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Author Topic: SG Junior upgrades  (Read 18579 times)

Dave Sloven

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SG Junior upgrades
« on: March 03, 2014, 06:24:29 AM »
I've started some more upgrades to my SG Junior this week after installing a Stockholm P-90 last year.

Upgrades completed so far are shielding the cavities and installing a new custom harness.

Here's the specs on the harness:

Quote
Modern Style SG Junior Harness With Bleed Kit
1x .033uf K7 (Russian) Cap
2x 500k Mojo CTS pots
1x Switchcraft Jack



Completely stock (that dark paint was conductive, but shield was not complete at all):



New harness (he included a spare 0.022 WD Music Mustard cap in case it turned out too dark)



Stockholm and new harness installed, with fully shielded cavities:



Phase 2 will be the installation of a Graph Tech TUSQ XL nut and ResoMax NW2 bridge.
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gwEm

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Re: SG Junior upgrades
« Reply #1 on: March 03, 2014, 01:19:56 PM »
neat job - do you notice an improvement in the noise?
Quote from: AndyR
you wouldn't use the meat knife on crusty bread but, equally, the serrated knife and straight edge knife aren't going to go through raw meat as quickly

Dave Sloven

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Re: SG Junior upgrades
« Reply #2 on: March 03, 2014, 02:37:23 PM »
I've only had the chance to check it on the solid state practice amp (a Roland 30X) so far, but even though the bridge and pickup are not set up properly yet - making it sound and play like cr@p - I seem to detect that the screech is not diminished, and seems to be a function of how close I stand to the amp.  Only once I have it better set up and playing through the Peavey will I really be able to tell if it has improved at all.

These are the things I did in an attempt to reduce the noise:

1. painted all cavities and the underside of pickguard and control cavity cover with double layer of conductive paint
2. installed a piece of foam under the P-90
2. installed a harness made from shielded military spec wire

If those don't eliminate the noise I'd have to say that it's just a result of playing a 15.9KΩ P-90 through a high-gain Peavey amp with a screamer etc into the lead channel.

That is a recipe for the screechies but my Nailbomb-equipped Explorer with the same three measures taken doesn't make much noise at all any more, even with the MXR Custom Badass Modified O.D. set up as a boost.

Interestingly, the one thing my bandmates always notice is if the ISP Decimator G-String II has accidentally been switched off, as the Peavey makes quite a lot of hum and hiss when it is off.  I think part of that might be where we practice - the electricity seems dirty.

The other thing might be that I was just muting poorly.  I have to determine whether it is still screeching when I play, or if it is just when I am not playing.  I am used to muting the Explorer at the moment and maybe I wasn't doing such a good job of that with the wraptail bridge.

Anyway I should have a better idea by the end of this week.
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gwEm

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Re: SG Junior upgrades
« Reply #3 on: March 03, 2014, 05:15:46 PM »
i'll be interested in the results..

screeching is often caused by something being microphonic and then using a high amount of gain.

do you hear anything microphonic if you tap around the pickup?
Quote from: AndyR
you wouldn't use the meat knife on crusty bread but, equally, the serrated knife and straight edge knife aren't going to go through raw meat as quickly

Guitarteach

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Re: SG Junior upgrades
« Reply #4 on: March 03, 2014, 06:01:41 PM »
As the last poster said, check for microphonics if there are screeching sounds and ringing if you tap the PU. Are they potted?

I have a couple of P90 equipped guitars and anything more than moderate overdrive reveals their inherent hiss and hum. I can only imagine an overwound pickup would magnify this. Boosters and gain pedals make mine noisy and i have to stand a good few feet away from the amp when using them. 

I think if I plugged them into a TV I would probably get a picture as they make such good aerials!

A classic sounding BKP humbucking version of a P90 would get my money!

A friend of mine has a Vox Virage with some interesting coaxial PUs - like a P90 but humcancelling. Not found them for sale alone though.





Got a few guitars - old to new and Boogie kit.
BKPS: Rebel Yell, Holydiver

Love old valve amps... But then I am biased!

