Parni_Valjak

Чети си статусите!

^^ Никони, C10 и C11 не са на място там. Елиминират същността на действието на R15 и R16. C6 и C8 са безмислени. Импедансът им в работния честотен обхват е в пъти по-голям от този на C7 и C9. С тях и без тях е все едно. Разбира се електролитите трябва да са изправни, за да е изпълнено това условие. C4 и C5 имат прекалено високи стойности. Дори без да се отчита изходният импеданс на фазоинверторното стъпало долната гранична честота е 7 Hz. С отчитане на изходния импеданс тази честота ще слезе доста по-ниско, а това е противопоказно за работния режим на изходния трансформатор.Долната гранична честота не бива да е под свободна 6-та струна (82Hz), или най-много да е малко под свалена 6-та - 70...65Hz. Това е в сила само, ако изходящият трансформатор е проектиран, конструиран и изпълнен за долна гранична честота по-ниска или равна на посочените . В противен случай изходният трансформатор ще се насища, ще товари крайните лампи и ще изкривява сигнала. Това за повече ниски с ECC85 е нобосновано. В смисъл, че от лампа не може да се получат повече или по-малко някакви честотни обхвати. Съвсем друго е влиянието на РЕЖИМЪТ в който е поставена лампата. Имайки предвид, че ECC85 е лампа разработена за приложение в УКВ диапазон ( 60...110 MHz) , режимът в който трябва да се постави за нискочестотен усилвател ще бъде различен от този на другите посочени лампи. ECC81 също иска различен режим спрямо другите лампи. Тя е с десетократно по-висок ток и по-нисък импеданс. С други думи, употребата на различни лампи си иска различни режими и съответно различни компоненти, за да може да се сравнява тяхното поведение. Постът публикувам със закъснение, поради проблеми с базата данни на форума от миналата нощ.

AES Press Release The Audio Engineering Society Publishes Groundbreaking New Standard for 3D Audio For Release: March 12, 2015 The Audio Engineering Society is pleased to announce the recent publication of the AES69-2015 standard, which provides an important framework for the growing binaural and 3D personal audio industries. The standard, which describes the format and exchange of spatial acoustics files, is the product of the AES Standards Committee, the preeminent source of professional audio standards worldwide. The AES69-2015 standard is seen as a boon to the evolving 3D audio field. Binaural listening is growing due to increased usage of smartphones, tablets and other individual entertainment systems that primarily present audio using headphones. An understanding of the way that the listener experiences binaural sound, expressed as head-related transfer functions (HRTF), opens the way to 3D personal audio. The lack of a standard for the exchange of HRTF data makes it difficult for developers to exchange binaural capture and rendering algorithms effectively. While 3D audio continues to gain popularity among end users, binaural listening could be the very first 3D audio vector with sufficient fidelity of HRTF. The new AES69-2015 standard defines a file format to exchange space-related acoustic data in various forms. These include HRTF, as well as directional room impulse responses (DRIR). The format is designed to be scalable to match the available rendering process and is designed to be sufficiently flexible to include source materials from different databases. This project was developed in AES Standards Working Group SC-02-08, with the writing group being led by Matthieu Parmentier and principal authors Piotr Majdak and Markus Noisternig. The standard builds upon an earlier project to define a spatially-oriented format for acoustics (SOFA), which aimed at storing HRTF data in a general way, capable of supporting any transfer-function data measured with microphone arrays and loudspeaker arrays. The use of convolution-based reverberation processors in 3D virtual audio environments has also grown with the increase of available computing power. Convolution-based reverberators help guarantee an authentic and natural listening experience, but also depend on the acoustic quality of the applied directional room impulse response (DRIR). Many such issues have been of growing concern in the industry, as were discussed in depth at the recent AES 57th International Conference in Hollywood, CA, which addressed topics including immersive audio delivery standards, headphone design and performance, 3D audio in ambisonics, binaural audio, more. The following requirements are supported: Description of a measurement setup with arbitrary geometry; that is, not limited to special cases like a regular grid, or a constant distance. Self-describing data with a consistent definition; that is, all the required information about the measurement setup must be provided as metadata in the file. Flexibility to describe data of multiple conditions (listeners, distances, etc.) in a single file. Predefined descriptions for the most common measurement setups, which are referred to as “conventions.” AES Standards Committee Chair Bruce Olson states, “AES69 represents a fundamental piece of architecture for taking personal audio to a new level of performance. Using this, product developers will be able to take advantage of transfer-function databases from all over the world to produce a truly immersive 3D audio experience.” AES Standards Committee The AES Standards Committee is the organization responsible for the standards program of the Audio Engineering Society. It publishes a number of technical standards, informational documents and technical reports. Working groups and task groups with a fully international membership are engaged in writing standards covering fields that include topics of specific relevance to professional audio. Membership of any AES standards working group is open to all individuals who are materially and directly affected by the documents that may be issued under the scope of that working group. Complete information, including scopes of working groups and project status is available at http://www.aes.org/standards.

