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Post by DarKnight on Mar 13, 2007 14:47:25 GMT -5
'lo! Just been thinking about building an amp... Many things point me to this way... Expanding knowledge about electronics (especially ac & high current and voltage), electrical safety, customising own amp, learning experience, understandin stuff in general... maybe price too, but I have weird gut feelin' that this will go over the top no matter what lol. ;D Been searching around web and amount of info is _HUGE_... Well my thoughts were first with tubes, but then I had in mind to go with hybrid design... Using maybe three switchable preamps... two tube (tweed/blackface & some marshall design?) and one solid state (just in case if I run out of money and can't afford tubes... or just want solid state sound)... prolly marhall tone stacks for every preamp... also some sort of automatic stanby-ready circuit for tube warming would be cool power stage would be solid state.. Me thinks around 100W solid state would be plenty for me... I also had thoughts adding some built-in effects like tubescreamer, some echo device, reverb and wah... wah-pedal would double as volume pedal with flick of a switch... wah could also be used without pedal... hmm.. what else... oh first I had thougts going with head and cabinet -desing, but then I thought about making it a combo... Something little larger than 4x12" cabinet with tilted front... amp in the center... above 2x10" open back cab and under 2x12" closed back cab... This is now at concept-stage and I'm just starting to find out what kind of stuff are possible... So some sort of recommendations and opinions are welcome... Dos and don'ts and so on.. Specially about what sort of preamp and powerstage designs I should go with... And also thoughts about construction are welcome... I'll post more info when I have more ideas... Too much info for now to tell anything in very detail...  Thanks anyhow... ;D Cheerios! Dark Edit: I hope this thread will be place to discuss about all around amp building too, so slight offtopic discussion is IMO allowed... It's fun to share thoughts... maybe we all learn something... over and out! ;D |
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jeremyo83
Meter Reader 1st Class
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Post by jeremyo83 on Mar 13, 2007 15:43:33 GMT -5
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Post by ChrisK on Mar 13, 2007 15:58:10 GMT -5
This is actually way more complicated than electric guitar wiring design. I first learned electronics with vacuum tubes back in the 1960's and I still know very little.
If you have interest in tube amps, the Aspen Pitman book on tube amps ($50 US in the US) has over 800 schematics of vintage and modern tube amps on the included CD. It's what I use for a reference. The Fender website under customer support has a lot of the most recent Fender amp schematics thereon.
While I think that building tube amps is worthwhile, solid-state amps are fairly complicated to build from an engineering design perspective and so relatively inexpensive that I would much rather just buy them (and I CAN design them).
The 100W Crate Powerblock amp was going for $99 late last year, so one can use a modeling pedal and a power (amp) block and avoid much of the messy design stuff. Even a bass power amp block can certainly be used for guitar if a guitar voiced preamp and speaker(s) are used.
While it may seem to be more efficient to think of big all-inclusive designs while you're at it, I would recommend a significant investment in learning the applicable theory, and to start small, or modular. Again, if you want a big solid-state power amp (where the goal is always the pure replication of the incoming signal), go buy a power amp block and focus your attention on the preamp voicing. If you keep effects modular, you can actually use screws to hold your design together rather than Velcro (the "hood" will always be open for "repairs and mods")!
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Post by sumgai on Mar 13, 2007 17:11:00 GMT -5
.......
The 100W Crate Powerblock amp was going for $99 late last year, so one can use a modeling pedal and a power (amp) block and avoid much of the messy design stuff. Even a bass power amp block can certainly be used for guitar if a guitar voiced preamp and speaker(s) are used. Make that 150 watts, please.  These sound so good, and are so easy to transport (5 lbs!), I had to go back and get another one, just for a spare. They'd gone down to $80, so I took my earlier purchase back, got a refund, and turned around and bought it again. Think of it: 300 watts in the palm of my two hands, for $160 plus sales tax. With new warranty. Can't beat that, no matter how hard you try. ;D Building one's own rig can be a righteous experience, but be it tube or solid-state, don't ever forget Chris's First Rule of Experimenting: Always keep one hand in your pocket. If you ask politely, I'm sure that worthy will dole out the rest of his rules for staying alive and healthy whilst forcing electrons to go where they ordinarily wouldn't bother going.  sumgai |
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Post by ChrisK on Mar 13, 2007 18:39:56 GMT -5
Oh just back off, Sparky!  220, 221, whatever. These are solid-state watts, so "all bits are insignificant" anyway.  Actually, the engineer's rule is to keep both hands in yer pockets and have a tech take the measurements (someone's always the fuse). Rules for successful living. Do __Get the cash, as much as you can. Forever How to get your own way; "Hold your breath until you turn blue." "If that doesn't work, hold someone else's breath until they turn blue." "Bill Cosby" In life, we get what we settle for. |
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Post by sumgai on Mar 13, 2007 19:53:10 GMT -5
Should we not expand that to reflect the correct meaning, sans the contractions? I believe the phrase is.... | Some one else is always the fuse. |
That's what them thar teachers learned me! ;D sumgai |
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Post by DarKnight on Mar 14, 2007 1:52:21 GMT -5
I love this community... ;D Nothing makes me happier than to read humorous posts in the morning... Yeah I know that amps go way over guitar circuits designin', but I'm just curious... that's why would like to build everything myself...  And I'm aware of dangers working with mains... my intention is to keep my fingers on fire only on fretboard... oh wait strings... well atleast when I play unplugged! hopefully... ;D This project isn't gonna happen in next, I say, year or so... I'm having my electromagnetics course going on right now and we're going to discuss basic AC-circuits... but I'm also aiming to participate some sort of AC-safety -courses which are held time to time... if I recall right... I thought also that I'll consult cousin(or someone) of my who is an electrician... First of all I want to build and amp that is SAFE for me and people around me... Okay moving on... I found this schematic last night... Interested about power-amp part... Also checked local supliers for transistors... Didn't found any mentioned in the schematic, but prolly some other models can be used too... How the power supply should be designed(or buyed) to run both tubes and transistors? They run in different voltages? Should I have two powersupplies? And btw. if I build effects in the amp... would they need own preamp(s)?  Dark Edit: Liked the idea to buy separate power amp, but in Finland it means ordering it from some other country... Means extra payment and maybe problems with customs.. :S We have rather narrow selection of instrument stuff available here...But I'll keep my eyes open... it would indeed reduce wirin' mess a lot... |
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Post by JohnH on Mar 14, 2007 6:33:05 GMT -5
Ive been experimenting with JFET transistors. These can be persuaded to respond to signals alot like tubes, but work at low current and voltage like a normal transistor. Overdriving them sounds much better than a bipolar transistor circuit. Theres lots of ideas at: www.runoffgroove.comI reckon a cool project would be a preamp based around one of those circuits, with an off-the shelf power amp module. John |
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Post by ChrisK on Mar 14, 2007 12:32:24 GMT -5
Well, most hopefully, but in the end:
someone IS always the fuse.
We had a "safety event" at our global company. A test/customer service/whatever engineer (the operative term being engineer) was operating some equipment outside of its enclosure. It had an off-line switching power supply (240 VAC mains) that had a capacitor case at about 120 VDC. He was reaching across the PCB (and the power supply section) to change some mini jumpers in a class 2 section. He touched the cap case and got a "tingle". The solution was to tell everyone in our 120,000 employee company that they decided to make protective covers for that cap (which a new written procedure will detail how to use them when the PCB is operated in the open), and to forewarn us (again) of the dangers of that there electrical stuff.
He's OK after this experience (experience usually comes from poor judgment), although I don't know about him being OK before this experience (just 'cuz yer finger fits into a light bulb socket.............).
Additional rules for successful living:
1. Don't reach across a dangerous section. Pay attention and learn of which you're fooling with.
2. Cover dangerous sections. Pay attention and learn of what you're fooling with.
3. Turn the thing off, change the jumpers, and turn it back on again. Pay attention and learn of what you're fooling with.
And 4. Pay attention and learn of what you're fooling with.
Of all of things that I learned in the Army (aside from the fact that I didn't want to be in the Army) was that:
"Prior Preparation Prevents Pi$$ Poor Performance."
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Post by johan on Mar 16, 2007 5:30:51 GMT -5
Ive been experimenting with JFET transistors. These can be persuaded to respond to signals alot like tubes, but work at low current and voltage like a normal transistor. Overdriving them sounds much better than a bipolar transistor circuit. Theres lots of ideas at: www.runoffgroove.comJohn When I found that site, I almost didn't come back here. But am really looking into doing a low wattage tube amp project. Know about Doberman kits, but ordering a $200 dollar kit from europe will cost me another almost $200 to get it here (tax and shipping etc). Does anybody know of low wattage tube amp kits in europe? meanwhile playing with my (d)umble...  |
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Post by DarKnight on Mar 16, 2007 8:12:53 GMT -5
johan in finland we have Uraltone which seems to have tube amp kit... 275€... people say it's very good for the price... IMO uraltone is a good company with good reputation (atleast inside Finland), so that might be one solution for your problem... I suggest you drop them a line and ask how things are... They also give technical advice if needed... that one popped in my mind... there are prolly other supliers for amp kits, that's a start... ;D Cheers Dark ps. I can help translating if there is something weird... seems that their pages are not yet complete in english... two very different languages mixed makes it rather weird to read.. |
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Post by UnklMickey on Mar 16, 2007 16:25:08 GMT -5
pm dunkelfalke for another possibility too.
he posted about a "madamp" a while ago. he did the research, but i don't know if he bought the kit.
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Thanks anyhow... ;D
And I'm aware of dangers working with mains... my intention is to keep my fingers on fire only on fretboard... oh wait strings... well atleast when I play unplugged! hopefully... ;D This project isn't gonna happen in next, I say, year or so... I'm having my electromagnetics course going on right now and we're going to discuss basic AC-circuits... but I'm also aiming to participate some sort of AC-safety -courses which are held time to time... if I recall right... 
