Wow, so indeed, for quite some time, this guy correctly guessed the Blowtorch core schematic:
Uskok preamplifier
The author seem to be a member on this forum http://www.diyaudio.com/forums/members/moamps.html so it would be interesting to hear some comments about...
No interest here, the ramblings of a bitter person that can't deal with the fact that internet posts become public domain. Maybe the laws are different in Serbia. Posting a circuit in public here makes it public domain i.e. anyone can use it for fun or profit. Interesting this guy attacks me even though I place everything I do into the public domain (take it or leave it).
Last edited:
Uskok preamplifier designer Mr. Milan Uskokovic is from Zagreb, Croatia , not from Serbia. It is a big difference.We only have common language.
After several years, I have some new sims of this circuit, and it proves to be perfect.
The absence of distortion except for third harmonic is questionable. Have measurements of the real thing been revealed in this thread for comparison?
I have no 'real thing'. The distortion profile I have shown is only in case that the input is driven balanced and output is balanced as well. In case of any single-ended I/O, the distortion rapidly worsens. I assume the simulation result is reliable (based on experience with other circuits), of course when you increase Y axis resolution you would see 2nd harmonic and some higher harmonics as well.
Sorry, I can't tell the difference at first glance.
(Note ref, Serbian or Croatian)
The university of Pittsburgh used to teach the Serbo-Croatian language as a single class. After the breakup of the USSR and the outbreak of war in what was Yugoslavia they had to split it into two courses.
They speak the same language but the Croats write it in Roman characters, the Serbs use Cyrillic. The Croats think the Pope is in Rome. The Serbs in Constantinople (Now Istanbul.)
The Croats at first sided with the Nazi's in WWII hoping to be freed from Serb "Oppression." Both sides have a long history of being nasty to each other.
Now as an interesting sidelight there is a Croatian Church (Roman Catholic) not far from here that as is covered with Icons done in the late 30's and early 40's. It shows the devastating scenes of war as the artist had just come from Europe. What is most interesting is the good guys helping the poor miserable victims are wearing helmets and military garb. The cut of the helmet is distinctly German.
Now as to the website. It is interesting to note his other circuit designs. All reasonably simple designs showing no trace of diamond (or as I prefer "bridge") discrete circuits. How interesting to see the dramatic jump in design technique!
Scott, welcome to the "Diss'd" club. I have a French non-fan. But your's does seem quite a bit crazier!
The Serbs in Constantinople (Now Istanbul.)
Why did Constantinople get the works? It's nobody's business but the Turks'.
Its like Vatican, the churches established their historic headquarters in places they had initially grown up.
In any case, I wish the guy well, and I hope that he sold a few units and made a profit.
That is a major reason for this thread, which is to promote this kind of design approach, similar to what Charles Hansen and I do with our best efforts.
That is a major reason for this thread, which is to promote this kind of design approach, similar to what Charles Hansen and I do with our best efforts.
(Note ref, Serbian or Croatian)
Scott, welcome to the "Diss'd" club. I have a French non-fan. But your's does seem quite a bit crazier!
One of my best friends in high school was Serbian, I got some first hand accounts. This thing was unfortunate, in retrospect I used words that were too harsh. Milan is obviously a very intelligent person and very well spoken in English more than I can say of my Serbo-Croatian.
Sy,
With respect, the Turks are the aggressive occupiers in Constantinople, which is part of Christian Europe (including the Church of Saint Sophia).
Of course, it all happened so long ago that possession became the law and without the conquest and sack of Constantinople by Mehmet Europe may never had it's renaissance, may never have sucesfully settled the America's (after mostly doing to the natives what Mehmet's armies had done to the inhabitants of Constantinople) and thus industrial revolution and the internet may have never been invented...
Ciao T
Why did Constantinople get the works? It's nobody's business but the Turks'.
With respect, the Turks are the aggressive occupiers in Constantinople, which is part of Christian Europe (including the Church of Saint Sophia).
Of course, it all happened so long ago that possession became the law and without the conquest and sack of Constantinople by Mehmet Europe may never had it's renaissance, may never have sucesfully settled the America's (after mostly doing to the natives what Mehmet's armies had done to the inhabitants of Constantinople) and thus industrial revolution and the internet may have never been invented...
