View attachment 343526
View attachment 343526
There is an old technology, but it is important as well.
Attachments
Last edited:
These wretchedly incomprehensible schematics have been posted several times in other threads, accompanied by even less comprehensible gibberish.
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.
Last edited:
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.
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
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
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.