Pics from Jeff Seal

Luke Duke

PRSlustologist
lukebefore001.jpg

http://i14.photobucket.com/albums/a336/JeffSeal/lukebefore001.jpg
lukebefore003.jpg

http://i14.photobucket.com/albums/a336/JeffSeal/lukebefore003.jpg

after....
lukeafter002.jpg

http://i14.photobucket.com/albums/a336/JeffSeal/lukeafter002.jpg
lukeafter003.jpg

http://i14.photobucket.com/albums/a336/JeffSeal/lukeafter003.jpg
lukeafter004.jpg

http://i14.photobucket.com/albums/a336/JeffSeal/lukeafter004.jpg

True beauty!!!
 
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Re: Pics from Jeff Seal

looks great!

fill us in luke

was this work jeff did for you? ... if so, what all did he do? .. what are the sonic changes (before / after)?

t4d
 
Re: Pics from Jeff Seal

You should just leave that baby open or put a clear plexiglass top on it. It's just to pretty to keep hidden. It looks great.

Are those huge orange tone caps?
 
Re: Pics from Jeff Seal

why does that amp look so familiar?? is that a 70's JMP 50w by chance?? if so, what did Jeff do to it because my '79 JMP need serious help and that looks like the kinda of help that would make me happy LOL.

Jeff, when you read this...we need to talk for sure!!

-Mike
 
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Re: Pics from Jeff Seal

tone4days said:
looks great!

fill us in luke

was this work jeff did for you? ... if so, what all did he do? .. what are the sonic changes (before / after)?

t4d

I haven't got the amp back yet, Jeff sent me the pics last night. He said he should be able to ship it out today after I pay him of course.

To be honest I'm not sure WHAT all Jeff did. I told him some tones I was looking for and problems I was having. He told me that due to the fact that my board was in such great condition he thought I'd be best off having the amp re-built then he could do anything, and in the future it wouldn't be so painful to work on. One thing we really talked about was a Post Phase Inverter Master Volume.

I just takled to Jeff and he said he'll be on to explain what he did.

Luke
 
Re: Pics from Jeff Seal

XSSIVE said:
why does that amp look so familiar?? is that a 70's JMP 50w by chance?? if so, what did Jeff do to it because my '79 JMP need serious help and that looks like the kinda of help that would make me happy LOL.

Jeff, when you read this...we need to talk for sure!!

-Mike

It is an 81 JMP 2204. Good eyes Mike!

When I picked it up it had 6550s in it which sounded pretty good, but I opted for some KT88s which really put some warmth and thunder into it.

I was planning on sending it to him, but a problem that occurred made me send it in sooner, rather than later. I get a dunce award for not thinking to move around the preamp tubes since they were new. What happened (from what I understand) is that a loose tube socket had blown one of them. Since the heater came on I didn't even think about it any further. :duh:

Now it is healthy..and happy. Soon I will be too.

Luke
 
Re: Pics from Jeff Seal

looks great bro!!! can' wait for final pics and a tonal review!!!
 
Re: Pics from Jeff Seal

msawitzke said:
Wow, thats cool...how much is this costing you?

All I feel comfortable saying online is NOT ENOUGH!!!

For this kind of work I expect some techs to change twice as much, maybe more.

Shoot him a PM and he can tell you more.

Luke
 
Re: Pics from Jeff Seal

bump for Jeff, so what did you do and when do you want to do it to my '79 JMP :D...seriously.

-Mike
 
Re: Pics from Jeff Seal

Luke: I talked to ya last night bro but I have to say that is a killer looking amp brother!

If it sounds half as good as it looks you'll be a happy guy! So, did you stay with KT-88's
 
Re: Pics from Jeff Seal

the guy who invented fire said:
Luke: I talked to ya last night bro but I have to say that is a killer looking amp brother!

If it sounds half as good as it looks you'll be a happy guy! So, did you stay with KT-88's

Yeah I decided that I'd keep em in there for a while because thus far I've really liked the results, but maybe in the future I'll try something else.

Luke
 
Re: Pics from Jeff Seal

Well, let's see...... first off Luke's amp arrived in pristine condition internally, and after watching one of the 12ax7's disintegrate in the tube tester, it was determined that was probably the cause of the massive "hum". Put in an old RCA and fired her up......awesome doesn't begin to describe the 2204 tone! So any changes would be better suited on a new platform and the entire original PCB came out (pots, jacks and all), thus insuring both the original circuit remained intact, while still achieving the desired results. (not like these amps are going down in value anytime soon) I get many old Marshall's in and most have been "altered" beyond recognition...which happens to be a "pet peeve" of mine.
Between all the amps I get in to be "modded, unmodded and re-modded" I have a rather nice collection of turret boards and used PCB's lying around, but not a single one as nice as Luke's.... So I grabbed a turret board and went to work!

