Cathode Follower Headroom

The working horse in the HotFET Pre is the high frequency J-FET amplifier J310 (). We can therefore choose any bias point that lies on the 2. (Similar to an NOS 5751 in gain without the price tag). The cathode follower circuits used on those two tube positions will degrade the preamp tubes at a faster rate than the other tube positions. The DC current load on the power supply is 0. It contributes probably the largest part of the improvement over the previous versions. As with the Ear+ HD, changes in the driver tube(s) will. The stack is also bypassable by a push/pull DPDT switch – without the tone stack it’s exactly like Revision 1a. Shop CM12se advanced audio microphone online at just $795. It was still nasty loud but the clean headroom was vastly increased. The choke loaded cathode follower. Start Free Trial Cancel anytime. Add a second gain stage, an input transformer and phantom power to make a mic preamp. As shown, with a typical guitar input, it is possible to get a very fat overdrive sound by winding up the volume, and then setting the master for a suitable level. That is the input is the grid, and 2 outputs. The ECC88 is a winner in this application because of its plate voltage requirements: less than half what is needed for the 6SN7. but for the kindness of strangers (angels part two) or headroom with just 30 volts B+. It is a bigger sounding, louder version of the London in some respects, endowed with great headroom and presence. The other problem was that the cathode follower circuit was flaky. triode circuits (no cathode followers) and ultra-high quality (If not esoteric) components. ALPS audiophile-grade balance and motorized VOLUME pots. The cathode follower is a very fast transient response circuit with nearly infinite headroom that is almost impossible to clip. We began this series with a basic tutorial on electricity, then moved on through passive components to tubes. I recently fitted the power stage of my Fender Hot Rod Deluxe with a pair of Ruby 6L6GCMSTR tubes. (Typically, a high end component will have a 1 or 2dB gain in their buffer circuits [set up typically as cathode followers in a tube type component] - simply stating there is an active component in line and there can be no true "0" gain stage when active components are in line. The first leg's output is DC coupled (no coupling capacitor) into a second leg (Fig. It can easily achieve 30kHz bandwidth. This combination, done with outstanding multiple regulated power supplies, provides the amazing dynamic range, transparency, and load drive capacity that we demand. I could get it working well, and it would rarely go more than a few weeks before something else crapped out. including the ground. The 460's capsule is a common 32mm K67 type, found in nearly every inexpensive large-diaphragm condenser ever made. 6V - we can use either a 6SN7 (6Vdc) , 12SN7 (12Vdc) or even the 8SN7 (on 6Vdc-starved mode). (1mA cannot drive 600pF!) Preamps with 12AU7 cathode-followers aren't much better, sounding very "tubey," rolled-off, and old-fashioned. Fender Amp Preamp Tube Layout and recommendations. 45mm (IEC 67) while the B9a is just 11. The cathode follower driver tube in the poweramp, which widely used in HiFi and Bass amps, ensures the crystal clean sound even on maximum volume. While discussing mods to the R-390 in the communications portion of the forum the discussion of audio quality came up and it was mentioned that I could get better quality if I replaced the first audio transformer with the cathode follower circuit the R-390A uses. I'm now seeing about 195 volts on the first stage, and 205 on the second - right in the sweet spot for good gain and headroom. One way to understand this is to realize that the tube can be presented works as a ground-grid amplifier here, with input signal (ripple) fed into the cathode. A little more voltage will increase both gain and headroom. The amp sounded better. In the TM20, you have a Driver and Cathode Follower, while the Phase Splitter is solid state. Dual channel bass/guitar blackface-style 1U preamp with transformer balanced low impedance outputs; In 2004, I built my own adaptation of an Alembic F-2B dual channel blackface-style bass preamp. It's basically me publicly taking notes on things I found to be interesting, or just wanted handy for quick reference. The Mark IV version ups the EG stage from a single Tone control to a full complement of Treble, Middle and Bass in a cathode-follower circuit derived from the tweed Fender Bassman, while still including. 