Its been said that the james is incapable of a bad tone. With fendertype stacks the bass and treble knobs mostly just boost, and the mids knob mostly just cuts. There is an inherent mid cut in a fender tone stack and its called a stack because thats what the circuit looks like on the schematic. Tonestack calculator for ios android the amp garage. Connect the output to your speaker cabinet for a neat experience. The james tonestack or passive baxandall is a twoband tone network. On this page i use the 5f6a bassmans tone stack but all the stacks component values can vary in other amps. Whilst i dont know this to be true, its quite possible that baxandalls circuit drew on the earlier, all passive james tone control, that used log pots and asymmetric capacitor values, with a controls flat insertion loss of about 22db. The fendermarshallvox tmb treble mid bass tone stack has been around.
Magnatone used it in a whole series of amps the 260a, m10a, 460, and 480. Yes the baxandall is usually flat with the bass and treble half way. To keep the mathematics from becoming overwhelming, well make a few assumptions. With the controls set to 5, the frequency response is essentially flat, as opposed to a std tmb tonestack, which has a midscoop and bass rolloff with the controls set the same. Download tone stack calculator free duncan amps xtronic.
The circuit discussed here is an example of the baxandall tone control circuit, illustrated in fig. I have lately found that there is a lot of interest in tone control circuits. I dont know if its of any help, but i think old orange guitar amplifiers used to use a baxandall tone stack. Looking at the passive baxandall tone stack, it has just two controls in its classic form, bass and treble. It basically replaces the pots with sliders for values and you can see what playing w the sliders does to the shape of the output. The james tone stack treble control is also like a tweed princeton tone control, whereas the james tone stack bass control is a pot that bypasses either one or the other of the 4n7 caps creating either more of a treble bypass, or alternatively more of a treble bleed, depending on which way you rotate the bass pot. Introducing a mid control element may get you close to what you are looking for, but you need to be careful to select a mid frequency of operation where you want your scoop to be centered, that is. Marshall, mesa, vox and many others use a similar inherent mid cut tone stack.
It does several popular types of tone controls not just the one you were using. The circuit given here can give a maximum cut or boost of around 12 db at 10 khz treble and 50hz bass. Diy audio projects forum baxandall tone control with buffer. From my experience the bass and treble are boost only, so flat is basically zero although putting both to zero gets you basically no output. It cannot function as a coupling cap like the fendermarshallvox tmb tone stack. The next plot below assumes the tone stack is driven by a 12ax7 voltage amplifier with an output impedance of 39k and a followon grid resistor representing an input impedance of 1m. Baxandall tone control circuit bass and treble control.
Tone stack calculator is a 32 bit application, and has not been tested to run under windows 3. Also, i think duncans tone stack calculator has something similar in its presets, the james stack. Has anyone ever done a baxandall tone stack mod on their amp. Its a deceptively simple design, equally versatile and forgiving.
With the tone control adjusted for maximum bass cut r 2. This is a baxandall circuit calculator for an active filter design connecting to an operational amplifier circuit shown above. Nice thing is that it shows what happens if you alter the components. When designing the dds2250v, i had the choice of the traditional fendervox marshall tone stack using bassmidtreble controls, or using a passive version of. First, well assume that the driving circuit has an output impedance of zero. Baxandall analysis electronics forum circuits, projects. Audio input is directly applied to the tone control circuit and then controlled audio signal is amplified by the operational amplifier and output is taken from the pin 6 of opamp. Here is the classic james tone stack as used, for example, in the 120watt orange graphic. Nov 07, 2019 mostly the tbm marshall or fender type tone stacks have a mid scoop that lends itself very nicely to guitars with magnetic pickups. Peter baxandall described his parallel and seriesresonant classd oscillators in 1959 in a paper in the proceedings of the british institute of electrical engineers baxandall, p. Two transistor tone control circuit tone control circuit using ic741 tone control circuit.
This is a very good utility, the most popular control. This is a tone stack collections, the most popular circuits, amps and pedals vox, marshall, fender, etc. This simple tone control circuit is designed based on the famous baxendall tone control circuitry. Mostly the tbm marshall or fender type tone stacks have a mid scoop that lends itself very nicely to guitars with magnetic pickups. The baxandall tone control is nothing new but imho suitable for the chipamps.
This bass and treble controller circuit is based on the classic baxandall tone control circuitry and provides a maximum cut and boost of around 10db at 10khz and 50hz. In comparison, the more popular fender tone stack is more interactive, changing the bass can affect the treble and vice versa. Im not aware of any actual baxandall stacks in guitar ampsthe baxandall circuit is actually an active eq circuit. Bastardized versions can be found in ampeg, orange, tweed fenders, sunn amps and more. New material on the musical instrument amplifier tone stack has been added at the end of this page. The james or passive baxandall treblebass tone stack allows more control with less quirks than the fendermarshallvox tmb tone. Ive read that the circuit looses a lot of the signal, but i dont think thats a problem because the signal can easily be boosted with a preamp or boost pedal. This will give us the possibility to regulate the range of bass and heights at the amps input without too many losses.
