My Modded Marshall 1959slp 100w Photos

[shredaholic]

History behind the amp:

I bought it in 2005 (october I think), and got a Metroamp PTP board for it with Mallories. When I got chance I replaced those caps with Sozo's, and replaced the crappy Output Transformer with a Metroamp Dagnall Clone (made to their spec by Heyboer). Along the way I've changed lots of things, added in extra tube mods, switches etc.

I finally got an old digital camera I had working, so I thought I'd use it to take some long-due pics of my amp and guitar. The custom Warmoth guitar isn't assembled at the moment (refinishing it), so I've only got my 2004 strat in the pictures.

Feel free to ask me about any of the modifications that I've done on it. The 4th preamp tube mod isn't connected at the moment, but you can see a row of parts in the middle of the extra circuit board - that's for the extra tube when I feel like hooking it up, to make it into a switchable 1959/2203.

The switch at the back of the amp is for a switchable V2a cathode bypass cap, selecting between a .68uF Sozo cap and a 330uF electrolytic. The capacitor and resistor near the far right hand upper corner of the chassis are substitutes for the presence control, as you can see theres a PPIMV in the presence hole instead.

All signal capacitors are Sozo Mustard+, the preamp used to be all CC but I replaced some of them that I didn't feel had any effect on the tone. My favourite mod is the 1k V2a cathode resistor (shown between the .68uf and 330uf capacitors) that's a (1/8w or 1/4w?) NOS carbon comp resistor I once found in a bag of old capacitors - the leads are mostly gone so I've had to wire it strangely but it sounds awesome. It's drifted up to about 1160 ohms.

to be continued in next post...

 

[shredaholic]

Re: Marshall 1959 100w Photos

Re: Marshall 1959 100w Photos

Since this was the first amp I ever worked on, and I've changed so much in this amp so many times, it's pretty dirty/messy inside. I'd like to rewire everything again at some stage but it's hard finding the time these days.

The tubes are JJ E34L's for the power tubes, Sylvania 12AX7WA for V2 and V3, and Sylvania 12AX7 (later version) for V1. Sometimes I use a Mullard in V1. When I use V0 (the extra gain stage tube) it's either a JJ ECC83S or an RFT ECC83.

The empty hole in the back panel is from a pentode/triode switch that isn't fitted at the moment - I took it out temporarily while I was doing some work around that area, it was getting in the way and I don't use triode mode as much these days.

 

[shredaholic]

Re: Marshall 1959 100w Photos

Re: Marshall 1959 100w Photos

More gut shots:

 

[darkshadow54321]

Re: My Modded Marshall 1959slp 100w Photos

Great work! I'd love to be able to do that!

But more importantly... how does it sound?

 

[shredaholic]

Re: My Modded Marshall 1959slp 100w Photos

Amazing?

I've not got the recording equipment set up right now, but I've posted some clips before of the amp in the tips and clips room - do a search for "bareknuckle VHII" and "plexi", they should come up. I'll record a clip with the strat ASAP.

 

[shredaholic]

Re: My Modded Marshall 1959slp 100w Photos

ok here's a clip:

http://www.soundclick.com/bands/songInfo.cfm?bandID=364256&songID=3915472

Strat > Plexi > 1960A cab > SM57 on '73 G12M

The pickups are all the stock Fender USA ones...

I'm just riding the volume knob to get the cleaner sounds. The guitar is set on 7/8 for the bridge and middle tone controls, and for the amp everything is on 10, except the PPIMV is on 1 and the treble control is on 7-8. I think the V2a cathode switch is set to 330uf here.

I'm just playing any random crap, hopefully this should be enough to demonstrate how it sounds with a strat. The e string is missing by the way, hence the boring playing. There's no extra gain stages here, and I don't think there's much in the signal path that wasn't in a late 60's 1959slp *except* there's less NFB (I'm using 100k on the 4ohm tap).

