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  • Tube Pre or Just Mixer?

    My question is simply this... Is having a TUBE PRE going to improve my overall sound quality over what I already have?

    I am not new to recording or sound engineering, but I just need some help to try and improve the quality of sound. Here's an example:

    Guitar Cab Miked with an SM57 into a Mackie 24.8 board. As it is now, from the Mackie to the interface into ProTools...

    From there I was going to add a Tube Pre from the output of the Mackie before the interface to warm up the tone. My reason being is so instead of un-hooking the cable from the back of the tube pre, I could just un-hook it from the mixer itself and re-route it that way. Is this the correct signal path?

    I would use the tube pre for just about everything I record. Drum Overheads, Bass, Guitar Cabs, and Vocals. Am I going to get better results from the Tube pre or should I just stick to using the pre's in my Mackie 24.8?

    Sorry if this is alittle confusing, thanks for reading, and hopefully offering some insight...

  • #2

    RedPandaRAMPAGE wrote:

    My question is simply this... Is having a TUBE PRE going to improve my overall sound quality over what I already have?

    In general yes

    tell us what tube device it is


    RedPandaRAMPAGE wrote:

    Guitar Cab Miked with an SM57 into a Mackie 24.8 board. As it is now, from the Mackie to the interface into ProTools...

    get rid of the Mackie, this is a terrible mixer, bad sonics


    your audio interface has no mic pre,

    or do you need more mics then your interface has mic pre?


    • WRGKMC
      WRGKMC commented
      Editing a comment

      No. It purely depends On the quality of the preamp.

      There are great solid state and tube preamp circuits and there are garbage circuits in both categories. Neither or either can be superior for specific applications ore general recording.

      With Tube preamps, there aren't (ore weren't) any made for under $300 that is a high voltage design. All you can find is the low voltage designs that use preamp tubes to color the sound. They do not preamplify the signal and at best provide less than a 1:1 amplification ratio. The voltage is low in these circuits and therefore the plate emission suffers from electron collision. There's not a large enough cloud of electrons streaming through then and the minimal electron flow and electron collision adds more noise than it does any kind of quality. The best these kinds of designs can do is add some distortion and darkness to the signal. They are by no means good designs. Most are just supplements to a solid state circuit intended to deceive the buyer into thinking the preamp has vintage tone. Its a deceitful way of making sales in my book and unless you compare the real deal to these starved circuit designs you wont realize the big difference between them. Difference.


       You want real tube tone you need a high voltage design that overcomes the ambient noise levels and operate under proper bias conditions in a class A or AB design. The components need to be high quality and the tubes require a transformer to provide a 12v heater (preferably DC to minimize hum) and up to 270Vdc bias. This is low current voltage but the voltage determines the amplification factor/gain of the circuit.

      Older circuits also used a tube vs. solid state rectifier to provide the conversion of AC to DC voltage. These kinds of circuits are known for their sag when the preamp/power amp are taxed with strong transients. This sag is part of the key to good tube tone. It compresses the signal to reduce transients while faithfully reproducing the harmonics in a musical manor.

      I'm not over emphasizing how good tubes sound. Having repaired musical gear since the 60's I've seen enough budget built garbage in all categories including tubes to know that even a mediocre solid state circuit can blow away a bad tube design.

      As far as mixers as a preamp, there is allot of misunderstanding. Many of your mixers aren't designed for recording. They are designed for live public address designed to drive a power amp and loud speakers. They contain filter circuits the rob the mic of frequencies that can cause boom, feedback etc and produce a natural tone in a theatre environment. A recording console used in analog recording was a different animal. It used the highest quality preamps designed to capture the entire frequency spectrum from 20~20Khz, and the EQ circuits, often times passive were used to EQ the full frequency spectrum without robbing frequencies or adding noise. Many of the pro consoles were hand built by engineers and tweaked for optimal performance. EQing the mic was done in a way that minimized the saturated of the signal on the tape and giving the best results. Tape has frequency and signal strength limitations. If the source contained frequencies that were too strong to be faithfully recorded, those frequencies were attenuated prior to being placed on tape. Tape is a soft medium that can be pushed into saturation in an artistic manor as well. Its compression and saturation characteristics are what required a deeper understanding of how far you could push the medium to obtain novel results.   