5V peak (+0. The result is a clean, high headroom boost that adds a lot of “shine” to the guitar at lower boost settings and dynamic, sparkling overdrive at high boost settings. The amplifier used a 5Y3 rectifier tube, while the preamp section was made up of a single metal envelope 6SL7 or a 6SJ7. triode circuits (no cathode followers) and ultra-high quality (If not esoteric) components. They make some great sounding and beautifully build amps, not to mention the way they look!. This combination, done with outstanding multiple regulated power supplies, provides the amazing dynamic range, transparency, and load drive capacity that we demand. Hook's "thing" is that it's basically a JCM800 with the cathode follower replaced by a mu-follower. Cathode Bias Class A Push/Pull Output Standard Speaker; American Made 12″ Eminence, Jensen Alinco Tubes: 1-5Y3, 2-6V6, 2-12AX7,1-6SQ7, 2-5879 Breaks up almost immediately, especially with humbuckers. at a quiescent current of 3 mA triode and 414VDC. But the Cathode Follower does much more than feed the tone stack. The audio is fed via potentiometer to the first half of a dual triode tube (12AX7 recommended) configured as a cathode follower. Carvin CTM100 Mods. That's local feedback to the tune of about 15 dB which linearizes the compound amplifier and reduces output impedance to around 400 ohms. The 2 6922s on the side are a bit idiosyncratic. Drawback is that pot (or MBB rotary switch) is referenced to a relatively high voltage, but at least it'll work. You will recognize some started up before you were born but you used them. You can use this as a guide to how to design cathode followers for low impedance loads. If a controller is used, or an emitter follower, or a cathode follower, the impedance mismatch can probably be overcome however. 3 Intermediary Production. The transformer isn't cheap but you can't cut costs on this if you're looking to implement a high-quality amp for your headphones. The DC current load on the power supply is 0. The BaconBits utilizes an input buffer which feeds into a negative feedback gain stage. One output stage features its own cathode follower which adds a subtle widening effect and an extra dimension to the sound, even when operating in mono. The anode/plate follower circuit is based on the grounded-cathode amplifier and its closest solid-state analogy is the inverting OpAmp circuit. I replaced the output transformer with a choke. The tube stage in the VTDI will enhance the sound of whatever stage amplifier you use. Exponential Current Change Chart; Oct. This topology is designed to provide a low impedance source to the following equalizer section at a gain of approximately 1. The Tung Sol 12AX7 is warm and big musically. Increase cathode resistor value = more head room Decrease cathode resistor value = more gain For Example: a 100k/ 1. In many cases, cathode followers are simply directly connected to the anode circuit of the preceding stage as shown in B). With the 2nd half of the 6SL7 being used as a follower-buffer, the front end can run very linear. To this end, along with the gain stage of the VTL 2. This drive voltage can be provided easily. Common manufacture types typically varied quite widely on noise, something about variable quality of the cathode interface (metal to oxide, and oxide to oxide). But the Cathode Follower does much more than feed the tone stack. The load Rload for this set is 600 Ohm. The lone transistor is an emitter follower, and maintains a low output impedance after the master volume control. Even 600Ω are not easy to drive by valve circuits such as White Cathode Followers and SRPPs. This combination, done with outstanding multiple regulated power supplies, provides the amazing dynamic range, transparency, and load drive capacity that we demand. Dual channel bass/guitar blackface-style 1U preamp with transformer balanced low impedance outputs; In 2004, I built my own adaptation of an Alembic F-2B dual channel blackface-style bass preamp. It has Edcor input transformers and Jensen in oil caps at the output. Going to 2. I was looking at a schematic last night which is the same as what I would like to build but it used an el84 as a cathode follower. I run the stock values, so 1. Loosely based on the 18 watt. This T1610 tube itself is a thing to behold. next stage, "simple triode amplifiersthey have low enough impedance to drive the output stage directly. Another mod to increase the clean headroom would be to remove