Softube Tape Plug-in Analysis

Softube Tape

INTRODUCTION
Softube Tape sounds really good, and is a popular plug-in at the school. It does not utilise too much CPU, therefore can do a lot of the heavy lifting, unlike the Studer and Ampex that consume a lot of DSP.
I thought I would change the format of these ‘Plug-in Analysis’ threads, making them less technical and more practical, let me know what you think.

TAPE TYPES

  • A - Studer flavour
  • B - Ampex flavour
  • C - EMI flavour

Tape Type A Frequency Response


Above is the frequency response of tape type A at 15 and 30 IPS. At 15 IPS, A has a realatively flat frequency response with a gentle low frequency roll off starting around 30 Hz. Interestingly 30 IPS low frequency response is identical to 15 IPS. However, 30 IPS has a high frequency boost starting around 2 KHz with a approximate bandwidth of 1dB.
I use A,when I am after the sound of ‘tape’ without the big LF response. A at 30 IPS sounds great on vocals.

Tape Type B Frequency Response


Above is the frequency response of tape type B at 15 and 30 IPS. B has a big and round low frequency response at both 15 and 30 IPS, with a 2 dB boost centred around 50 Hz - sounds ‘phat!’ 15 IPS has a 1 dB high frequency boost starting around 5 KHz; 30 IPS has a 2.5 dB boost starting around 2 KHz.
B at 30 IPS is the tape type I use the most often due to the above characteristics, it has a ‘big’ and ‘weighty’ LF response with an ‘open’ sounding top end.

Tape Type C Frequency Response


Above is the frequency response of tape type C at 15 and 30 IPS. 15 IPS has a 1 dB low frequency boost centred around 50 Hz with a gentle high frequency gradient. 30 IPS has a relatively steep low frequency roll off starting around 60 Hz with a steeper high frequency gradient.
I rarely use C, it sounds very retro. at 15 IPS, I find B LF response is ‘rounder’ and compliments the source more. At 30 IPS C sounds ‘thin’.

HARMONIC SATURATION
For this test, I ran a 100 Hz sine wave through Tape at its calibrated level (-14dBFS). I then drove the plug-in at various ‘Amount’ settings to evaluate Tape’s harmonic saturation behaviour.

Tape Type A - Amount 5.0 - Tape Speed N/A


Tape Type A - Amount 7.5 - Tape Speed N/A

Tape Type A - Amount 10.0 - Tape Speed N/A

Tape A has a strong third-ordered harmonic. Driving the Amount increases the third, as well as introducing the fifth and seventh harmonic.
This harmonic structure is associated with ‘richness’ and ‘depth’ due to its interval relationships: The third harmonic adds a fifth, the fifth harmonic adding a major third and the seventh a minor seventh.

Tape Type B - Amount 7.5 - Tape Speed N/A

Tape Type B - Amount 9.5 - Tape Speed N/A

Tape Type B - Amount 10.0 - Tape Speed N/A


Tape B generates both even and odd, non-linear low and high-ordered harmonics. High-ordered harmonics are less consonant than lower-ordered harmonics and therefore, add ‘edge’ and bite’.

Tape Type C - Amount 7.5 - Tape Speed N/A

Tape Type C - Amount 9.5 - Tape Speed N/A

Tape Type C - Amount 10.0 - Tape Speed N/A


Tape C generates a strong third harmonic (an octave plus a fifth), which is associated with ‘fatness’. Driving the Amount introduces the second and fifth at relatively low amplitudes.

SOFT CLIPPING BEHAVIOUR
For this test, I ran Tape at its calibrated level (-14dBFS) through PluginDoctor’s ‘Dynamic’ module. I then drove the plug-in at various ‘Amount’ settings to evaluate Tape’s soft clipping behaviour.

Tape Type A - Amount 5.0, 7.5, 10.0 - Tape Speed N/A

Tape Type B - Amount , 7.5, 9.5, 10.0 - Tape Speed N/A

Tape Type C - Amount , 7.5, 9.5, 10.0 - Tape Speed N/A


Interestingly, none of the tape types soft clip at unity setting of 5.0. Tape A, has a small amount of soft clipping at 7.5, which you do not see from Tape B or C until reaching the 9.5 mark. Tape A also has a softer knee and has a gentle soft-clipping behaviour, shaving approximetely 7 dB off the top compared to 2 and 3 dB for Tape B and C respectively.

One thing to be mindful of when driving Amount is it has a significant impact on frequency response for Tape A and C when passing the 9.0 setting.

Tape Type A - Amount 5.0, 7.5, 10.0 - Tape Speed N/A

Tape Type B - Amount 7.5, 9.5, 10.0 - Tape Speed N/A

Tape Type B - Amount 7.5, 9.5, 10.0 - Tape Speed N/A

CROSSTALK

Tape Type A - Amount 50% - Tape Speed 15 IPS Crosstalk 75%


For this test I utilised Tape A at 15 IPS, as this has the flattest frequency response out of the tape types. Crosstalk boosts low frequencies with a relatively large boost at 50 Hz with a little complimentary dip at around 80 Hz. Crosstalk also boosts high frequencies starting around 1 KHz. This explains why I like the sound of this parameter so much! Crosstalk is relative, the more you increase the greater the frequency shift. In this example Crosstalk is at 75%.


Organe = No Crosstalk
Blue = Crosstalk 75%
However, Crosstalk does not just change frequency response, it also effects the stereo image, as both channels are fed into one another. This typically makes the source more ‘mono’ but with particular phase relationships it can also widen. Take a look at the octave between 2 and 4 KHz, the Crosstalk version is actually wider.

HIGH FREQUENCY EQ

Tape Type A - Amount 50% - Tape Speed 15 IPS


Very smooth and gentle EQ curves, a Baxandall shelf boost when clockwise, and a resonant filter in the anti-clockwise position.

WET/DRY MIX
Tape Type B - Amount 50% - Tape Speed 30 IPS


I remember when this plug-in was released I thought “you can’t have a wet/dry mix knob on a tape plug-in”, as this would cause phase-interactions. In the above image Wet/Dry is at 100% and 50%, essentially where the two lines are different there will be adverse phase-interactions.

CONCLUSION
I believe this plug-in sounds very good, with a light CPU footprint. Crosstalk is perfect for ‘fattening’ and ‘monoing’ the low end. However, it does not behave like tape, and it does not have the parameter interactions I would expect. Nevertheless, it provides a tape-like flavour that sounds great and responds well to dynamics. The plug-in is also up-sampled so less likely to cause any aliasing.
What are your thoughts on Softube Tube, what instruments you like it on, any good techniques to share?

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Great analysis @Paul! I’ve had this plugin since it was released, but never really given it the chance it deserves. I’ll put it in my default template now and play around with it. Having your breakdown of it will help. Please, if you remember, always feel free to tag me in your future analysis. I find them very, very useful and informative. Thanks! :clap:t2::pray:t2::blush:

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Thanks Paul! I use it on every track as my tape saturation. I find I usually prefer the A on brighter sounds and B on sounds I want to fatten like kicks and bass. If I am using it on the Master Buss it depends on the type song but often I use B

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love this plug and the ease of use.
it has replaced the studer for me on individual tracks because I just find it easier to dial in and it sounds great.
ATR-102 still dominates every mixbus though

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New Fabfilter Pro Q3 post just added :slight_smile:

Great job as usual Paul. I do like the in depth technical analysis that you do but with this format I didn’t feel overwhelmed :slight_smile: Either as often as you can works for me. I appreciate when you recommend where one might use certain settings etc. This is my goto tape plugin for the mixbus.

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Great! I will keep this in mind for next post :slight_smile: