Go Back   UG Community @ Ultimate-Guitar.Com > Instruments > Gear Building & Customizing
User Name  
Password
Search:

Reply
Old 12-10-2006, 02:54 PM   #1
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
Kerry's Valve Junior Mods

Hey again fellow UGers,
Today I broke down and couldnt hold back my wanting to mod my Valve Junior. I decided to only do one mod today, but thats ok because its a good one .

I know your all like finish your pedals and stuff, but this only took up one morning so its good. Ok so what is it you may be asking. Well its a Gain switch. It goes between higher gain and lower gain.

Pictures (Sorry for a bit of blur, but you can make it out):






I plan in the future to do some more mods like to change the Fender Low style input into the Fender High style input for a higher input impedence and more sparkle.

Kerry
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-10-2006, 03:04 PM   #2
False_God
ios 5 compatible
 
False_God's Avatar
 
Join Date: Nov 2005
Location: Irelando
thats pretty cool man!!!
False_God is offline   Reply With Quote
Old 12-10-2006, 03:14 PM   #3
crazylaughboy
Jason Becker!
 
crazylaughboy's Avatar
 
Join Date: Oct 2005
cool, ever since i got my new amp ive been wanting to do stuff to my valve junior.
__________________
Tons of Gear For Sale!
crazylaughboy is offline   Reply With Quote
Old 12-10-2006, 04:38 PM   #4
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
Heres the soundclips!

1. This one is with the amp by itself. PRS Custom 24 Ten-Top on treble pickup. When the switch it down its on the lower gain, when the switch it up its on higher gain.
http://aronnelson.com/gallery/albums/album90/Alone.mpg

2. This one is using my built Marshall BluesBreaker (75% Gain, 75% Tone, 100% Volume), and my So Simple Compressor V2 (Compression Sensitivity 0% [This doesnt mean no compression, its about the same as 100%], Volume 100%). With my PRS as the guitar on the treble pickup. When the switch it down its on the lower gain, when the switch it up its on higher gain. This is one of my favorite tones I have gotten out of this thing!
http://aronnelson.com/gallery/album...With_Pedals.mpg

Kerry
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-10-2006, 05:08 PM   #5
HamrEnterprises
Registered User
 
HamrEnterprises's Avatar
 
Join Date: Nov 2006
Location: Gilbert, AZ
I am by no means an expert in electronics but it looks like the switch simply acts as a bypass for that particular resistor (the one you soldered to on each end) to give you the higher gain setting? Is that all you needed to do to achieve this mod?
__________________
Guitars:

Epi LP Standard HB W/ EMG 81/85
Ibanez RG470
OLP Tin Top

Amp:

Epi Valve Standard

Effects:

Custom Pedal Board

Boss DS-1 | Boss TU-2 | MXR Blue Box | MXR ZW-44 | DOD YJM308 | VS Jekyll & Hyde | Vox ToneLab SE
HamrEnterprises is offline   Reply With Quote
Old 12-10-2006, 05:19 PM   #6
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
Yea :P . But thats not the only mod I am doing. What this gain switch does it go either through the resistor, or replace the resistor with a jumper.
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-10-2006, 05:21 PM   #7
That_Pink_Queen
My Avatar Kills Fascists!
 
That_Pink_Queen's Avatar
 
Join Date: May 2005
Location: Portland, OR
It looks like he added a switchable jumper on R9.



If you replaced that resistor it looks like you'd just get a gain boost.


EDIT:
Which he already said I see:

Quote:
Originally Posted by call1800ksmyazz
Heres the soundclips!

1. This one is with the amp by itself. PRS Custom 24 Ten-Top on treble pickup. When the switch it down its on the lower gain, when the switch it up its on higher gain.
http://aronnelson.com/gallery/albums/album90/Alone.mpg

2. This one is using my built Marshall BluesBreaker (75% Gain, 75% Tone, 100% Volume), and my So Simple Compressor V2 (Compression Sensitivity 0% [This doesnt mean no compression, its about the same as 100%], Volume 100%). With my PRS as the guitar on the treble pickup. When the switch it down its on the lower gain, when the switch it up its on higher gain. This is one of my favorite tones I have gotten out of this thing!
http://aronnelson.com/gallery/album...With_Pedals.mpg

Kerry

Oops.