one (or both) cathode bypass caps; I am reluctant to do this because: a) I really like the tone right now. Of course it is equally well usable LC or RC coupled or as a cathode follower. The Chinese stock tubes (12AX7B marked China with a 9 in ink on the bottom) in amps are supposedly better than they were years ago, and did seem a bit better than previous stock tubes, but they still had a rather sterile clean channel and some fizzy (in a bad way) highs on the distortion channel. I have been a nurse since 1997. This utility finds unscrambled words from anagram or Jumble(R) input letters, crosswword solution words from missing letter patterns, Scrabble(R), Jumble, Jamble, or Literati words that can be made from input letters, and verifies valid words existence. Net wrapper for OpenCV Brought to you by: canming. The 6L6's are currently cathode biased with a common resistor. First SRV used heavy gauge strings (13s) tuned down to Eb, grab an Ibanez tubescreamer and old Blackface Fender Amp turned up between 7 and 10 and you're halfway there. Rated 5 / 5 Lee Jackson XLS-1000 Not a NOS tube. For the past few years, Mesa has been using two types of 12AX7 tubes: ones originating in Russia (Sovtek EH), and ones originating in China. Loosely based on the 18 watt. However they had a 475 or 511 ohm resistor in series with the output capacitor. You will recognize some started up before you were born but you used them. 0012RLOAD V(0-Peak) = 0. It is generally used because it has a low output resistance. It is tonally accurate, open, dynamic and dead quiet. Noble Intro by Dick Olsher: Jon Noble returns to these pages with a DIY project that should be of great interest to anyone desperately seeking a fab sounding tube buffer stage. Basic cathode follower with a choke for the cathode resistor. I'm now seeing about 195 volts on the first stage, and 205 on the second - right in the sweet spot for good gain and headroom. The downside is that the 6AS7 needs quite a bit of juice to get glowing, 2. The sound of many great Rock ‘n’ Roll players such as Ritchie Valens, Buddy Holly and Chuck Berry were defined by amps with cathode follower preamp stages. It is much like the 6505+, the difference being the 6534 has EL34 power tubes instead of the 6L6. It also excels at the more common applications for small diaphragm, vacuum tube condenser microphones such as acoustic instruments, cymbals, stereo. brown_freq worrisome worry worry-worryin worrying worse worsened worsens worship worshiped worshipful worshiping worshipped worshippers worshipping worst worst-marked. is a 12 watt push pull EL84 based amp with a cathode follower Marshall style tonestack. Built on the newly designed silver. But new production KT66s, both Chinese and Russian, has serious problems with high screens voltages (anything above 520-530V is risky). I prefer the AC-20 because it doesn't have a cathode follower so doesn't suffer from these problems. Specifications. Tip 77 (September 2011) To CF or Not to CF (cathode follower), that was the question - building a 12B4 zero-gain DAC out to line input buffer stage - J. It is in fact one section of the 6SN7, with both the grid and the plate on the top, with caps. In the case of concertina/cathodyne phase inverter, the cathode is also raised quiet high and one has a similar problem, but with a long tailed pair P. There is a breathtaking degree of ignorance out there over what electric power even is, let alone the factors involve with its generation, transmission, switching and distribution. Even 600Ω are not easy to drive by valve circuits such as White Cathode Followers and SRPPs. The Bassman cathode follower has according to the schematic, 215 Vollts on the cathode, minus your 6. For more clean headroom in your amp, order this tube with the low gain option at no extra cost. A FDP'er has a 4x10 Bandmaster he made. Max Headroom by Bryan Talbot (1) May 1978 (1) May is British Hooligans month (1) May is Ghetto Action Month ! (1) Maybe by Thom Pace (1) Maynard's House (1) Me and Joe Priest (1) Mechanismo (1) Mel Ramos RIP (1) Meltdown Man (1) Meltdown: A Race Against Disaster (1) Men Like Rats (1) Men of the Legion Part One (1) Men of the Legion Part Two (1) Merlin by John Buscema (1). I also swapped the cathode follower for an AX7 & it sounded straight up metal, but, the amp lost it's character. regarding headroom of both cathode follower vs common cathode and tube vs solid state: what exactly would you define as headroom here? Onset of distortion at. Cool White-follower