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P12 response at different master volume levels

P12 response at different master volume levels
« on: February 27, 2019, 09:48:31 PM »
Hey all. I’m wondering if anyone knows how “linear” the P12 analog amp is. In a lot of older analog equipment there is a sweet spot for master volume where all circuits are maximizing their harmonics/overtones etc. Basically a setting where you are getting the “best” out of the equipment. Forgive my ignorance, but is this even a thing with modern synths, specifically the P12? Basically I’m wondering if anything is lost by keeping the master volume super-low. If anyone from Sequential would like to chime in too, I’d love to hear your thoughts. Thanks!

Re: P12 response at different master volume levels
« Reply #1 on: February 28, 2019, 07:47:01 PM »
Generally, you want to keep the master volume at full output, if possible.   This allows you to turn down the gain on the inputs to the mixer or interface to the DAW.  This reduces the background noise to the lowest possible. 

It's a recording trick I learned many years ago from a master recording engineer.   

General rule:  Outputs high as possible with input gains correspondingly low results in minimum amount of system noise. 
« Last Edit: February 28, 2019, 07:52:02 PM by jdt9517 »
Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S-90; Yamaha Montage 8, Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.

Re: P12 response at different master volume levels
« Reply #2 on: February 28, 2019, 10:27:26 PM »
Thanks - I’m solid with best practices (have been fortunate enough to have access to studios for 23 years or so ;))
My question was intended to be a little more academic... my prophet is connected to an RME input without any discrete gain control, other than the -10dBV/+4dBu chooser. The prophet’s master is the only fine input gain control, so this control may be anywhere from max to somewhere around half. I find that -10 leaves enough headroom for most patches with the P12 master maxed, but there’s just a few when the level needs to come down. So my question still stands - I’m curious how the prophet master affects the overall tone if at all.
« Last Edit: February 28, 2019, 10:30:48 PM by Zac Kyoti »

Re: P12 response at different master volume levels
« Reply #3 on: March 01, 2019, 12:44:49 AM »
This is a very interesting question, since the gain staging in the Prophet 12 is a quite important aspect of the synth.

Others with more experience making patches for it might very well have a different view, but to me it is much more important to consider the amplitude response in the earlier stages of the signal path: the oscillator, character and filter stages.

There is quite a lot of headroom along the way, and the level of the signal going into the filters has a huge influence on the harmonic content of the final sound. It has been established in several discussions that many who complain that this synth sounds harsh and non-appealing to them have been using a rather high input level into the filters, and that by reducing the oscillator levels the sound becomes much softer.

This effect is so large, that I have not even considered any effect the final output stage might have. Again, others who have spent more time recording the output from this synth might have a more informed opinion.

The fact that you find that different patches have different output levels reflects that the creators of the patches utilised this aspect of the synth. Does this difference perhaps mean that there is not a universally best master volume level?

I am sorry that this doesn't really answer your question, if you only want to record presets at the best quality, and not create your own patches.
« Last Edit: March 01, 2019, 12:50:09 AM by mhult »

Re: P12 response at different master volume levels
« Reply #4 on: March 01, 2019, 02:54:25 AM »
Im also interested in this. I dont feel like it matters much for the sound quality, but i havent tested anything concerning it. As the previous comment says, the programe control and the osc and drive levels affect the sound a great deal, and have something closer to the harmonic sweet spot you are describing. But i dont feel the same for the master output.

I think that it makes a difference from a purely physiological standpoint with amplitude changes affecting harmonic content both in the cable signal path, but also in the auditory frequency response. But i know too little of the technicalities of amplitude gates and so on. (I assume the master output is a gate that subtracts the sound from the VCA), im probably 70% wrong about that though!

Great question, btw

Re: P12 response at different master volume levels
« Reply #5 on: March 01, 2019, 03:03:10 AM »
There is another compromise to consider. Whilst there is probably an optimal volume per voice it is different for each voice (and different for parts A and B of each voice). I run A and B through separate stereo volume pedals, play live and spontaneously decide which of over 200 voices I will be using. So I am forced to compromise and have an 'Average maximum volume' to reduce the likelihood of unwanted jumps in volume as I change voices or between part A and B.

Re: P12 response at different master volume levels
« Reply #6 on: March 01, 2019, 11:00:35 AM »
Awesome responses everyone. I agree with the above. There is huge tonal variation in the P12 depending on how you drive it’s internal gain structure. It’s part of what makes this synth so versatile. Personally, I have not noticed any tonal difference between a signal with the master at max, and a signal recorded with the master lower, then boosted in the DAW to match the former. The master volume seems pretty linear and unbiased in terms of its effect on tone.
« Last Edit: March 01, 2019, 11:10:10 AM by Zac Kyoti »

Re: P12 response at different master volume levels
« Reply #7 on: March 01, 2019, 09:00:27 PM »
Awesome responses everyone. I agree with the above. There is huge tonal variation in the P12 depending on how you drive it’s internal gain structure. It’s part of what makes this synth so versatile. Personally, I have not noticed any tonal difference between a signal with the master at max, and a signal recorded with the master lower, then boosted in the DAW to match the former. The master volume seems pretty linear and unbiased in terms of its effect on tone.

Ditto.  That's been my experience too.  Also, with the P-08 and Pro 2.  There was a thread talking about how Dave Smith designs his synths with the best performance at max gain on the master volume.  He would even go so far a removing the master volume if he could, but too many people want to have that control for various reasons. 
Jim Thorburn .  Toys-  Dave Smith: Prophet 08;
Pro 2; Prophet 12; EastWest Orchestral soft synths; Yamaha S-90; Yamaha Montage 8, Yamaha DX-7; KARP Odyssey; Ensoniq ESQ-1.  All run through a Sonar DAW with a Tascam DM-24 board.

Re: P12 response at different master volume levels
« Reply #8 on: March 09, 2019, 02:46:54 AM »
Purely anecdotal, but the P12 output seems very clean to me as well. I would agree with the items stated below: internal gain staging is vital in sound design with this synth, but the output stage (negating distortion circuit obviously) does not color the sound noticeably in a nonlinear way. I too would be curious what the DSI engineers would have to say in this regard.

 I would like to add something to the aforementioned comments: I've worked as a live and studio engineer for many years and, in my experience, clean op amps are not standard on all keyboards. As a rule of thumb, I usually start with master volume of the instrument at 70% as that allows headroom at both the instrument's opamp as well as headroom at the mixing console's preamp. This technique will, in most cases, give you the cleanest and most uncolored sound. That being said, I have noticed zero coloration on the P12 at 100% master volume, given that I have headroom at my consoles input stage.
 Cheers.

Re: P12 response at different master volume levels
« Reply #9 on: April 17, 2019, 07:46:32 AM »
Something I hadn't put that much thought in but makes perfect sense. I always adjusted the osc volumes but never put that much thought into the layer volumes. I normally just used it for finer adjustments. Looking forward to seeing how much this affects the timbre

Thank you for the insight