This should show how much gain the amp can get with a stock strat with a bridge pickup of around 7k. With my Bareknuckle VHII's the gain is a lot higher, and gets even more cool :smokin:

 

[gtrst gone wylde]

Re: My Modded Marshall 1959slp 100w Photos

from the back and the majority of the wiring look extremely similar to my jcm800, mine even has the 4th preamp tube socket too, mine isnt connected either :lol: whoever had the amp before me was planning on using it for an effects loop as they drilled holes in the back but i restored mine back to stock except i left their stage 2 gain mod in

gotta love old school marshalls, and great tube selection, JJs are the best and i love their E34Ls......they have that unmistakable midrange tone and more power than el34s gotta love the headroom

awesome amp man, i bet it set you back a pretty penny

 

[shredaholic]

Re: My Modded Marshall 1959slp 100w Photos

Yeah I've spent quite a bit on the parts for it, but not as much as you might think. I bought the amp *almost* new in October 05, and looking at the amp's details I've found it was made in 2005. The amp cost £525 from eBay, and I've probably spent about £300 on parts for it. That's still about £400 less than a 1959HW would've cost me, and this eats a 1959HW for breakfast in terms of component quality and sound (maybe not in neatness though!). The great thing about getting a cheaper 1959slp was that there was no guilt whatsoever in hacking into it for any mods that I've tried, since I'm never gonna sell it and even if I did want to sell it as it was before in stock condition, it wouldn't go for much anyway.

The vintage tubes I've bought never cost me more than £3-5, the new production E34L's were the most expensive at around £35. The OT cost about £120 to upgrade, the PTP board and PPIMV was about £40, new filter caps about £15, etc.

 

[gtrst gone wylde]

Re: My Modded Marshall 1959slp 100w Photos

hmm that seems pretty reasonable for everything, im not exact on the us-dollar conversion but i tihnk that is fairly cheap

those reissues are too expensive for me to buy new :lol: i got my jcm800 used and abused for $600 last year, the tolex is all messed up and the amp is 2 years older than i am but i love it

yeah i like buying slightly cheaper things that you dont feel bad about modifying too, it also gives the amp more character and value to you because yu did it yourself....i think thats cool

 

[gtrst gone wylde]

Re: My Modded Marshall 1959slp 100w Photos

wow i just listened to the soundclip and your amp may look similar to mine but yours sounds totally different than mine.......it could be the strat but i think its probably the gain stages in the amp being different......nice AC/DC riffs

 

[shredaholic]

Re: My Modded Marshall 1959slp 100w Photos

Thanks man - they do sound a little too dark without the high e string though...

It's definately got lots of character - sometimes I feel it's got a life of it's own lol. I think the difference in sound will probably be mostly the fact it's a strat (with singlecoils) but also the 56k/250pf tone stack - that shifts the character of the amp quite a lot, and was replaced by the 33k/500pf stack found on later Superleads, MV's and JCM800's in 1968.

 

[JeffB]

Re: My Modded Marshall 1959slp 100w Photos

Shred, I always love your clips...you got chops, and that RI of yours just has *THE* SLP sound (for me). It's a little "hot" and crunchier than alot of the "real" Plexis. It always reminds me of my 1987X...I know you've modded yours , but the tones are very similar to my old RI, and yours still retains the Marshall character unlike many modded marshalls. :bigthumb:

 

[oldschoolrock]

Re: My Modded Marshall 1959slp 100w Photos

Definetly still got that recognizable Marshall Tone. I hear a lot of JCM800 type crunch in there as well. Definetely sounds more like a plexi with less gain. Sounds great...do you have a LP or a SG? I would love to hear a clip with both of those guitars plugged into it.

 

[oldschoolrock]

Re: My Modded Marshall 1959slp 100w Photos

Oh one question...did you get a lot more bottom when you replaced the transformer?

 

[joelap]

Re: My Modded Marshall 1959slp 100w Photos

So that's the beast I've heard so much about?

Looks pretty good man. I gotta figure out what the heck I'm going to do about my money situation. I literally have 35 dollars to last me until the second week of June, so my AC30 is on hold. I've got the sozo caps in and the chassis, just waiting for the resistors, silver mica, and filter caps to come in from Ceriatone, then I'll build a mock board out of cardboard to keep myself occupied until I get the money to start ordering the parts and whatnot. Has anyone on the metroamp forums done the caswell mod yet and recorded a clip of that amp cranked? last I checked the only clip had the PPIMV low and it was all preamp gain and sounded more like early van halen than GnR. Just curious about the concensus on the mod over there?