Ciao T
Is that all? '-)
No,
Entirely off topic and out of rules boundary would be the tale of why there are places that have Popes. But anyone interested can Wiki that,
We could discuss the Vatican sound systems, but not very surprisingly bribery was involved in the design of at least one of the systems I am aware of. (Along with a few respectable threats...)
Interesting spin off the houses of worship international PA systems info. I have seen very elaborate ones in reinforcement industry's brochures, websites. In usually equally elaborate acoustically treated huge spaces with interesting interior blending design. Are there any special acoustics crafted for such installations? Like some differentiated reverberation time bracket of client acceptance or different standards for the cabinets & mic arrays than for music halls? I know they would accept only AKG condensers & column array speakers in most local orthodox churches for instance and would pay one off and in cash if chuffed.
Interesting spin off the houses of worship international PA systems info. I have seen very elaborate ones in reinforcement industry's brochures, websites. In usually equally elaborate acoustically treated huge spaces with interesting interior blending design. Are there any special acoustics crafted for such installations? Like some differentiated reverberation time bracket of client acceptance or different standards for the cabinets & mic arrays than for music halls? I know they would accept only AKG condensers & column array speakers in most local orthodox churches for instance and would pay one off and in cash if chuffed.
At first in the US, RCA was the dominant force in public use sound systems. They built a central amplifier and would wire primarily schools with it and a switch bank. It could be used for a classroom intercom system, a school all page or even to provide sound just in the auditorium.
Altec Lansing started selling equipment to the electrical contractors through a national electrical equipment distributor (Graybar.) This lead to establishing specialty sound contractors. One Altec Vice President (Don Davis) developed a method for designing sound systems and spent enough time doing this that he upset the sound system consultants. So he went off on his own. (Probably not by entirely his choice!)
Well in the US, Don Davis used to give courses in how to design sound systems. He developed a method based on a central cluster system (point source) and lots of rules using scientific calculators and decibels. Basically he assumed that people spoke 2 feet away from a microphone and that the distance from the speaker to the microphone determined how much gain you could get before feedback. He modified this distance by a directivity factor called "Q." He also allowed for a gain reduction by the square root of the number of microphones or speakers in use. You also tossed in a safety factor of 3db. There also was an absolute limit of the maximum speaker to microphone distance due to reverberation. He used the critical distance for this.
When you produce a continuous sound from a source the reverberant field will build up to a steady level. At some point the direct field due to the inverse square law will diminish to that level. That is at the critical distance.
The idea was to place the cluster high and centered, calculate the coverage angles and pick a speaker with a "Q" that would meet the design goals. The design goal was for everyone to have a sound level equal to being 8 feet away from the person talking. He also had a formula for predicting speech recognition. You were supposed to do all of these calculations using decibels. When simplified to divided the length of the room by 8 and make sure the speaker is that far away from the microphones the method seemed to loose a bit of it's magic luster.
He was influential enough that most professional manufacturers listed "Q" values on their data sheets.
However in Europe there were far fewer church sound systems and they were just changing from having folks such as Phillips & Siemens do them to using smaller firms. The smaller firms only knowing the physics and not having been properly "trained" reverted to the older form of loudspeakers designed to project in reverberant fields. So they used sound columns, now called line arrays.
As these caught on worldwide there was controversy from the Davis camp. (I got really nasty letters from them for an article I did on Bruel & Kjaer's Rasti meter that not just said it was useful, but that the assumption of Davis that speaker throw increased by the square root of "Q" was not accurate.)
Around the same time Wolfgang Anhert (E. Germany) had developed a modeling program that was brought to the US by Renkus Heinz. (Some interesting stories there!)
Well since worldwide line arrays and prediction software were adopted sales of pro sound equipment that were basically stagnant have now tripled.
Now interestingly enough very few folks know how to apply sound absorption treatments and it is much easier to sell electronics, so only a few specialist consultants use acoustic treatments. Even when such treatments are done, after ten or twenty years the reason for them is forgotten and they get painted over ruining them. Even worse is the organist who "knows" more reverb is always better gets them removed.
So churches with bad sound systems will just buy new ones every few years hopping for some magical improvement.
Last edited:
I know of a church in St Paul that has been doing just that. Still can't get it right.
Do they have money? 🙂
- Status
- Not open for further replies.
- Home
- Member Areas
- The Lounge
- John Curl's Blowtorch preamplifier part II