As i am beeing telling you friends, my country is interesting, "We are the world", because wide world countries have many representatives living here.
Mr. Fabio Mauricio Timi, probably an Italian descendent, living in the South of my country, is making good and clean designs.
My country south have also German towns, Polland towns, Russian towns... of course, all them borned here, but their ascendents came from outside countries.... normally they construct cities alike Europe, talk the mother language together Portuguese and love Brazil deeply. One of the most friendly countries around the world.
Enjoy beeing happy visiting his site:
http://www.geocities.com/capecanaveral/9096/projetos.htm
regards,
Carlos
Mr. Fabio Mauricio Timi, probably an Italian descendent, living in the South of my country, is making good and clean designs.
My country south have also German towns, Polland towns, Russian towns... of course, all them borned here, but their ascendents came from outside countries.... normally they construct cities alike Europe, talk the mother language together Portuguese and love Brazil deeply. One of the most friendly countries around the world.
Enjoy beeing happy visiting his site:
http://www.geocities.com/capecanaveral/9096/projetos.htm
regards,
Carlos
Carlos,
Interesting circuit.
I like the feedback on the cascode VAS, bootstrapping the voltage reference; and in particular I like the use of a mosfet driver, which effectively removes the influence of reactive load phase shift from the Voltage Amplifier. Clever, something I first saw in Steve McCormack's designs.
Clearly a low feedback design, cunning way he has rearranged the diff pairs to look like cascodes!
Don't care for the way he sets up the bias pot; it should be in the base/emitter circuit rather than the collector/base circuit, so that failure mode shuts down the amp rather than biasing it into destruction.
Cheers,
Hugh
Interesting circuit.
I like the feedback on the cascode VAS, bootstrapping the voltage reference; and in particular I like the use of a mosfet driver, which effectively removes the influence of reactive load phase shift from the Voltage Amplifier. Clever, something I first saw in Steve McCormack's designs.
Clearly a low feedback design, cunning way he has rearranged the diff pairs to look like cascodes!
Don't care for the way he sets up the bias pot; it should be in the base/emitter circuit rather than the collector/base circuit, so that failure mode shuts down the amp rather than biasing it into destruction.
Cheers,
Hugh
Very happy to see you here, visiting this thread
As i said before, i am always honored with your presence.
Related my know how, it is a bit complicated to me, and i tried to make contact by mail with him, to ask him to make something more usual to the more easy to construct, and cheaper also.
Unfortunattelly, this one is that kind of difficult people, he wrote a page of rules to follow before write to him.... this one is very difficult man.... a kick..... yes!
We have some "specimens" this way too. But they are not common.
This one i will call by phone. (town telephone central computers)
Carlos
As i said before, i am always honored with your presence.
Related my know how, it is a bit complicated to me, and i tried to make contact by mail with him, to ask him to make something more usual to the more easy to construct, and cheaper also.
Unfortunattelly, this one is that kind of difficult people, he wrote a page of rules to follow before write to him.... this one is very difficult man.... a kick..... yes!
We have some "specimens" this way too. But they are not common.
This one i will call by phone. (town telephone central computers)
Carlos
We had some audio small industries closed.
I am colecting their schematics to show the forum friends.
Also searching pictures, i love to see those things, unfortunattelly people do not show often their own country equipments.
This way, i will start, maybe some people will follow me.
I need informs about copyrigth, do not know nothing about that!
I suppose cannot put factory drawed schematics, but if i put in Multisim i suppose i can, because others doing.
Really, i need some informs, not to break international rules and agreements.... we do not care too much about this subject here, because we know, the real world, people is copying hard, because no more space to start from zero..... result will be an amplifier coupled with condensers, and with output transformer.
But, others have different ideas, this way, if someone can inform the rules i will be happy.... related what i can show, what cannot, if i can put links, as i made to people follow and go to brazilian site, if i can put schematics in multisim, not talking about who design them (maybe i done it!, why not?).
So, when we face a lot of ideas, better to follow the International agreements related copyrigth....
Please, the one that want inform me some...... come in... and tell me some.
regards all
Carlos
I am colecting their schematics to show the forum friends.
