Preamps. I'm skeptical or explain to me what I don't understand.

Discussion in 'Fred's Barcalounge' started by NJDevil, Oct 26, 2021.

  1. NJDevil

    NJDevil Country Gent

    Age:
    48
    Jul 9, 2014
    Commack, NY
    OK. Let me just start out by saying I know what a preamp is, what it does the how it figures into the whole scheme of things from the moment the strings are touched to sound hitting my ears.

    Here is what I am...how should I say it?.....voluntarily fighting what I have found out about "additional ones".

    The additional ones I am referring to are preamps in pedal format. I really like the guys from That Pedal Show on u-tube and really enjoyed the video below. I heard what they were saying, I heard their narrative reflect from the samples...both clean and distortion but I am skeptical. Some questions currently asking....Why not just turn the amp up? What not just use a clean boost like a Vertex SSS or Gladio SC, amongst others? What about dual overdrives like the Protein by Browne Amplification, or just a any tube screamer?

    I am lead to believe that the pedal preamps color the tone to a much different dynamic than my current setup. OK, but that is what pedals are for......some color more than others, where others distort, modulate, and reverberate or just add clean boost and thicken a clean tone......Right?

    So I watched the video, loved the tones but left asking why I need those preamp pedals to get what I heard? I can expand but will leave the question open for those who know more than I do (which usually is everyone!!) and the video below.

     
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  2. NJDevil

    NJDevil Country Gent

    Age:
    48
    Jul 9, 2014
    Commack, NY
    Almost forgot which leads to a bit more confusion I have. The Kingsley site proclaims V1 of the Maiden preamp pedal "The single Tungsol 12ax7 runs at high voltage for a full, rich and dynamic tube sound. The 9VDC power supply (provided) is converted to both 6.3VDC for the tube heaters and 250VDC for the tube plates"

    How can 9V of supplied power be converted to 250V?.....in this case for the tube plates?
     
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  3. Hammerhands

    Hammerhands Country Gent

    Aug 26, 2011
    Winnipeg
    A DC-DC converter will convert 9V to 250V. These are usually switching power supplies that use high frequencies and a tiny transformer.

    They use such convertors in some LED screens.

    You can buy a sealed DC-DC module, or a single chip version. Many of them are unsealed modules.

    https://www.digikey.ca/en/products/detail/xp-power/A03P-12/5873491
     
    Last edited: Oct 26, 2021
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  4. Hammerhands

    Hammerhands Country Gent

    Aug 26, 2011
    Winnipeg
    If you have AC voltage, you can use a bunch of voltage doublers, which just use diodes and capacitors.
     
    Last edited: Oct 26, 2021
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  5. NJDevil

    NJDevil Country Gent

    Age:
    48
    Jul 9, 2014
    Commack, NY
    On a completely different thread a while ago on the TGP(Gear page), the same thing was brought up in a thread about pedals with tubes in them like the Beekeeper and Lightkeeper by the Tubesteader company.

    I'm still having trouble with "how" a preamp pedal can turn an amp into a different beast (if that is what they really do). Then of course there is the preamp in pedal form and then those in the more expensive rack form.

    I know there is a chunk of info that I haven't read or need to be more proactive in it because there certainly is a market for these things. The Edge used the JHS Crayon preamp pedal on more than one U2 tour and used the Boss FA-1 on "The Unforgettable Fire". So the whole "preamp in a pedal"-thing really is amongst an early generation of pedals before effects pedals took off into the market place with the footprint realized today.
     
  6. Hammerhands

    Hammerhands Country Gent

    Aug 26, 2011
    Winnipeg
    Here’s something I learned about the Fender tone-stack. I made a simple chip preamp, I think it was an LM386, then I added a Fender-style tone-stack in-front of it, and it sounded a lot more like something you would use. There was a lot of Fender in the sound. That tone-stack is a huge part of the tone.

    I think that’s the key to many of these pedals, try to make something sound like a tube stage, maybe using a bit of compression and soft clipping distortion, run it through a tone-stack designed after some amp, then maybe through another tube-like stage.
     
