of course i can provide complete schematic of this one..by mail, as this may have copyrigth with the Italian Fratellos
What about to have something new?
regards,
Carlos
An externally hosted image should be here but it was not working when we last tested it.
Member
Joined 2009
Paid Member
OS,
You have shown the charge suck out cap across the driver emitter resistor, from Self. But Self doesn't always show the base stopper resistors on the output devices. I'm thinking that if you incorporate the base stoppers then you want to move the charge suck out cap over to the bases of the output devices. At least that's what I assumed (and did).
You have shown the charge suck out cap across the driver emitter resistor, from Self. But Self doesn't always show the base stopper resistors on the output devices. I'm thinking that if you incorporate the base stoppers then you want to move the charge suck out cap over to the bases of the output devices. At least that's what I assumed (and did).
Member
Joined 2009
Paid Member
I was commenting on carlo's amp... GOD NO !!! I would never use IGBT'S , MOSFET'S yes , but IGBT's... NAH !!
A pair of mosfet drivers (irf 610/9610) running a pair of BJT's would be interesting. As would a more powerful , compact OPS for the symasym (IRF240/9240) - mosfets are cool.
To answer the original question, the position of the "suckout" does not seem to matter on a single Op pair amp. On a multiple pair stage it would be unpractical as well. The R/C of even a 10r basestopper with a .05u-.1u cap would only be seen at very HF. The Cob of the output device is a much larger factor.
OS
Carlos and Ostripper
You two are both behaving badly. Please stop attacking each other and keep the discussion on topic and based on facts.
Carlos:
You have done a great service to the forum by sharing your amp design. The design has been recorded for posterity and for many years people will discover it when they search the forum. However, when you share you must expect others to experiment and try their small variations. This is the essence of what DIYaudio is all about.
OS:
I find it hard to support your position when you are so aggressive with your replies. It seems you are fanning the flames here. Please post with a calmer tone.
Thank you.
edit: OT posts deleted
Half the content of this thread is Carlos's ,and half of that is implying IP violations or that my endeavors are a waste of energy.
A few members agree with me. It strike me that he gets congratulated with recommendations and salutations while I get scolded.
If that is the way it is I guess this thread is dead and I concede the amp is DX corporation property...
I understand entirely...
OS
Hi ostripper,
I am very interested in the modified SymAsym. Are you going with BJT outputs (I hope) or mosfets? Sorry for the O.T., but I wanted to comment before I forgot where the post was. The original 5.x SymAsym is a great little amplifier. Perfect for probably a solid 80% of what most people really need.
A quick look at your layout looks like it's fine. A simple, easy build for many DIYer's.
Hi Carlos,
I understand your point that you are making, but I find I can't agree with you. Most every commercial amplifiers out there are only variations on a theme. If people couldn't design or use anything slightly different from your amplifier, most of the early amplifiers wouldn't exist. The basic idea is so widespread that your amp was copied before it was designed!
One thing you must remember though Carlos. The board design and choice of components (families of parts, not the brand name) will determine the more subtle sonic signature of an amplifier. That is the IP. Even the current levels you run the diff pair at will influence the sound and component values elsewhere.
Look at things another way then. You successfully sparked interest in a very old, basic amplifier design. Other people are now playing with the design. That's much what you had done. It's entirely fair to change a design slightly to see if the design can be improved. Of course it can, money would seem to be the only limiting factor in what you can do. As for current mirrors and current sources, that is the direction I would have taken with this design.
Always remember, the DX concept amplifier is yours. You introduced it. It's also basic enough to be very worthwhile experimenting with. Therefore, a great learning tool, that's a good thing.
-Chris
I am very interested in the modified SymAsym. Are you going with BJT outputs (I hope) or mosfets? Sorry for the O.T., but I wanted to comment before I forgot where the post was. The original 5.x SymAsym is a great little amplifier. Perfect for probably a solid 80% of what most people really need.
