jnewman Posted March 31, 2005 Report Share Posted March 31, 2005 Check out the 18 watt clones. There is a forum dedicate to 18watt builders. Those are killer sounding amps. Tons of info, schematics and support by folks that are in the same mess. Google it, I can't remember the site name. ← Do the 18 watt amps have the signature early marshall tone? I've never gotten my hands on one to try it out. Some day I'm going to go crazy and build myself a 1x12 combo with one input switchable between tweed champ electronics for clean and a low-power gain amp for dirty (which is why I'm asking about the 18 watt, it's an ideal candidate). I've never built a guitar amp before, but I've built several hi-fi audio amplifiers, so I ought to be able to manage it without killing myself . Quote Link to comment Share on other sites More sharing options...
lovekraft Posted March 31, 2005 Report Share Posted March 31, 2005 ...ok lol i respect you but, i can easily get stuff from an electronics wholesaler... And I'm not disrespecting you, but if you make an amp out of those parts with that switching power supply, it may well sound great (or not - who knows?), but it won't be a Marshall (not even close) - details are kinda important. By all means, do as you wish, and best of luck to ya. Keep yer fingers away from that switcher! Quote Link to comment Share on other sites More sharing options...
mledbetter Posted March 31, 2005 Report Share Posted March 31, 2005 Check out the 18 watt clones. There is a forum dedicate to 18watt builders. Those are killer sounding amps. Tons of info, schematics and support by folks that are in the same mess. Google it, I can't remember the site name. ← Do the 18 watt amps have the signature early marshall tone? I've never gotten my hands on one to try it out. Some day I'm going to go crazy and build myself a 1x12 combo with one input switchable between tweed champ electronics for clean and a low-power gain amp for dirty (which is why I'm asking about the 18 watt, it's an ideal candidate). I've never built a guitar amp before, but I've built several hi-fi audio amplifiers, so I ought to be able to manage it without killing myself . ← I've never gotten my hands on an 18watter.. it's supposed to be super vintage vibe though.. I've listened to a ton of clips from folks that built theirs. www.18watt.com is the site. I have a fender pro jr.. 2 84s, one ax7 and 1 at7 maybe? i don't remember.. Dude from www.eurotubes.com put together a package for me. Excellent price and the JJ tubes i absolutely love. I told him i wanted early breakup and a super tasty distorted sound and the combination of tubes he shipped me were dead on. It's only got a volume and a tone knob. Used to break up at 8 or so (out of 12) and now it gets gritty at 4-5. I just crank it to 12 and use my volume knob to go from clean to dist. It's a beautiful thing. 15 watts though and it's still loud as hell. I have a 6db cut attenuator that I made for it. That keeps the peace. Quote Link to comment Share on other sites More sharing options...
bond163 Posted March 31, 2005 Author Report Share Posted March 31, 2005 So out of a choice of Tubes: # Sovtek EL34WXT # Electro Harmonix EL34 EH # J.J. EL84 Tesla which are better? Sovtek 12AX7 or Mullard 12AX7 Quote Link to comment Share on other sites More sharing options...
mledbetter Posted March 31, 2005 Report Share Posted March 31, 2005 So out of a choice of Tubes: # Sovtek EL34WXT # Electro Harmonix EL34 EH # J.J. EL84 Tesla which are better? Sovtek 12AX7 or Mullard 12AX7 ← i'm a jj man Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 1, 2005 Author Report Share Posted April 1, 2005 hmmm ther not el34... but i can prob get JJ el34 and can anyone garauntee me that el34 are used in JCM800 master volume? in the better of the circuit diagrams, all thats written next to the main valves is the voltage in 480 ... Quote Link to comment Share on other sites More sharing options...
hendrix2430 Posted April 1, 2005 Report Share Posted April 1, 2005 I use Fuchs ODS amps. I also have a Tone King Comet that I use for cleans strictly, or when I use pedals for dirt. Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 2, 2005 Author Report Share Posted April 2, 2005 just finished component list: Quote Link to comment Share on other sites More sharing options...
lovekraft Posted April 2, 2005 Report Share Posted April 2, 2005 You've forgotten input/output jacks, a standby switch, a fuse and holder, and a pilot light. That's assuming you've made arrangements to build a board and a chassis, and already have all the parts for the power supply. And why do you need 6 12AX7s and sockets? Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 2, 2005 Author Report Share Posted April 2, 2005 (edited) because i need 6 12ax7's and whats the pilot light for? i am gonna build a 20w valve first before this, but i'm gonna order all components at the same time. i've only built solid state before .... Edited April 2, 2005 by bond163 Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 2, 2005 Author Report Share Posted April 2, 2005 i've highlighted the 6 12AX7's Quote Link to comment Share on other sites More sharing options...
