Good power amplifiers 6W---25W4R

[adorn751]

Good power amplifiers 6W---25W4R.
Other audio transistors and the Franco-Polish licenses do not are not good for audio stuff.

 

[adorn751]

Flow forum and flow your amp schematics, and all the amplifiers are working on bad dynamic resistances driver transistors.

 

[toprepairman]

There are some strange looking devices on the bases of the driver transistors.
This won't be a very good amp as it is very old technology with quasi-complementary outputs, and looks like it'll need to be capacitively coupled to the load.

 

[adorn751]

View attachment 343526 View attachment 343526 There is an old technology, but it is important as well.

 

[godfrey]

strange looking

These wretchedly incomprehensible schematics have been posted several times in other threads, accompanied by even less comprehensible gibberish.

 

[adorn751]

Only he knows what he sees truth in the diagram.

 

[adorn751]

Only he knows what he sees truth in the diagram.

Rdc =400R(=2x 800Rcd -2x BC313/211)

 

[adorn751]

Realistically, there is no other schemes expensive and clean amps.

 

[east electronics]

again and again ....here is what i am going to do ...I will find some Polish friend i have write a few lines for you in polish and try to make understand what i think ...

 

[adorn751]

sakis keram751,a, gmail.com -no problem

 

[Ian Finch]

Good power amplifiers 6W---25W4R.
Other audio transistors and the Franco-Polish licenses do not are not good for audio stuff.

Of course, you are entitled to an opinion on what is "good audio stuff" but when it was obsolete >40 years ago, you need to consider whether collecting and using such antique components is sensible for others who read this but can't economically source them. You will be aware that original Philips BD139 /140, for example, are unobtanium so you can only buy approximate substitutes or fakes anyway.

Use modern leaded components while they are still in production. These are much cheaper and every bit as good as the old steel cased ones though many Japanese types are far better performers again in some applications. Read a bit of other people's work - get out and about and see the possibilities in different components and topologies to the basic ones we grew up with. If the limitation is the library of your software, it's time to get another free package like Simetrix's Simplis version or LT Spice perhaps -at least others can then easily read and understand them.

 

[east electronics]

Ian .... me and other members told him already more than 10 times ... still i dont get the point of all this but as said i am willing to find someone from PL make an email to him in his language to explain a few things ...

may be something good will come out of it

Kind regards
Sakis

 

[adorn751]

Nothing better and nothing could be better.

 

[Ian Finch]

Nothing better and nothing could be better.

Well, with imaginative claims like that, you must think we are idiots! You choose old designs, rework the values and components to something in your drafting software and claim something like this...???

Give us a break Adorn, or give us some test or simulation figures that support your opinions. That may include independent, alternate assessments or comparisons even.

Also, tell us what you mean by "clean". It could mean low noise, low distortion or tonally neutral. Either or all can be achieved with many topologies other than those presented. If you claim these old designs are better than more recent ones, let's see them compared formally and open the discussion to people who may be interested in the results.

 

[adorn751]

Nothing else will show you how I showed.



BD140/139 (Rcd=800R) Ic max=25mA-Io=10mA min=15mAp max!!!.

BD313/211 (Rcd=800R) Ic max=25mA-Io=4.5mA min =20mAp!!!

XTR. Rcd>50R Ic max =25---27mA max!!!
BD355/354 Rcd<25R Ic =250mA max -Io=20mA min =230mAp max!!!

 

[adorn751]

MJE1531/MJE1528 Motorola dreiver: Ic=450mAp+Io45mA=0.5A max, Rcd<25R Uo=Rcd x Icp, 25R x 450mAp=11Vp.
Rcd=35R /MJE1531/1528 -35R x 450mAp=15Vp max.
Rcd=25R (2x BD355/354 -2x Rcd=50R ---2x 220mAp=440mAp).

 

[Ian Finch]

http://tranzystor.com.pl/photos/tranzystor-mocy-cemi-bd355b-to66-p-n-p-najtaniej-2847979431.jpg
Along with BD354, only made by Unitra, Tesla and only shortform specs. available. Is it as good a driver as Toshiba's 2SC4793/2SA1837?
....Linear?
http://www.customworks.cz/wp-content/uploads/2012/09/2sc4793.pdf
BD139/40 are not manufactured to Philips original specs.
http://www.datasheetcatalog.org/datasheet/stmicroelectronics/5238.pdf
http://www.datasheetcatalog.org/datasheet/philips/BD139-16.pdf

 

[adorn751]

edited

 

[kasey197]

You have 20 schematic there including speakers etc. maybe you can select one and expand it size, remove non-standard symbols, give some explanation etc so we have a chance to understand ?

 

[wahab]

Either it s a prototype software that is posting
or it s a guy that has lost touch with reality ,
be it the virtual one of the internet.