output stage provides low 50 Ohm output impedance. ) make use of a cathode follower after the tone stack. Finally there is an ALPS Black Beauty volume potentiometer. The Bassman has a holdover from the more aggressive tweed days, a cathode-follower section, giving it a noticeable "ummpphh!" and ability to overdrive and get a bit of a Tweed/Marshall level of preamp overdrive. It can put out up to 50VRMS into high impedance loads (over 75k). The cathodyne phase inverter's main downside (w. It is around 13 inches tall (presumably to accommodate the parallel triode elements mentioned above) and is capable of putting out up to 50 watts of pure, single-ended class-A power. a unity-gain buffer (another cathode-follower) which drives a flip-flop, V155 (in the form of an emitter-coupled MMV). Normally the tone of the amp usually shifts when it is time to replace the two tubes. This lead to his use of an output transformer in the Tuba design. Because the earliest tube guitar amps from the 1950s weren't intended to overdrive (though it wouldn't be long before rock 'n' roll pioneers harnessed the glorious sound), the negativefeedback circuit was implemented as a way to reduce distortion. The original designs used filters designed around valve cathode followers. I gave a full review of the Ruby tubes in an earlier blog post. The circuit uses no negative feedback for more natural tonality. 5 mH RF choke. It is a bigger sounding, louder version of the London in some respects, endowed with great headroom and presence. Marshall Class 5 Mods. he SVT's preamp uses the 12DW7 (half 12AX7, half 12AU7) with the "12AX7" side as a gain stage and the "12AU7" side as a cathode follower. Avoid these in high voltage cathode follower (CF)spots. Tallackson FEBRUARY 1968. And when the pedals are off, you get an amp that’s clean and loud, yet warm and rich in overtones. Bring it on. From a linage of successful microphone designs by David Royer, the MA-100SP's cathode follower circuitry provides ample headroom for high SPL applications such as drums and guitar amplifiers. 1 Follower Tetrodes, Beam-Tetrodes and Pentodes Headroom Tone Controls and Filters. 047 uF coupling cap from the plate of the second half of the 'AX7 to the grid of the 6C4 with a 470 k grid resistor to ground, a 1. It has unity gain and is intended to plug "thru" to your stage amplifier. This is much better than a boring plain ol' cathode follower. The GEMTONE JR. My earliest idea had been to use one 6SL7 per channel in long tail pair but people on other forums warned about them crapping out if the 6F6's hit positive bias. Emitter and Cathode followers have a gain of just under one or less. Six 12AX7s give this amp a lush reverb along with a cathode follower tube that extends the punch and adds an immediacy to the feel as well as headroom and clarity. To my ears, the Super II sonics are difficult to distinguish from those of the previous models without setting up a careful A-B test situation. We have multiple mod options for this mic, both sonic and cosmetic. 5v although the 12ax7 srpp stage was directly connected to the grid of el84. The design simply comprises a filter buffered by a follower. a MOSFET source follower for current gain (with a LM317 voltage regulator IC configured as a constant current source). #1: Capsule Replacement. Its input signal gets inverted the output; the input impedance equals the value of R1; and resistors R1 & R2 set the gain, where. The bias of the cathode follower also sets the bias for the 6550's. On the original machine the valves were only just able to drive the LCR, so headroom was limited as was channel matching. Thanks to Tim’s suggestion to implement Allen Wright’s Super Linear Cathode Follower (SLCF) which forces the valve to operate in constant voltage (in addition to the constant current) by bootstrapping the cathode to the anode using an extra follower, distortion is reduced further. If a controller is used, or an emitter follower, or a cathode follower, the impedance mismatch can probably be overcome however. If you intend to retain the cathode follower , try a CCS load on this also Al. The cathode follower is a long-used method of driving high impedance circuits in guitar amps, usually tonestacks or FX Loops, and the fairly rare oddball reverb circuit. In addition, the DC-Coupled cathode follower can also be used to produce a unique compressive quality, and is to be found in most of the classic amp designs. Remembers this amp and the story behind it. The EL84s need