i has a new amp

deaddonkey

it has 2 knobs
it sounds like complete crap
i'm modding it

p.s. - anyone got tips for making solder stick to PCBs? do i need to buy some flux to clean up the joint so the solder takes?



pics and descriptions of mods will follow when complete

p.p.s. trying to buy parts in maplins is a pain, the guys are sound, but the music is thumping and it's a mess and you can't concentrate.
gah.

this is an opportunity for donk to learn how amps work, reading up can only get me so far, i gotta get my hands dirty.

Fingers Mcginty

Is that a wee tube amp? also lovely looking axe you got there...what is it?

deaddonkey

yeah it's a 5 watt epi valve junior, 1 12ax7 and 1 el84

the guitar is a korean made 'vintage' gretsch copy, that should suck, but is really, really fun to play.

Karl Hungus

Not too shabby at all. Definitely worth modding, I'm sure there are lots of guides out there for the Valve Jnr that'll do the job, because I've heard that HB one is pretty much identical. Good luck with the mods.

deaddonkey

haha, open this thing up, and you can see where it said valve junior on the PCB and they've scratched it out, hahaha
thomann are plagiarists, but they're classy plagiarists.

this thing is identical to the VJ. i've done a few mods, it's improved it a lot, i'm trying to trace the source of some unwanted noise.

gonna add a loop and a master volume tomorrow, as well as a cap to brighten it up, it's quite bassy.

Karl Hungus

deaddonkey wrote: »

haha, open this thing up, and you can see where it said valve junior on the PCB and they've scratched it out, hahaha
thomann are plagiarists, but they're classy plagiarists.

LOL!

Very classy indeed!

judas101

deaddonkey wrote: »

yeah it's a 5 watt epi valve junior, 1 12ax7 and 1 el84

doesnt look like an epi valve junior to me

deaddonkey

judas101 wrote: »

doesnt look like an epi valve junior to me

try reading the whole thread, it's fun and easy!

Fingers Mcginty

the finish on that guitar is very impressive

Johnny Storm

deaddonkey wrote: »

haha, open this thing up, and you can see where it said valve junior on the PCB and they've scratched it out, hahaha
thomann are plagiarists, but they're classy plagiarists.

this thing is identical to the VJ. i've done a few mods, it's improved it a lot, i'm trying to trace the source of some unwanted noise.

gonna add a loop and a master volume tomorrow, as well as a cap to brighten it up, it's quite bassy.

For my info, what was wrong with the sound to begin with?
And what mods did you do?
I had intended to mod my EVJ but the instinct for self-preservation kicked in :rolleyes:
There are indeed a bajillion sites dedicated to modding the EVJ as I'm sure you've seen.

Fingers Mcginty

johnny.....give us a :Dclip

Johnny Storm

Heh.. you really don't want to hear my playing

deaddonkey

Fingers Mcginty wrote: »

the finish on that guitar is very impressive

thank you sir. tis a nice axe to play.

Johnny Storm wrote: »

For my info, what was wrong with the sound to begin with?
And what mods did you do?
I had intended to mod my EVJ but the instinct for self-preservation kicked in :rolleyes:
There are indeed a bajillion sites dedicated to modding the EVJ as I'm sure you've seen.

well the stock VJ is very, very dark sounding and needs brightening up. it's also quite flat and compressed sounding to me.

the preamp circuit has some dodgy values - it attenuates a lot of signal before hitting the first stage of the 12ax7, and the input to ground impedance is suspect aswell. I cut out R2 and replaced it with a wire to let all the signal through for more preamp distortion

there's also some funny choices of capacitors on the cathodes of the 12ax7, leading to a darker sound than i'd like, and the gain is attenuated again before reaching the second stage of the preamp valve, so i'm putting a pot in there to control preamp gain aswell as volume. i'll also add a master volume in place of R5, and maybe an fx loop and an attenuated output with a small lightbulb to attenuate and compress the signal if i want to.

out of the box with so much signal attenuated it's not that loud, with a few mods when you're getting more of what the amp has to offer, 5 watts is very, very, very loud indeed.

Johnny Storm

Thanks, dude!

FYI the best info I found on EVJ modding is now at sewatt.com in the section "archive from 18watt". The main thread is 180 pages long! :eek: