#1
So tomorrow I am going to embark on the modding of my new Valve Junior. I like it stock, but it can sound a tad harsh sometimes. I think I am going to go for the jumper on R6 for the gain boost, and a bit later I am look into headroom boosting mods and/or Marshall-y mods or the BitMo voicing mod. First though, I want to make sure I don't kill myself. So the question is, how do I discharge filter caps? Thanks.
Guitar
Ernie Ball Music Man Silhouette Special
Washburn WI64
Martin D-15
Amps
1960s Harmony
Rocktron/Egnater TOL 50 2x12
Rivera Chubster 55
FX
Fulltone OCD v.1
Keeley TS808
Voodoo Labs Superfuzz
Wilson WH10
Boss DD-20
#2
First get two crocodile clips and some wire (just make sure its not too thin). Put one clip to ground (the chassis) and run the wire to the next clip. Put on some gloves and make sure you are not touching the chassis. Then put the second clip on the cap's positive prong. There you have it.

EDIT: Here is an indepth look at the process.
#3
Are caps polarized, or does it not matter which leg of the cap I attach the clip to?
Guitar
Ernie Ball Music Man Silhouette Special
Washburn WI64
Martin D-15
Amps
1960s Harmony
Rocktron/Egnater TOL 50 2x12
Rivera Chubster 55
FX
Fulltone OCD v.1
Keeley TS808
Voodoo Labs Superfuzz
Wilson WH10
Boss DD-20
#4
Is this the head? They have bleeder resistors in them meaning you won't have to drain the caps, just wait a few minutes after you shut it off. I think the newer combos have bleeder resistors as well, I know the older ones didn't though. If the filter caps leads aren't exposed on the top of the board it probably the bleeder resistors it.

#5
It's three day old head. Thanks for the help, it should be fun! Feel free to post links everyone to VJ modding websites too!
Guitar
Ernie Ball Music Man Silhouette Special
Washburn WI64
Martin D-15
Amps
1960s Harmony
Rocktron/Egnater TOL 50 2x12
Rivera Chubster 55
FX
Fulltone OCD v.1
Keeley TS808
Voodoo Labs Superfuzz
Wilson WH10
Boss DD-20
#8
Quote by kurtlives91
I just got one of the newer heads and you dont need to do anything. They are safe to work with.


No. Turning it off and getting modding straight away can kill you. ALWAYS discharge caps (preferably through a 1M 1w resistor) and check the caps voltages with a multimeter before you go anywhere near it.
"Everybody, one day will die and be forgotten. Act and behave in a way that will make life interesting and fun. Find a passion, form relationships, don't be afraid to get out there and fuck what everyone else thinks."
#10
^No (if you want to risk your life, that is)

Newer cars has airbags in them, so you don't have to use seat belt ^^
"I never liked those Deep Purples or those sort of things. I always hated it. I always thought it was a poor man’s Led Zeppelin"
// Angus Young

+1
#12
Keep it going. Hope you die
"I never liked those Deep Purples or those sort of things. I always hated it. I always thought it was a poor man’s Led Zeppelin"
// Angus Young

+1
#13
Quote by kurtlives91
Well all I know is many people have told me the same thing as what I said.

I have also modded a new VJ without any discharging and I was fine.


You know, most people who get killed or hurt badly say "Oh nothing happened to me/it won't happen to me" Bleed off resister or not, ALWAYS check your caps. What you're saying is like "Oh I refueled my hot lawn mower with gas and it didn't blow up I'm fine"
#14
Quote by Thewolf_and_man
Keep it going. Hope you die
That's juvenile and uncalled for. Stop it NOW.


RHCPfan01, I've sent an e-mail to Gibson/Epiphone service requesting information to verify whether or not bleeder resistors have been added to the latest versions of the VJ.


Even if they have been added, as rumored, your amp might be "old stock".

Proceed with caution. Getting knocked on your ass and/or having your heart stop because of a shock from several hundred volts is nothing to take lightly.

