5e3 cathode bias So I am starting my next amp design and am thinking something similar to a 5E3 or 6G3 (Not sure about the tonestack yet. 3v center tap. The cathode bias resistor is intended to be shared by both 6V6. donation. Don't wait to be asked. V1B's bias is set by R6. If you want to use the RCA unmatched tubes, why not just use a separate cathode bias resistor and cap for each 6V6. The 5E3 Deluxe circuit is a push-pull pair (aka double-ended amp) of 6V6's, in cathode biased configuration. Mainly the difference in the phase inverters. I suggest you The 5E3 is cathode biased whereas the 5F11 and the 6G2 Princeton are fixed biased. I'm not getting a negative DC voltage at pin 5 of the power tubes. In a cathode biased amp like the 5E3 you do not need one ohm resistors. Dissipation at Pmax is normal for this amp. From what I understand, the plate dissipation for 6V6GT should be at 14 watts or under, correct? 250 ohm: Outer Tube I'd think any decent 6V6s should be able to tolerate 13. 10K would be better). And a few others will do a "Tweedle Dee" mod. Check Details. ) I really like the sound and the concept of selfbiasing in a cathode biased amp but I would like to try a LTP instead of When the Fixed bias is not active, how is the cathode bias circuit still connected? as per the 5e3 schematic, it shows it's tied into the junction point of the two 220k resistors. 词组、短语、俚语及习惯用语 • cathode analysis 阴极分析。 • cathode anchor 阴极锚(电子管阴极零件),阴极支架。 • cathode arrester 阴极放电器。 • cathode assembly 阴极装置。 • cathode beam 电子束。 • cathode bias 阴极偏压。 • cathode bias resistor 阴极偏压电阻器。 • cathode bias separation 阴极偏压分离。 5e3 schematic fender deluxe tweed amp schematics board 6v6 guitar push pull tube bias build turret circuit cathode gif schemFender tweed deluxe 5e3 clone build based on tad tweed deluxe kit : 18 Fender tweed deluxe schematicFender tweed deluxe schematic. It still gets filthy on '12'. 11-04-2008, 02:51 PM. :) 5E3 cathode bias resistor value. That is the reason for the better bass response. Yes the 5E3's are biased pretty hot,but you are biased at close to 100% at idle,thats hot even for a 5E3. They are referred to as "tweed" amps because of the tweed-like fabric glued over the wooden cabinet. with some voices that do at least tip their hat to the 5E3. Post by DustyBadlands » Sun Jul 27, 2008 7:43 pm. Fender deluxe schematic – electronic service manuals. The other common type of bias circuit is Some modern high gain amps bias their preamp triodes cooler using a 2. https:/ It's a lot cleaner and brighter than a regular 5E3, with considerably tighter bass, closer to other narrow panels. Then again, having checked the power amp structure of a 5E3 and 6G3 (basically the cathode bias vs fixed bias; and the levels of the negative feedback resistor), and being able to keep sorta the same plate voltage (~360-370V) that is kinda right for them amps, made me go Notice the V1 cathode bias resistors and caps at the far right of the circuit board. This is not required if your power transformer has a 6. Sticking with stock values, Its either going to have the headroom of a fixed bias amp, or the breakup of a cathode biased amp. Joined Dec 30, 2019 Posts 7,460 The 6G3 is fixed bias but I’m doing cathode bias more like a 5E3. How worried should I be with the 6V6GT power tubes running at 40mA and 38. I'm currently working on a project that is a modified 5E3, with the preamp a bit different, but the power amp side the same as a 5E3 with the exception that I'm using a dedicated 330 Ohm/25uf combination for each Cathode of my 6V6's, rather than the 250/25uf that's shared REPRODUCTION 1959 FENDER 5E3 NARROW PANEL DELUXE AMPLIFIER COMMISSION ANOTHER DAY, ANOTHER QUEST the vintage tones just seem to begin to fall out of the amp all the way up. Cathode biased amps can safely run at 100% plate I used the 250ohm cathode resistor with a pair of “matched tested” RCA 6V6. 2) Ground the cathodes of the power tubes. 007vac Well that ain’t good. It used a 6SC7 pre-amp tube and 6N7 phase inverter. None of the above applies. Increasing resistance raised cathode voltage (above gnd), and lowered plate current. 4w on the tung sols (104% max) using the cathode resistor drop method. It has a fixed-bias output stage, very different from the 5E3 Deluxe, to which it is sometimes compared, which is cathode-biased. ) B+ will change (increase) when you switch to fixed bias. (the 5E3 being a cathode biased amp). The PT I’m using makes fixed bias a sort of pain and I wanted to keep this amp simple. 5mA per tube, and dissipation of about 12. Joined Jun 16 The cathode bias 6V6s giving you that sweet compression and instant touch sensitivity that allows you to go from clean to scream with just the turn of your guitars volume control. 7 divide. O autor encoraja a experimentação com Fender schematic 5e3 deluxe tweed amp schematics tube amplifier diy board guitar 6v6 push pull bias build turret circuit cathode. 5W of total cathode current in a cathode biased push pull amp with older softer 12W plate rated 6V6GT tubes Have stronger 6V6GTA tubes in there You just measure plate-to-cathode voltage, voltage drop across the bias resistor, and (amp off) actual bias resistor ohms. You are the reason people come here for no BS answers. schematics blackface layout ab763 amps5e3 schematic fender deluxe tweed amp schematics board 6v6 guitar push pull tube bias build turret circuit cathode gif O documento discute modificações para o amplificador Fender 5E3 Deluxe, focando em como torná-lo mais versátil sem comprometer seu timbre original. 142vac and it just completely died with a gzzz and wont turn on anymore!!! no lights nothing. I would stick with the 8k. The circuit is pretty much a straight Model/Circuit Number: 5E3 Years of Production: 1955 – 1960 Era: Narrow Panel Configuration: Combo Controls: Chrome top facing w/ white screened labels, controls numbered 1-12 Bias: Cathode Bias Rectifier: 5Y3GT Comments: A speaker jack and ex. This is such a simple mod and very easy to do on a Hoffman turret board. (Cathode bias voltage changes automatically with increasing or decreasing current across the fixed resistance, so the 6V6s will stay in their happy place. The 250R/5W cement resistor on the far left side of the board is providing cathode bias for the 6V6 power tubes. Collapse. 8V for bias (grid to cathode). I know NFB in 5E3s is a common option but not for me. X Hey guys, this amp has been hanging out on the local Craigslist and I’ve been considering going for it because I’m curious about the 5E3 and have never owned one. For more modern Fender amps you would apply the tape to the underside of the top of the cab. 270 ohm Cathode Resistor is shared between both power tubes. Post by DustyBadlands » Sun Jul 27, 2008 7:37 pm. The bais table says 24mA at 350v is where it should be to run at 70%. Eventually I will simply tack some in and try different values but I was wondering if somebody can tell me something like, a 100uf bias cap will have more bass or that a 25uf cap will make it tighter. This leads to a more balanced bias point and reduces harsh Lil Dawg Custom Deluxe 5E3 Amp. Summer Fund Drive:C'mon guys lets show some support!If this site has helped you an you haven't recently donated Include your username so I know whos donatingPlease consider making a donation. Design Concerns-Bias shifting trem in fixed bias amps that vary power tube bias have several issues: 1. Cathode biased 12AY7 preamp, 12AX7 paraphase inverter, Negative Feedback circuit removed, 2 cathode biased 6V6GT power tubes putting out about 14 watts. Just wondering if that's normal. These 25 watt resistors are adequate for 15 watt amps such as a 5E3 Deluxe or other cathode biased 6V6 push-pull amps. Later, I dropped in a Mojotone eyelet board for a number of reasons. OT BLU lead to plate 2 = 164. Both will reduce headroom and boost preamp Hoffman Amplifiers Tube Amp Forum, 5E3 bias. The 5E3 power section inherent tone is based on the (1) Cathodyne drive with virtually no gain (2) Cathode "self adjusting" bias and (3) No negative feedback. The 5e3 Tweed Deluxe is known for its distorted and cranked tones which comes easily when setting the volume and tone above 12 o’clock. V2's bias With the switch set to 10% both jacks will be 8 ohm with 90% of the amp power turned into resistor heat. Note the color coded legend at upper right. However, because a 5E3 is cathode-biased and uses "fairly low" voltages, you can run the 6V6 closer to maximum. : fender deluxe 5e3 clone oxblood (cathode bias) 120hz buzz! Thread starter tim0090cooper; Start date Feb 13, 2023; P8 Cathode (black) Last edited: Feb 14, 2023. I have owned them alland like them all. The first gain stage is cathode biased like the 5E3 and 5D3 Deluxes. I measured the Well, yes and no. 6 posts • Page 1 of 1. Would increasing the value of cathode bais resistor help? (using 250ohm 5w). 3) Lift the junction of the two 220k ohm screen grid resistors from ground. While that's true, in many amps (like the 5E3, for example), the cathodyne is one triode in a twin triode bottle, usually a Cathode Bias Question on 5E3. It sounds really good at low volume (don't have much opportunity to crank it). I had no reliability issues but I never loved the tone. Similarly to V1, the 25uf The 5E3's V2A is a very generic gain stage with a nice center bias for maximum headroom and symmetric clipping. I've never seen a mod like this for a 5e3 Deluxe or other cathode bias circuit, and you ? Also if I can unserstand the reason for the 150R resistor and 1K trimmer I'm not sure which is the action of the 500K trimmer, seems something as to do with balance, but I'm not able to understand K p. You can get an accurate resistance measurement of cathode If your amplifier is cathode biased you must replace the cathode resistor to change the bias level. Any visible concerns in terms of construction or wiring/component quality here? The post seems to imply it can do the 5E3 thing with I have been trying to fully understand the 5E3 circuit and I have gotten to the Phase Inverter. That's the rule of thumb I use anyway for fixed bias. Hey guys, Cathode Bias Question on 5E3. You could split the cathodes on the first triode and voice/bias to your taste. Common R was 220 (equiv to 440 per tube?), so ran a 390 to one tube and a 560 to the other. 10w+ cathode resistor and 50V+ rated cathode cap recommended for output The 5E3 is a distinctive circuit, and though hundreds of mods exist, that doesn't mean most of them can remove its peculiar charms and vices. Go to 6L6GC's running 465+ volts biased in around 40ma and the heat generated will ruin a 10W fairly fast. The early distortion is partly explained by the lack of a negative feedback loop and the 6V6 cathode the Fender 5E3 has a 250R 5Watt Cathode Resistor, aacording to the Schematic. Hammond P-T1750J Output Setting the 5E3P Power Tube In your 5E3, where the cathode bias target is around 100% MPD or more, a 'typical' or 'bogey' 6V6 might hit 100% MPD with PC anywhere from 24mA (at PV = 500) to 60mA (at PV = 200). There will be varying opinions on that. Attached is a gif file of a cathode biased power section half, quarter and full power switch drawn by a member of the Hoffman amps forum some time ago. 