Bora is a nice guy from Serbia - Yugoslávia

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#524
You probably haven’t look both schematics very carefully. They have several significant differences. For your information, MODUS (old name TECHNO) has been done in 1992 i.e. several years before Zack unit, but in very basic, TECHNO is not originally my idea either! They and many similar schematics have roots way back in 1977 from famous Hitachi application of MOSFET-s. That topology was “in fashion” after that and so many amps around the world are based on that idea and topology.
 
#525
boraomega said:
I believe it’s a great amp Adrculda, but I seldom want to talk and promote my designs. Self-promotion is a type of attitude I deeply disrespect in spite of the fact that it is so “in fashion” this days. I follow my "moto" about modesty under my posts...
Here is what other people that built TAG have to say:
(Those are posts from some Serbian forums)

""" PILE :
When I saw that the Bora is in the functional prototype stage, and what Bob Cordell thoughts about ThermalTrak transistor I got no doubt any longer. Such a challenge I need.
Amplifier that still nobody has managed to make (factory application does not count), huge potential, and names like Mr.. Cordell et al. and Dr Jagodic...
On this occasion once more I want to thanks Bora which uploaded a prototype and helped to push the project to the end.

TAG was born... TAG stands for = Talisman Audiophile Grade

Dual mono block. 2 transformer 500VA, 4 x 25,000uF Sprague "blue jars".
For the input level 2 transformer 50VA and stabilized power supply.
Technical details, I won't explain. It has been already done by the above mentioned gents.
The amplifier is very demanding to create. Requires a great adjustment precision and matching of important components (input section). Several times I even changed the whole group of transistors and some more components until I achieve results I wanted. Amplifier, although of a fantastic speed, is very stable. DC Offset doesn't exist, noise-hum on speakers too.
Powering up is quite quiet and "cultural" so that I have neither delay nor protection of the DC output.

ThermalTrak transistors definitely turning a new page and give the possibility
constructors throughout the world to push the boundaries a little further and offer us amplifiers that are a little closer to the truth.

Now how it plays. Tremendously.
I will use the phrase audiophile, but I will try to describe in my own words.
Reproduction fidelity is typical of a well designed bipolar amp.
What distinguishes it from other amplifiers... the speed, power, control.
Speed (slew rate 200V/μs simulated) enables much greater flow of information, and this you can hear.
The music is richer, with more details. The complex that is more pronounced.
Symphony with a full orchestra, and my favorite Elgar sound completely different. Removed the curtain in front of the orchestra. Each artist is where it should be, it is possible to follow certain instruments which wasn't possible earlier because of the "blur".
Because of oversized power supply, current is tremendously capable.
Now I sound like a commercial for car tires. What is a meaning of power without control. Tag controls amperes perfectly and that can be heard as a very deep, firm, well defined bass. If it were not so on Friday, membranes of my small woofers would ended on the opposite side of the room.

Now we have a new problem. 6.5-inch mid bass is not able to demonstrate the full potential of TAG. It is asking for a three way box with serious bass.
This is the pre-final version that was supposed to demonstrate the potential of the new transistors.

*********************
MLAVA:
I'm still under the impression of the pre-final version. Knowing PILE (PILE is a forum NICK of Mr. Bane Tasic) this pre-final always make me panic slightly, because I know what it means... days and days of fine trimming, adjusting and tests. That man rarely says "that's it". Chicken (word PILE in Serbian language means small Chicken!) otherwise have a gift to bring every detail to perfection. His devices combine careful planning and more carefully making. Is it bad or not I don't know, but its devices look like they came from factory top devices.

I just have to mention that the front panel made by Leonardo put a dot to the "i". Frankly I have no idea what else could be done to an amp to sound better. Great unit - great sound. All instruments are on the number and accurately positioned whatever music it plays. I think that here fall into the water a myth that one amp is excellent for one type of music
and another amp for other kind. Whatever was submitted to the TAG it delivered correctly. And how much should be. You want to destroy the walls? OK... looks possible with TAG. You want it quiet? Easily... without any loss of quality, detail, no distortion ... I never heard an amp with greater power reserve! We arrive at the aforementioned three-way speaker box. TAG killed our last hope that two-way box (no matter how perfect component it contains) can play all properly. It can, but ... It is next "mental worm" that slowly begins to work. Plans are already here.

What about constructor? He is to blame that he spoiled us, so that we can only expect such designs from him. And what's more, every next we expect to be better. Therefore, what's the point of any comments. What kind of comment one can give about the man known throughout the
planet. His works speak for itself.

TAG of course has a big disadvantage.
TAG is not mine.
"""
Click to expand...

Thank you Dr. Bora 🙂
Now the only thing of mine always have been is the number of output devices 😛
How hard would it be to DOUBLE the number of output devices ???
From my point of view it would fare better in terms of driving relatively nasty reactive loads that can dip quite low requiring a higher current / voltage that would strain the output transistors.
For me, there's no such thing as too many output devices but only weak power supply's :headshot:
 
#537
Scheme and PCB!?

Hi everyone!🙂
Thebes me reliable audio amplifiers (scheme and PCB), which will be powered with the Us= ±55...60V. Output transistors to be in the TO-3 housing (as MJ15003/MJ15004, etc..)
Thank you,🙄
 
#539
@radio
I understand what you are asking for and this amp is best suited for your needs. It was designed for a guitar amp, but it is useable as any other amp. Very reliable and robust. Only minus is - I don't have PCB design any more because I lost it. It was drawn on paper (no PC-s back then! ... end of '70-es) and I can't find that paper any more! Of course, now it has more modern components available today.
 

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#540
Techno

boraomega said:
Wasim, disconnect preamp or any source of signal, short your PA inputs, adjust BIAS and DC in the output, connect speaker and listen. If there is hum from the speaker it is probably related to your wiring and grounding of amps PCB-s and PSU. Some really minor noise-hiss from tweeters with your ear very close to that driver is possible and acceptable.
Click to expand...

Hi Dear Sir,

Hum problem has been resolved. Now Techno is working very well.

Thanks
 
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