#de-esser

[tastierearranger]

Sta arrivando Korg Pa5X 1.4.0, ma non si sa quando

La notizia è sicura ma la data ancora incerta. Non abbiamo ancora una previsione ufficiale del giorno di rilascio, ma il 24 giugno scorso il sito ufficiale di Korg ha confermato l’imminente uscita della versione 1.4.0 del sistema operativo di Pa5X. Sin dal primo annuncio nel giugno 2022, l’assenza di funzioni importanti si era fatta notare e l’attesa era divenuta febbrile. Cinque aggiornamenti…

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[atomiumamps]

Orban 526A restoration

This is a 1970s mic preamp and de-esser, notable for its presence in pictures from the Thriller sessions. The de-esser portion is an early “level-independent” circuit that compares relative treble and bass energy, but it can’t do that over as wide a dynamic range as the DBX circuits. That said, the proprietary (and secret, look at that black box) detection recipe used in these units is really well-executed. They’re quite natural-sounding and have very low distortion for something that acts on the entire audio spectrum, with such fast attack and release. The gain element is a FET, not a VCA.

The entire audio path consists of two transformers and two single opamps (Signetics NE5534s, stock). Gain staging is kind of funky, to accommodate the FET as a shunt resistance for gain reduction -- all the variable gain happens in the input stage, but then the signal is attenuated -35dB before the gain cell, and subsequently amplified back up +35dB by the output stage. Yet for all that, it’s remarkably quiet. The input is really a mic input; the ‘line input’ switch just inserts a pad in front of the transformer. Mic input impedance is 1.2k, line input is 10k.

Even apart from the excellent de-esser action, the 526A is worthwhile purely as a mic preamp, though it lacks phantom power. It has a narrow but usable gain range: +28 to +56dB in mic mode, -6dB to +22dB in line mode. The input transformer is a Beyerdynamic “peanut” mic transformer, which gives you +16dB of noise-free passive voltage gain. Since the signal path is so minimal, there’s really not much to go wrong. THD with the de-esser bypassed is typically much better than spec, without any modifications.

Still, I was able to improve noise and distortion performance on this unit by changing the input amp to a FET input OPA1641 (which also raised the input Z a little), and the output amp to a bipolar OPA1611. I chose a FET amp for the input stage because the 1641 has only slightly higher voltage noise than the stock 5534, but exponentially lower current noise -- which matters quite a bit, given that the surrounding impedances of the stage are fairly high. At the time the 526A was designed, the 5534 was just about the quietest opamp available, and the TL072 was the FET-input alternative -- its voltage noise is 5x the 5534′s. The parts we have today make FET opamps a better choice in many older circuits that use bipolar-input amps, where the source impedance or feedback resistances are >2k. The voltage noise is comparable, but the current noise is exponentially lower, and this is where most of the benefit lies.

I replaced all the resistors in the signal path with low-noise metal film, which helps a lot since there are lots of high values and voltage dividers with large attenuation. And I replaced the tantalum feedback shunt caps with bipolar electrolytics (tantalums have pretty high distortion, and modern audio-specific bipolars are much better).

These pieces are really nice to work on -- the top and bottom plates of the chassis come off, so the PCB is easily accessible from both sides. At this age, every electrolytic cap should be replaced, and the supply caps should be bumped to at least 2x the stock values. Opamps have local decoupling caps stock, but they should be increased to at least 100nF everywhere. I used even higher values in positions that pull big current pulses, like the output amp and the sidechain rectifier. Quieting the supply is important because there are a couple places in the layout where a power rail is used as a shield trace to protect a signal trace from interference -- most notably, on the gain pot traces. All the opamps are socketed, so no soldering is required to change them out.

For comparison, after modification this preamp is quieter than my ISA Two. Hum/buzz is completely inaudible. That’s quite a feat, since the ISA’s noise floor is insanely low already, so low that a Cloudlifter actually increases the noisefloor when running ribbons or an SM7B into it. I wouldn’t hesitate to use an SM7B for speech or singing through the Orban, with no need for a mic booster (or the phantom supply it’d require). The de-esser is just an added bonus. If I needed a compressor, I’d be just as happy patching the Orban after the compressor on a channel insert. Either way, it’s not adding anything to the noise floor in any normal configuration.

The service manual recommends terminating the output with a 600-ohm resistor, to damp ringing in lieu of a Zobel network. It’s a bit much; 1k works fine there, and can help the output amp run a little happier. In any case, don’t leave it unterminated -- the OT rings badly at about 40kHz if it’s not loaded.

[atomiumamps]

DBX 263X De-esser

This is a much less-well-known sibling of the 163X OverEasy compressor, part of the same series of simplified half-rack budget prosumer processors. These date to the late 80s and early 90s. The 263X looks like the 163X, and uses the same VCA, but they are very different otherwise -- it’s not just a 163X with a frequency-selective sidechain. Steve Albini calls the 263X a “vastly underrated piece of equipment,” and I agree.

What makes it so cool is that it’s actually both a multi-band compressor and a dynamic EQ. The sidechain uses two RMS detectors -- one is fed the lows, and the other the highs, with the crossover frequency defined by the front panel control. The control voltage is derived not from the absolute level of incoming signal, but from the difference between the bass and treble RMS levels. This is the essence of “level-independent de-essing.” When the treble power is greater than the bass power, the sidechain activates. When the bass power is higher, it turns off. That means that the 263X can de-ess the hiss right out of your noise floor, but then not be attenuating anything at all when a huge broadband signal comes blasting through.