      Digital recording has made mixers obsolete. The matter here is the green technician not understanding the differences between analog applications and what's available for recording. A musicians vision of what a studio costs of is a big studio console and therefore to get great sound a Mixer is what's needed to get that professional sound.

      That's old news and not the reality any more when it comes to getting good digital recording. The dynamic range of the medium is so great there is no reason to pre filter the mic signal and the entire frequency spectrum of the mic can be faithfully stored without distortion even with extreme transients. Therefore no mixer is needed. All the transient shaping and frequency filtering can be done in the box mixing.

       The goal in digital recording is to capture everything the mic senses, both the good and bad and filter it out later mixing. There is no reason to use a mixer other than to combine several mics into the same channel or provide phantom power. Most of the analog mixers aren't very good to begin with and will degrade the signal quality. Even if the mixer is good, it still has to pass through some of the interfaces preamp circuitry which bottlenecks any quality improvement the mixer or preamp provides. The best it can do is provide a different tone and/or maximize the interfaces preamp efficiency.

      I find using different mics does that better than trying to EQ a mic to do something it can't. Garbage in garbage out is the old axiom that applies here. If the interface has poor converters and lacking preamp, there's nothing you're going to place before it that's actually going to improve the results. The best you may do is fool yourself into thinking its better, which makes your artistic ability expand to mix better with what you have.

      Even if you only have one or two interface inputs, multitracking with those inputs eliminates the need for a mixer. If more simulations inputs are needed the cost of multichannel interfaces have never been lower. Save the expense spent on a mixer that gets you noplace and buy an interface with more channels. Problem solved.

      If an interface has only line level inputs for example or the interface preamps can be bypassed, then you can substitute the first few stages of mic amplification with a different preamp including Tube, solid state or the solid state preamp section of a mixer. Some prefer to do this. It may be they feel more comfortable pushing knobs or really like the tone of the board, but even there, you can buy a midi controller that will give you hands on control. You can purchase 8 channel controller like the korg Mini as low as $50 now so using a mixer to accomplish manual control isn't even a factor now.

      There are some other notable reasons to use external preamplification. Many interfaces have a digital SPDIF input that bypasses the interfaces preamp and converters. They make high quality preamps with built in converters that can be connected to the interface and provide the signal quality the interface lacks. Another option is to purchase a second high quality interface with maybe a single or dual channel that's used for say vocal work where you want stellar quality. You simply switch over to tracking with it when you record.

      There is also another option that's gaining acceptance in recording that may satisfy those who want the hands on experience, and those are the newer digital mixers available. Digital mixers can record directly to a computer or work as a stand alone. They can also work as an analog PA mixer so an individual who records and performs doesn't require a full analog and digital recording setup to do both. Allot of cash can be saved and there's not a huge gear related learning curve to master. Just set the channels for a good live performance and press record. Then mix at your leisure connected to some high quality monitors.  


  • #3

    it's a great option/colour to have

    i use a universal audio solo 610 for some stuff and love it... yet i don't like it for other applications... it works better with some mic's than others

    there are wonderful tube and wonderful solid state pres out there

    if it were me, i'd be more likely to either go straight to the interface with the new pre or go to the line input of your mackie with the mackie's pre gain all the way down... or (i'm not 100% sure you can do this with the mackie) go straight to the insert point to bypass the mackies pre altogether


    • WRGKMC
      WRGKMC commented
      Editing a comment

      ^^^ The universal audio solo 610 is a real tube preamp consisting of a high voltage Class A preamp. Its not what many are led to believe they are buying when they purchase a cheaper Tube preamp with a starved circuit design. They may add some color, but not all color is good, and I've yet to find a starved tube circuit design that comes anywhere close to a real tube design. The solid state portion may be good, but that's not the same as a tube preamp with an actual high voltage transformer to supply the plate circuit.