Wanna be slash! Need a marshall 2555 or 2550! Can it bebuilt

[tranceboy]

Hi there fokes!

been checking the site for a while! some great ideas here!

I know i should be going for something simple for the first amp but its not really very cheap and wanna go for what i want!

I like the idea of buil;d a marshall 2555 slash style amp head

but maybe in a 50 watt version!

I thought about building an 18watter and maybe later rebuild and using a 2555 style preamp! I guess this would sound ok with el84s?

Thing is i can get transformers to build a 50 watter almost just as cheap and its the same amount of tubes etc so i am really unsure what to do?

Has anyone every built a marshall slash replica or even anything close to this? Any links chaps?

Any ideas very grateful as i am verging on ordering the trannys b4 the weekend!

many thanks
andy

[tranceboy]

Have I upset you friends has nobody got any opions on this subject?

[Professor]

the cost for both kits would be fairly close so that shouldn't be too much of an issue the main concern would be volume

if a 50watt will work fine for you then it might be cheaper to just try and find a reissue.

if the volume is a concern im sure the preamp would work fine, but im not sure it would sound exactally the same, the cathode bias would tend to change the tone some.

[Professor]

im sorry i meant to add that the difference in volume between 50 and 100 watts isn't as dramatic as some think 100 watt usually tends to give more clean headroom which im not sure is exactally what youre looking for.

[tranceboy]

has anyone tried using diodes in the signal path like some of these marshalls, not quite as bad as all the solid state in the jcm800 etc , but if you look at the 2555 there is a couple of diodes in there?

[danelectro]

theres nothing in a jcm800 thats solid state...

therese a few diodes in the power supply, but thats not "solid state". solid state implies things like opamps

there is however diode clipping in all the jcm900s except the slash version which is all tube as far as the signal path goes

[tranceboy]

this is the slash 2555 amplifier as far as im awair and it does seem to have diodes around the top? can u explain? im a bit confused with some of the schematic around the top left! Would this amp design running as 50watts with 2 el34s? Using the transfomers from james`s site? Ordered some caps off ebay today so getting a collection together now!

[zaphod_phil]

Well the bunch of diodes and LEDs just above R8 seem to be connect to a pot that says "Lead Master". So I guess when you engage the Lead channel, they switch in. The other pair D4 &D5, appear to be switchable via a push-pull pot. So although the amp has some diodes, they're all switchable, so you don't have to use them if you don't want to. And overall there's a hell of a lot less diodes and SS stuff in there than in a regular JCM900...

[tranceboy]

Ok ive ordered the trannys from james at amp components and am possibly going to order a plain chassis and some other bits from tubesandmore.com there prices seem good!

Does anyone have a clearer or redrawn schematic of the marshall slash series amp?
Or any of the silver anniveresy series.

many thanks
andy

[dazco]

Both the Jubilee and the channel switching 800's have diode clipping. i've had both and i gotta tell ya, the jubilee was really good at being consistant in different rooms and for cutting thru in a very consistant way. but the tone wasn't near as good as an 800. But the 800's didn't cut thru as consistantly and i found that the slower the song, the better the tone would cut. Then it woulkd sound great and blow away the jubilee. I guess you could say it's like the tortoise and the hare......the hare was faster, but the tortoise kept an even pace and therefore won in the end

At home for bedroom level playing, i felt the jubilee was one of the worse marshalls i ever played. It really only works at stage levels, and while it's very consistant (a very hard to find quality in an amp) the tone really wasn't anything to write home about.

If you think you'll sound like slash with one, trust me, you won't. The tone isn't near unique enough, and your playing style will overpower any tonal aspects similar to slash.

[zaphod_phil]

However, bear in mind the Slash amp is very different from a regular JCM900, and it gives the option of switching the diodes out of circuit.

[SteveinTempe]

I dont know if I would try and clone it
but it does rock I have experimented with diode clipping
You may be better to build the jcm 800 style
and add the diodes on a switch, or build a combinations vintage
plexi /2203 / ...

I have not been over here in ages been banished to the ax84 site doh!