Furthermore, you can choose whether the detection compresses the whole signal, or just the treble part of it. DBX intended this feature to account for both tape tracking and tape mixing situations, and they explain this in the manual. But even with digital, having both options increases the flexibility enormously. I generally find that broadband mode works best and most transparently for subtle control of sibilant speech, and shows fewer artifacts when cranking up the “more” control. On the other hand, the high-frequency mode works better for noise reduction, mic response shaping, or cases where there is steady-state low-frequency information that you don’t want modulated by the highs.

Given the price these go for, the 263X is a no-brainer addition to a podcasting rig or a home recording vocal chain. It greatly reduces the finicky aspects of mic selection -- e.g. “this mic sounds great on my singing but too harsh on my speech” -- and allows really natural sounds from many overly-bright modern condensers.

The x63X series has a reputation for being “dirty” and “noisy” but I’ve not found that to be true. They’re really quite well-designed and still totally usable in their stock form. Input and output headroom is about +21dBu, full pro line level, and I suspect that when people encounter noise it’s because they’re driving them with tiny consumer- or instrument-level signals. Proper gainstaging reveals the true capabilities. But it’s also easy to improve them.

Most of these units are old enough now that they need re-capping. There are two positions in the 263X where polar electrolytics are used to couple signal, and these can end up slightly reverse-biased. It’s best to replace those with high-quality bipolar electros. I haven’t found that massively increasing the supply reservoirs has much benefit (though it doesn’t hurt either), given that the supply is regulated downstream and current draw isn’t enormous. I did bump the size of the caps after the regulators, though. And the 1uFs in parallel with the big reservoirs are there as RFI bypasses, since large caps tend to be more inductive. You can improve the performance in that role by replacing them with 1uF stacked non-inductive film caps, though most big modern electrolytics have much better decoupling characteristics than the original components (I use Panasonic FC series because of their low ESR, high ripple current, and long life + temperature tolerance).

All opamps have 10n ceramic local decoupling caps, a really nice thing that allows you to drop in most modern opamps without much worry. However, you can do better by replacing these with 100nF non-inductive film or ceramic caps, especially if you’re swapping in higher-bandwidth opamps.

For opamps, U1 needs to be a FET-input type. As usual, I find the OPA1642 works wonderfully here, because of its low noise and current draw. U7 is the output amp, which is a Signetics NE5534, stock. This is a great opamp and doesn’t need changing, though it is somewhat overcompensated -- best to reduce C24 to 33pf or 22pf, though you should increase the local decouplers to .1uF if you do this. U5 is the crossover opamp, and it does pass signal to the output when you’re in high-frequency mode. The stock 4558 is really too noisy and slews poorly for the application. I replaced this with an NE5532 and found that both noise and distortion performance improved by about 5-8dB.

The front and rear inputs are identical, except that the rear input shorts out the input gain control. The input impedance for both is 390k, which is not really optimal for either high or low-impedance applications (most DIs have a 1M input Z). I opted to DC-couple the input (shorting C2) and changed R2 to 100k to reduce input noise a little further. 100k is still easily drivable by the typical guitar pedal, for example. You can also move C1 to the other side of R1 (i.e. in parallel with R2), to create a better input RFI filter. This makes sense because most modern sources you’d drive this with have very low output impedance, so strapping a cap across the input doesn’t do anything because it’s just in parallel with the cable capacitance. Putting it after R1 creates a lowpass filter -- and no, it won’t cut into the audio range; the corner frequency is about 1MHz. Even if you were driving the unit from a passive guitar pickup, the corner frequency would still be up around 75kHz.

Lastly, all x63X models almost universally need calibration, just due to normal drift from age. I found that the VCA symmetry trim was off by quite a bit in this 263X. I don’t think that it’s necessary to replace the VCA -- the 1252, aka 2150, is fine -- but most people replace them with trimless THAT2180s, which explains why they see a performance increase (you don’t need to calibrate the symmetry on the 2180). You get most of the same benefit by just calibrating the unit and leaving the 1252 in there.

Service manual is here.

[world-modern]

¿Qué es un De-esser? Vestir sus voces

¿Qué es un De-esser? Vestir sus voces

Al principio, el término de-essingpuede sonar técnico y avanzado. Pero, de hecho, de-essing significa exactamente lo que parece , para reducir “s”. Y un de-esser realiza la tarea de de-essing. Hacemos “s” sonidos todo el tiempo en el habla regular (la palabra, “habla” es un buen ejemplo), o para producir ciertos efectos como silbido. Cualquier lingüista o fonetista le dirá que estos sonidos…

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[visionrecordingstudios-blog]

(via https://www.youtube.com/watch?v=dVtQHKAD8lI)

[audioreporter]

Entendendo o De-esser

Um De-esser é um compressor que atua somente na redução de intensidade de uma banda de frequências específica. Entenda de uma vez por todas tudo sobre essa ferramenta

  – Pra que serve?

É um método para reduzir a intensidade de frequências geradas por sibilância.

– O que é sibilância?

Sibilância é o nome dado à ocorrência de sons como “ssss” ou “shhh” na pronúncia da pessoa que está cantando. O…

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[learnreason]

De-Essing Vocals with the Main SSL Mixer and more

If you are using Record+ you can De-Esse your vocals very easy without the need for any complicated wiring and patching in of cables.

[99-9xfm]

Overview of iZotope Alloy 2 | Essential Mixing Tools

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this thing has a little bit of everything - looks pretty awesome ....  :D