Also searching pictures, i love to see those things, unfortunattelly people do not show often their own country equipments.
This way, i will start, maybe some people will follow me.
I need informs about copyrigth, do not know nothing about that!
I suppose cannot put factory drawed schematics, but if i put in Multisim i suppose i can, because others doing.
Really, i need some informs, not to break international rules and agreements.... we do not care too much about this subject here, because we know, the real world, people is copying hard, because no more space to start from zero..... result will be an amplifier coupled with condensers, and with output transformer.
But, others have different ideas, this way, if someone can inform the rules i will be happy.... related what i can show, what cannot, if i can put links, as i made to people follow and go to brazilian site, if i can put schematics in multisim, not talking about who design them (maybe i done it!, why not?).
So, when we face a lot of ideas, better to follow the International agreements related copyrigth....
Please, the one that want inform me some...... come in... and tell me some.
regards all
Carlos
Under UK copyright law, and I'm guessing most other countries are fairly similar,
To re-post the original artwork here without permission is wrong; to post your own drawing of a section of the full schematic for "non-commercial criticism, review & educational study" (with links to the full published circuit on the author's site) seems quite above board IMHO.
Those informs, are precious to me.
I Had no idea about this matter, this way you are been helpfull a lot .
Believe me, that you are Helpfull, and can go on beeing helpful, going deep related this subject.
Nothing you said is obvious to me., because my knowledge is week, and informs received ,are beeing precious.
Unfortunattelly, my country do not care too much with those businesses, this way, common people has not enough knowledge related to that, if not applied to all my people, i can ensure you , i am the one, that is completelly ignorant related that.
Thanks, regards,
Carlos
I Had no idea about this matter, this way you are been helpfull a lot .
Believe me, that you are Helpfull, and can go on beeing helpful, going deep related this subject.
Nothing you said is obvious to me., because my knowledge is week, and informs received ,are beeing precious.
Unfortunattelly, my country do not care too much with those businesses, this way, common people has not enough knowledge related to that, if not applied to all my people, i can ensure you , i am the one, that is completelly ignorant related that.
Thanks, regards,
Carlos
Which schematic is in discussion, the green sch or the white sch?
AKSA, what do you think of Darlington or Triple darlington emitor output at the output stage? They can reduce bias needed in the VAS stage, but are they adding more complex phase shift so they are more vunerable to oscilation, compared with direct output transistor from the VAS/Vbe multiplier?
If darlington is good, is it better to use mosfet as the buffer, like you said in post #2 ?
AKSA, what do you think of Darlington or Triple darlington emitor output at the output stage? They can reduce bias needed in the VAS stage, but are they adding more complex phase shift so they are more vunerable to oscilation, compared with direct output transistor from the VAS/Vbe multiplier?
If darlington is good, is it better to use mosfet as the buffer, like you said in post #2 ?
Hi Lumanauw,
I try to avoid triple darlington EFs in output stages.
As you say, they shift phase more than the usual double EFs, and while in a powerful amplifier you might need to run a high stage current through the VAS, with proper transistor choice you can still make them sound good. There is also the question of local stability; EFs are prone to self-oscillation because of negative resistance characteristics on the base, so three in a row is probably more susceptible than two.
I have not yet done work on use of mosfet drivers, but hope to look at it soon. This idea shows great merit, I feel, because it makes the amplifier more load tolerant. The final frontier is driving an electrostatic with a PP Class AB SS amplifier.
Cheers,
Hugh
I try to avoid triple darlington EFs in output stages.
As you say, they shift phase more than the usual double EFs, and while in a powerful amplifier you might need to run a high stage current through the VAS, with proper transistor choice you can still make them sound good. There is also the question of local stability; EFs are prone to self-oscillation because of negative resistance characteristics on the base, so three in a row is probably more susceptible than two.
I have not yet done work on use of mosfet drivers, but hope to look at it soon. This idea shows great merit, I feel, because it makes the amplifier more load tolerant. The final frontier is driving an electrostatic with a PP Class AB SS amplifier.
Cheers,
Hugh
Is this why some designs have base resistors (like 20-100ohm) for every stage of triple darlingtons?