专利顾如平台提供关于 voltage phase 的专利信息查询，本次查询共找到了444585条关于 voltage phase 的专利信息，专利顾如是创新者都在用的专利研发平台,专利检索,专利深度分析跟踪平台 I put this semi Fender looking clone together over the holidays. But, tell me, is the amp capable of driving the 6V6's to clipping? Any comparison you could make to a 5E3 would be great. Post by bal704 » Wed Oct 16, 2013 1:45 am. switching between the two is easy, as is building a fixed biased 5E3, or cathode biased 6G3. Fender 5E3 Deluxe Preamp tubes: one 12AY7, 12AX7 PI Output tubes: two 6V6GT, cathode-bias Rectifier: 5Y3 tube Controls: Independent Volumes for each channel, shared Tone. Rob gives a step-by-step: To use the Tube Dissipation Using Cathode Resistor Voltage Drop calculator enter your Tube Type and Plate-to-Cathode Voltage at the top of the page, then enter the Number of Tubes that share a cathode resistor, the measured Voltage Drop across the cathode resistor and the Cathode I think an essential character of the 5E3 is the cathode biased 6V6s and no NFB. 5e3 tweed tad clone instructablesFender deluxe tweed narrow panel 1960 1955 amp tube (818) 998-7791. This Amp was built by Jim Nickelson at Lil Dawg Amps. One kinda of big change or mod is the addition of a bass control. To reduce the impedance will make it hotter. You don't want to exceed the tubes' rated maximum power dissipation in cathode bias, or about 70% of the max in fixed bias) I've been going back and forth on the 5G9 vs. Originally developed in 2014 as one-off, this truly unique de Lisle design offers four amps in one; tweed 5E3 Deluxe, tweed 5F11 Vibrolux, Princeton Reverb and a variation of our Rutgers Reverb. 5W in cathode bias -- what is that, 112%, kinda the bullseye for a 5E3? *If* the Tung Sols die and you don't like the JJ sound (some here agree with you) any pair of decent NOS 6V6s should likely work and sound good. Wharfcreek; Jun 12, 2015; Tube Audio; Replies 18 Views 3K. the 5E9a. 5E3 Cathode Bias. Os mods mais recomendados incluem o Feedback Negativo comutável, canal Lead e Master Volume, que melhoram o headroom e a compatibilidade com pedais de efeito. In this case they chose to elevate the filament center tap as well, for hum reduction. I have read that it could be the reservoir capacitors after the rectifier? im pretty sure i know which ones it is Hi, so I’ve just completed a 5e3 build using the classictone PT and OT (PT on 355-0-355 and 240v taps). The early Tremolux’s bias-modulating tremolo sounded great, but presented a potential instability in the bias circuit. A few will use separate R/C for cathode bias on V1a and V1B. Aim for no more than 12. Fender Bassman Ab165 Schematic. The amp is the 6G2 circuit design. Attempts to reduce it by using a larger rk negatively effect the tone of the amp With these cathode biased amps, changing rectifier tubes changes the voltages and bias dissipation, so do measure before and after. If you are serious about knowing how it will sound then you are the only one that I wish I could do a comparison for you but my Pro Jr II was gutted and turned into a 5e3 years ago. Logged A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Advanced Search Wishing everyone a Happy New Year and many repairs in the coming Months. Scott S said: WTF? The 5E3 is cathode biased. 0 ohms. You don't need to do the fixed bias thing he used, (the resistor network on the grid) but some people call it the "Paul C" mod and really like it. Reverb pro amp fender sch 1st preview Schematic fender bassman tweed 1959 annotated 5f6 guitar 5e3 amps work deluxe component signal function path robrobinette. The Princeton Reverb has no power tube grid stopper or screen resistors just like the 5E3 Deluxe. The 5E9 is cathode bioased, but the PI is a paraphase, not quite was I was thinking of. Also, people will often mistake cathode biased amps for being 'class A' case in point, the item's description that the OP posted lists The cathode biased 5E3 is a heavier load (more current) than the typical fixed biased 6V6 amp, so the B+ will be sucked down more (sag) due to the heavier load. Hey all, I’ve spent the past few days experimenting with bias resistors and settled on a 330R (326 ohms) that got me to a reasonable plate-cathode voltage (369), current of about 33. o5 cap. 5k and 56k resistor joint to make sure the new bias does not affect the Proper 6V6 Bias for 5E3 V1 is grid leak bias with . 0 LOL 0 Wow! 1 Wisdom . Installing a bias pot usually means converting your amp to fixed bias. Mar 5, 2012 #9 ; mr. Reactions: tim0090cooper and YellowBoots. Also, the DR uses a 5AR4 rectifier and 5E3 uses a 5Y3 rectifier. March 2020. He did his testing on a Deluxe Reverb (fixed bias), but I would think the There are a lot of 6V6 cathode biased amps with tremolo using a concertina (also referred to as cathodyne) phase invertor similar to 5E3 Comparing 5E3 & 5E9-a schematic/layout showed small set of straightforward changes, albeit sans tremolo. A 5E3 Deluxe is a good example of a cathode biased amp. I'm currently working on a project that is a modified 5E3, with the preamp a bit different, but the power amp side the same as a 5E3 with the exception that I'm using a dedicated 330 Ohm/25uf combination for each Cathode of my 6V6's, rather than the 250/25uf that's shared 5E3 Cathode Bias. Please login or register. In the 5e3 schematic, the bias voltage is typically obtained by using a bias resistor network connected to the tube’s grid. By the Bench. V1 is conducting much harder, current is higher, therefore plate voltage is lower. Divide by about . ? Do the math on each tube using the correct value cathode R to balance the tubes draw. With the ability to switch between fixed bias and standard 5E3 cathode bias I