[dazco]

However, bear in mind the Slash amp is very different from a regular JCM900, and it gives the option of switching the diodes out of circuit

Yes, but only on the clean channel with the crunch pull knob NOT engaged. So the only way to use it w/o diode clipping is totally clean, which leaves you with a tone that will not crunch untill you're at the volume levels of a 747. Oddly i have talked to a few people who said thiers weren't that loud, so maybe it is possible to crunch the clean chan at less than horrific levels with some of them. But mine was the loudest marshall i ever played bar none. When we got real loud my master was on 3 at the most! I kid you not......that thing was utterly rediculous. The only thing i can figure as to the others who said thiers wasn't loud is that maybe they had crappy tubes and/or bias. I only know that to make my clean crunch there isn't a club we ever played at that would tolerate 1/2 that volume, and i think i'm being conservative.

[tranceboy]

Maybe i will try building a slash style 18 watter what do you think?

Would this work or not?

[Ballz]

Tranceboy, previously you wrote "Ok ive ordered the trannys from james at amp components"....so it´s a bit late changing direction now, huh?



Whatever road you finally choose - good luck with your build! It´s a rewarding experience when done.

/Richard

[zaphod_phil]

I have not been over here in ages been banished to the ax84 site doh!

Banished? You're SteveO...?

[tranceboy]

I have sent payment to ampcomponents for the 50w output tranny and the 350 - 0 -350 150ma transformer, but it looks as if this will not be enough to power two el34s, infact it sounds more like the amp will go into meltdown from the requirements for 2 el34s ive been seeing at around 250ma. The reason i chose this transformer was beacuse james at AC recommended it, so im wondering if i should try to change the order to 300 - 0 - 300 tranny and 18watt output tranny for my first tube amp? And maybe put in some features of the slash amp on the preamp section! I have emailed james and explained and asked him to hold fire with the delievery until im sure on the specs required for EL34s, which i am still not.

Comprenday?

Nope im totally F$£$ing lost , havent got a clue - HELP

[dazco]

May i suggest you try building a regular 18 or the TMb version with more gain and full tone controls? I really think you'll be happier with it than a slash. I haven't yet played an 18, tho i'll be done building in a couple days. But i can tell you that i've owned and played a few vintage style amps who's strength is simplicity and purity of tone, and they just kick the crap out of the slash. If the 18 is anything like the ones i've played, theres no contest.

There are many reasons slash's sound is what it is, but a modern marshall like that cannot get tone quality anywhere near what a simple vintage style amp can. I really suggest you get the trannys for an 18 and try that 1st. The slash will also be infinatly harder to build. But if you do the 18 it'll make it easier to do the slash.

[Ballz]

Yess, I´ll second that any moment. The 18W (or any of its variants) is a good starting point. Mine is a 18W Lite II, and it sounded 98% right at first startup, just needed a smaller cathode cap on the preamp tube for tighter bass.

Go for the 18W. The 50W can always be built later if you decide you got the taste for tube amps, and be partly funded by selling the 18W amp...

Cheers /Richard

[zaphod_phil]

I have sent payment to ampcomponents for the 50w output tranny and the 350 - 0 -350 150ma transformer, but it looks as if this will not be enough to power two el34s, infact it sounds more like the amp will go into meltdown from the requirements for 2 el34s ive been seeing at around 250ma. I have emailed james and explained and asked him to hold fire with the delievery until im sure on the specs required for EL34s, which i am still not.

350-0-350V will give you about 490V when solid-state rectified. 150mA times 490V (the current spec is for the rectified DC voltage) is 73.5W. Now a normal EL34 can only dissipate 25W on average, and an E34L will handle 30W. With either of these, you're comfortably below the transformers rating, and the 12AX7/ECC83s only consume a few milliamps each. And the spec on the web site says the transformer is rated at 160mA, which equates to 78W. Plus it provides 4.5A of heater current. That's a meaty transformer.

So why are you panicing for no reason?

And BTW James at Amp Components is a reputable guy who would never con anyone.