Ммммм, Убавина! Най-голямото удовлетворение ще е да откриеш Де се скрил Ground Loop-a, дето убръмчава цялата система !

Не е MINI, но пак е MOOG... А тримцата са една от най-забележителните групи за електронна музика. Разпознаването оставям на вас. (Steppenwolf да не бърза; нека да видим кои други ще успеят.)

In this first installment documenting the journey of the Minimoog synth through the 1970's, we explore the musicians and the people that were instrumental in bringing the instrument to prominence. We also sit with one of Moog Music's earliest engineers, Bill Hemsath, who recalls the process of the Minimoog's birth and sheds some light on what sets the Moog synthesizer apart from other analog synths.

Стара информация от 2014 година. R.I.P. iPod: Sony unveils cassette tape that can hold 64,750,000 songs BY CHRIS COPLAN For a time, the cassette tape absolutely dominated the sales market. In 1990 alone, a staggering 442 million tapes were sold. However, with the rise of the CD, the birth of the mp3, and the eventual resurrection of vinyl, sales dwindled, and by 2007 only a mere 274,000 individual cassettes were sold. Sure, cassette-centric labels like Kissability and Mirror Universe Tapes have offered the cassette a new and niche following, but it’s a clear sign of the times when the cassette’s accompanying Walkman is regarded like some alien artifact. Now, though, Sony has brought the cassette back from the dead by unveiling a tape that can hold a whopping 148 gigabytes per square inch. If you can’t do the math, that’s 185 terabytes of total data. We’ll wait as you toss your iPod into the trash. The tape, which was unveiled this weekend at the International Magnetics Conference in Dresden, holds approximately 74 times the amount of data of standard tapes. (For comparison, by 2010, most standard tapes could only store about 29.5 GB per square inch.) Divine influence or magic aside, how exactly did Sony manage to boost the potential of the 50-plus-year-old magnetic tape technology? According to Gizmodo: “The tape uses a vacuum-forming technique called sputter deposition to create a layer of magnetic crystals by shooting argon ions at a polymer film substrate. The crystals, measuring just 7.7 nanometers on average, pack together more densely than any other previous method.” As ITWorld explains, “By tweaking the sputter conditions and developing a soft magnetic underlayer on the film, the manufacturer was able to create a layer of fine magnetic particles with an average size of 7.7 nanometers.” So, just how much data can a tape with 185 TB capacity actually hold? Here’s a few handy comparisons (via ExtremeTech): – It’s three Blu-rays’ worth of data per square inch. Or, a total of 3,700 Blu-rays on a single tape. That’s a stack of boxes that would be nearly 15 feet high. – A single tape holds five more TB than this hard drive storage array, which has to be custom-made and runs for $9,305. – A total of 64,750,000 songs. If the average song is, say, three minutes, that’s enough music to last you 134,896 days. – The entirety of the Library of Congress represents about 10 total TB. One tape can hold 18.5 versions of the Library of Congress. The tape will be available for commercial sale, but no word yet on a release date. However, as Gizmodo points out, the super tape was originally developed for “long-term, industrial-sized data backup” and not necessarily for music, game, and video storage and playback.

Moog Music Inc.

Sorry, made mistake in the headline... Blue Oyster Cult's Minimoog Model D: as heard on "Flaming Telepaths" and "Secret Treaties".