measured the amp bias with both 6V6GT and Tung Sol 5881 reissue tubes. Jul 11, 2022 #7 ; tubeToaster Tele-Meister. As noted, 50% is the cold end of normal even in a fixed-bias amp, and is way cold in cathode bias. Therefore, same PT will give higher B+ for fixed bias amp due to lighter load. I'm looking at doing a couple of 5E3 builds this summer, one 6V6 and another 6L6 Neil Young modified Deluxe. But they don't halve the cathode bypass capacitors. The Tweed PRinceton is single-ended and cathode biased as well. the rectifier reads 4 and 6 12vac and 2 and 8 read o. V2 is cathode bias with 1. The 5F1's V1 and V2 use "common cathode biasing", also referred to as "self biasing" or just "cathode biased. I've been tinkering with the cathode bias on my latest project, and everytime I increase the cathode resistance, the B+ increases. I'm currently working on a project that is a modified 5E3, with the preamp a bit different, but the power amp side the same as a 5E3 with the exception that I'm using a dedicated 330 Ohm/25uf combination for each Cathode of my 6V6's, rather than the 250/25uf that's shared Hello guys been a while. Fat Jimmy #100. Cathode bias is fundamentally different to fixed bias, can’t just run the power valves cooler without detrimentally <pet peeve> Everybody (Dumble, RobRob, Hoffman, etc. It's really loud! I must also say that a big part of the sound of both of my 5e3's LED Cathode Biasing in 5e3 Most people want the 5E3 to be true to the original. Current was 32/35 mA. The cathode of the triode will ideally be a clone of the grid signal. a. ICBM Frets: 77092 . The 5E3 remains popular in its own right exactly as it was first conceived, both via reissues from Fender itself, and in myriad clones from makers like Victoria, In essence, almost any smaller-mid-sized combo that This is a 1955 5D3 Deluxe converted to 5E3 specs many years ago by my tube tech. Jul 26, 2008 #6 ; TelZilla Friend of Leo's. It is possible to make cathode bias "adjustable" but this is almost never done. ANd the 5G9 uses a LTPI, but has fixed bias. Basically they say that for cathode biased amps the EuroTube widget measures actual DC voltage and subtraction isn't necessary. Measure the voltage drop on the cathode resistor to ground. Taking the grid bias from B+ gives (IMHO) the same effect that having an infinite big cathode bypass capacitor. A higher value cathode resistor will cool the bias, a lower value will warm the bias. (Current x Voltage = Wattage. 3ma of cathode current using the transformer shunt method and 49. Unfortunately Jim isn't shipping from the USA anymore. Find the 6g3 brown deluxe diagram and use that circuit, just leave off the tremelo circuit starting at the intensity pot and the . the onset of breakup is smooth and subtle owing to the cathode bias, lack of negative feedback, and the buildup of harmonics in the paraphase, and 4-position dual-throw switch. Take a look inside a Clark, Victoria or Richter, All of their 6V6 equipped 5E3's run 10 or more watt cathode resistors. Thread starter ceylon; Start date Saturday at 4:01 PM; Prev. Fender champ wiring diagramsSchematic fender 5e3 deluxe tweed amp schematics tube amplifier diy board 6v6 push pull guitar bias build circuit turret cathode Fender rumble sch rev 2010 preview 1st manual serviceFender deluxe 5e3 schematic annotated service manual download. This network consists of one I read in Megantz' book, one is needed before a Cathodyne PI, and he mentions the Fender Deluxe, but the 5E3 has two regular cathode biased gain stages leading up to it. 37w. The combination of the tube rectifier, cathode bias, and Alnico speaker makes it limit the pick attack and then naturally compress the tail of the note very smoothly for Built from the fender 5e3 schemo and layout at schematicheaven. Useful for cathode bias amps and tons simpler. 30 May 2024. I'm currently working on a project that is a modified 5E3, with the preamp a bit different, but the power amp side the same as a 5E3 with the exception that I'm using a dedicated 330 Ohm/25uf combination for each Cathode of my 6V6's, rather than the 250/25uf that's shared My understanding of why the hifi guys like the cathodyne is that the cathode biased cathodyne is self balancing. Search in titles only Search in 5 E 3 only. My limited Also should I increase my cathode resistor? Tubes: 2 x JJ 6V6S OT CTR tap = 373V Plate 1 = 368V Plate 2 = 368V OT BRN lead to plate 1 = 151. Fixed bias amps have a bias 5e3 Adjustable Cathode Resistor Mod stage design exercise & show that if the supply voltage is within reason for "tweed Deluxe with Class A 6V6," then the cathode bias resistor will land "near 250Ω. 9V for bias (grid to cathode). ) helpfully splits the V1 cathodes and properly doubles the cathode resistors. For a complete new 5E3 build you may consider to a) connect the 1M resistor directly to ground instead of the 1. To separate V1A and B's cathodes you must change the existing cathode resistor from 870 ohms to 1. 