I have done already a PCB with one single pair TO3 altogether with the rest of the ampli. TO3s are mounted on the back side.
But if you want to add more pairs the separate PCB looks more flexible.
I just wonder about the Rc elimination. I have NEVER seen a so done multiple pair CFP before in literature (not that I have seen many more with the conventional collector resistor ones , for that).
thanks
effebi
But if you want to add more pairs the separate PCB looks more flexible.
I just wonder about the Rc elimination. I have NEVER seen a so done multiple pair CFP before in literature (not that I have seen many more with the conventional collector resistor ones , for that).
thanks
effebi
What is wrong with ESP P3A?
So, here we go.
As many have seen I am posting here several time on the ESP P3A and possible mods. I love this simple design from the first time I have seen it, a neat implementation of the Occam's Razor on SS Ampli field. But, as any design, it could be improved. I wanted to go thru a thorough modification to suit my DIY needs (i.e. low impedance speakers) .
But I have seen NO INTEREST at all for it in this forum, with one notable exception. Since I have seen here debated much more sillier questions, with the intervention of eminent forum members, some doubts raises to me.
Is the PA3 / ESP BANNED from this forum? Are there copyright or other issues pending with the Author? (He is very welcome to come in if he is reading).
Or is it just forum oldtimers snobism against a newcomer? While I can tolerate the latter (I am member of many technical forums from before internet was born and I know how it works) I cannot bear the former.
If there is a ban here, just let everybody know, then I will discuss of it somewhere else, or nowhere at all, depending on the issue.
P.S. Note for the Moderators:
Feel free to take any action you find appropriate on my regards.
I am NOT soliciting answers (that is against the policy of every forum) but I am soliciting politeness and transparency.
effebi
So, here we go.
As many have seen I am posting here several time on the ESP P3A and possible mods. I love this simple design from the first time I have seen it, a neat implementation of the Occam's Razor on SS Ampli field. But, as any design, it could be improved. I wanted to go thru a thorough modification to suit my DIY needs (i.e. low impedance speakers) .
But I have seen NO INTEREST at all for it in this forum, with one notable exception. Since I have seen here debated much more sillier questions, with the intervention of eminent forum members, some doubts raises to me.
Is the PA3 / ESP BANNED from this forum? Are there copyright or other issues pending with the Author? (He is very welcome to come in if he is reading).
Or is it just forum oldtimers snobism against a newcomer? While I can tolerate the latter (I am member of many technical forums from before internet was born and I know how it works) I cannot bear the former.
If there is a ban here, just let everybody know, then I will discuss of it somewhere else, or nowhere at all, depending on the issue.
P.S. Note for the Moderators:
Feel free to take any action you find appropriate on my regards.
I am NOT soliciting answers (that is against the policy of every forum) but I am soliciting politeness and transparency.
effebi
I don't think ESP(Rod Elliot) is banned. He has his own forum for the discussions of his projects, and thus, it is unlikely that he will be here. He makes his living on selling his circuit boards, so out of respect, I would not post any PCB designs relating to any of his projects.
My 50 Watt into 4 ohm P3A (with 18V tranny) sounds far more dynamic and lifelike than my other 200W ss amp and is currently my reference power amp.
My 50 Watt into 4 ohm P3A (with 18V tranny) sounds far more dynamic and lifelike than my other 200W ss amp and is currently my reference power amp.
does that raise any doubts about the design/implementation of your 200W amplifier?
hmmm ... To my opinion there is a couple of things to be noticed on this ...
From starts Rod and all from esp pages done so many things for diyers giving so many designs and so well documented for free fro the community I see no more than fair that Rod is making some small money from selling PCB for his design ...
So the only thing is not given for free from Rod is the pcb ... but !!! feel free to make your own nothing against that also .... some designers in the forum give also the pcb files for free ...so make the all thing what i call fastfood electronics
At least none of Rod's designes need debugging befor constructing many of the projects that are "given" for free in the forum need loads of debugging and that arrise the obvious question : """Is the project trully for free ? or is it placed in the forum as a piece of paper? """" so from a piece of paper is a very long road to a working device .