How to prevent audio feedback By Brandon Graham Harman engineer Brandon Graham offers his top tips on setting up and EQing a system to avoid this common problem, as well as explaining the best way to use suppressors. We’ve all probably been exposed to far more feedback than we’d like (even one exposure is one too many). As performers and live sound engineers, it can be frustrating when we’ve done all that we can and still encounter problems with feedback. This article is intended to help you prevent it, and get the most out of feedback suppressors. There are many things you can do to passively prevent feedback, and it is important to address these issues first before you start maxing out gains and setting filters. Passive Solutions Check the polar patterns of your mics. Make sure that your monitors are aimed at the nulls in the pattern to minimise feedback loop gain. Keep your mics off-axis from your speakers when possible, because the gain is lower there (especially for high frequencies). Keep as much distance between your mics and speakers as possible. The feedback gain reduces with distance. Less is more. The fewer microphones and speakers you have in your system, the fewer feedback paths. These feedback paths can build on each other, so you may get more gain-before-feedback by using less equipment. Watch out for room reflections. They can be strong enough to cause feedback. Now we reach two conflicting goals: achieving the ideal tone for your performance and maximising gain-before-feedback. If you are still experiencing feedback problems after doing your best with passive reduction, you will have to start using EQ. EQ Solutions For maximum gain-before-feedback, EQ for a flat response coming from your mics. One broad EQ boost can result in several feedback problems. Better to solve the EQ problem now than to deal with feedback later. A room full of people has a different response than an empty room. This is one reason why a feedback suppressor is useful, because you can never anticipate all feedback problems ahead of time. About Automatic Feedback Suppressors As a signal processing engineer at Harman, I contributed to the development of the latest dbx feedback suppression products. During that time I had the opportunity to test feedback suppressors from all major brands, and one thing became clear – everyone has improved their algorithms significantly since their first generation of suppressors. They are better at distinguishing between feedback and music, faster at eliminating feedback, and more careful about how much they notch out of your audio. In some ways, we often ask automatic suppressors to do the impossible. We can imagine what our high-gain setup would sound like without feedback, so we think that it should be possible to maintain perfect sonic integrity at those levels. This is like expecting a refrigerator to preserve your food without allowing it to lower the temperature. There may be some tricks it could try, but when it gets really hot something is going to spoil. If we understand the limits of automatic suppressors, we will be more capable of using them to their full potential. Note: if you operate near maximum gain, be aware that you are adding strong comb-filter-like EQ to your sound. Well-placed feedback suppressor notches can cancel some of that and help you get closer to your desired response. Your feedback suppressor should be used for two things – revealing and eliminating potential feedback before your performance, and quickly eliminating any feedback during the performance. Before the Performance Every feedback suppressor has some form of ‘Setup Mode’, which is intended to help you address your main feedback problems before the performance starts. Use it! It is far better to deal with it now than during the show. Here are some useful tips to make your suppressor setup more effective. Rerun your setup mode for every show you do. Don’t expect to save a preset and have it be totally effective the next time you set up. Feedback frequencies are dependent on many factors, including mic and speaker positions, where the performers and audience are, and even the room temperature. As you ring out your system, have the performers stand in their positions (with ears covered) if possible. Feedback often occurs as a performer nears a microphone or speaker. You can tap the micropones or clap to elicit feedback. Be aware that in setup mode, feedback suppressors don’t distinguish well between feedback and music. Ensure your performers don’t talk or sing into the mics, as you may get some filters set on them. If all of your notch filters are lumped together in a small group, this is an indicator of a larger EQ problem. Do a second round of EQ to address the problem and then try again. It’s likely that the first handful of filters will address the worst problems and give the most benefit. After that, you may find that you can’t increase the gain much before running into several new feedback tones. This is a good indicator that you are nearing your maximum operating gain. During the Performance Every feedback suppressor has a ‘Performance Mode’ where it works hard to distinguish between music and feedback. This is meant to monitor your performance and only kick in if feedback happens. If you’ve set up your system correctly and aren’t pushing the limits with your gains, this should only be an issue when the unexpected happens (ie, when the vocalist points the mic at the monitors). For the fastest response, use the widest filters possible. This ensures that each filter tackles the broadest potential feedback region possible. If you’re worried about tone, use the narrowest filters and operate at the lowest practical gains. You can also set your filters to auto-remove based on a timer. This ensures that they are only active for the short time they are needed during a feedback emergency. For more on feedback prevention, a detailed paper on the topic can be found here. Or here: A Detailed Look at Feedback Prevention & Suppression (for educated ones)

RCA-Understanding-Hi-Fi-1956 Полезно четиво, което изяснява основни положения на Високата вярност на възпроизвеждане - High Fidelity, както е била замислена преди години. Сега нещата са други. Изместени и отдалечени от основните принципи.

Можеш да извадиш високочестотния конус като използваш коресилин в спринцовка с игла. Бавно, на малки порции се впръсква върху лепилния шев (между конуса и мембраната), без да се позволява протичане навътре към шпулата . С леко раклащане на конуса се разбира когато лепилото омеква и тогава може без усилие да се измъкне от мембраната. Незабавно след това трябва да се постави капачка, която да закрие отвора към магнитната система.