4 ma. The 6G2 uses a split-phase inverter (cathodyne); the circuit design gives the amp The Fender 5E3 Deluxe of the ’50s (and earlier models) are certainly legendary for their toothsome, player-friendly sag, as are smaller Champ and Princeton models. As if the 5E3 needs more bass! The bypass caps should be 12uF or 6uF if following the 5E5 schematic. It's interesting that although Fender lists the improvements, the move to cathode bias is not My bias is at 65% in fixed and 100% in cathode. Just the right volume for most places I'm gigging. As such, a look inside the 5E9-A displays 5E3-related elements such as a split-phase (cathodyne) inverter, cathode-biased 6V6s, a 5Y3 rectifier, those three 16uF filter caps on the left of the eyelet board, and more. Unbalance fixed! At least the plate current. The 5E3 tweaks the design further. May 24, 2023 Bias If anyone is keeping score, here's an update on my optimized 5E3 build and bias: Using the information provided by the venerable Uncle Doug, I measured and calculated the plate dissipation with 3 different cathode bias resistors. Jim is a ma Most small cathode biased use pre-amp tube bias shifting trems but there is version that modulates the bias indirectly through the grid leak resistors of the power tubes. I don't think I'll have to use two rectifiers and I don't need a bias voltage tap. All Tweeds through the 1954 schematics were cathode-biased. 5E9 Tweed Tremolux phase inverter question. The signal chain is: 1974 Les Paul Standard, MXR Compressor, 1955 Fender Tweed Deluxe (converted to 5e3, has a smaller OT than later 5e3's), resistive load box with 50k line out and isolation transformer, Binson Echorec II, TC Electronic Hall of Fame 2, CMI Re: 5E3 cathode bypass cap question « Reply #3 on: June 25, 2011, 03:23:48 am » I've heard of people using up to 2,000uF for the bypass cap on the self-bias on output tubes. Fender ramparte 9w valve ampFender tube audiofanzine 2592 1936 2m weight uploaded format size combo guitar amp Fender ramparteUnveiling the sonic secrets: examining the fender ramparte schematic. FOR SALE: Fat Jimmy Custom 20 FJ #100 Up for grabs is a very special Fat Jimmy build. You would need a 5W rheostat or a 15W adjustable resistor. I have been trying to troubleshoot my 5E3 Deluxe build, (built by a famous builder but now probably 10 years old) it makes a pretty loud popping noise on an intermittant basis. </pet peeve> In the preamp stage, voltages such as the plate voltage, cathode voltage, and grid voltage can be measured to determine the amplification factor and biasing conditions of the tubes used. Hello I'm working on a 5E3 Deluxe. What difference in any way would it make, if I would change the Value to 220R 5Watt? Cheers, 2018 5:08 pm. Later amps of this era have logo tags that include Cathode Bias Question on 5E3. BASSMAN Tweed deluxe amplifier fender 5e3 vintage diy Fender amp guitar tube reverb twin layout deluxe blackface diy board 1963 schematics amplifier pedal choose electronic valve. Just remember it is YOU who helps this site be what it is. At first thought I was going to do the 5F8 Twin preamp, but with the presence treatment of the 5F4 Super. The 5E3's big coupling and cathode bypass caps and lack of grid stopper resistors all work together to cause extreme blocking distortion known as "farting out. I'm currently working on a project that is a modified 5E3, with the preamp a bit different, but the power amp side the same as a 5E3 with the exception that I'm using a dedicated 330 Ohm/25uf combination for each Cathode of my 6V6's, rather than the 250/25uf that's shared Cathode Bias Question on 5E3. I just noticed a small difference between the two builds. In cathode I'm about 38ma and fixed about 21ma at 374v(cathode) and 395v(fixed). The plate voltage is 365v. -User Name Remember that a 5E3 output stage is cathode-biased, so you don't need to worry about changes in B+ voltage (to a point) because cathode-biased stages are 'auto-biasing'. Current was 41/39 mA. Moderators: pompeiisneaks, Colossal. 5k and install an additional 1. The cathode-bias / fixed-bias switch would have to: 1) Remove the 250 ohm cathode bias resistor (and 25-25 cap) from the circuit. speaker jack were located under the chassis. If you go with a switchable bias, you will have the ‘softer’ and earlier breakup of the 5E3 deluxe cathode Biasing as well as later breakup with a harder edge that comes with the fixed bias. The BF amp uses a 6. I was thinking about the Send/Receive thing too! That The 5E3 is cathode biased. Rebias the output section for proper dissipation. New Month We are at $40 this month in Donations. As I said before, I have ruined several 10W cathode resistors before switching to The Ohmite brown Devil hollow wire The voltages you report look typical. I would go the Foreign Made route and measure some more voltages to figure out what's going on. That is always the danger that one would run into when dealing with such kinda projects. The cathodes of the power tubes connect to ground, but being cathode biased, the cathodes are elevated at 20 volts by the cathode resistor. The output of Now, I wonder if the 1500 bias resistor on the cathode of the 5E3 splitter causes the output on the cathode side to drop by a few %, and that the reduction of the plate resistor was to match the p-p voltage to the cathode. What I'm thinking of would be a mixture of the two, LTPI with cathode bias. This particular 5E3 build is for studio recordings and my goal is to groom the amp to cover a wide range of styles and do everything I can in the build to reduce noise floor hum hiss ETC 5E3 Cathode Bias. Output: 15 watts RMS +/- Speaker: Jensen P12R or P12Q Ah, the glorious Nar-row-panel 5E3 tweed Fender Deluxe – such a ubiquitous design it would seem there’s no point detailing There's no good substitute for running at the "ideal" plate voltage, but in cathode biased amps boosting the cathode R even farther is useful. Divide this voltage by the value of the cathode resistor. Fixed bias amp idles at much less current than cathode bias amp. s. . Are your plates glowing?Does the amp sound okay?You say it is too hot to touch,this amp is known to put out some heat,but if the amount of heat makes you worry,just Thanks. The plate voltage difference between the two isn't enough to make a big difference in overall tone. I'm also wondering what the smart folks think about the effect on volume when running a 4-ohm tap with 8ohm speaker! I'll take a look at Rob's proluxe voltages, thanks for the reminder I got the bias switch installed and with a JJ GZ34S rectifier and JJ 6L6GC power tubes I get 397v B+, 52. I would hold onto the 250Ω and 300Ω in case you need them, but would use 270Ω as the 5E3 Cathode Bias. You can measure the voltage drop over the cathode resistor and calculate bias measuring current draw 1. 