    Last edited: Oct 26, 2021
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  7. TV the Wired Turtle

    TV the Wired Turtle Gretschified

    Jul 25, 2009
    Sandy Eggo
    I can answer in one sentence.. its almost impossible to help the listener through video compression, actually sense the dynamic reaction of a good preamp. Let alone feel it..cuz that part has to be experienced tactile-ee-ish :) Tell you what, give me your address and I'll send a loaner atomic brain for you to experience. Even if you dont get all gooey about mine, it is an excellent example of dynamic interplay between a guitarists fingers, strings to amp/speakers.
     
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  8. Synchro

    Synchro The artist formerly known as: Synchro Staff Member

    Jun 2, 2008
    Tucson
    Admin Post
    This is one of the areas which becomes murky, at times. When you strike the string of an electric guitar, the string vibrates in a magnetic field and induces current into the pickup windings. The thing is, that it’s a tiny, tiny trickle of alternating current, probably in the millivolt range.

    So, this tiny little current goes out the output jack and through the patch cable, to the first stage of the amplifier, where it feeds into the grid of the first tube in the amp, which increases the amplitude of the signal, basically a voltage boost. And that boosted signal goes through more stages of the amplifier’s preamp, until it reaches the power amp stage, where the current is increased.

    At any stage, if the input signal is too strong, the tube will be unable to handle that signal and will clip the peaks off of the waveform, which we hear as distortion. So, for instance, if you crank a Deluxe Reverb up to 6-10, you will hear this in action. Back it down below 4 and the distortion will quit happening and you’ll have a clean signal.

    Now that is a very basic way of establishing the environment into which a preamp pedal is placed. A preamp pedal takes the amplitude of that tiny trickle of AC and increases it. If you boost the signal within the limits of the preamp, the output should remain undistorted, but if you crank it beyond those limits, it will clip, and cause distortion. The nature of that distortion would vary, depending upon the nature of the preamp. For example, I have a couple of preamps which are FET (Field Effect Transistor) powered, and if they are cranked high enough to overdrive, the breakup is pleasing and musical. With some types of transistors, the breakup could be harsh, and abrupt.

    But even if the signal leaves the preamp in an unclipped state, that boosted signal could overdrive the front end of an amplifier into distortion. I have a Catalinbread Super Chili Picoso preamp that adds a volume boost, but also makes the sound a pitch more sharp-edged. The amp is closer to natural overdrive when I engage this pedal and it’s sort of an interesting sound. It’s basically clean, but with a harder edge.

    Other preamps may change the sound and behavior of an amp in different ways. They can run the gamut, from a subtle volume boost, to something that drenches the front end of the amp in such a high amplitude signal that the amp’s preamp is completely saturated and breaks up at almost any volume.

    That Boss FA-1 is sort of an unusual design, and probably behaves differently from many other preamps. It looks like a very cool preamp, and from what I have read, I suspect that it’s quite controllable.

    I have an interesting FET preamp in my Stanley Blue Nebula. It’s not meant to operate as a signal boost, so much as it is an elaborate, and very effective way of controlling the signal level coming out of the pedal and because you can control the gain at various stages of the preamp, you can boost some of the desirable overtones. It is not intended to be used for overdrive, but I have inadvertently overdriven it and can report that it’s very, very touch sensitive and elastic, as compared to some preamps.

    One of the murkier areas is the line between a clean boost preamp and an overdrive. A preamp can be used for overdrive, and some of them sound pretty good when used as such, but most overdrive pedals are made to clip the signal, in one fashion or another, while a preamp would most likely pass the signal with little, if any, change to the shape of the waveform.

    I keep an FET based preamp on my Swiss Army Board, where there is abundant room, but it’s rarely used. In my case, the Catalinbread Super Chili Picoso boosts and tends to make things a bit raspier, which is good for a handful of situations, but it’s not an overdrive.

    One thing a preamp can do, is to function as a buffer. If the patch cable is long, the impedance matching provided by virtually any device will help to keep the signal intact through the length of the cable, but this isn’t a matter of signal amplitude, but actually a matter of impedance matching. IMHO, buffers are better just being buffers and not incorporating any boost.
     