Guitarteach

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Re: SG Junior upgrades
« Reply #5 on: March 03, 2014, 06:32:46 PM »
Just looking at the space in the control cavity, you could look at a dummy coil? Not tried it yet - but I am intrigued by the idea now for one of my P90 guitars

Pic here...


http://www.ca-music.de/GITARRE/CA-SIX/abschirmung.html


Got a few guitars - old to new and Boogie kit.
BKPS: Rebel Yell, Holydiver

Love old valve amps... But then I am biased!

Alex

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Re: SG Junior upgrades
« Reply #6 on: March 03, 2014, 09:15:27 PM »
I've only had the chance to check it on the solid state practice amp (a Roland 30X) so far, but even though the bridge and pickup are not set up properly yet - making it sound and play like cr@p - I seem to detect that the screech is not diminished, and seems to be a function of how close I stand to the amp.  Only once I have it better set up and playing through the Peavey will I really be able to tell if it has improved at all.

These are the things I did in an attempt to reduce the noise:

1. painted all cavities and the underside of pickguard and control cavity cover with double layer of conductive paint
2. installed a piece of foam under the P-90
2. installed a harness made from shielded military spec wire

If those don't eliminate the noise I'd have to say that it's just a result of playing a 15.9KΩ P-90 through a high-gain Peavey amp with a screamer etc into the lead channel.

That is a recipe for the screechies but my Nailbomb-equipped Explorer with the same three measures taken doesn't make much noise at all any more, even with the MXR Custom Badass Modified O.D. set up as a boost.

Interestingly, the one thing my bandmates always notice is if the ISP Decimator G-String II has accidentally been switched off, as the Peavey makes quite a lot of hum and hiss when it is off.  I think part of that might be where we practice - the electricity seems dirty.

The other thing might be that I was just muting poorly.  I have to determine whether it is still screeching when I play, or if it is just when I am not playing.  I am used to muting the Explorer at the moment and maybe I wasn't doing such a good job of that with the wraptail bridge.

Anyway I should have a better idea by the end of this week.

2 things:
- Did you also paint the pickup cavity?
- Did you ground the body/paint? A screw with a wire somewhere underneath the pickup should do.
Current BKPs: Miracle Man, Nailbomb, Juggernaut, VHII
Past BKPS: Holy Diver, Trilogy Suite, Sinner, Black Dog

Dave Sloven

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Re: SG Junior upgrades
« Reply #7 on: March 03, 2014, 10:37:48 PM »
2 things:
- Did you also paint the pickup cavity?
- Did you ground the body/paint? A screw with a wire somewhere underneath the pickup should do.

Yes, if you look at one of the small photos in that montage above you can see the pickup cavity, and it also has the same paint underneath the pickguard covering the cavity area.

I did ground the paint this time, you can see that in one of the photos above.  I actually used the pickup wire from an old slot car , cut the tang down a bit and screwed that into the cavity wall, painted over it thoroughly with the shielding paint, and tested the wire (and everything) with the continuity tester before soldering it to the back of the volume pot.

The pickup came from BKP wax potted.  Ben was really good about overseeing the whole process, it was a custom build with the Stockholm winding in a Nantucket case.  I put a piece of the foam from the bottom of the BKP pickup box in the bottom of the pickup cavity to reduce vibrations.

As you can probably tell I've done pretty much everything I can here ... the only thing I can thing off as a last resort is to paint the underneath of the plastic pickup cover with the shielding paint the next time I have the strings off ... I've read somewhere about people doing this, and it makes sense.  It would have a similar effect to using a metal cover.  Stockholms normally have metal covers (in the HSP-90 format) and on the BKP site it says "With the higher output of the Stockholm, dynamics are more controlled providing excellent sustain while the solid nickel silver covers provide an extra degree of screening to help reduce background noise."

Anyone know of any downside to painting the inside of the pickup cover?
BLACK HAWKS
IMPULSES
COBRA-T
WAR PIGS
STOCKHOLM
COLD SWEATS
MIRACLE MAN
TRUE GRIT

https://slovendoom.bandcamp.com/releases

Dave Sloven

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Re: SG Junior upgrades
« Reply #8 on: March 03, 2014, 10:49:18 PM »
Just looking at the space in the control cavity, you could look at a dummy coil? Not tried it yet - but I am intrigued by the idea now for one of my P90 guitars

Pic here...

http://www.ca-music.de/GITARRE/CA-SIX/abschirmung.html


That's a possibility.  I do have the original pickup of course ... I assume that is just a pickup wired in via a push-pull pot. The guy who made my harness joked that I have room to hide a Mars Bar in there.