How about the sound. The amp with darlington or triple darlington EF stages, and an amp who drives output stages directly from VAS, are they sound different?
Also, I see mosfet output stages, or Lateral ones, usually dont have driver. The gates attached directly to VAS. Are mosfet output stages dont need big VAS current?
There are lot of amplifiesrs with triple EF, and they sounds good (Mark Levinson large amplifiers).
I made some amplifiers with MOSFET ouput, even with 4-5pairs of IRFP240/9240. For this amplifiers I used high current VAS stage. The highest current was 100mA, with MJE15032/15033. I applied some emitter followers between the input and VAS.
sajti
I made some amplifiers with MOSFET ouput, even with 4-5pairs of IRFP240/9240. For this amplifiers I used high current VAS stage. The highest current was 100mA, with MJE15032/15033. I applied some emitter followers between the input and VAS.
sajti
I will put a lot of Brazilian circuits, the first will be Quasar, Mr Snerewsky brand
Mr. Snerewsky, old Tcheco-Eslovakian family living a century in my country, borned here, made a Amplifier Industrie, together his father and 2 brothers.
From 1962 to 1982 the made wonderfull amplifiers, and schematic, always the same.....long tail, differential input, CCS, complementary drivers and complementary output, protection is the old one, using some voltage developed over emitter resistors.
Schematic has no values, this way i am preparing it, cannot put the factory one to not broke rules.
The factory close its doors because of Government decisions.... the amplifiers where expensive, only to rich people, not cheap ones, all the enclosure where heatsink.
Some models used big needles to measure power, consider the design related to 1962!!!, this design is already beeing discussed in our forum.... so, take a look as Mr. Snerewsky was a Pioneer!
Factory closed in 1982, thousands units already working, and as new, because anodized metal works.
One of the Snerewsky brothers are living in USA, he is connect with appartment and houses sales...my god!.... what we loose!
The problem here was the decision to evolute Amazon State, the capital Manaus, inside Amazon Jungle, and near Amazon RIver needed some help, had big development early 18 hundred, passed century, because or Englishman exploration of natural Latex to make rubber.... and now a days, not doing that anymore because some better Asiatic Markets.
This way, my Government decided to open the Market, with no taxes to free import and export from Manaus, a free place to business... and all rich factories moves to Manaus, and from them received boards completed from China...mounting and putting brazilian names on their panels.... this way, Brazilian QUASAR died!
I will put "THE MAN" picture, the factory old picture and one image of their amplifier.... schematic will delay some time.
regards,
Carlos
Mr. Snerewsky, old Tcheco-Eslovakian family living a century in my country, borned here, made a Amplifier Industrie, together his father and 2 brothers.
From 1962 to 1982 the made wonderfull amplifiers, and schematic, always the same.....long tail, differential input, CCS, complementary drivers and complementary output, protection is the old one, using some voltage developed over emitter resistors.
Schematic has no values, this way i am preparing it, cannot put the factory one to not broke rules.
The factory close its doors because of Government decisions.... the amplifiers where expensive, only to rich people, not cheap ones, all the enclosure where heatsink.
Some models used big needles to measure power, consider the design related to 1962!!!, this design is already beeing discussed in our forum.... so, take a look as Mr. Snerewsky was a Pioneer!
Factory closed in 1982, thousands units already working, and as new, because anodized metal works.
One of the Snerewsky brothers are living in USA, he is connect with appartment and houses sales...my god!.... what we loose!
The problem here was the decision to evolute Amazon State, the capital Manaus, inside Amazon Jungle, and near Amazon RIver needed some help, had big development early 18 hundred, passed century, because or Englishman exploration of natural Latex to make rubber.... and now a days, not doing that anymore because some better Asiatic Markets.
This way, my Government decided to open the Market, with no taxes to free import and export from Manaus, a free place to business... and all rich factories moves to Manaus, and from them received boards completed from China...mounting and putting brazilian names on their panels.... this way, Brazilian QUASAR died!
I will put "THE MAN" picture, the factory old picture and one image of their amplifier.... schematic will delay some time.
regards,
Carlos
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.