Often designers place thier schematics so naive diyers will construct , crush, start asking for help so the all thing is "autodebugged" after long posts and after some real experts seen the project and add thir opinions ...
---------------------------------------------------------------------
As about the P3A is an actually old amplifier and i think that the particular project evolved as much as this was possible for this type of circuit
What i try to say is that all the goodies ( small ) added to it like matched ltp, fast drivers , decoupling bypass, caps on board a bit of this and a bit of that probably made the best possible from this amplifier
Obviously either you belive that small changes like that will make perfect or you dont .... There is no such thing as a perfect amplifier ... Trust me when i say that the DX amplifier is better than the P3A ... the problem is that its too sharp too acurate and to precise next to the P3A ..the P3A though is more "free" more musical creates other type of soundstage and headroom and fits better to my ears ....
there is another small thing also ... all the P3A i built and study are based on original 2SA1302 2SC 3281 original toshibas that i have in stock Dx amplifier is built around 1943 5200 ...dont know if it helps
that was my 2 cents
From starts Rod and all from esp pages done so many things for diyers giving so many designs and so well documented for free fro the community I see no more than fair that Rod is making some small money from selling PCB for his design ...
So the only thing is not given for free from Rod is the pcb ... but !!! feel free to make your own nothing against that also .... some designers in the forum give also the pcb files for free ...so make the all thing what i call fastfood electronics
At least none of Rod's designes need debugging befor constructing many of the projects that are "given" for free in the forum need loads of debugging and that arrise the obvious question : """Is the project trully for free ? or is it placed in the forum as a piece of paper? """" so from a piece of paper is a very long road to a working device .
Often designers place thier schematics so naive diyers will construct , crush, start asking for help so the all thing is "autodebugged" after long posts and after some real experts seen the project and add thir opinions ...
---------------------------------------------------------------------
As about the P3A is an actually old amplifier and i think that the particular project evolved as much as this was possible for this type of circuit
What i try to say is that all the goodies ( small ) added to it like matched ltp, fast drivers , decoupling bypass, caps on board a bit of this and a bit of that probably made the best possible from this amplifier
Obviously either you belive that small changes like that will make perfect or you dont .... There is no such thing as a perfect amplifier ... Trust me when i say that the DX amplifier is better than the P3A ... the problem is that its too sharp too acurate and to precise next to the P3A ..the P3A though is more "free" more musical creates other type of soundstage and headroom and fits better to my ears ....
there is another small thing also ... all the P3A i built and study are based on original 2SA1302 2SC 3281 original toshibas that i have in stock Dx amplifier is built around 1943 5200 ...dont know if it helps
that was my 2 cents
Hi Andrew,
It was properly implemented - DC coupled, 500VA tranny, 50,000uF per channel etc, etc. However, for the same listening levels (75dB with 90dB peaks @ 4m), the P3A was clearly the leader in dynamics, bass and realism.
If you take the oppotunity to have a look on the last simplified schematic I have posted, You will see that this is not the case. This configuration is different from any that I have seen proposed by ESP. My post was just about the stabilty of such output configuration.
Are you speaking on behalf of the Forum? Because, after all this time, I believe somebody should have told me directly or maybe those threads closed.
If this is the case, my apologies, I was not aware of such heavy restrictions, and I kindly ask the moderators to remove any picture reagarding ESP from my posts (or to remove my posts at all, for what matters). My intention was only about technical discussion for hobby purposes, in waht I believed was the spirito of the Forum, I never tried to endorse anything of the Author property.
I also believe that keeping the discussion hot about the subject should be helpuful for the Author, no harm was intended.
But I do not see how we can discuss about a circuit without presenting schematics. So it is simple : forbidded schematics = forbidded discussion.
I am aware that ESP sells the original PCB, so I NEVER had posted here about PCBs. But, as I told you I like do it by myself, I do not have technical problems with that.sakis said:
I beg to disagree. I believe that is a lot of room for interesting modifications, but since we a re not allowed to think about them, I will not do , of course. BTW I am not comparing it with the very nice DX design, (that I like as well for the matter), I just wanted to make a P3A that suited my needs in terms of power and impedance.sakis said:
Hi effebi,
You are still allowed to think about mods, but you might now understand why you are not getting as much feedback as you thought you would get. I too have built a P3A, have an alternative PCB designed and thought about modifications I would make.