less drive than EL34s so the TMB stage adds unnecessary gain IMO and was hard to control. They had a big resistor on the cathode follower and lacked headroom and balls, they also had the low B+ of 370vdc that made them brown out quite quickly. At first, I used a power mosfet to do the job. Foot switchable FET and tone stack BYPASS control * TREBLE, MIDDLE and BASS tone stack controls * 7 position HIGH and LOW filter switches * Reverb SEND and RETURN controls * Presence. Note: Part 1 is here, part 2 is here, part 3 is here, part 4 is here and part 5 is here. Taking him up, I ordered the components to add another gain stage and a cathode follower onto the circuit. This is a simple viable option for increasing clean headroom in many amps that use DCCF circuits (the many derivatives of the 5F6A Bassman). It's just a different way of biasing the PI stage. The GEMTONE JR. And when the pedals are off, you get an amp that’s clean and loud, yet warm and rich in overtones. Finally there is an ALPS Black Beauty volume potentiometer. Filament supply floated 80V above chassis ground for quieter operation and longer tube life. Again, the active load V2b loads the cathode follower V2a with a copy of itself, reflecting nonlinearities. Emitter and Cathode followers have a gain of just under one or less. with cathode-follower and "Bass and Treble Tone-Control". Featuring 2 x 10"speakers and switchable wattages from 7 all the way up to 30 watts, this amp provides everything you'd need to from the bedroom all the way to the stage!. The Russian (Sovtek) tube is NOT reliable as a cathode follower. They recommend using either low plate resistance, low mu triodes like 6CK4, or use the pentode as a cathode follower to drive the primary of the driver transformer. Cathode follower for the tone stack This doesn’t sound like much of a plan at this point but I promise you that all these problems can be overcome with a little thought and a couple of tricks. First SRV used heavy gauge strings (13s) tuned down to Eb, grab an Ibanez tubescreamer and old Blackface Fender Amp turned up between 7 and 10 and you're halfway there. The Cathode Follower supplies a low impedance signal to the tone stack to keep the tone controls from affecting the amp's output volume too much. From my experience with building similar circuits, the cathode follower should be able to drive each individual grid to 160 V P-P, so there should be ample drive as the 811A spec is for 130V "grid-to-grid," or approx. Most tube headphone amplifiers use cathode followers in some form or another. Infinite sustain, that could normally be produced by an overdriven amp on full blast. Roundup: Four New 50-Watt Tube Heads Reviewed The 50-watt head remains a popular workhorse for guitarists who require the kind of power necessary to take it to a larger stage, while also valuing the headroom and full-throated voice that only large output tubes and big iron deliver. Power came from four low noise shunt voltage regulators and inductors for the RIAA network were provided by Jonathan. The audio stage is all tube, using 12AT7 tubes for gain and 12AU7 tubes as cathode followers. I would suggest a 10 Ohm resistor in each cathode leg of these in order to measure the current and ad a tiny bit of local feedback, I am also very happy with the damping control. Running an 18V supply, self biasing the gate at -1. The cathode follower is an excellent buffer stage for driving a tone stack or effects loop, or any circuit which would otherwise present a heavy load to a "normal" stage. Then, it will start clipping/compressing and reduce your gain. The difference is that the 2nd triode is configured in grounded grid mode. A crossword puzzle generator that creates valid crossword puzzle configurations from the command line. In the tube era you not only needed two tubes but an impedance matching transformer as well and output impedance was still high. The stack is also bypassable by a push/pull DPDT switch – without the tone stack it’s exactly like Revision 1a. That's local feeback to the tune of about 15 dB which linearizes the compound amplifier and reduces output impedance to around 400 ohms. Octal valves (so called for their 8 pins) are much larger than the B9a equivalents. The gain of the second voltage amplifier made of two E80L's is 105 times. Bring it on. attractive arrangement would be to convert the cathode follower section of a Foreplay III pre-amp to the high-pass filter, and add an auxiliary low-pass function in solid state form for the