Luke was after what quite a few people are after, not tons of gain like a Mesa, but more of a "Marshall on steroids" type tone. SO..... the circuit you see is a combination of a 1959(super lead) 2204, 2210 and a 2555. The basic premise was to create a 2204 with a PPIMV but without the "drawbacks" the new MV create's. (that is a discussion within itself!) The layout is gain, gain, gain, tone stack(plate driven) MV then another gain stage.
Besides being incredibly loud, the amp now has twice as much gain, but with the ability to clean up nicely at all levels. Single handedly the coolest thing is that little trimpot located to the bottom about halfway through the board. It allows the rate of which OD is achieved to accomodate playing styles by either increasing or decreasing the onset of OD while simultaneously "boosting" the level proportionately. Basically all the way down is standard 2204 gain structure, up is closer to TSL. This allows the use of the guitar's volume control to further dictate the amp's OD amount. (if that made any sense at all!)

..it's just a bad*ss Marshall!:)

Jeff Seal
 
Re: Pics from Jeff Seal

Jeff Seal said:
Well, let's see...... first off Luke's amp arrived in pristine condition internally, and after watching one of the 12ax7's disintegrate in the tube tester, it was determined that was probably the cause of the massive "hum". Put in an old RCA and fired her up......awesome doesn't begin to describe the 2204 tone! So any changes would be better suited on a new platform and the entire original PCB came out (pots, jacks and all), thus insuring both the original circuit remained intact, while still achieving the desired results. (not like these amps are going down in value anytime soon) I get many old Marshall's in and most have been "altered" beyond recognition...which happens to be a "pet peeve" of mine.
Between all the amps I get in to be "modded, unmodded and re-modded" I have a rather nice collection of turret boards and used PCB's lying around, but not a single one as nice as Luke's.... So I grabbed a turret board and went to work!

Luke was after what quite a few people are after, not tons of gain like a Mesa, but more of a "Marshall on steroids" type tone. SO..... the circuit you see is a combination of a 1959(super lead) 2204, 2210 and a 2555. The basic premise was to create a 2204 with a PPIMV but without the "drawbacks" the new MV create's. (that is a discussion within itself!) The layout is gain, gain, gain, tone stack(plate driven) MV then another gain stage.
Besides being incredibly loud, the amp now has twice as much gain, but with the ability to clean up nicely at all levels. Single handedly the coolest thing is that little trimpot located to the bottom about halfway through the board. It allows the rate of which OD is achieved to accomodate playing styles by either increasing or decreasing the onset of OD while simultaneously "boosting" the level proportionately. Basically all the way down is standard 2204 gain structure, up is closer to TSL. This allows the use of the guitar's volume control to further dictate the amp's OD amount. (if that made any sense at all!)

..it's just a bad*ss Marshall!:)

Jeff Seal

Thanks for taking the time to post Jeff!

Sounds like a winner for sure. I can't wait for it to come in! The trim pot sounds extra cool. You might want to let give the guys some idea of how the KT88s sound compared to the EL-34s, especially with the mods, I'd like to know that too.

Jeff has been super cool guys, especially in putting up with me. I've been ultra paranoid since my amp has been in Texas and he has been MOST gracious in dealing with me.

Luke
 
Re: Pics from Jeff Seal

Beautiful!.. if you are a guitar/amp geek, that is :D

Seriously nice looking work you guys.
 
Re: Pics from Jeff Seal

This is why when people email me for a fire-snortin' beast of a Marshall gainiac I send them to Jeff. Beautiful work as always.
 
Re: Pics from Jeff Seal

Jeff Seal said:
Well, let's see...... first off Luke's amp arrived in pristine condition internally, and after watching one of the 12ax7's disintegrate in the tube tester, it was determined that was probably the cause of the massive "hum". Put in an old RCA and fired her up......awesome doesn't begin to describe the 2204 tone! So any changes would be better suited on a new platform and the entire original PCB came out (pots, jacks and all), thus insuring both the original circuit remained intact, while still achieving the desired results. (not like these amps are going down in value anytime soon) I get many old Marshall's in and most have been "altered" beyond recognition...which happens to be a "pet peeve" of mine.
Between all the amps I get in to be "modded, unmodded and re-modded" I have a rather nice collection of turret boards and used PCB's lying around, but not a single one as nice as Luke's.... So I grabbed a turret board and went to work!

Luke was after what quite a few people are after, not tons of gain like a Mesa, but more of a "Marshall on steroids" type tone. SO..... the circuit you see is a combination of a 1959(super lead) 2204, 2210 and a 2555. The basic premise was to create a 2204 with a PPIMV but without the "drawbacks" the new MV create's. (that is a discussion within itself!) The layout is gain, gain, gain, tone stack(plate driven) MV then another gain stage.
Besides being incredibly loud, the amp now has twice as much gain, but with the ability to clean up nicely at all levels. Single handedly the coolest thing is that little trimpot located to the bottom about halfway through the board. It allows the rate of which OD is achieved to accomodate playing styles by either increasing or decreasing the onset of OD while simultaneously "boosting" the level proportionately. Basically all the way down is standard 2204 gain structure, up is closer to TSL. This allows the use of the guitar's volume control to further dictate the amp's OD amount. (if that made any sense at all!)

..it's just a bad*ss Marshall!:)

Jeff Seal

Saw the quote "Swords & Tequilla carry me through the fight" in your signature. That's a great RIOT song, loved that band. That whola album is killer. Are there any clips of your modded Marshalls on-line?
 
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