Basic theory using 21stcentury technology to design vacuum tube preamps, power amps, and power supplies system design a professional methodology for crafting a complete guitar amplifier circuit simulation modeling vacuum tube guitar amplifiers using spice here is the classic james tone stack as used, for. Apr 19, 2016 here the baxandall tone control circuit is connected at the input of operational amplifier ic 741 this amplifier connected with negative feed back. Jul 16, 20 the tone stack doesnt work like a graphic eq. Also, both bass and treble can be independently adjusted. Why dont more guitar amplifiers use a baxandall tone stack. The free duncan tone stack calculator program is a free, very cool and easy to.
With the bass and treble up above 3, and the mids set to 6. Currently, the pot in the treble spot is the tone control per the original schematics. Baxandall, wireless world, october 1952 operator adjustable equalizers. Transistor q1 bc109 and its associated components r1. It usually drives a tone stack, which would otherwise present quite a heavy load to a normal gain stage and would result in considerable signal attenuation. Jan 21, 2012 this video belongs to page 70 from my book. Duncans tone stack calculator specifically designed for use with electric guitar, this is perhaps the simplest combination of the lowpass and highpass networks shown above. Its beginning to seem as if 23 of the earths surface is covered by water and the remaining is covered with diagrams of tone. However, those accustomed to fender treblemiddlebass controls might find it.
I built the amp on a 5e5a chassis so there are holes there for both. Understanding blackface eq telecaster guitar forum. So the settings on any particular amp will not be the same as what the calculator predicts that you should use. Try just about any ampeg amp to experience a james tone circuit. For guitar work, it is more appropriate to halve the treble point due to the lower frequencies involved. Among those versions using active devices we must make mention of p. Hi check out duncans web site for tone stack calculator. Below is a link to a downloadable amp tone stack calculator app. I encourage anyone interested to download the duncan tonestack calculator, which. The tone stack as it is commonly known is only suitable for guitar or other musical instrument amps. Either way, you can expect a tone stack that behaves as described above. Values can be altered simply by doubleclicking on the component. I understand the baxandall tone stack is popular in hifi system tone controls, though it has been used in some amps over the years better suiited to low gain i amps, i read.
Audio tone control using the tlc074 operational amplifier. If a baxandall tone stack sounded any good, bogner, friedman, cameron, fortin, and everybody else would be doing a baxandall mod and charging big bucks for it. Baxandall calculator this is a baxandall circuit calculator for an active filter design connecting to an operational amplifier circuit shown above. Ive created a crossplatform mobile app called tonestack kit that builds on dave cigna and duncan munros work in duncans tonestack calculator.
The first stage that is built around bc109c transistor acts as a buffer and provides the circuit with a high input impedance at around 250k the gain of the stage is nearly unity. An analysis of the circuit performance does not verify the graphs. Use the james tone stack and play around with the values to get what you want. You cant change the circuit arrangements, but you can change any component value, source and load. Why dont more guitar amplifiers use a baxandall tone.
Whether stacked with various overdrives, fuzzes, or muffs, it can make all of your other pedals sound even better. Its very difficult to know where it came from opinions abound, but proof is hard to come by, but tone stacks are used by most guitar amp manufacturers almost exclusively. It is important to take into account that tone stack calculators like the one above are not going to reflect what is going on in a real amp where the input and output impedance of what the stack is connected to comes into play. Its also been used in some commercial guitar amps, such as the orange 120 mkii. Parametric equalizer improves baxandall tone control. Although it doesnt include baxandall, if you havent come across duncans tone stack calculator i suggest that you download it and have a play. The magic is the 2 band baxandall eq circuit, which offers up a different approach to tone control. Thurmond, new devices for equalization, 52nd convention of the aes, abstracts, vol. In this article we shall analyze the james network also known as the passive baxandall tone control, obtaining its design equations.
The tone stack calculator on the duncan pages demonstrates curves for this. With fendertype stacks the bass and treble knobs mostly just. Baxandall tone control circuit this active baxandall tone and bass control circuit has 12 db boost and cut for frequencies less than 50 hz, and greater than 15 khz. If thats not enough, the rook is one of the most stack friendly drives on the market. The baxandall tone stack is much more powerful and versatile than the fmv tone stack.