subwoofer. Increasing the cathode voltage draws more current through the bias and tail resistors. The lone transistor is an emitter follower, and maintains a low output impedance after the master volume control. A JFET follower also has a high input impedance, making it an excellent input stage. It is greater at 82Hz. It is almost like a 47K loaded single tube and data sheet shows that we can expect very low distortion. Drawing on its infamous heritage of blowing the faces off the world with its unmistakeable sound and looks, Orange now bring us the Orange Rocker 32 - a 30 Watt Stereo Tube Combo. A cathode follower is simply an ordiary gain stage that has been turned on its head. 56K has less gain that 68K and the maximum 'gain' is 100K. In all honesty, this is difficult load for most tube preamps, with 12AX7 cathode-follower preamps falling down the worst. In the TM20, you have a Driver and Cathode Follower, while the Phase Splitter is solid state. HI-FI quality 3D sound and great dynamics, headroom and extreme sensitivity make the Custom Clean unique. The shunt regulator is a superior power supply, more stable (especially at lower frequencies) and more linear. Instead, know that the gain will be somewhat less than 1, so focus instead on the output signal, as implied by the plate voltage axis. The cathode follower's lower output impedance increases the transient response, the damping factor and the lower 5:1 ratio will provide 6db more output. This topology is designed to provide a low impedance source to the following equalizer section at a gain of approximately 1. First, an introduction. The cathodyne phase inverter's main downside (w. amp, or with tube driven effects you don't need (maybe tremolo, or reverb), you can steal a tube from these circuits, and use them for a gain boost. The GEMTONE JR. Common manufacture types typically varied quite widely on noise, something about variable quality of the cathode interface (metal to oxide, and oxide to oxide). (1mA cannot drive 600pF!) Preamps with 12AU7 cathode-followers aren't much better, sounding very "tubey," rolled-off, and old-fashioned. Joey Landreth playing through a 150 watt 4x 6550 Two-Rock Silver Sterling Signature. The greater the transconductance, the lower the output impedance, as the greater the transconductance, the greater the change in current due to a deviation in output voltage relative to input voltage. Saturation is not an issue in the modified PAS because of its enormous headroom. This was one of the first amps Joe Morgan built, in his home garage, long before he ever considered starting an amp company. This is by all means a "hats off" amplifier. Normally you use a cathode follower to preset a low-impedance source to the tone stack but the tone stack in an AC-30 doesn't present that great of a load anyways. In this case these transistors would amplify voltage too and so they need way less drive voltage for getting the headroom reaches the whole range between negative and positive supply voltage. 65 volts Peak for each individual grid. org/jira/projects/NETBEANS0/issues) !!. For more clean headroom in your amp, order this tube with the low gain option at no extra cost. The working horse. In this case the modulator module PCB needs to be modified. (like overdriving an output stage). If you do use channel one, this tube is the most critical to tone for that channel. Headroom is derived from the difference in maximum operating signal output to the output level of the signal at the threshold of clipping. This drive voltage can be provided easily. The power amp driver circuit was originally found in Ampeg SVT Bass amps and gives this version of the SSS an incredible low end punch and enormous amount of headroom. at a quiescent current of 3 mA triode and 414VDC. Apex 460 Mods. The two plates have 106 and 150 volts on them. These black and white visual images were received inside the watch via a tiny lens at the top edge of the watch face and translated by an optical to electrical transducer into binary data. With good tubes in V2 and V3, I decided to mess around a little. I like single end for good sound and cathode follower for performance on. Unlike most Gibsons of the day, these were fixed-bias rather than cathode-biased, meaning the amp was a little tighter and had more headroom, with a firmer bass response too. He put a cathode follower in it and it left Mesa a factory Mark II C plus with a cathode follower tube. The White Follower offers high current drive and a super-low output