  9. Synchro

    Synchro The artist formerly known as: Synchro Staff Member

    Jun 2, 2008
    Tucson
    Admin Post
    Good point, Tavo. The dynamics are something tactile. I have the Blue Nebula, and even though I am not signal boosting with it, there is an added element which affects both the sound and the sensation of playing through that signal chain.
     
  10. Henry

    Henry I Bleed Orange

    Apr 9, 2014
    Petaluma
    For a different tack, temporarily set aside the theory and try some. Either it sounds better to you or it doesn't. Take up Tavo's offer. Or pay for shipping and you can borrow my extra Atomic Brain (actually have 2 at the moment, one being in a mystery brain).

    I actually regularly have 2 preamps active in my chain, the Automatone (which I use as an EQ, overdrive and fuzz) and the Atomic Brain. J think of my pedals more functionally than labelly.:confused:

    And preamp are like many other categories of pedals - there is a wide variation and you may like one and hate others.
     
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  11. oneforsorrow

    oneforsorrow Synchromatic

    814
    May 15, 2020
    Iowa
    This is a fantastic discussion and I hope it evolves further. This topic is very relevant to me right now.

    I just finished mixing a rough cut of a song my wife wrote as part of a songwriting group she's joined to re-ignite her writing. In doing so, I gain staged two signal chains of the same source (her acoustic guitar through a mic and a DI) in drastically different ways. On the mic channel, I ran a lower output ribbon mic (although it's an active ribbon mic -- sE VR2) through a Chandler Little Devil Pre with the gain and output cranked a bit. That fed into the Chandler Little Devil EQ (which may slightly boost the gain although I did attenuate the low end a touch) and from there it hit a Grace Designs compressor with the output boosted a touch. Upon mixing, I applied a Pultec eq plugin which adds a touch of gain and then added another gain stage via a Shadow Hills Mastering plug-in (compressor). The DI ran through a Neve 517 pre but was boosted on the way into Studio One via a UA 610-B plugin and then it also hit both a Pultec eq plugin as well as the Shadow Hills Mastering plugin. Finally, they were summed into a Waves J37 tape emulation and then into a Lurssen Mastering plugin. The only reason I enumerate this endless nerd talk is because aside from my ears telling me that's what I wanted to hear, it also illustrates the lengths we go to in order to achieve what we're after -- chasing that darn sound in our head.

    I'm certain we've all stacked pedals, adjusted our volume/tone knobs on both guitar and amp, tweaked input/output on master volume amps, redirected our speakers accordingly depending on the room, etc. It's all in the interest of achieving a desired sound or result. But I too have this strange hesitance towards preamp pedals. I've been considering an Atomic Brain for a long time but I'm underwhelmed by the demo vids I hear as to whether or not it would best suit my needs/wants. I've also seriously considered the Pettyjohn Lift (or his since retired "Predrive") but again, the demo vids haven't sold me yet. And while I can intellectually grasp the feel vs heard phenomenon, it's so hard to translate that into action. Not to mention how precious few demo vids employ our beloved Gretsch guitars!!!!!! (Forgive the gratuitous punctuation but this is a sore spot for me)

    I think @TV the Wired Turtle and @Henry both offering to ship an Atomic Brain for you to try is inspiring. I would jump on that in a heartbeat. Everyone raves about the Atomic Brain (and the rest of Tavo's line for that matter) but experiencing it firsthand takes all of the guesswork out of the equation. It reminds me of Michael Joly of Oktavamod before he retired the business. He had a set of his modded mics that he would ship around to folks who couldn't afford to buy them. It would allow them to use the mics on their recordings before passing them on to the next person.

    Just thinking out loud here, but wouldn't it be cool if we had a pedal library for GT members where you could contribute a pedal or some cash to help fund the library and get to "check out" the myriad offerings for the mere cost of shipping?

    In any case, I do hope the preamp conversation continues because I am fascinated by the topic. And thank you @Synchro for such a thorough explanation!
     
  12. NJDevil

    NJDevil Country Gent

    Age:
    48
    Jul 9, 2014
    Commack, NY
    Nice Tavo......this is actually a great point as I remember when I used the Mystery Brain a few years ago. I forgot whose guitar I was using but as much as I liked the guitar, it was the sound coming out of the amp. I remember making a comment and the immediate response was to tell me that what I liked so much was not from the amp but it was the affect of the preamp of the Mystery Brain. There was a special "something" that transcends tone....there was a feel to the tone....a piece of magic. To say a lot of good stuff just seemed to bloom is an understatement.