Пробвай най-напред с всичко оригинално. Говорителите на Ригондата може да се окажат доста по-добри. Елиминирай само връзката с радиоприемната част и запиши звука, за да го имаш за сравнение. След всички други варианти, които трябва да се запишат при абсолютно еднакви условия с оригинала, направи сравнителни прослушвания. Дори едновременното прослушване би дало най-точна преценка за приликите и разликите между раличните варианти. ВК201Б са разработени за възпроизвеждане на ниски честоти (баси). Показания вариант с добавен ВЧ конус е куцо магаре или нещо като свинче със звънче. Явно някой комсомолец се е направил на специалист, след обучение в интернет . Система с меко окачване и голям ход , комбинирана с високочестотен илъчвател има големи доплерови изкривявания. Затова мисля, че няма да е добро решение за предложения проект. Ако трябва да съм откровен, за никаква система не е добро решение. Ако пък са втвърдили окачването на трептящата система, един Господ знае какъв резултат се е получил . Едно обаче е сигурно - името ВК201Б не е на място.

Не става ясно до колко твърдението е вярно. Самият израз "...on all outputs of the Konnekt 6." е лишен от смисъл. Фазова разлика се дефинира само между 2 сигнала. Когато става въпрос за повече сигнали, е нужно да се дефинират фазите на всеки сигнал спрямо избран такъв. Реално в писанието има само твърдения, без доказателства, като измерване например. Не твърдя, че няма някакъв проблем - възможно е. Но повече ми прилича на аудиофилска изцепка. Готов съм да направя истински измервания, ако това е необходимо. Искам само да отбележа, че когато се работи с цифрови входни сигнали, може от там да идва евентуален проблем.Т.е.да има дефазиране още в цифровия сигнал .

Номограми за радиолюбители (DIY) Брускин В.Я. Удобни средства за избягване на сложни формули и пресмятания. Особено са подходящи за хора намиращи се над откровенното копиране без разбиране, но все още недостигнали до сериозната наука. Както пише в заглавието - за любители. Има достатъчно раздели , касаещи нискочестотна техника, захранвания и други, директно свързани с тематиката на форума.

Комплекти за домашно кино от VISATON Конструктивни решения за DIY озвучителни тела на немската фирма Visaton. Определението "за домашно кино" не е задължително. Много от конструкциите спокойно могат да се приложат за съвсем други цели, стига да се преценят правилно параметрите им.

Съвсем разумно решение!

Че не върши работа, е ясно. Но, искате ли да започнем от идеята? Какво е заданието, за да се прецени къде е несъответствието? Какво се иска да върши това устройство? Дали е възможно и при какви условия би могло да се получи покриване на изискванията? От тук нататък темата може да стане сериозна и ангажираща. Няма да е нито лесна, нито приятна. Ще се наложи да се мисли и да се чете литература (техническа, научна ...). Предупреждавам, няма да стане наготово, да е ясно! Мога да насочвам и да консултирам, но хамалогията няма да е моя. Сега е момента да прецените силите си и да се прекрати или да се задълбае. Какво решавате?

Влез в imgur.com , поогледай се, и за нула време ще се запознаеш с основните положения. После с времето ще се ориентираш и в подробностите. Не критикувам нито идеята, нито изработката. Становище от мен трудно ще се поеме. Така и не се научих да обяснявам академични дисциплини на разбираем език.

N.B. Във връзка с проблема касаещ вмъкване на изображения, предлагам моето виждане. Не използваш правилния сървър за изображения. Всеки си има особености, затова не всеки е удобен за споделяне във форумни платформи. Давам пример от споделените адреси в публикацията - Това е твое изображение, избрано и вкарано в imgur.com през CHROME . Инсталирано е разширение за imgur, за да става лесно с две кликвания цялата операция . ( По отношение на акустичния екран имам принципни забележки, но това е тема за друг разговор )

AMS Neve reveals 1073DPX dual preamp AMS Neve has unveiled the 1073DPX dual 1073 microphone preamp/EQ unit. Using the original Neve 1073 circuit design and components and combining them with modern manufacturing techniques, the 1073DPX promises the best sounding microphone preamplifier unit with convenient extra features for an unbeatable price . The unit's design centres around two independent Neve 1073 transformer-coupled microphone preamplifier/EQ circuits in a single 2U 19in rack mount enclosure, with Neve Marinair transformers used on each input and output stage. It features connections for mic, line & DI inputs on front of the unit, with switchable mic/line input connections on the rear.Also featured is switchable +48v phantom power with hi/lo impedance, -20dB pad and DI ground lift on the input stage, alongside switchable phase, EQ in/out and independent channel output level controls. Seven-stage LED signal level meters for each channel display stage level for mic/line/DI input, EQ or output up to +24dB, while the Insert Send and Return features allow external equipment to be connected easily to the 1073DPX audio chain. The 1073DPX is available now and priced at £2,749/$4,749.