impedance. The microphone's high-voltage cathode follower circuit offers incredible headroom and dynamic range that is ideally suited for capturing a wide range of sound sources. Dual channel bass/guitar blackface-style 1U preamp with transformer balanced low impedance outputs; In 2004, I built my own adaptation of an Alembic F-2B dual channel blackface-style bass preamp. This circuit can drive up to 3uF of cable capacitance and can put out +22dBu into a punishing 600 Ohms. Notably, only the Bassman and Twin of 1958-'60 were given the long-tailed-pair PI. Regarding the ZBOX, it sounds like it uses the tube in a cathode follower configuration, and has an Alps pot at its input for gain control. PLATE VOLTAGE – The voltage that is applied to the plate of a vacuum tube. BF/SF Bandmaster heads are like the Bassman head's more anemic cousin. Saturation is not an issue in the modified PAS because of its enormous headroom. This requires ample amplification-more than 40dB plus headroom-to implement properly, one tube stage is not enough. Because the quiescent grid voltage of each output tube must be set individually to control its quiescent (dc) current, one driver tube (TU5-TU8) is required for each output tube (TU9-TU12). To draw a cathodyne phase inverter's load lines we have to consider the tail load resistance and how the tail load resistor affects the cathode and grid voltages. The lower the value, the greater the gain. In this case these transistors would amplify voltage too and so they need way less drive voltage for getting the headroom reaches the whole range between negative and positive supply voltage. So if I were to put a lower gain tube (5751, 12at7, etc) in V1b would it clean up the crunch channel without lowering the gain of the OD channel?. They recommend using either low plate resistance, low mu triodes like 6CK4, or use the pentode as a cathode follower to drive the primary of the driver transformer. Because the earliest tube guitar amps from the 1950s weren't intended to overdrive (though it wouldn't be long before rock 'n' roll pioneers harnessed the glorious sound), the negativefeedback circuit was implemented as a way to reduce distortion. 97V by the LT3083, but the anode voltage goes to whatever voltage is required due to the feedback action of the LT8614. The circuit uses no negative feedback for more natural tonality. I love the sound 6v6's fully cooking in later Deluxes that employed the Long-Tailed Pair PI but still love the cathode follower tone stack of the tweed years and it seems like this is something most players would be interested in. Audio Research LS8 line preamplifier Page 2 The use of two gain stages in series provides correct signal polarity, while a cathode-follower output confers wide bandwidth and low output impedance—in this case, a claimed 200 ohms. I measured 345V on the plates (and 310V for Vg2) of the EL84. But it delivers clean sound for modern production preamp tube. Each amp and speaker model has three versions consistently named to make identification and selection easy. Good poweramp tubes will help your post eq (bass, headroom, tightness, etc), so think of these variables when you decide on your tubes. We continue to use our high quality, heavy duty, 24-step volume attenuator and fast, wide-band polypropylene caps. The Carvin CTM100 is a clone of the Apex 460; like the 460, it is a wonderful platform for DIY modification. In the cathode follower 100% of the output signal comes off the cathode while the cathodyne's signal is split between cathode and plate. I prefer the AC-20 because it doesn't have a cathode follower so doesn't suffer from these problems. In the TM20, you have a Driver and Cathode Follower, while the Phase Splitter is solid state. The preamp of this amp runs three 12ax7’s in a very unique way that combines stacking cathode followers with one of the most versatile EQ’s ever placed in a guitar amp. A little more voltage will increase both gain and headroom. This 4 watt cathode based amplifier came with an 8” field coil speaker. This apparently requires -300V to feed as well as another +150V. It provides a low output source resistance which is very helpful for many purposes. Sorry to bump an old thread, but I am curious about the 22h as well. The unused half of the 6072a is incorporated as a direct coupled, cathode follower, resulting in a much lower output impedance than that of the original circuit. SLCF stands for Super Linear Cathode Follower. We began this series with a basic tutorial on electricity, then moved on through passive components to tubes. The JCM800 uses a cathode follower for this and has the cold clipper at the second preamp stage. Now, let's step backward from the output tubes. The cathode follower is a very fast transient response circuit with nearly infinite headroom that is almost impossible to clip. The one mod left is someone strapped a 1. 