 

[STRATDELUXER97]

Re: My Modded Marshall 1959slp 100w Photos

Nice amp brother and glad it's working out great for you also....As a fellow amp tweaker,modder,and user of a soldering iron....

Just some constructive criticism upon looking inside your amp brother....I see alot of solder being used and what look like cold solder connections and some ghouled up and unshapely looking capacitors on the sides...Other than that,nice job...Again....Just constructive stuff...

 

[Guest]

Re: My Modded Marshall 1959slp 100w Photos

Very cool Shred! and it sure sounds AMAZING!

I'm jealous! :smokin:

 

[shredaholic]

Re: My Modded Marshall 1959slp 100w Photos

Nice amp brother and glad it's working out great for you also....As a fellow amp tweaker,modder,and user of a soldering iron....

Just some constructive criticism upon looking inside your amp brother....I see alot of solder being used and what look like cold solder connections and some ghouled up and unshapely looking capacitors on the sides...Other than that,nice job...Again....Just constructive stuff..

Yeah the main reason it's messy is I've used the same board so many times, and have never really "cleaned it up" so to speak. I don't own any de-soldering braid so I need to get some of that. When I first did the PTP board last year, I wasn't that good at soldering, and I used the lead-free stuff which makes the joints look dull. Even though I'm now using the 60/40 leaded stuff, a lot of the joints still have the old solder on them.

The capacitor that looks most strange is the .68uf on V1b's cathode - the reason that and others look that way is because I used some of the caps for an experiment where I tried to replicate the mustard coloured covering on the old Mustard caps. After finishing the experiment, the caps were cleaned up with paint stripper, which unfortunately took off the writing on them and damaged some of the yellow wrapping outside. They still work and sound fine though - I call it character

 

[shredaholic]

Re: My Modded Marshall 1959slp 100w Photos

Definetly still got that recognizable Marshall Tone. I hear a lot of JCM800 type crunch in there as well. Definetely sounds more like a plexi with less gain. Sounds great...do you have a LP or a SG? I would love to hear a clip with both of those guitars plugged into it.

It might actually sound more like a JCM800 because the only part (*i think*) on the amp right now that wasn't found in an original Marshall 1959 is the value of the NFB resistor, which is 100k. They didn't use 100k until the 2203 (MV's, JCM800's) came out if my memory serves me right. Lessening the negative feedback is such a killer mod on a Marshall, and makes the amp have more poweramp gain.

I've just got my strat and the warmoth custom that has Bareknuckle VHII humbuckers in, a lot has changed in the amp since I last made a clip with the Warmoth so I'll have to make some new clips once that's finished being repainted. My mate has an Epiphone LP ('special II'? i think) that I might be able to borrow a bit sooner and make some clips with.

Oh one question...did you get a lot more bottom when you replaced the transformer?

Sortof yeh - the old transformer seemed to be 'choking' the harmonic content and the low end, making it sound a bit sterile and harsh. That and vintage tubes are easily by far the best upgrades for a 1959slp.

 

[shredaholic]

Re: My Modded Marshall 1959slp 100w Photos

Shred, I always love your clips...you got chops, and that RI of yours just has *THE* SLP sound (for me). It's a little "hot" and crunchier than alot of the "real" Plexis. It always reminds me of my 1987X...I know you've modded yours , but the tones are very similar to my old RI, and yours still retains the Marshall character unlike many modded marshalls. :bigthumb:

Thanks Jeff , the reason it still sounds like an original Marshall is because I've tried out all the different values that old plexi's used, taken the best sounding ones (to me anyway), and put those values together into my amp. The only thing in the tonal path right now that was never in a plexi made from 1967-1969 is the 100k NFB resistor.

By lessening the NFB I managed to make it more powerful sounding, and increase the power amp gain; most amps lose the Marshall character because they add gain through the preamp and compression. This type of gain is totally the opposite - it's huge, open sounding gain and sounds almost the same as power tubes being driven hard. It makes the amp more responsive to guitar volume changes, and seems to increase the harmonic content and controllable feedback.