1V Cathode resistor 250 ohms. 1 ohms. Common Cathode Resistor & Bypass Cap question. I think the 5E3 is cathode biased. The Fender 5E3 Deluxe is a cathode biased Class AB amp. The 5E3 and 5E5 I would not go to fixed bias from cathode bias in a 5E3. Jun 14, 2015. 1; 2; First Prev 2 of 2 Go to page. If it were fixed biased then likely the NFB would be needed. Search. Where it differs from the original is the amount of Resistance readings look what 5E3 OT typically has so most likely you did measure correct places? Cathode resistor voltage divided using resistance give combined cathode current 84,5mA. Whether 270Ω is right or not depends largely on plate voltage. Joined Jan 21, 2007 Posts 3,860 Location Cleveburg, USA. Does anyone know if the 5e9a has any more headroom than a 5E3? The vibrolux has tons of headroom (it doesn't break up till about 5 or 6 on the At some point, Fender switched from fixed to cathode bias on the IVs. No bias adjustment needed with a cathode biased circuit. Post by chuckulaa » Wed Sep 18, 2013 8:29 pm. Overview; Brands; Articles; Warranty; Articles; Search for: Search Fender bassman ab165Bassman bias cathode circuit schematics tweed 5e3 fixed deluxe back bf sf Bassman ab165 120hz fender attack issues layouts schemesFender reverb super schematic schematics sch amp preview 1st pdf schem champ. You can also put a voltage divider on the screens to keep them down as that will also control plate current. Then average tube The more important aspect is how much plate current you have for the particular idle voltage that you have. MIJ_Pioneer; Jun 21 Fender rhodes schematic Fender schematic 5e3 deluxe tweed amp schematics tube amplifier diy board guitar 6v6 push pull bias build turret circuit cathode Fender rumble 60 sch service manual free download, schematics, eeprom You could do some things to try to get it a little hotter, adding bypass caps, changing the cathode resistor values or maybe even converting the first gain stage to grid leak bias, but your best bet would be adding another preamp stage, along with more guitar amp friendly tone and volume controls. chuckulaa Posts: 21 Joined: Tue Aug 06, 2013 9:52 pm Location: Boulder. 5k resistor is connected to the cathode of For my first amp build I put together the Tube Depot 5e3 kit with a PCB. I'm currently working on a project that is a modified 5E3, with the preamp a bit different, but the power amp side the same as a 5E3 with the exception that I'm using a If your amp has 1 ohm bias setting resistors then enter '1' into the Cathode Resistor's Ohm Value field. X The triode is biased such that the voltage amplification is only unity. Like Fender’s big boys The circuit is differs more than any of the versions that came after it. 6 This reduces gain and increases input headroom. I’m looking to wrap up the build but the plate dissipation that I’ve calculated is a tad over 14w - 14. 148vac pin7 3. 5f8 schematics tweed 1st preview manual5e3 schematic fender deluxe tweed amp schematics board 6v6 guitar push pull tube bias build turret circuit cathode gif schem. Hopefully this So if I hadn't gone old school enough with my 5E3, I decided to compare its tones to the 5C3. About Us . Wishing everyone a Happy New Year and many repairs in the coming Months. Donations Search in titles only Search in Maintenance, Troubleshooting & Repair only. Did it Cathode biasing also gives a softer attack and more compression, that people might associate with 'sag'. Hey guys, 5E3 cathode bias resistor value. Load line in red, cathode load line in magenta, AC load line in yellow and The traditional 5E3 has cathode bias while most of the bigger tweed amps using 6L6's have fixed bias. With the voltage on the output tubes higher you need more voltage on the grid so an additional cathode resistor in series with the So do the calculation for that. The 300Ω resistor will bias the tubes colder. DustyBadlands Posts: 63 Joined: Wed Jul 23, 2008 11:55 pm Location: North of Detroit, Michigan. 5mA . My 5E3 type OT was from AES; yes, nearly 300 ohms p-p! To me, the point of getting the VB+ My idea of going with the 5E3P Cathode Bias is to maybe have the best of both worlds and swap in 6V6's, flip the switch to cathode bias and roll with the 'stock' 5E3 sound. com Added modern power switch/standby and eliminated ground switch ala Mission 5e3a With cathode bias we've raised the cathode Cathode Bias Question on 5E3. Is an imbalance normal on 5E3 cathode bias design? I got a bias measuring tool for the Bassman and Plexi kits I am building. Sansui 7000 Restore. . I LOVE the change in tone from the paraphase inverter. If you have a lower plate-to-cathode voltage, you can have more plate current before a 6V6GT exceeds its recommended (12W) dissipation. especially compared to what you’d see like on a 5E3however, take a look at this model 413 schematic that I Schematic fender bassman tweed 1959 annotated 5f6 guitar 5e3 amps work deluxe component signal function path robrobinetteDoes a phase inverter tube affect tone/output? Fender bassman blackface headBassman bias cathode circuit schematics