A quick look at your layout looks like it's fine. A simple, easy build for many DIYer's.
Hi Carlos,
I understand your point that you are making, but I find I can't agree with you. Most every commercial amplifiers out there are only variations on a theme. If people couldn't design or use anything slightly different from your amplifier, most of the early amplifiers wouldn't exist. The basic idea is so widespread that your amp was copied before it was designed!
One thing you must remember though Carlos. The board design and choice of components (families of parts, not the brand name) will determine the more subtle sonic signature of an amplifier. That is the IP. Even the current levels you run the diff pair at will influence the sound and component values elsewhere.
Look at things another way then. You successfully sparked interest in a very old, basic amplifier design. Other people are now playing with the design. That's much what you had done. It's entirely fair to change a design slightly to see if the design can be improved. Of course it can, money would seem to be the only limiting factor in what you can do. As for current mirrors and current sources, that is the direction I would have taken with this design.
Always remember, the DX concept amplifier is yours. You introduced it. It's also basic enough to be very worthwhile experimenting with. Therefore, a great learning tool, that's a good thing.
-Chris
You are among the many , I am very pleased with it . Powerful , reliable , very stable and cheap. But now I wonder , will I be accused
of copying/stealing or denigrating Mike B's excellent design.
In this thread ,I originally acknowledged RCA ,aska and the DX as the inspiration for this simple amp. I even thanked Carlos for the inspiration , instead of being mad that I was asked to leave his thread. This makes me "gunshy" about any further contributions.
I did promise many by email a "SUPERSYM" PCB package , And I will keep my promise.
Thanks ,Chris..
OS
Hi ostripper,
No, you will not be accused of copying or stealing. You are only developing that amplifier further. This is what people do with almost any design. Besides, how on earth can any amplifier be designed without being based on pre-existing technology? Earlier designs are called "prior art" in patent land. You may even get assistance from some of those earlier designers of the SymAsym.
I am sure many people are looking forward to a new amplifier. If I may add a request? Can the input impedance of your amp be raised to a higher value? 50 K would be nice. The noise would be dominated by the source and it's output impedance. I think the feedback network impedance might be fine, but we will be looking at higher wattage parts as a result. That concept does not make me feel very good.
Thank you for taking on this project. Many have built the SymAsym and are happy with it. I am still playing with mine. J Fets for me when I'm done.
-Chris
No, you will not be accused of copying or stealing. You are only developing that amplifier further. This is what people do with almost any design. Besides, how on earth can any amplifier be designed without being based on pre-existing technology? Earlier designs are called "prior art" in patent land. You may even get assistance from some of those earlier designers of the SymAsym.
I am sure many people are looking forward to a new amplifier. If I may add a request? Can the input impedance of your amp be raised to a higher value? 50 K would be nice. The noise would be dominated by the source and it's output impedance. I think the feedback network impedance might be fine, but we will be looking at higher wattage parts as a result. That concept does not make me feel very good.
Thank you for taking on this project. Many have built the SymAsym and are happy with it. I am still playing with mine. J Fets for me when I'm done.
-Chris
chris, I had always thought it was better to keep the input impedance of an amplifier low as possible to minimise the effects of Johnson noise in the feedback network.
It's always been my understanding that the input resistor to ground should be the same value as output to inverting input resistor in order to minimise dc offset.
This is why I've always gone for 22K for these values. I may consider trying higher ones to see. I'm planning to give my little "Adastra" amp a go with some parts I have on hand, after designing a rather tight pcb!
It's always been my understanding that the input resistor to ground should be the same value as output to inverting input resistor in order to minimise dc offset.
This is why I've always gone for 22K for these values. I may consider trying higher ones to see. I'm planning to give my little "Adastra" amp a go with some parts I have on hand, after designing a rather tight pcb!