Daniel Sorbera Posted April 2, 2005 Report Share Posted April 2, 2005 whers your output transformers on the parts list? Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 2, 2005 Author Report Share Posted April 2, 2005 im gonnna convert a pc psu into one Quote Link to comment Share on other sites More sharing options...
lovekraft Posted April 2, 2005 Report Share Posted April 2, 2005 i've highlighted the 6 12AX7's No, what you've highlighted is 3 12AX7s - the 12AX7 is a dual triode! And you also don't seem to understand that regardless of what you use for a power supply, you're still going to have to have a 100 watt output transformer if you're using 4 EL34s. Your lack of understanding of basic tube technology worries me almost as much as your aggressive, "can't-be-wrong" attitude - I wish you the best, but I really don't expect to ever hear that you've completed this über-Marshall you've got planned. I strongly recommend a little less hubris and a lot more research before you unsheath your soldering iron - as always, free advice is worth every penny you paid for it, so feel free to ignore it, and be careful around the high voltage. Remember, air isn't nearly as good an insulator at 700 volts DC as it is at house current levels. Don't hurt yourself! Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 2, 2005 Author Report Share Posted April 2, 2005 thank you for clearing that up i'm sorry if i've been rude but generally i have an excuse for every mistake .... in fact i generally all ways have an answer and i've said this is my first time with tubes thats why im building a 20w first ... and i know 700v can kill me (after many zaps when little from points i know what 240v feels like ...) Quote Link to comment Share on other sites More sharing options...
lovekraft Posted April 3, 2005 Report Share Posted April 3, 2005 No worries! I'm not your mom, so I'm not going to tell you how to act - I just want to make sure you know what you're getting yourself into before you get a bunch of money and time tied up in a huge project that you can't possibly complete, and that might potentially prove fatal if you're careless. Been there, done that - it sucks! Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 3, 2005 Author Report Share Posted April 3, 2005 lol ... well, i just finished my wah circuit ... it works well ... now for a pedal .... Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 4, 2005 Author Report Share Posted April 4, 2005 well the original Power Transformer was 340-0-340 around 200ma 6.3VAC IOut so i'll work out the cost of modifying a pc powersupply against a $200 transformer .... and hope i can put in a few less turns when re-winding the transformer to produce 375volts Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 4, 2005 Author Report Share Posted April 4, 2005 and then that would then be rectified an put through a smoothing cap ... 530v .... hmmmm Quote Link to comment Share on other sites More sharing options...
bluespresence Posted April 4, 2005 Report Share Posted April 4, 2005 bond163.....please use the "Edit" button and add to your post so you're not posting 3 times in a row. Thanks! Quote Link to comment Share on other sites More sharing options...
lovekraft Posted April 4, 2005 Report Share Posted April 4, 2005 If it helps, I think most old school EL34/6550 Marshalls ran the plate voltages between 420 and 480 volts, screens around 350-400 volts, but that's just off the top of my head, so don't quote it. And don't forget that you're going to need plenty of heater current to run a quad of EL34s. Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 4, 2005 Author Report Share Posted April 4, 2005 like how much? apparently modding this psu to 400v will allow 200w Quote Link to comment Share on other sites More sharing options...
lovekraft Posted April 4, 2005 Report Share Posted April 4, 2005 Like 7.5 - 8.5 amps for filaments ( a quad of EL34s will suck up 6 amps by themselves at 6.3 volts, and figure 300mA for each 12AX7, and add 10-20% for a safety margin), and between 200 and 400mADC for the HV supply (depending on yourvoltage, bias, etc.). 400mA at 450 volts works out to 180 watts, so you're covered there, so long as the psu can actually put out 200 watts. I'm really uncomfortable about loading high voltage switchers heavily, but it could just ne my age showing. Quote Link to comment Share on other sites More sharing options...
bond163 Posted April 4, 2005 Author Report Share Posted April 4, 2005 (edited) well i found the perfect pedal only prob will be that it will be a log as oposed to linear, which i hope wont make to much of a noticeable difference, but then again, i might make this type of pedal famous!! i'm also begining construction of a: big muff, sustainer, distortion, solo boost (i'm gonna build a few different boosters), electric mistress and a fuzz with many knobs, a crybaby wah Edited April 4, 2005 by bond163 Quote Link to comment Share on other sites More sharing options...
mledbetter Posted April 4, 2005 Report Share Posted April 4, 2005 i still can't figure out why the heck you want a 200 watt amp!! Who are you trying to kill/torture..A 50 watter will blister any drummer and a 100 watter will play to any arena you might dream of playing in.. Besides.. if you get on stage you're just going to be mic'd and run through the house anyway.. If you are into vintage tone (judging by your pedal projects I assume you are) go for quality over quantity.. a good 30 - 50 watt unit will give you absolurely everything you need. Check out www.18watt.com It's a whole community of folks that have finished their amps. They are a killer sounding amp, clones of the vintage 18 watt marshalls. There are 100 different variations and schematics.. you really can't go wrong there if you are careful. Although I would dare you to find anyone there that would agree with using a PC power supply.. those things are horrible. It's easily worth the money for a real output transformer over the time and headache in converting a PC one. There is another site online that goes into detail on how to wind your own transformers if you are just looking for a project.. Quote Link to comment Share on other sites More sharing options...
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