tweed 5e3 fixed deluxe back bf sf Fender bassman head blackface chfBassman schematic fender. Join Date: Oct 2006; Posts: 139; Location: North Carolina; Share Tweet #2. " A cold clipper's very large 10k to 39k cathode resistor sets a cold bias that leaves little room on the shutoff side so the input guitar signal can easily be clipped when the signal The question all this comes down to is this : would it be better to stray from ideal by going lower with the plate voltage and the chosen cathode resistor to then also be able to properly bias with fixed bias, or should I make things ideal for cathode bias and live with whatever departure from ideal is brought on by having too high a voltage yes i can force it. dwhutchens. Tie both cathodes together, add a few resistors and remove/swap out capacitors, and in the process The 5E3 is a simple design (well actually a very complicated simple design) utilising: - a 12AY7 for the two channel inputs, using the same cathode capacitor/resistor pair - a 12AX7 as the a second gain stage and as a cathodyne phase inverter - two 6V6 power valves, which are cathode biased Cool. The Fender 5F1 Champ is a Class A cathode biased amp. These are A few years ago I bought a 5E3+ kit from TubeDepot. It doesnt change your tone much actually. The Tube Depot kit has an extra resistor on the power tube sockets going from pin 1 to pin 4 cathode bias resistor bypass cap challenge. The bias must be set correctly on the power tubes for the effect to work. " Maybe "220Ω" is ideal, maybe "330Ω" is ideal, but "near 250Ω" will often be about right. So "5E3" = 1950's Narrow Panel Deluxe. The 6G2 Princeton’s fixed-bias output stage takes it out of the nominal-class-A camp of the cathode-biased tweed Deluxe and the like, but its cathodyne inverter (a. 6k output transformer while the 5E3 uses a 8k. split-phase inverter) puts it in sort of two-steps-forward, one-step-back situation. General discussion area for tube amps. I understand how the Cathodyne phase inverter works but I am confused why the 1. Then I pick up an old phono amp (Webcor MT-1755), with 6v6 P-P and a Paraphase PI, and IT has a cathode follower stage before it (after a standard cathode bias input stage). M. According New Month We are at $25 this month in Donations. Maybe not as loud, but more use out of the dial in the clean range. separated the common cathode bias into two. The 6L6 amps went to fixed biased in '55 with the exception of the 5E5 PRo. I made this as a personal amp for myself to (ICPs) are frequently operated in pulsed modes [17–21] or driven by arbitrary bias waveforms [22–24], resulting in IVDFs that evolve over time. Go. Before you laugh about the half power switch, I've had a handful of 5E3 customers complain about the amp being too loud for home use and that is why I have implemented it. Joined Nov 9, 2007 Posts 380 Location For instance, a Fender 5E3 Deluxe uses a 25uf cap on the cathode bias. The 820Ω cathode resistor for the second stage is not bypassed by a capacitor, creating negative feedback from cathode degeneration. Sometimes, I think we over analyze this stuff. Cliff Schecht I use the cathode biased input for cleans and the grid-leaked side for heavy, raunchy distortion. Think about it We obsess about biasing our fixed biased amps at 70%, but our cathode biased amps typically run at about 90-100%. Should there be a negative voltage measured at the cathodes? The 250 ohm resister measures 247 ohms and the 25 uf capacitor is a brand new Sprague 25 uf x 50 V. I've since built one of their Marshall kits (head only). it reads- left tube- pin2 3. I'm currently working on a project that is a modified 5E3, with the preamp a bit different, but the power amp side the same as a 5E3 with the exception that I'm using a dedicated 330 Ohm/25uf combination for each Cathode of my 6V6's, rather than the 250/25uf that's shared 5E3 cathode bias resistor value. k. In push-pull cathode bias, as in the 5E3, ~80% is cool, ~100% is hot (but at least in the 5E3, should be safe). I was gonna do fixed bias and variable NFB ( I'd call it a soul control, but I think the name is stupid) on the 5e3 4x10, but with the bigger 5f4 tranny I've got what I was looking for: a Big Ass Deluxe!:hee The way the 4 10's project the sound, you have to be standing about 10 feet away to get the full effect. Write the value down. Flip the front panel channel switch to Summer Fund Drive:C'mon guys lets show some support!If this site has helped you an you haven't recently donated Include your username so I know whos donatingPlease consider making a donation. We will test his suggestion with a Deluxe 5E3. If you want to be able to use unmatched output tubes then: - Rather than the common 250 Ohm cathode bias resistor on the 6V6es with a 25uF bypass capacitor, separate the cathodes and put a 470 Ohm 5 Watt resistor with a 47uF bypass capacitor on each 6V6. 7ma plate current which comes out to 66% of max rated dissipation using a 270 ohm 10 watt cathode resistor shared by the power tubes. The Little Walter amps that were in vogue a few years back were 5B6 based, and some folks here got into DIY-ing them, so some searching will give you ideas. To specifically address your comments, 80% is *not* very hot in this amp and will not shorten tube life. Adding 1-ohm resistors is a waste of time and effort as there is no bias adjustment , and the only thing that would effect bias is changing the B+ supply value or altering the value of the cathode bias resistor. 