EDIT #2:
And he just posted again at the same time.
__________________
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
That_Pink_Queen is offline   Reply With Quote
Old 12-10-2006, 05:30 PM   #8
greenbox
The lazy one
 
greenbox's Avatar
 
Join Date: May 2006
Location: San Diego
Quote:
Originally Posted by call1800ksmyazz
I plan in the future to do some more mods like to change the Fender Low style input into the Fender High style input for a higher input impedance and more sparkle.

Kerry


I'm not sure about the epiphone valve jr (though I'm pretty sure this applies), but usually the input resistor is chosen to match the input to the first preamp tube.

Edit:
Looking at the schematic, you could replace the two 68k resistors with 1-33k resistor.

Last edited by greenbox : 12-10-2006 at 05:34 PM.
greenbox is offline   Reply With Quote
Old 12-10-2006, 05:32 PM   #9
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
But I have heard that this amps input section is based on the low input of a Fender amp. I havent studied many Fender amp schematics, but this amp probably has a few things based off of Fenders.
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-10-2006, 05:36 PM   #10
greenbox
The lazy one
 
greenbox's Avatar
 
Join Date: May 2006
Location: San Diego
you might be thinking about the input styles between a isolated ground and attaching a 1-Meg resistor to ground from the input (atleast, I think that's what you might be talking about). Anyway, if you change the input resistor, you'll also get twice the gain (since the 2-68k resistor's act as a 34k input impedance with a voltage division of 1/2.)

Atleast, that's what I thought you were talking about, you might or might not want to do that.
greenbox is offline   Reply With Quote
Old 12-10-2006, 05:40 PM   #11
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
Thats basically what I am talking about. The mod is to take away the 68k resistor to ground, and replace the first input resistor (68k) with a 22k resistor. This changed it from the Fender Low input to the Fender High input, or as they say.
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-10-2006, 05:56 PM   #12
That_Pink_Queen
My Avatar Kills Fascists!
 
That_Pink_Queen's Avatar
 
Join Date: May 2005
Location: Portland, OR
__________________
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
That_Pink_Queen is offline   Reply With Quote
Old 12-11-2006, 01:33 AM   #13
sempri_fi
Banned
 
sempri_fi's Avatar
 
Join Date: Jan 2006
Location: the red house
your time is well spend modding it
a new OT is probably a good idea too,
and the gain, bright, and master volume mods are also pretty fruitfull
and you might go ahead and inprove the power supply filtering as well, along with a nylon input jack, to help with any noise you are probably getting

there is so much you can do with that amp in terms of modding though, thats why im getting one, for christmas

i'll be watching this thread..
sempri_fi is offline   Reply With Quote
Old 12-11-2006, 09:23 AM   #14
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
My next mod is going to be a Master Volume after the second half of the 12AX7 and before the power tube. This is so I can put the full preamp tube overdrive without the sometimes crazy powertube overdrive/saturation.

Standby switch really isnt needed in this amp. So I dont really need to waste a switch.

I am also going to do the higher impedence input when I open it up again.

The power supply fix has already been done in the new V2 Valve Junior Heads so thats no problem. The jack is also fine, but if I do change that, thats at the bottom of my list.

My dad suggested me getting a new speaker or cab for it. I think im going to get a Celestion (probably V30) and put it in my Hartke. Or we may go to a car place that puts speakers and stuff in cars, and see if they have a speaker box without speakers we can use to build a cab.
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club

Last edited by call1800ksmyazz : 12-11-2006 at 10:00 AM.
call1800ksmyazz is offline   Reply With Quote
Old 12-11-2006, 06:14 PM   #15
greenbox
The lazy one
 
greenbox's Avatar
 
Join Date: May 2006
Location: San Diego
you're not really changing the input impedance, you're actually lowering it, but what you are doing is removing the voltage divider (so you effectively get an extra gain of 2 in your amp)

same idea though. Although, for the longest time now, I've been meaning to make an octave down or a tube screamer. I've just been really lazy.

as far as the master volume pot goes, sounds like a good idea (i'm not entirely sure, but it looks like you could just replace the 220k resistor after V1 with a 250k pot or something. But i'm sure you know what you're doing.
greenbox is offline   Reply With Quote
Old 12-11-2006, 07:20 PM   #16
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
^-I am exactly replacing the 220K resistor with a 250K pot. That was my whole idea. I guess now it has been approved since you came up with that too.