I wonder though exactly what causes the screeching. The dummy coil would address hum, but I'm not sure that hum is the issue here.
BLACK HAWKS
IMPULSES
COBRA-T
WAR PIGS
STOCKHOLM
COLD SWEATS
MIRACLE MAN
TRUE GRIT

https://slovendoom.bandcamp.com/releases

Telerocker

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Re: SG Junior upgrades
« Reply #9 on: March 03, 2014, 11:15:41 PM »
I vote for the Mars bar!  :lol:
I'm interested in the final result. Still like the salmon colour.
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Philly Q

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Re: SG Junior upgrades
« Reply #10 on: March 03, 2014, 11:16:24 PM »
A classic sounding BKP humbucking version of a P90 would get my money!

Yeah, a hum-cancelling P-90 would be the perfect pickup!

There are quite a few on the market - Kinman, Fralin, Lace, The Creamery, Kent Armstrong - but all quite expensive to just take a punt on.  I would like to hear the Fralins, he seems like a guy with a good ear for vintage tone.
BKPs I've Got:  RR, BKP-91, ITs, VHII, CS set, Emeralds
BKPs I Had:  RY+Abraxas, Crawlers, BD+SM

Dave Sloven

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Re: SG Junior upgrades
« Reply #11 on: March 04, 2014, 12:51:53 AM »
i'll be interested in the results..

screeching is often caused by something being microphonic and then using a high amount of gain.

do you hear anything microphonic if you tap around the pickup?

When I tap the pickup I just get the usual tapping a pickup noise, the old 'bok bok' that you get with any pickup.
BLACK HAWKS
IMPULSES
COBRA-T
WAR PIGS
STOCKHOLM
COLD SWEATS
MIRACLE MAN
TRUE GRIT

https://slovendoom.bandcamp.com/releases

gwEm

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Re: SG Junior upgrades
« Reply #12 on: March 04, 2014, 04:48:48 PM »
I guess if you roll the volume off then the screeching stops?

If not then it could be an amp problem - probably a valve.

If yes, then its probably a microphonic pickup problem. When the screeching happens, mute the strings with your hand - does it continue? Then feel parts of the guitar if anything metallic is vibrating. Sometimes mounting springs and things like that can vibrate if they are loose which can cause microphonic feedback.

But most likely it is a microphonic pickup I think. BKP have a lifetime warranty, so I'd have thought they'd repot it for you if you asked.

Are you using really high levels of gain/volume? On one particular amp I tried at rehearsal I could get my ceramic warpig to go into microphonic feedback with loud high gain levels.
Quote from: AndyR
you wouldn't use the meat knife on crusty bread but, equally, the serrated knife and straight edge knife aren't going to go through raw meat as quickly

gwEm

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Re: SG Junior upgrades
« Reply #13 on: March 04, 2014, 05:00:40 PM »
A classic sounding BKP humbucking version of a P90 would get my money!

Yeah, a hum-cancelling P-90 would be the perfect pickup!

There are quite a few on the market - Kinman, Fralin, Lace, The Creamery, Kent Armstrong - but all quite expensive to just take a punt on.  I would like to hear the Fralins, he seems like a guy with a good ear for vintage tone.

Philking tried some hum-cancelling P90s in his WezV SG. I tried said guitar also. They sounded sadly sterile. I forget which brand they were, but it was a boutique brand of some sort.

Don't P100s sound quite sterile too?
Quote from: AndyR
you wouldn't use the meat knife on crusty bread but, equally, the serrated knife and straight edge knife aren't going to go through raw meat as quickly

Guitarteach

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Re: SG Junior upgrades
« Reply #14 on: March 04, 2014, 08:07:40 PM »
Most comments on hum bucking P90s seem to say same - sterile or lacking something.  So i have not taken the plunge. But i also feel the humcancelling postions 2 & 4 on my strat sound a little 'dead' too.

I may try a dummy coil from an old single coil PU I have to just switch in for high gain bits - from what I read they do not colour the P90 as much.
Got a few guitars - old to new and Boogie kit.
BKPS: Rebel Yell, Holydiver

Love old valve amps... But then I am biased!