Link to the lulu website where you can see it is in. You can interactively see the effects of different types of tonestacks. The lowpass network lower consists of r1c2, and the high pass network upper c1r2. Baxendall tone control circuit electronic circuits and. Anyone wanting to fiddle around with tonestacks, for real or just for fun, simply must download duncans tone stack calculator. This article helps compute the component values required in an active filter such as this. Mojo hand fx rook overdrive w baxandall tone stack. The low output impedance of a cathode follower, however, can drive current into heavy loads more easily. Unlike the fender tone stack you can achieve a mid hump by setting the treble and bass controls low. This works best when the opamp package has fet inputs, as there is no currentcompensating resistor between the noninverting input and ground. It is intended to be of interest to amplifier technicians, amp modifiers, hobbyists and students. Commonly found in hifi designs usually centred around a midrange frequency of 1khz, while most guitar amp tone circuits are centred around a midrange frequency from 300hz to 500hz.
Independent adjustment of bass and treble frequencies in high fidelity audio amplifiers is usually accomplished utilizing specially designed tone control networks. In another thread, audioguru posted an example of a baxandall tone control circuit with bass, midrange and treble controls. Simply click on the appropriate tab to bring up a different schematic. Vacuum tube calculators basic theory using 21stcentury technology to design vacuum tube preamps, power amps, and power supplies system design a professional methodology for crafting a. You may want to check out more software, such as diamond calculator, free investment calculator or gold calculator plat edition demo, which might be. The common filenames for the programs installer are calc. May 15, 2019 the tone stack calculator is designed to help you check out the design and response curves of a variety of tone stacks used in popular guitar amplifiers. I want to calcute center frequency but it is difficulty for me. For hifi use, it is traditional to set the bass turnround point at 100hz, and the treble at 10khz. Peter baxandalls tone control has been mentioned in another thread, so rather than go too far ot there, ive uploaded a zip of my simulations of two versions of it as baxandall in ltspice. There is greater overall attenuation and a slight shift upward in the frequency at which gain is minimum, but the response is not dramatically different.
Fender modern, vox, marshall, james passive predecessor to baxandall, fender e series, steve bench, hiwatt tone stack, and now the big muff tone stack used in fx units. When you remove the circuits ground by pulling the treble knob. The baxandall or james tone stack must have a coupling cap between itself and a tube plate. Simple active filters are used here to build a continuouslyadjustable parametric equalizer having the same general response as the popular baxandall circuit, which uses a switchselectable scheme for bass and treble equalization. It demonstrates typical amp tone stacks and their effect on frequency changeresponse.
Tone stack calculator free download windows version. I find a baxandall circuit in the internet but i dont understand how to calculate center frequency. A 1ma pushpull pot can be used as a raw switch to effectively remove the tone circuit from the amp. The james tonestack or passive baxandall is a twoband tone network popular in hifi, as well as classic ampeg and orange amplifiers. Diy audio projects forum baxandall tone control with. Whilst i dont know this to be true, its quite possible that baxandall s circuit drew on the earlier, all passive james tone control, that used log pots and asymmetric capacitor values, with a controls flat insertion loss of about 22db.
Jun 11, 2014 the audio spectrum of fender, marshall, vox, and james passive baxandall tone stacks utilizing the duncans amp tone stack calculator 6. The guitar sound is then routed thru a baxandall tone stack with bass and treble controls. Also included was a graph of the response of the three controls at full boost, full cut and flat. The tone stack calculator is designed to help you check out the design and response curves of a variety of tone stacks used in popular guitar amplifiers. This allows you to model fender threeknob, vox, marshall, james, eseries, bench, and bigmuff tonestack circuits.
Peter baxandall s tone control has been mentioned in another thread, so rather than go too far ot there, ive uploaded a zip of my simulations of two versions of it as baxandall in ltspice. Download the tone stack calculator and give it a shot. Im thinking about putting a baxandall tone control circuit inside a guitar with a single pickup, so ill have a vol, bass and treble controls. There are versions for these tone controls based only on passive components, such as. It will do all the calculations for you and show graphically what happens. The audio spectrum of fender, marshall, vox, and james passive baxandall tone stacks utilizing the duncans amp tone stack calculator 6. It was used in many hifi amps spanning from the 50s through to today. It is then fed to a preamplifier prior to going into a 14watt audio amplifier. A baxandall tone stack is a simple highlow shelf eq. The first stage that is built around bc109c transistor acts as a buffer and provides the circuit with a high input impedance at around 250k.212 570 1274 24 679 707 565 630 1001 318 1490 1609 340 1594 614 1111 107 192 1029 54 242 1224 1445 294 1110 1093 498 1255 28 969 1086 953 871 822 1624 1619 875 879 245 107 808 30 139 1129 699 870 908