Until you're CERTAIN you have bleeder resistors and how long it takes to discharge after power off, use the proper caution this demands. Put a multimeter set to read DC volts across the filter caps, and verify they have been discharged. If not discharged, bleed them manually the first time. Then permanently add a large (1 meg ohm) resistor across ONE of them. This will allow all of them to gradually discharge whenever the power is turned off.

I hope to have more info about this in a day or two.

Be safe, and good luck.
SYK
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#16
V2(b) and V3 heads HAVE bleeder resistors. Epiphone put them in due to the number of people modding it after the amp was released. You can't get to leads on the filter caps (which nobody has mentioned) unless you flip the board over which at times can be fairly difficult, and if you think there still residual voltage in there, dangerous. If you want to double check the voltage use your DMM and connect to one of R10 leads and then to ground. R10 is connected to C6.

I can assure you though TS your head has bleeder resistors in. I've been in my head countless times and just got done modding a V3 version today. Wait a few minutes after having it on and you'll be good to go.

#17
Quote by Thewolf_and_man
Keep it going. Hope you die

Reported

I have talked with Epi. All the new VJs (ones with black PCB). They all have bleeder resistors and are safe to work with.
#18
If I were you, I'd still check the caps. Once I was working on an old bi-linear amplifier (for CB radios) and I forgot to drain the four 8950's and I literally got the piss knocked out of me not once, but twice! When I measured the discharge voltage, it was 1564 volts. So yeah. I should be dead.
#19
Quote by kurtlives91
Reported

I have talked with Epi. All the new VJs (ones with black PCB). They all have bleeder resistors and are safe to work with.


Baha. Isn't it you that should be reported? Risking peoples lifes...?
"I never liked those Deep Purples or those sort of things. I always hated it. I always thought it was a poor man’s Led Zeppelin"
// Angus Young

+1
Last edited by Thewolf_and_man at Nov 7, 2007,
#21
Quote by dark_scientist
are the caps in the harley benton ga5(combo) the same as in the VJ?


They should be in the same range (around 100uf) and probably the same voltage.

ALWAYS DISCHARGE YOUR CAPS AND THEN TEST THEM WITH A MULTIMETER, NO MATTER IF YOU'VE GOT BLEEDER RESISTORS OR NOT.

I don't want to see somebody get hurt/killed because of some silly advice they read on the internet. Not only are you a LOT less likely to get injured, you'll also develop good habits for working on any amps that might not have bleeder resistors.
"Everybody, one day will die and be forgotten. Act and behave in a way that will make life interesting and fun. Find a passion, form relationships, don't be afraid to get out there and fuck what everyone else thinks."
#22
^ ive ordered the Harley Benton GA5 Head, so nice to see this thread has hit my issues with that already!!

so if it passes the multimeter test, theres no issues? mod away? B-E-A-UTILFUL
<*ELECTRO*>
XXXXX
XXXXX

______________________________________
Quote by ShadesOfNight
I'm not a sadistic person, but I'd like to pull the wings off every fly in the world so they all starve to death or get eaten alive by spiders

#23
Quote by the_random_hero
They should be in the same range (around 100uf) and probably the same voltage.

ALWAYS DISCHARGE YOUR CAPS AND THEN TEST THEM WITH A MULTIMETER, NO MATTER IF YOU'VE GOT BLEEDER RESISTORS OR NOT.

I don't want to see somebody get hurt/killed because of some silly advice they read on the internet. Not only are you a LOT less likely to get injured, you'll also develop good habits for working on any amps that might not have bleeder resistors.

if somebody got killed from playing with amps... would u hear it tho? and would u know if it's somebody here? i think that's low probability but okay.


waht i did was (because i didn't have crocodile clip jumper wires or 1 watt resistors) i let my amp sit for a 24 hours. after that, i checked the voltage and it was 0.01V. i hoped that wouldn't kill me.

and guess waht? i'm still posting here.
Call me "Shot".

ShotRod Guitar Works

Custom Hand-wired Amplifiers and Effect Pedals.

Est. 2007


Source to everything I say about Guitars, Pedals, and Amplifiers: I make them.


UG's Best DIY PedalBoard