I will attempt to build this



Recently it came to my attention that our chaplain had in his possesion a nonfunctional Line 6 spider 3 75w amp. I offered to see if I could fix it and after much research and a bit of poking around inside the answer is no, I cant.

Which leaves us amp less out here at FOB Normandy and I just can't abide that. Nosir, I cant. So I decided to continue my lil adventure in DIY and get what I needed to build a simple Tube amplifier. I ordered everything I need last night. Cant wait for it to get here.

I'm spending a bit more than the wife would like on this project, but its still going to be way cheaper than getting a manufactured amp, and hopefully I learn a lot in the process. I've allready been looking into as much 1930's technology as I can on the internet, pretty suprising how much you can learn about it

I should have it all in the next couple of weeks and will get started ASAP

This sounds awesome dude what tubes you ordered?

It comes with a 12ax7 and an octal tube. I'd have to wait to see what brand they are usually Electro-Harmonix, JJ, or Sovtek are shipped with the kit. Once I get it working I might play around with tubes and see how it affects the sound, but for now I'm just going with what is included in the kit. From what Is said about it everything they put in is of a very high quality so I may end up happy with what they send me. I'm still learning right now, about how it all works, but the more I read the more I start to understand and I'm feeling more and more confidant that I can do this.

Amp from scratch, hell yeah dude.

John do you recon you could send me any copies of amp manuals and what not that you have if they are online copies? Or if they are books then could you reference them for me? I have been trying to persuade my dad to learn so we can build a Bentley amp. Also do you have the link for the tube kit you purchased?

sending you a pm

What sort of amp are you going for?

Its going to be a lil guy, about 20 watts. It will be switchable between 4, 8 and 16 OHM's output so I will be able to use it with a single speaker (what I have here) or a 4x12 cab of any normal configuration. I am thinking about deviating from the plans I have to give it some extra headroom so I can use pedals in front of it, and be able to switch to a clean sound via the dirtbox. I'm loving the BYOC Muff I built and i think it will go well with this amp.

Sounds sweet. Don't you need atleast 2 EL84's or 6v6 tubes to get about 20 watts though?

I'm not going to claim to fully understand all the math, I am going to build it to spec, and try to work out how to increase the headroom a bit. Its been done by others, so essentially I will be duplicating thier efforts, and trying to plug in a few mods. Heres a sample of what I am dealing with. Bear in mind that its been a while since I was in school and I am not a huge fan of math.

"This ground connection references the secondary signal to zero volts, so it is alternating current around the circuit's zerovoltage
point. In the case of the XXXXX the voltage swings from 0V to +400V, back down to 0V, then to 400V,
and back to 0V. In the US, each cycle takes 1/60 of a second. Perhaps you are questioning the value of 400V, because the Hammond transformer specifications say the secondary voltage is 275VAC. Transformer secondaries are generally specified by their RMS AC output voltage. RMS is a measure of voltage delivered into a load over time rather than a measurement of an instantaneous peak voltage. To get the peak voltage you must multiply the RMS voltage times the square root of 2 (approximately, 1.414):"

so yeah, it takes a bit of working out for me to have even a clue. But I know how to safely discharge a capacitor, thier are exelent guides available on how to safely do your first power up on the amp, and I have learned how to read the schematics to the point that I feel I will be able to put it together correctly. there are also layout diagrams and pictures of other peoples builds that i can refer to if i get confused. I think I can do this.

You seem very competent with this stuff I'm sure it'll come out great

Parts are finally here! I has TOOBZ!

Time to make some br00tal muziks

Yezz, can't wait to hear the results of this project.

I can't wait either, but trying to take my time. I have checked everything out in the kit and have set up the basic layout of how its going to go. I had a bit of a rough time Identifying two of the capacitors, but I have it sorted now. One has a value that is slightly off. it should work however and I am not to worried about it. The kit came with NO instructions so I am trying to double and triple check where everything goes before I start to solder everything in place. I dont want any errors here! I'll try to get some pics up later, my internets is being extra slow right now.

where did you learn all this stuff man? I wish to build an amplifier to as well or at least do mods on a Epiphone Valve Junior or some sort. Right now I am learning how to read schematics but I don't know of any good books or websites that would show me how to build or modify an amp safely.

I also wish to build amplifiers for a living but I want to learn more until I feel comfortable on doing so...please help me out man..

I'm still learning myself. A good place to start is over at AX.84.com
They have a lot of links to different sites and also to some technical manuals that are helpful. I dont know your background, but if you are still in school a would recomend you get some classes that involve electronics. I wish I had.

Way to go man !!

If you are going to enter the world of tube amp building and modding I thought I should give you some old links I have so I can give you a hand of help with it

There you go....

http://www.sonicdeli.com/ThunderTweakWeb/bias_calc2.html

http://www.pentodepress.com/home/amplifier...hode-capacitor/

http://www.webervst.com/tubes1/calcbias.htm

http://taweber.powweb.com/biasrite/br_page.htm

http://www.ax84.com/contrib/biascalc.php

http://www.bandslink.com/randall/bias.htm

I wish you best luck with your project man!

If I can be of any assistance please let me know

Cheers,
VolTatz

thanks man. I was not aware of some of those. I cant wait to get back to it, finally have a soldering iron unpacked so....

No problem man! I just can't wait to hear this project ROCKIN' !!!!

Though be carefull with high voltages....

Hey AxAxSxS,

How is it going with the project mate ?

Any progress ? Some pics or sound clips maybe ?

Take care,
VolTatz

I just got the boxes that had everything in it shipped from Iraq. I'm still unpacking and have a lot of stuff going on so its kinda on hold. Today I have to rewire our bassist's squire wich is making wierd noises like there is a short and I have 3 old amps tthat need some work. Add on full time work and band practice and it might be a bit. I WILL get to it though, wishing I had had time to finish it while I was deployed though.

Hi :-)

I'm sorry for your band member That really sucks I really hope he gets better...
You said



May i ask if you are in the army ? I mean your job...

Take care,
VolTatz

yep I'm an infantry guy, wich accounts for my high IQ :p
thanks for the kind remarks regarding brian.

Cool. My father was in the army ( helicopters , apache etc ) he is now retired. And my brother is in the war navy . He just started his training in sea-hawk helicopters :)

I think now it is a good period , i mean there aren't so many wars nowadays which is nice.



Cool man

By the way, my friend who i told you was fixing my Logo he is finished with his work, I also made some artistic ( epic fail -> my artistic is pretty bad ). Anyway, I'll open a new post in a few days, so you tell me if you like it ( and everybody here of course )

Take care man,
VolTatz

But oldschool infantry, wearing an axe to battle instead of guns! Guns are for people who are scared to fight up close! REAL MEN SPLIT SKULLS WITH AN AXE!!