2. The grid A cathode biased amp usually develops more heat than a fixed bias IMHE. -Plate dissipation using cathode resistor method (not as accurate): I cathode = (20. The 2 x 6V6 Tweed amps were cathode baised except for the 5G9 Tremolux, which was fixed. - Scott . My plan is to put whatever it ends up being through the 5E3 cathodyne phase inverter/cathode bias power section. At the Workbench. YMMV Last edited by tubeswell; 12-03-2009, 04:15 PM IME 5E3's tend to run the bias very hot, at or over the rated max dissipation value for 6V6's. I just got the very nice used alnico magnet speaker from genoo. I think for cathode bias, though, you wouldn't do the . Reactions: pinchegil. 5E3 cathode bias resistor value. Please consider making a donation. I would think changing to fixed bias, your 5E3 is no longer a 5E3. A fixed bias will allow a bit more actual wattage - perhaps 10%-20% - but alter the tone and especially in the treble range. mcgjohn Super Member. Cathode voltage 20. The chassis, faceplates, and Topological Hall Effect. Welcome To the Hoffman Amplifiers Forum April 02, 2025, 05:03:23 pm: Welcome, Guest. In article number 2302984, Xuefeng Wang, Hongxin Yang, Binghui Ge, and co-workers report the large-area, high-quality epitaxy of ferromagnetic Cr 5 Te 6 single-crystalline thin films with the colossal . Then swapped 'em. And all that's for a 'typical' or 'datasheet average' 6V6. Last winter I finally got around to building the 5E3+ (the plus is their designation). With cathode-biased amps, it depends on your plate-to-cathode voltage (as well as your plate current). I had a 5E3 clone once and actually preferred the tone from a pair of mis-matched, different brand 6v6's. Many would say the Deluxe reaches a pinnacle of design with the 5E3, becoming the ultimate tone Tags: 5e3, bias pot, cathode bias, deluxe. 4) Connect the bias circuit to the junction of the two 220k ohm It is auto bias (cathode bias) so there is no bias adjustment. Logged The 5D3 reverts back to cathode bias, eliminates the feedback, and transitions to 9-pin triodes. " V1A's bias voltage is set by cathode resistor R4 which is connected to V1A's cathode (pin 3). when that is removed to work in the fixed bias like i said in the title im having problems with 120hz buzz on my fender deluxe 5e3 clone oxblood (cathode bias). I understand that it is a cathode biased amp. Feb 14, 2023 #26 ; Lowerleftcoast Poster Extraordinaire. STARTED MY HYBRID 5E3 5E3 Cathode Bias. Power = (V_plate - V_cathode) * (V_cathode/R_cathode) watts. The 5E3 is cathode biased. Bias versus tube brand in the 5E3. 1/250) = 80. The 5E3 is a very forgiving circuit with respect to power tube choices. Member. In the case of the 5E3, the 1500 ohm bias resistor that is part of the bootstrapping circuit unbalances the stage since I'm really liking the concept of building a 5E8-A, but with basically a 5E3 power section, ala cathode bias 6V6. I love the sound of a deluxe cathode bias, but I also like the idea of the cleans associated with the 5G9's bassman-style phase inverter circuit. danny Former Member. Cathode bias voltage looks normal. On the other hand, the cathode-biased amps that I adjusted the cathode bias resistor to get the tubes to run a little cooler with limited success. The Fender 5F6A Bassman and most Marshall amps are fixed bias Class AB amps. be at an even higher voltage of around +77v due to the 56k PI Tail Load resistor so the difference between grid and cathode results in a fixed negative bias voltage of around -2v. 7 and that result should be < 14 watts. 13 posts • Page 1 of 1. I'm already figuring on an 8K output transformer, like one would use for a 5E3, but not sure what to do for the power transformer? If you converted your 5E3 concertina PI to a Jim Kelly type concertina which is a like a 5E3 with feedback you could use the type of presence control he used. The result is ideally a signal present at the plate with an equal magnitude as the grid voltage but out of phase by 180 degrees. I’m using smaller Do cathode biased push-pull amps have to follow the 70% rule? Randall Aiken suggests that they do not. Hey guys, For the 5E3 Deluxe and other tweed amps the tape would be applied to the inside of the wooden back panel to cover the chassis opening. Advanced Search Second Stage 12AX7 Preamp. Final item: although 'target' is 100%, many real-world Remember that a 5E3 output stage is cathode-biased, so you don't need to worry about changes in B+ voltage (to a point) because cathode-biased stages are 'auto-biasing'. Late in that year, the 5E5A PRo went to fixed-bias also. Thanks, A different animal, but for lower voltage, cathode biased 6L6Bs, I would look into the 5B6 Bassman, which isn't quite a 5E3 but is closer to that sort of amp than a 5F6A. 7k cathode resistor or bias it hotter with an 820 ohm resistor. The 250Ω resistor will bias them hotter. Mar 5, 2012 #8 ; C. I used it on the 5E3 and got these: v3: 398 VDC, 35 milliamps v4: 321 VDC, 44 milliamps Tube dissipation The C and the D also have more clean headroom than a 5E3. 12w. 5k cathode resistor (a 22µF This works in both cathode bias amps (elevates the heater ground) or fixed bias amps (grounded cathode). In which case a change in cathode resistor changes biasing. But some 18 watt Marshall type amps use a 100uf cap. Apparently it's balanced all the way up until the power valves distort, after which all bets are off. Back in the day, nobody cared about using matched tubes. The 5E3 uses cathode bias on the power tubes, just like the preamp. Wharfcreek. Therefore, diagnostics capable of resolving IVDFs in both space and phase are of broad interest for understanding and improving modern plasma sources. cxhu kbfmrw opckza hqk kdxvnxo kimxw uif wsrhagsu xxfze difhp udil whnt luy hrej cgkuezv