5% or 1% THD, or - taking into account the only gradual increase of distortion especially with tube circuits - further beyond that, closer to the point of clipping?. The ProLogue Three boasts tube rectification using TWO 5AR4 tubes, one for each channel. I measured 345V on the plates (and 310V for Vg2) of the EL84. The Mark IV version ups the EG stage from a single Tone control to a full complement of Treble, Middle and Bass in a cathode-follower circuit derived from the tweed Fender Bassman, while still including. Avoid these in high voltage cathode follower (CF)spots. Normally you use a cathode follower to preset a low-impedance source to the tone stack but the tone stack in an AC-30 doesn't present that great of a load anyways. The cathode follower has very low input capacitance and a very high input impedance so it will not load down the previous stage. A grounded cathode amplifier inverts the signal it sees. next stage, "simple triode amplifiersthey have low enough impedance to drive the output stage directly. One output stage features its own cathode follower which adds a subtle widening effect and an extra dimension to the sound, even when operating in mono. In contrast, the follower option yields a very linear transfer curve, low distortion, large headroom and very low output impedance. Also, as the cathode voltage increases, the V2 grid remains fixed at its bias voltage. So I took advantage of knowing this to improve the sound of my Audioengine D2. Piping department then finalises the pipe thickness, and other piping details like standards for valves fittings, gaskets, bolts and nuts etc. Naturally all clipping within those has been achieved with solid-state devices. Very consistently made tube. Definitely worth rereading. V6- Cathode follower 12AX7WA (Use proper cathode follower tube. It is an online store, offers professional recording studio microphone, best microphone for music production, professional microphones for singing and recording. In the cathode follower 100% of the output signal comes off the cathode while the cathodyne's signal is split between cathode and plate. The anode follower is similar in action to that of a cathode follower, but allows for a gain greater than one. W-7405-eng-26 Instrumentation and Controls Division MSRF: DESIGN AND OPERATIONS WORT Part IIA. The choke loaded cathode follower. I also use it to determine the DC load RaV1. See Two-Rock for recommendation) V7-V10 - 6L6WGC, Output (100 Watt) ; 6550, Output (150 Watt) Each fine production tube is tested and matched to our exacting specifications. With a octal double triode tube , we now only need one (1) piece tube , and with a flexible users choice of 6. I would suggest a 10 Ohm resistor in each cathode leg of these in order to measure the current and ad a tiny bit of local feedback, I am also very happy with the damping control. It has been used in many popular guitar amps including the Fender (push-pull) Princeton, most Orange amps and several Ampegs. As a matter of fact, my favorite power amp and phono amp designs all through the decades used cathode follower circuitry with very satisfying results, both, tonally and dynamically. The ca11 uses an SRPP (Series Regulated Push-Pull) circuit for high gain, low distortion and very low output impedance by using a variation of the White Cathode Follower. It's been selected for its relatively high Idss (24. The topology offers good headroom and low distortion:. It had the usual tone stack and coupling mods, plus the cathode follower, TO20 output transformer, and 6V6 conversion. It IS a compressor/limlter with a wide range of what I like to call "nuance headroom. They had a big resistor on the cathode follower and lacked headroom and balls, they also had the low B+ of 370vdc that made them brown out quite quickly. Headroom is derived from the difference in maximum operating signal output to the output level of the signal at the threshold of clipping. Additional followers also isolate the low pass filters, which are a difficult load, from the driver stage. You can use this as a guide to how to design cathode followers for low impedance loads.