Because Rod has requested PCB layouts are not published here or on his own forum and also Rod believes the design is complete, I seldom post about the P3A or any of Rod's designs. This situation is always a problem with designs that are not 100% DIY. Commercialisation is always a spoiler for pure DIY but I understand both sides of the situation.
Imagine if you put months of work into improving the design and you can not share the PCB and people are hesitant to get involved.
regards
I only speak as a Member.
As far as I know this Forum has never banned discussion of any of ESP projects.
We even discuss his articles.
It is ESP that does not give permission to post any of his ESP pics here.
He asks on his website that we put in a link to his site and pic.
That way he gets a little free advertising and keeps his designs from the general public.
Equally, he also does not want pictures of his bought products posted and I presume that is so that fakers cannot copy his PCB layouts.
Many of his projects do not list all the components values, again he does not give permission to reveal those values even if you buy from ESP.
You are perfectly able to post questions about ESP projects and if a schematic is necessary to understand or explain then give the link to the ESP pic. You are perfectly able to propose a change in topology or component type and/or value. We can and will discuss what you have in mind.
Just respect ESP's intellectual property.
As far as I know this Forum has never banned discussion of any of ESP projects.
We even discuss his articles.
It is ESP that does not give permission to post any of his ESP pics here.
He asks on his website that we put in a link to his site and pic.
That way he gets a little free advertising and keeps his designs from the general public.
Equally, he also does not want pictures of his bought products posted and I presume that is so that fakers cannot copy his PCB layouts.
Many of his projects do not list all the components values, again he does not give permission to reveal those values even if you buy from ESP.
You are perfectly able to post questions about ESP projects and if a schematic is necessary to understand or explain then give the link to the ESP pic. You are perfectly able to propose a change in topology or component type and/or value. We can and will discuss what you have in mind.
Just respect ESP's intellectual property.
It's comes down to a moral decision. Years ago the DIYAudio owner/moderators decided to respect Rod's request because of his valuable contribution to DIY.
If you post Rod's work here, the moderators will remove it, guaranteed.
Sorry for going off topic and repeating what has already been discussed before numerous times, but over time, with new members and moderators it can be beneficial to revisit the topic. Who knows, in time, DIYAudio's position may change.
if you changed some components, you could explain why you chose to change them and what the effect was. You would not get permission to show ESP's original design.
You could post pics of the completed assembly and in my view this would be OK, provided the detail of his PCB and the component values could not be read.
You could show how you wired it up.
It is only ESP's intellectual property that ESP asks everyone to respect.
I just built a P3A (Rev B) for myself and it's one of the best sounding SS amps I have ever heard or owned. The thing is musical and it has bite. No tweaking necessary. At the standard supply voltage of 35 it has ample power without bridging. I always buy the boards from Rod. He gives us the designs after all, so buying HIS boards seems a very fair way of going about the hobby IMO.
Audio Projects Class-AB Midrange Amplifier
Audio Projects Class-AB Midrange Amplifier
Last edited:
An amp with a superior sonic qualities. I used these transistors q1q2q3=2n5551 q4=bd140 q5=2sc2073 q6=2sa940 q7=2sc5198 q8=2sa1941 q9=2n5551.
Tested Speakers: bose 301 and klipsch synergy .
power supply 6 amperes 24V 0 24V>>>outpur +33V/-33V
capacitors 2=10,000uf tsw ceramic caps 220pf, 100pf, 0.1uf
perfect match for my bose 301 and klipsch synergy
Tested Speakers: bose 301 and klipsch synergy .
power supply 6 amperes 24V 0 24V>>>outpur +33V/-33V
capacitors 2=10,000uf tsw ceramic caps 220pf, 100pf, 0.1uf
perfect match for my bose 301 and klipsch synergy
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.