spring cleaning for my signal path

[dagosto]

I grew up during the tube revolution. Everywhere I looked people were sticking tubes or tube emulations into there units, and what for? Everyone wanted to add that tube grit to their digital recordings and make everything nice and "warm." Man, "warm" must have been the most overused term at that time.

I'm not knocking tube warmth, I'm just saying that in my experience most consumer grade tube or tube emulation gear (my studio is full of this junk) ends up just smearing everything out. Phase coherency is not something that is given much thought to in the consumer/prosumer level of audio equipment. Anyways I've found ways to get around most of this by either being easy on the gear or bypassing the tube emulations.

Last big addition that was made to my studio was an Avalon 737sp. It's a great sounding channel. The EQ is beautiful. However I have found that when I use it as a front end I am not always happy with the results. It can be really nice on certain vocals with a really clear mic (a TLM103 in my case) but my tube mic just doesn't work with it. I believe there is just too much coloration on that pre for most applications. I mic up a lot of tube amps, very often heavily saturated and I've gone back to my focusrite Platinum Penta's for most of this stuff. Same deal with percussion.

So this brings me to my point. Guitarist and Bassist are already shelling out thousands to get that nicely smeared distortion that is all the rage with the kids. Why are we spending thousands to "warm things up" further? What is warm enough?

So I've taken this idea and have been applying it to my recordings. I find that when I keep things as clean as possible it is easier to listen to and you can get more percieved volume without loosing all your dynamics. Perhaps this whole obssesion with warmth in digital recording has brought us to the point where contemporary mixing techniques have become a bombardment of peak limiting and a hodgepodge of non-descript square waves interacting at 0dbfs. Although the 737sp is a great channel for vox I think I may need to repace it with something like a DW Fearn or a John Hardy (one tube and one solid-state, both known for being clean, both expensive) in the near future.

[/rant]

[Nubus]

It is strange to me when people say something sounds clean but to me it sounds like tubes working hard. I guess it is people's perception of clean. I don't really think of it as clean. I like to abuse tubes to get an overdriven sound on instruments, and what I think they do inside of mics can be nice to drums and voice but I don't think of it as sounding warmer. I'm not really sure how to use the word warm. Like a wool sweater over the speakers? I'd call that wooly.

[dagosto]

I think most people use the word warm to describe a slightly distorted sound. Tubes add certain hamonics which gives us the sound of tube distortion. Certain distortion sounds warm, others sound harsh.

I guess what I mean by clean is minimal coloration caused by distortion, phase shift, and anomolies in the frequency curve. The main thing I guess is headroom. The more headroom the cleaner and easier to listen to the recording will be. This is another thing that is missing from a lot of prosumer gear. Coloration is usually something that adds frequencies to the signal, adding voltage. This makes it more likely you will top something out causing harshness or clipping. That has been my "philosophy as of late. Do you think this makes any sense?

[Nubus]

Originally Posted by dagosto

I think most people use the word warm to describe a slightly distorted sound.

I'm not so sure about this. It's such a subjective term that a lot of times the meaning ends up lost in translation.

I like the insight into coloration. You mention energy build up. I'd like to think coloration could also be subtraction of certain frequencies due to phase incoherence and or a limited bandwidth.

I don't know about the addition of voltage. Voltage is a potential difference, in the case of A/C with respect to ground. You might be thinking of bias. D/C voltage is directly related to headroom.

[Whoopysnorp]

I'm a little more into a clean sounding mic preamp myself. I don't have anything as high-end as you do, dagosto, but in my apartment I have a VTB1, which I bought because I liked the idea of being able to dial in the 'tube' tone to taste. I use the quotes because being a starved-plate design, it's not really a tube preamp, though it does do a pretty passable tube overdrive sound all things considered. Anyway, I pretty much always have it pegged over to the solid-state side.

[mikegee]

hmmm, this conversation reminds me of my Cubase SX program, which offers tape emulation, which is a synthetic way of making your songs sound more warm than typical digital recordings. it seems to warm up the tone some, you can set it to different amounts of saturation. Anybody else have any experience with this? or similar warmth emulation?

touching on yer original points, i wonder if it even makes sense to combine digital with tube when it comes to recording tracks. maybe they just dont blend well...

[dagosto]

Originally Posted by Nubus

I'm not so sure about this. It's such a subjective term that a lot of times the meaning ends up lost in translation.

I like the insight into coloration. You mention energy build up. I'd like to think coloration could also be subtraction of certain frequencies due to phase incoherence and or a limited bandwidth.

I don't know about the addition of voltage. Voltage is a potential difference, in the case of A/C with respect to ground. You might be thinking of bias. D/C voltage is directly related to headroom.

I agree with your first two points. As per the addition of voltage I was reffering to what tubes usually do which is add harmonics. It has been a while since my last electronic class but isn't amplitude the measure of peak to peak AC voltage? Harmonics have the potential to raise amplitude and as you said decrease as well. I was just bringing this up as a theoretical possibility that I've been messing around with in my head.

[Nubus]

Originally Posted by dagosto

It has been a while since my last electronic class but isn't amplitude the measure of peak to peak AC voltage?

Peak amplitude is measured with respect to ground. I can't recall what you call the measurement from peak to peak, but it is probably called peak to peak amplitude.

Amplitude pertaining to audio is measured using the decibel. Amplitude can be measured in voltage, but you'd have to specify dBV.

I was just thinking you wouldn't say it was adding voltage if you meant that a system added certain frequencies.

[dagosto]

Originally Posted by Nubus

Peak amplitude is measured with respect to ground. I can't recall what you call the measurement from peak to peak, but it is probably called peak to peak amplitude.

Amplitude pertaining to audio is measured using the decibel. Amplitude can be measured in voltage, but you'd have to specify dBV.

I was just thinking you wouldn't say it was adding voltage if you meant that a system added certain frequencies.

Yes, peak volatage is measured from ground but it is an absolute value when you are dealing with AC. 5 volts peak voltage is acually plus or minus 5 volts of AC at the top or botom of its waveform (assuming your wave has a standard period). Peak to peak is the difference between the crest and trough of the waveform. 5 volts peak is actually 10 volts peak to peak. Just wanted to make clear what I ment by that.

As per your second point, in it's electrical form, voltage is the measure of amplitude. If you look at an oscilloscope you are looking at voltage graphed against time. In the air amplitude is measured in a unit of pressure like a Pascal. The Decibel in any form (dbu, dbvu, dbfs) is a ratio derived from a relationship of power. In short the dB is not a unit. It is a number that helps us explain a function. Volts (after being manipulated with othe units and funtions) are one of the units that can be used to get a decibel measurement.

When I spoke of coloration or warmth adding harmonics I was thinking of a wave form on an osciloscpe. If you add any harmonic there could be either constructive or destructive interference between the two sine waves. In the case of constructive interference the peak to peak voltage (or in the air the difference in pressure between the compression and rarefaction of particles) could be raised above the uncolored signal, possibly causing an electronic device to bottom out for a portion of the wave cycle. This is what I am looking to minimize.

[Nubus]

Originally Posted by dagosto

As per your second point, in it's electrical form, voltage is the measure of amplitude.

Voltage is a potential difference. It isn't just the measure of amplitude... there isn't any amplitude unless current is allowed to flow.

Think of the pendulum on an old grandfather clock. The pendulum swings between points A (all the way to the left) and B (all the way to the right). The distance from equilibrium to either A or B is amplitude and; in this analogy, can be thought of as the voltage. Without power to the clock that voltage is still there as the potential difference, but since there is no current the amplitude is zero.