m-j500

[picopos]

hi everyone
i pretend to clone this amp and mod it to see if i learn and have the best of this design....
i attached the pdf that honestly i think it's in bad condition to do anything so i'll try to make the schematic of one channel without the Dc detect part and everything that i'm not interested on...(it will take some time)
purpose:
my level of knowledge it's basic,measuring tools-multimeter,althoug my time is limited and i'll take some time to post anything worth here (the complete schematic readable) i would love to see someone experienced building this design and ear from it(i dont want no one to do the job for me but honestly i dont have enough know how,i'm aware of some stuff,understand some concept but i dont have the practice in the field)and i dont feel like burning parts everytime i power on.....

i'll post soon

marco

[picopos]

am i violating copyright??if so let me know moderators....

[picopos]

hmm
a link if anyone wants to chek it out in case it does'nt go up here

http://cid-b2d816676605bcda.skydrive...500%7C_SVM.pdf

[Nrik]

A japaneese main-stream amp design that is 18 years old?

Dont clone that.
You can make a better and easier amp with from a lot of other designs.

Here is Symasym - with PCB layout and everything. It will probably be easier to build and sound better sounding:

http://www.lf-pro.net/mbittner/Sym5_.../symasym5.html

[Nrik]

...or start from scratch with Carlos newest design:
http://www.lf-pro.net/mbittner/Sym5_.../symasym5.html

...easy, safe, and with good oppertunitites for help if you experience trouble.

[sakis]

if you look at the schematic ....the only thing that is diefferent between the three amps is the safety measures ....

otherwise and more or less they are almost identical

and the truth is that most of amplifiers presented in the forum vary from comercial amps only there ....::::

----very often we see amplifiers that dont have VI limiters ( cause these are sonic killers )

----they have no "guarded input " meaning that input filter is designed for astronomical bandwidth ....

----Vas miller cap is calculated as less is possible and often not even there

----often all the calculations are made without a complete zobel (inductor included )

-----often use of extreme parts is recomended ....

if you clone any pioneer or other comercial amplifier under these specific rules of course it will perform almost the same with a DX amplifier or a symasym ( if not better )

[sakis]

if you tweek any pioneer or other comercial amp under these specific rules .....

recaping (banks )
recaping (boards /quality )
add ( decoupling /bypass)
rewire ( what ever needed )
matched ltp pair
common heatsink ( for ltp )
beef up idle ( with in a safety margin )
remove the VI limmiter if exist
add multiturns (idle /ofset)
play with miller caps
change critical (why not all ) resistors to metal film
check or relocate zobel ....

then i bet you my a** that the pioneer amplifier will sound more or less like a Very good amp !!!!!

the thing is that for sure after all that you probably not going to have the same aspect of safety from this device ....

one will ask why to do all that ....

i will only give one reason

the sound of an originaly made japanese semiconductor is simply unbeatable !!!!!

[Nrik]

Sakis: You might be right about sound quality.

But a well-described 'kit' with pcb-layout is probably easier to build.

[sakis]

is a totally diferent story .....

i only wanted to point that in most comercials amplifiers if safety measures are remooved then amplifier can become a lot better but for sure not the same stable

[picopos]

hey
thank u all for ur time
i really want to make this design anyway, i'll try to have a better soon...
why?
well this amp has been miss treated for years (not in the last 7 years,but i still make it hot),with infra and ultra freqs by mystaque(creating synth sounds),playing bass on it,loud, i record stuff and before i lived by myself and i could make noise for hours,besides cutting the sound with weird signals it never complaint,thats the endurance part,by the other hand i cant give u measures ,and i'm not going to say that he beats this one or that one, i never had hours with a top notch amp and speakers,but playing very low,now volume pots,direct to pc based audio interface u put this amp the lowest u can ear and it's all there still(in my opinion)...judge me but in a treated room i had before with speakers assembled by me,very low noise floor,very low volume,this amp show's me acoustic guitar players hiting the floor marking the tempo(common in a recording session,in this case it's on Pink floyd the wall)...bla bla bla i know i know this tell nothing but i made comparisons with a kenwood,an onkio,another pionner,sony and some of them showed that but not the same way,the onkyo one with an stk i couldn't ear it,once again not quality amps to compare......enough with reasons.....
i'll try to have a scheme and values soon here,but i guess the vac fed to the regulator is 53-0-53 and caps r 7200x2....

the bjt r not made anymore i guess so i guess it will be the 2sc2500 and his mate,
i'll post soon hopefully some more values
have to watch the little one

peace