Perfect sound search, this idea, HELP!, the long and insane search...

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I was informed by Rabbitz, the one sent me Yamaha brochure from model 2000.

So... as you can see, idea is not mine... i have just tried something using very simple circuits.

And there they told me nice things.

They told are avoiding crossover, using new kind of circuit... two amplifiers NOT operating in push pull mode.... operating push push or pull pull mode...all transistors the same... NO PNP together NPN...or all PNP or all NPN.... no crossover and class A operation.

Those two amplifiers are combined into a single channel, alike a bridge i think... load goes into the midway... the middle... receiving both output signals that will be out of phase one compared to the other.... complementary phase will be there combined... will be there into the output load, the speaker.

I felt the idea GREAT!... and i have tried.... sounded PERFECT!....but efficiency was very low (2.5 percent to single ended half cicles units..direct coupled, class A, now swithing circuits)

Into the input i have used a single transistor to invert....one channels captured into coletor and other into emitter...all folks class A...............2.5 watts to 100 watts of consumption...AWFULL!

HELP!.... have any idea to make this thing better?.... can you do some?.... have a good idea?.... can you contribute with me, with yourself, with forum and with mankind?.... let's do something better?.... together?

But DO THINGS too!... do not come only to produce brainstorm and produce ideas TO ME TO BUILD.... do some too.... also ideas will be nice..but i do not ensure i will try all ideas, unless they were tested real life.... there are a lot of crazy "simulator" folks down there to produce zilions of things that may sound good, bad , awfull or even not sound..as simulators are nice too but guarantees nothing.

regards,

Carlos
 

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Up and down you see two amplifiers, direct coupled

of course DC amplifiers...all folks hot, class A monster.

The upper one receive one phase and the other receive the complementary phase... the down left stage inverts... gain one class A stage (colector and emitter resistances have same value).

Into the output, the upper amplifier is combined with the lower channel into the load...the off set there is small..the amplifiers are almost the same...so... the colector voltage into the upper one is 17 volts... and the colector voltage into the lower one is also 17 volts... difference is 40 milivolts or less...so... we can combine both into a single resistance or speaker, as will not flow DC.

But AC will flow!... clear...perfect sound..superior.

But terrible!...awfull!...ridiculous in efficiency.

Wanna help?... wanna do it by yourself?... wanna have fun?

regards,

Carlos
 

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Hi Carlos

I have tried the idea of using a single transistor as a phase splitter and found it isn't quite as simple in the real world as it should be. The junction capacitances of the transistor are not the same for collector and emitter. Neither are the output impedances. This will cause a phase shift in one of the signals with relation to the other vs frequency. (In addition to the 180 degree shift your trying to achieve.) Any phase shift like that will create distortion across the load at the bridged output. I don't know how Yamaha does it, but I have found it is better to have a single end to balanced converter "circuit" to feed both equal amplifiers. Hard to achieve with just 1 transistor. It might work great in a simulator with an ideal transistor, but simulators don't make much sound.:) One could build a balanced amplifier, but most balanced amps I've seen require a balanced input so you still need a conversion. There are good quality signal transformers out there, but I personally don't like signal transformers in SS, JMO. There are IC's available out there that are SE to BAL converters, but they're not cheap. Of course it certainly is possible to do it with discrete small signal SS.:cool:

:2c:
 
destroyer X said:

Produces losses... also differences in level.... terrible!

But i have tried.... we have to try.

regards,

Carlos


Hi Carlos

I have tried and have a circuit. It hasn't ever been simulated, but it has been built with actual electronic components and real transistors.:D I hate to give away all of my ideas :rolleyes: but I could discuss it if your interested.


These waveforms are each output to be bridged across the speaker, source is a single end input, my function generator.
 

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I am always interested into new circuits CBS240

And you are a good designer, creator, inventor, researcher.

BUT, i feel your circuits too much dense to me to try (lazy i am and i have some beliefs AGAINST too much complicated designs)

If you want to share...be sure that if i appreciate it will tell forum and whole world, will ask you license to produce a clone following your instructions to keep some of your secrets non published...i may built, will use, will share with the Universe, will give copy even to extra terrestrians, will produce enormous noise, will produce thousand pictures, they will be into the internet alike a virus, will build together my group of audio idioholics into the Orkut, maybe will manufacture under licence and will have my name together yours.... CBS Dx Zippity dee doo dah!


ahahaha... do not like to share?

