Bora is a nice guy from Serbia - Yugoslávia

[Tom2]

Steven,

Yes, will do.

Tom

[DR_PONJA]

Hello members of DIY-Audio Forum! I’m from Serbia, like Dr. Bora, Viktor, Boban and others. I wish to say hello and to our neighbors, The Croats, The Bosnians, The Slovenians, The Macedonians and The Montenegrins. Simply, The Yugoslavs.
I was really happy when I read all posts in this thread, especially the Subject: "Bora is a nice guy from Serbia - Yugoslavia".
Bora is really nice guy from Serbia! He gave me some his projects and, I can say, 24 hour building support ;-) I made his project called Studio, but with two modules, so I got then stereo Hi-Fi amplifier. It has 2 x 85 W at 8 ohms, Slew Rate 50 V/us, THD 0.003% in frequency band between 20 Hz and 16 kHz etc. You can see details about this project on, now very famous, Boras WEB presentation: www.bas.abshost.net.
Studio is working excellent! I tested it on my Starlet speakers with Visaton drivers (I made them, too)… and overall impression was - "Lets rock 'n' roll!!!". Later, I tested it with some softer music, like Pink Floyd, Simon & Garfunkel, Muddy Waters, some Dixieland music groups… My impressions where then on higher level… I can not use any English word for this… I hope that my Serbs will understand me ;-)
Back to the "Studio"… I added him device for the remote volume control, and 100% my addin for remote on/off…


All in all, I wish to test Studio on better speakers. I think Studio can snow better sound on better speakers than I own.
I have plans to build Boras Legend with The Tube Limiter and The Lead Pro for my guitar. I think that will be good combination for rockin' and blues/jazzin' ;-)


PS: Excuse me for my bad English, but I'm learning… ;-)


Ponjavić Dušan

[destroyer X]

texts posted.....always you conduct your opinnions and evaluations in a kind way and beeing always fair.

Also you have the use to talk clear what you feel without the intention to hurt people...i could see that.

I could see that you had not bad intentions related your opinnion...and i could see that people that have too much experience, do not turn excited easily, when observe some sligtly different amplifiers, as already watched thousands.

But it is good to see that you have this love inside your heart, related those things, our circuits, amplifiers and simple ideas too.

I feel good with that, this means that my future will be better than i suppose....i was thinking that we had the chance to loose some interest when advancing in knowledge....you saying the opposite, is very good to listen.

regards,

Carlos

[destroyer X]

This way, i think that his problem related his father health is still beeing hard to him.

All of us, soon or latter, we will have to face those life things...the fact that we can be sick, and that the life is not ethernal for no one of us.

I already lost all my more important parents...father and mother already gone... also Grandmother and Grandfather..... i go missing them hardly, with daily rememberings, but feeling happy, as they had good lives, and that i am lucky, as i never lost any of my sons.

My best wishes for Bora.

regards,

Carlos

[DR_PONJA]

I didn't knew for that Boras tragedy. I'm really sorry for that. I can almost feel that pain because I've lost my mother five weeks ago. I'm sad because I can not materialize my feelings, maybe that will bi too much to try.
Bora, life goes on, you must keep walking through it, with had up to sky.

[DR_PONJA]

Here is a pic of Studio.

[destroyer X]

It is so pretty, that i think you could spend some time more to make it completelly perfect.

The output cables can go together inside gray plastic tube, that will confuse it's color with the bottom panel.

Also the wire you have at your rigth can follow the same idea...inside tube, all them together, and panel cables (the ligth red ones... the pretty ones, can be hidden soldered under the board.

This way...you can choice some ligth color....iluminate corners and put some glass or acrilic top....to watch this pretty machine daily.

It will be something to show!...really!

I save the image, it is pretty to see.

You may think..."what a boering guy!, searching for defects in my construction!".... not exactly this way.... i could not silent about that, because your construction is so near the perfection...so close!...why not to turn it perfect?...my intention is positive.

By the way, Doctor Ponja, world languages are very interesting, and there are names that have strange meanings in other languages.... for example, i have the use to smile when i read your nick name (Ponja, do not know if family name).... this remenber in my language, esponja... sponge may be in english... some material that absorbs watter...alike a plastic foam that absorbs watter...and we use here, to call our friends that drink too much...we call them esponja...because they absorb alcoholl alike some sponge can do....the name sounds good to me...if i laugh someday about that.... i was laughing with you, together you...not laughing of you!...completely different.

regards,

Carlos

[RSK]

Hello to all members. I have completed and tested the Studio Amp by our Dr.Bora

Construction,
Input stage matched by hfe DMM.
Output stage using MJ15003/15004.
DC offset around 5mV.

I listened to all type of music with this amp and all I can say is,
What a marvelous piece of electronics.
This amp is fantastic. Soundstage is wide, bass deep and powerfull and the highs are clear and not sharpe.
BTW, my speakers are JMLab.
The preamp used is also Bora's contribution. A headphone amp, full discrete (which I built earlier). Bora recommended it as preamp as well.

To have a second opinion, I took the stereo set to my friends house to compare with his amp (a commercial unit costing over 1,000.00 USD). But I have big problem now!!
I find difficulty to take it back

My heartfull thanks to Bora for all his assistance during constructing the headphone amp and Studio amp.

Sorry I have to borrow a digital camera for the image.
I will do it later once I have completed the full casing.

Cheers.

[viktor1986]

MJ15003&MJ15004 for output?2SC5200&2SA1943 is better.

[jmateus]

Hi all

I had a chance to build the Studio amplifier by Dr.Jadovic some
time ago and recently I exchange some e/mails with him who
asked me my impressions about this amplifier.Of course I couldn't more positive about its quality, it is in fact a marvellous amplifier
and I do not understand why people didn't post more opinions
about it. Probably because not too many people built it...or too
busy commenting about other devices.....

Anyway, Dr. Jadovic gives on his schematic several alternatives
about the output transistors including the MJ15003/15004. But
he leaves to the consructor the option to use any of the 5
different BJT outputs that are included in his schematic.

One thing is for sure, the 15003/4 are not a good choice, they
are the 2N3055/2955 in a beefy version but still outdated
transistors that do not render justice to this excellent design.
I used the On semis MJ21193/21194 with great improvement
over the 15003/4 (wich I tried also) but I also tryied the MJ802/
MJ 4502 and these are not bad even though the voltage ratings
are quite low if you want a good margin of safety.

All in all the 2SA1943 and 2SC5200 are the best outputs you
can use on this amplifier...and on all the amplifiers that take
BJT's.