the circuit for Rec & Repro heads affects the sound very different, all tape machines / brands had a "sound" different than others, some aimed to clean & transparent sound, like late Studer but most tape machines sound different, each had a flavour, there are plugins that emulate that, like Steinberg Yamaha Vintage Open Deck, emulates 3x decades of Studer + 1x Ampex ATR-100, allows different Rec & Repro circuits, but all same US EQ, Not the same as Real Tape. Avid Heat plugin for DSP sounds very nice, for CPU Not much... the Heat name is misleading, does Not have Tube emulation is Tape, toneboosters emulated Teac & Revox, etc... circuits were very different: old MCI JH-16 / 24 had custom Transformer i/o to balance / un-balance the signal, but later models were replaced with custom op-amps mci 2001, dont have direct replacement, most people replaced with 5532 "works" but Not the same, all op-amps have a "sound", depending on the impedance of the circuit, because op-amps are miniaturized discrete amplifier circuits like jensen 990, api, etc... Ampex MM-1000 1100 1200 machines had optional hi-fi rec & repro boards with Lundlah transformer, some companies went to extreme levels, created Tube Amplifiers for Repro. most Pro Studios had MRL Calibration Tapes, there is tons of Tutorials on YouTube, but small home studios used machines as is, from factory, No cabliration unless done by local technician. some machines had US Eq, and others Euro EQ, NAB / IEC if you record on Euro EQ circuits or if you record on US EQ circuits, and playback on the other circuit, affects the sound, one sounds brighter, the other darker, some artist used that for creative purposes. old Cakewalk Fx-2 tape machine emulation DX plugin had that ability to select different curves, but the sound its "CPU". a very popular tape plugin emulation today for "Digital Home Studios" are the Universal Audio DSP, but i like more Avid DSP. UAD allows to change Bias, and stuff like Steinberg plugin, Avid only has 1 know that does All. https://www.manley.com/legacy/thpa https://reel-reel.com/tape-head-preamps/ https://bottlehead.com/product/tube-repro/ https://www.erhard-audio.com/Titan.html http://www.dehavillandhifi.com/222_Tape_Preamp.htm https://rtzaudio.com/legacy/ ________________________________________ From: Fons Adriaensen <fons@xxxxxxxxxxxxxx> Sent: Sunday, October 20, 2024 4:31 AM To: linux-audio-user@xxxxxxxxxxxxxxxxxxxx Subject: Re: Tape emulation - is it worth the effort ? On Sat, Oct 19, 2024 at 03:30:56PM -0500, Chris Caudle wrote: > What is your guess at how many studios correctly biased their recorders? > The orange trace in your graph looks like fairly soft saturation. Do you > think under-biasing like that would have been common during the time tape was > common, or would most facilities have correctly biased up to the more linear > curve with harder saturation? I've never heard of such practice, nor remember it ever mentioned in the professional media, e.g. Studio Sound monthly magazine. Keep in mind that sound engineers at the time were not looking for what is today hyped as 'tape sound' - they just wanted the highest quality. Also the minimum tape speed used in music recording studios was 15 IPS (38 cm/s), 8 times the speed of a Compact Casssette, and master tapes often used 30 IPS. This provided a much higher quality than most people imagine today. And once noise reduction systems (Dolby-A, DBX, Telcom-C4) were available there was much less need to record at very high levels. > > The only effect that remains in a complete simulation is > > the result of the EQ applied to the signal to be recorded. > > The inverse is applied on playback? Wouldn't a high cut shelf type filter > applied to a clipped signal make it sound a little more like soft saturation? Maybe, but exactly the opposite was done - HF was attenuated in the record path and boosted on replay [1]. The reason for this is that HF signals are not only attenuated by the magnetic recording process, they also saturate at lower magnetic flux levels [2]. It's just not possible to record them at the same high level as LF signals. So in order to provide full level output at HF, they must be boosted on replay. [1] In order to ensure that a tape recorded on machine A could be replayed on machine B, tape machines were aligned to a level and EQ standard. What was standardised was not the actual equalisers used, but the level and frequency response of the magnetic signal on tape. All standards specified a first order lowpass for this in the record path, e.g. -3dB at 3180 Hz for the NAB standard used in the USA. [2] The actual parameter that controls this is not frequency, but wavelength on tape, i.e. tape speed divided by frequency. This is the main reason why higher speed is better. Ciao, -- FA _______________________________________________ Linux-audio-user mailing list -- linux-audio-user@xxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to linux-audio-user-leave@xxxxxxxxxxxxxxxxxxxx _______________________________________________ Linux-audio-user mailing list -- linux-audio-user@xxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to linux-audio-user-leave@xxxxxxxxxxxxxxxxxxxx