I am the last one you may think to share.... i am very social and i love to share... i hate to keep good things only with me...i also hate to have more than one amplifier when others has no one...i hate when i have hundred dollares in my pocket... without use to this money... i use to give it to poor folks.

I am crazy CBS.... better to keep your secrets...otherwise it will be flashing into neon displays in New York City.

I do not like class A.... too much hot... also i do not like Fets...hard to find, strange sonics locked into a cotton cage , loose voltage into the biasing voltage... will try this one...but in advance i feel will not even be aproved... can sound good as a hell..but hot that way i will not stand for.

Dear daugther is always around with her snake mood:

- "What is that old thing youre building daddy?... sounds alike a "crab" daddy.... do not loose your time dear dad... listen DHR Turbo!... the best you have built ever."

.... "poor dad" she use to say...always trying "ship" things when have already good sound units made.

ahahahahah!


be happy.... i use to try to be daily.

Carlos
 

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I have a transformer...in the reality i have 3 different ones

One of them may fit.

BUT!... i will not assemble...will stop...if really needed a transformer or a phase splitter, or phase inverter gain one......because the amplifier will not be more simple the way i have appreciated it.

No more stages...if needed... i will probably stop... quit!

Because if assembled...and even sounding good... i will be sure the transformer will be sacrificing... sound would be better without that thing into the input.... so.. will be a matter of confidence... i will loose confidence.... because in my mind a transformer is not a good thing to use into the audio input.

Phase splitter or phase inverter gain one stage is one more stage..the amplifier will be no simple anymore..the quality to be simple will be lost..will be three stages alike others..no advantage.

regards,

Carlos
 

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Re: I am always interested into new circuits CBS240

destroyer X said:
...BUT, i feel your circuits too much dense to me to try (lazy i am and i have some beliefs AGAINST too much complicated designs)...


Ahhh then a signal transformer might just be your solution.:) My circuits might have a few components more than yours, but they have grown over the last years. When I ran out of board space with the TO-92 parts and 1/4W resistors, I changed my philosophy. IMHO:cannotbe: , you don't need power in an amplifier until the final stages. So, make everything smaller with less current and suitable devices so you can cram it all in on your PCB so it will be smaller than a PC motherboard.:D The project PCB I'm working on now is a 5" X 4" double sided PCB. It is a completely discrete modular balanced amp. Bet you can't guess how many transistors are in it.:p It's not about how many transistors are in it, but rather how it performs. If I wanted to build something to sell, I would cut the circuit down to it's simplest form, loose all the cascodes, use cheaper parts, none of those THAT transistor arrays or Caddock resistors.:) Those things drive the price up very quickly.:eek:


The pre amp circuit in this project does the SE - BAL conversion along with gain. It is a balanced bridge, in which the bias for each differential is a CCS instead of resistors. This normally would not work because the bridge would over bias the CCS and the voltage would cut out. But if you sense the voltage change on the CCS generated by the common mode current, then feed that signal back to the common mode input of the input transistor differential, it will create a reference for the DC bias in the bridge relative to the CCS. This bias is very stable, no matter how the temperature varies, it is always the same....set by the CCS.
By deliberately mis-balancing the bridge with adding an extra resistor to the positive output load (single ended input phase), the common mode signal references the error and feeds it back to the common mode input which is modulated with the input signal to create the balanced output. Phase and magnitude are balanced and the imbalance is shifted to the output impedance. But if you follow it with a buffer, it becomes a non-issue. In my circuit, +out is about 35K and -out is around 50K. These outputs have to drive nothing but the gates of 4 small J-fets with an equivalent input Z greater than 1M. Also this circuit is designed to be coupled with 2 DC servos to maintain 0 VDC at both outputs.

GOD I hope it works! Should get PCB's by the end of the week. It sure isn't cheap to create these things, I can't afford to waste. However, I take comfort in the fact that this UGLY AMP version I built almost a year ago still works. Every time I turn it on, no noise, and perfect sound.:D


be happy.... i use to try to be daily.

Carlos


YES be happy with perfect sound....and other things....

(My tomatoes....MMMmmm yummy heirloom variety I've been cultivating for the last couple years.....not those cheap shwagg Mexican tomatoes sold terribly overpriced here in the US:whazzat: ) If I can keep the catapilars from munching away on the small ones....:rolleyes:, BUT there'll be no poisons used here.:skull:

and all that Basil smells so sweet!;)
 

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