Wow I just decided to try my Hartke 12" 60w speaker with my Valve Junior instead of my Hughes and Kettner's Jensen 10" 30w speaker. The difference is incredible.

The Jensen:
*More trebly.
*Gets tube overdrive when amp is on 25%.
*Gets full tube saturation when amp is on 50%+.

The Hartke:
*Much, much warmer and thicker.
*Extremely loud! Freaking 10 times as loud as the other speaker. I was playing at 25% volume with my BluesBreaker overdrive and Compression pedals, with my guitar at 2 volume, and now I have a headache from it!
*Absolutely NO tube saturation and barely any tube overdrive, even with an overdrive pedal.

Conclusion:
The Jensen can get a GREAT heavy classic rock tone with overdrive and compressor. The Hartke has an amazing clean tone with the overdrive and compressor and every note is easily picked up. However the Hartke has NO good heavy tones.

I am probably going to get a Celestion V30 or Greenback and mount it in a cab (I will probably build a cab) and then I will have a good selection in all of the tones I need!
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-11-2006, 09:23 PM   #17
zekk
I am me as you are we
 
zekk's Avatar
 
Join Date: Jun 2006
Maybe you could wire the amp to all of the speakers with a switch for each one...
__________________
Founder of UG's David Bowie Fan Club. Pm to join.

Founder of UG's "Rockers against being freakishly skinny" Club. PM to join.
zekk is offline   Reply With Quote
Old 12-11-2006, 10:30 PM   #18
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
Yea I keep going back to play through the amp. I just got the absolute BEST tone for classic rock through the Hartke cab. I can get Marshall Plexi-like tones from this baby. Then with the H&K's Jensen speaker, I can get the oldschool metalish tones.

I just realised that this amp could possibly be one of the best I have tried with my pedals backing it. At least I know that I have found my tone. And finding your tone is a long and hard journey. Well... making pedals is good because it adds to your personal tone and you find what you like
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-12-2006, 09:55 PM   #19
call1800ksmyazz
Affectronix
 
call1800ksmyazz's Avatar
 
Join Date: May 2004
Location: South Florida
Well anyways... I did it. I spend the last few hours adding the Master Volume, and fixing the Input resistors to give a higher impedence and a clearer, sparklier sound. This input mod makes a hell of a lot of difference on the amp's muddy/bassyness when clean. Its not that bad standard, but a lot better with the treblier sound.

Heres where I removed R5 (220K) and replaced it with a 250K pot. Thats the Master Volume and comes after the second half of the 12AX7 preamp tube.

Heres where I took out R2 and R1, the input resistors, and replaced them with a 22K resistor and a 1M resistor.

Heres the new front of the amp. Yes I am going to get a new Master Volume knob. This is all I have at the moment.


The new, triple modded VJ is awsome... Whats comming next? I dont even know yet...

Kerry
__________________
Marshall BluesBreaker
4uzz Face
ToneBender and SupaFuzz
Bobtavia
Tube Reverb
Phase 45 Univibed
Modded VJ 1
18 Watt Plexi TMB
Modded VJ 2/3
VF-10 Amp
Affectronix

Modder Extraordinaire of the VJ Cult
Über God of the Affectronix Club
call1800ksmyazz is offline   Reply With Quote
Old 12-12-2006, 09:58 PM   #20
lookie here
ExpldingAstros
 
lookie here's Avatar
 
Join Date: Mar 2005
Location: Brampton, Ontario, eh?
Aw sweet i would never trust myself to mod a amp unless it was something shitty. But good job Kerry
__________________
Quote:
Originally Posted by rabidguitarist
I even tried dressing up as a fly myself, and throwing myself out of the window in the hope that they will follow me. But to no avail.

Quote:
Originally Posted by daytripper75
we have a Llama forum, and still no drum forum.
lookie here is offline   Reply With Quote
Reply


Thread Tools Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -4. The time now is 01:53 PM.

Forum Archives / About / Terms of Use / Advertise / Contact / Ultimate-Guitar.Com © 2014
Powered by: vBulletin Version 3.0.9
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.