    I remember thinking that it couldn't be the Gretsch I was playing as I knew what it could. Instead, this was an experience that far surpassed any pedals I ever borrowed for gigs or other pedals I tried. A few weeks later, I remember going to Guitar Center to grab the Carbon Copy. I liked it and it is quality for sure and was satisfied enough with my rockabilly playing for some slapback action......but "the feel" from the Brain was missing and then I remembered being told that the Brain was more than just an effects pedal and the sound that turned to feel was the preamp. I walked out of Guitar Center without the Carbon Copy. That is one point that also stuck with me from video I posted of That Pedal Show...the guys were talking about how you feel the preamp.

    I love the effects pedals I've picked up. The Echorec brings the atmosphere/mojo I was looking for....the Ventris has surpassed expectations. Any feeling I get though is from my playing. So yeah, I know exactly what you're talking about but just didn't connect the dots.

    So just like I was watching that video last night vs. playing the equipment from it, I have to accept there is a "something". How and why? Well, I'm reminded of the preamp magic of the Mystery Brain in addition to what the Pedal Show duo was talking about that certainly has a high price line of hardware going strong.

    I know Synchro and others have talked about the value of playing clean. No argument there but in doing so for almost 30 of my 32 years of electric playing, I'm in a new world with toys that is taking my abilities as a guitar player to levels far outside the boundaries of playing clean.
     
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  13. NJDevil

    NJDevil Country Gent

    Age:
    48
    Jul 9, 2014
    Commack, NY
    Playing clean all of those years got me to a level I didn't realize I was at until the last few years of gigging. Now I am experimenting and not afraid to ask questions. When I bought the Echorec, I said I'd still get a Mystery Brain and JR Barnyard. A new venture in playing is taking me away from Rockabilly and my gigging material.

    Budget permitting, 2022 will bring recording gear for a home studio....I'm researching now and the preamp clip took me by surprise. I'm realizing there is a lot that I do not know.....But having fun!!:)
     
  14. NowEarThis

    NowEarThis Gretschie

    Age:
    70
    231
    Jun 23, 2021
    Northern Rivers NSW Australia
    This subject could go on forever and get very technical.
    Suffice to say pre-amps, pedals and what have you, are like paint and brushes to an artist. Some like to draw in pencil, while others will explore the whole colour spectrum. :)
     
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  15. NJDevil

    NJDevil Country Gent

    Age:
    48
    Jul 9, 2014
    Commack, NY
    I told myself last year that getting the Echorec wasn't going to stop me from the Mystery Brain....different beasts. I appreciate the offer Henry but Tavo's post, which I read first, shook out the cobwebs and reminded me that the preamp had some "special sauce" and from the posts here, I can see how just listening to a video clip cannot capture that as a player. I will certainly be getting one.

    I loved what I heard in the video but without "the feel", I was skeptical. Those Kingleys brought a certain dynamic and loved the effects pedals also in the chain. However, I think the price of each is north of $600...probably more so outside of the budget. I also love the music I am creating right now. Ideas are taking shape and expanding my creations with simple loops.

    The Vox Lil' Looper I bought years ago isn't cutting it so I might want to upgrade to the Ditto Plus for loop length and layering......although accelerating the purchase for some recording gear would be ideal.

    Right now I'm just creating and playing a lot. Also still playing my acoustic an hour/day so having fun from all directions.
     
    Last edited: Oct 27, 2021
  16. NJDevil

    NJDevil Country Gent

    Age:
    48
    Jul 9, 2014
    Commack, NY
    Agreed. I think "test-driving" these more expensive preamps is the only route to go considering the cost. The equipment I saw in the videos were fun to see, hear and question. I have to remember I stumbled upon it vs. identifying it as a tool to get me to a place that I already had in the plan.
     
  17. NowEarThis

    NowEarThis Gretschie

    Age:
    70
    231
    Jun 23, 2021
    Northern Rivers NSW Australia
    Exactly. I wouldn’t lash out and buy something without test driving it first, just like I love hot chillies… but do you?
     
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  18. ruger9

    ruger9 Country Gent

    Nov 1, 2008
    NJ
    Toe-MAY-toe/Toe-MAH-toe. IMO, "preamp" and "overdrive" are used interchangeably these days. AND doing what you mention- running an SSS (clean boost) into the front of an amp IS using it as a preamp; it is not creating distortion itself: it is causing the V1 tube stage to distort due to higher input signal. That seems to jive with what Tavo has said, having owned several of his preamps over the years, they don't really create their own distortion as much as send a much louder signal into the amp to make the amp sound like it's turned up more. To me, that is a "preamp".

    A tube screamer- which does create it's own distortion- is an OD pedal. However.

    ODs can also be used as preamps.... SRV famously had the drive way DOWN and the level way UP on his tube screamers, which is using that pedal more like a preamp, and less like a dirt box. Shades of dirt, if you will. There is an overlapping area amongst:
    -clean boost vs overdrive
    -drive level vs vol level
    -how hot the amp is running to begin with
    -not to mention how hot are your pickups (big difference between a Fender strat pickup and a Duncan JB)

    In general, don't fret too much about the technicalities/descriptions; just plug in, turn knobs until you get what you want. It's just music, you aren't building a spacecraft that has people's lives inside of it on top of a controlled explosion LOL.

    But I will repeat- what Tavo was talking about, with the touch sensitivity stuff, that's the biggest difference *FOR ME* between what *I* call a "preamp" and a "drive". For me, if I want that touch sensitivity with a certain level of dirt, I turn up the amp. Or use an OD on a low setting. I have not had much luck with clean boosts, except to boost an already-dirty amp, using it for more compression more than anything. But a clean boost into a clean amp is not something that's ever worked for me, I prefer a drive set low for that.

    Disclaimer:
    The way I run my amps, if I've got RNR level dirt, it's coming from the amp, not a pedal. I'm a BIG fan of amp dirt, not pedal dirt, in general. There are exceptions, but I am not a "clean-amp-pedal-platform" guy, when I'm playing rock, my dirt is coming from the amp (Fender Supersonic, Bad Cat Hot Cat, Roland Blues Cube Artist w/Ultimate Blues tone capsule).
    I DO run low-gainers in front of clean amps (like my PRRI) when I want to get just a little grit, like simulating a tube amp that's turned up some.... that's actually where I live most of the time. Sometimes I get there with a drive, sometimes I turn the amp up and use an attenuator, and sometimes a master volumes works, but not often. Even really good MV seem to choke touch sensitivity.... but then so do many attenuators. Sigh.

    So now that I've talked myself in a circle, I hope I didn't confuse you even more! LOL

    PS: I don't think the term "preamp" has to at all imply the pedal is re-voicing the amp to sound like something else. Technically, the V1 tube in your amps IS the "preamp". Preamp is all about signal level. Getting the level up enough to send it thru a tone stack. Some preamps do have their own tone stack. But a one-knob clean boost IS a preamp, IMO.
     
  19. stevo

    stevo Friend of Fred

    May 1, 2012
    Atlanta
    It changes your tone...intentionally. A good preamp adds dynamics and at times a tone shift that you may not get from your amp alone. If you're happy with your tone as is, you don't need a preamp. But if you play through one and find that when you dig in, those bass notes thump or you get a stronger mid range push when you pick harder - then maybe you want one. It's all about the non-linearity and pushing the front end of your amp.

    Your amp of course has a preamp in it and it's got it's own thing happening. That could be enough for you. But changing the tone and dynamics and/or increasing the signal before your amp is essentially dressing up your guitar's signal a bit before it hits your guitar amp. Not everyone likes the result.

    But quite a few professionals use them and when chasing down a certain guitarists tone, it's often that preamp that is overlooked.
     
    Last edited: Oct 27, 2021
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  20. stevo

    stevo Friend of Fred

    May 1, 2012
    Atlanta
    So when you crank a Deluxe Reverb to 6-10, that's preamp distortion? I always thought it was mostly power amp distortion.
     
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