Marshall 1959SLP build - Your opinion?

[ivan H]

Hi, dont let lack of design knowledge hold u back from building, u'l find it very rewarding & educational. I would suggest also joining the Metro Amp forum, between this forum & metro amp forum u'll get any help u may need, & the meto amp forum more or less specialize in plexi marshalls (1959 etc). There is a sticky on their site on calculating r/c constants & like here, there's some very knowledgeable people there. Just to correct wot was said about the 2203 master volume marshall a few posts back, the first (Hi Input) gain stage of the 2203 & 50W 2204 models is the same as the first "Bright" stage on a 1959 or 1987, the output of this is then routed, via a 470k/470pf treble peaker, thru the Lo input to a cold biased stage with an unbypassed 10k cathode resistor. From there its pretty much the same as a plexi bright channel with the exception of the last gain stage b4 the cathode follower using a 470k grid leak,,, & of course the master vol, inserted between the tone stack & PI. BTW, a Les Paul straight into a plexi or JCM800 is one of the definitive classic rock tones. Cheers

 

[ivan H]

Hi, just to let u know, Metro Amp is again offering 50 watt plexi kits. They r not advertised yet in the store section, but I saw in the 50 watt forum this morning that as of Nov 1 they've been taking orders for, & as was pointed out in the last post, Metro's are as good as it gets when it comes to replicating plexi's. I dont know the friend ur considering building for's situation, but is he really in need of a 100 watter. If he's never stood in front of a cranked full stack (& cranked or near craned is where they sound best), let me tell u, its bloody loud. A 50 watter is more practical in that u can use it at most venues like clubs & pubs & the like & have it turned up to where it sounds & feels good, where as a with a 100 watter u would need to use some kind of attenuator. Also, FWIW, many players actually prefer the tone of the 50 watt model 1987 plexi, like Jeff Beck. Admittedly, if u r in a position to b able to use the full troated (& very loud) roar of a cranked wide open 100 watt plexi, there is nothing else like it. Just make sure he is sure of his needs. I would love a 100 watt full stack, but realistically, I couldnt use it, which why I have built 50's & I'm now starting on a SIR #39 build that will also b a 50 watt. Cheers

 

[dagerman]

Hi, just to let u know, Metro Amp is again offering 50 watt plexi kits. They r not advertised yet in the store section, but I saw in the 50 watt forum this morning that as of Nov 1 they've been taking orders for, & as was pointed out in the last post, Metro's are as good as it gets when it comes to replicating plexi's. I dont know the friend ur considering building for's situation, but is he really in need of a 100 watter. If he's never stood in front of a cranked full stack (& cranked or near craned is where they sound best), let me tell u, its bloody loud. A 50 watter is more practical in that u can use it at most venues like clubs & pubs & the like & have it turned up to where it sounds & feels good, where as a with a 100 watter u would need to use some kind of attenuator. Also, FWIW, many players actually prefer the tone of the 50 watt model 1987 plexi, like Jeff Beck. Admittedly, if u r in a position to b able to use the full troated (& very loud) roar of a cranked wide open 100 watt plexi, there is nothing else like it. Just make sure he is sure of his needs. I would love a 100 watt full stack, but realistically, I couldnt use it, which why I have built 50's & I'm now starting on a SIR #39 build that will also b a 50 watt. Cheers

Thanks Ivan. You know, I had asked him the exact same question, because I know how loud my little 2x8W Single Ended HiFi Tube amp is that I built...
He said he wanted the 1959SLP because that's what Jimmy Page used and he is after that sound. What do I know, I don't even play guitar. ;-)
He also said about the 100W - and I quote - that "I want this because going to town on my Les Paul with 100W of valve amp wide open is what I do to prevent me from killing people."
I don't think he's really that violent, but that probably does for him what playing Squash for four hours each week does to me... (other than getting me closer to this ).

I will ask him again, though. It would make testing the amp easier for me as well, because I neither have a 100W dummy load nor a speaker/cabinet that would not go up in fumes with that kind of input. Oh yeah, and no guitar either.

Thanks for your additional thoughts, much appreciated!!

 

[ivan H]

Well, if that keeps him from killing people. It'd b a good idea to check out the 50 watt Metro Amp kit. For around a grand u get a complete 50 watt head kit with Heyboer Transformers & choke, with the option of Mercury Magnetics (probably add cost, I'd take Heyboer, thats wot I use), choice of valves, sozo caps, Point to Point board,, very complete & quality kit complete with cabinet. They are also available in partial kits I think. My last build I just used the Metro JTM45 chassis & plexi panels & got Heyboer trannies & choke & PTP board from links on their site, then sourced Mallory & Sprague caps, F&T electro's, Vishay Dale 1w metal films, valves etc myself for around the same cost, but if a kit had been available at that time, b easier. Cheers

 

[ivan H]

Just to correct about the 50w kits, (I read the post date from wrong post), the chassis & plexi panels r available from Metro, with site links to Heyboer or Mercury Magnetics, with the component kits being available thru Valvestorm, also site linked. The 1959 is also available. U can also get chassis & transformers from Marstran, who also do good products. I have a PT from Marstran,,, well made. Cheers

 

[bear]

You should be aware that even if you copy the schematic perfectly, the final amp may or may really sound like a vintage amp of the same type.

Even if you try to copy the parts *types* from the vintage amp and build new, it still may not sound the same. It could be different, better or worse, but very likely not quite the same.

I have seen lots of people try to copy name brand amps, and what you get is an amp that is just somehow different.

It would help to have a genuine Marshall OT and Power iron to get off to a good start, and stick with the same type and power resistors and pots, not switching to "better" parts.

But these are good fun projects...

tubelab, I seem to recall seeing "Park" amps around and thinking, "huh, somebody is copying Marshall, it's probably cheap crap..." Ha ha.

_-_-bear

 

[ivan H]

Yes, this is true Bear. Even with origonal amps, no 2 really sound "exactly" the same, & the transformers have a bit of variation, OT's can have a few ohms difference on either side of the primary, B+ voltages vary, & the same models can have different brand transformers, ie Radio Spares, Drake or Dagnall, plus marshall was continually making small changes to the circuitry, so a plexi is not really an exact specific circuit, which year plexi does he want. My last build I used a M@rsh@ll PT & a Heyboer OT that is an exact rewind of an old origonal that is supposed to be "aged" to sound & react like a 35+ yr old transformer, tho how they do this I dont know. Some people swear by sozo caps while others will tell u that the Mallory 150 series caps sound closest to wot was orionally used. Alpha pots & Cliff jack sockets r pretty well standard. Some also will use carbon comp resistors tho I prefer Vishay Dale 1w metal films for a low noise floor. Regardless, if u take the time to do it properly & ask about anything u r unsure of u'll end up with an amp that will very much get u in the ballpark soundwise, maybe even sound better than some if ur lucky, & the building experiance will be very rewarding & u'll learn a bunch along the way. Cheers