Hi jaycee,
The resistances really do not have to be equal between input and feedback. You can still maintain a lower feedback impedance within reason. At some point you will begin dissipating substantial power in your feedback network. We don't really want to do this, but if we must, then allow for all that extra heat and provide a means to correct for resistor tolerances in that network. I am looking at a Carver Lightstar output PCB that died when the feedback element burned. There is a large oval burnt clear through the PCB where this part used to be. This was an ECO, because all of these amps were capable of doing this exact same thing. The rails on this amp at max are + / - 125 VDC, just for reference.
If you use fets for your input, differing impedance will not make a large difference. You can calculate the error for BJT pairs and inject a correction current. A servo could also repair the DC balance.
I feel that chasing the noise number in a power amplifier is detrimental considering the trade offs that need to be made. If that noise is important, then you can either buffer the input signal to present a higher impedance to the outside world, or take any of the corrective actions I listed above.
That make any sense? It's just how I feel about this.
-Chris
Yes, it is. That's if you only look at that one factor. My view is that you should try to balance many factors without focusing on one or two only.
The resistances really do not have to be equal between input and feedback. You can still maintain a lower feedback impedance within reason. At some point you will begin dissipating substantial power in your feedback network. We don't really want to do this, but if we must, then allow for all that extra heat and provide a means to correct for resistor tolerances in that network. I am looking at a Carver Lightstar output PCB that died when the feedback element burned. There is a large oval burnt clear through the PCB where this part used to be. This was an ECO, because all of these amps were capable of doing this exact same thing. The rails on this amp at max are + / - 125 VDC, just for reference.
If you use fets for your input, differing impedance will not make a large difference. You can calculate the error for BJT pairs and inject a correction current. A servo could also repair the DC balance.
I feel that chasing the noise number in a power amplifier is detrimental considering the trade offs that need to be made. If that noise is important, then you can either buffer the input signal to present a higher impedance to the outside world, or take any of the corrective actions I listed above.
That make any sense? It's just how I feel about this.
-Chris
A little. My Adastra won't be very high power... i'm looking at 30-50W. Ideally I want to run it on 25V rails. I might go up to 35V but ive a feeling the heatsink in the case i plan to use is a little too small (it was originally a 60W mono PA amp with a transformer output).
It'll be an integrated amp so it'll have some opamp based preamp in front of it. I've got a design there which already has a 47K input impedance.
It'll be an integrated amp so it'll have some opamp based preamp in front of it. I've got a design there which already has a 47K input impedance.
Hi jaycee,
BTW, for our members just starting out, music normally has a 10 to 1 peak to average ratio. It's 15 to 1 for CD's with very wide dynamic range. That means a 30 watt amplifier (or so) is just about right to keep from clipping.
Now, if you started with a 60 watt PA amp, it should be fine for 30 watts in stereo. I would hazard a guess that the heat sink in question might even be more than enough for a 50 watt per channel stereo. Most PA amps were run into clipping for hours on end.
I'd say that you should go ahead and build it. If I'm wrong about the heat sink, a small, low sped fan might cure your troubles. I still don't think you are going to have a problem.
-Chris
There is nothing wrong with that power range at all. In fact, it's perfect for in-wall speakers, computer sound, office sound and most garage systems. I have higher powered equipment, but using it for applications where you might never go over 2 ~ 3 watts continuous seems silly to me.
BTW, for our members just starting out, music normally has a 10 to 1 peak to average ratio. It's 15 to 1 for CD's with very wide dynamic range. That means a 30 watt amplifier (or so) is just about right to keep from clipping.
Now, if you started with a 60 watt PA amp, it should be fine for 30 watts in stereo. I would hazard a guess that the heat sink in question might even be more than enough for a 50 watt per channel stereo. Most PA amps were run into clipping for hours on end.
I'd say that you should go ahead and build it. If I'm wrong about the heat sink, a small, low sped fan might cure your troubles. I still don't think you are going to have a problem.
-Chris
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