Daaaaaaaaaaaaaaamn!!!!

That is so sexy. Congratulations.

Well ladies and gents, here it is...




The previous owner had some work done to it in the form of new (Chinese) tubes, screen resistors and some electrolytics having been replaced, as well as the input voltage and output impedance selectors. The rest is still original it seems...

When I powered her up, I just noticed that the power indicator is not working, but apart from that (and some minor cosmetic issues), she's perfect... Almost no hum or unwanted noise, perfect sound...

I haven't cranked her yet and I tried the trick where you bridge the I and II channels, but I prefer the I channel. Its nice and sharp. The II channel is a bit too bassy...
Anyway, THAT SOUND ??? ?
The cleans (Thats all I could reach so far) are stupendous... I am not worthy of this incredible amp and it is a big honor to be able to own one of these gems.

Wonderful! Great through a 4 x 12! Rib vibrating power! You will end up with one arm longer than the other if you gig without roadies though. The only solution is to get another and then just play large concert venues! I remember mine causing enough pressure to blow my trouser legs! It's an old sixties, big block, Corvette Stingray of an amp!

I have one and have done the pulling tubes trick and sadly it doesn't do too much you still have low volume until just before 1 on the amp and then LOUD and LOUDER!! My 50 watt superlead lets you go quite a bit louder.

But that tone, shooweee I don't even know why they bother making any other amps at all ?

Enjoy it.

Congrats, enjoy your new old amp. Did you get that from that chap in Kloof, Durbs? If so, I remember having a look at it when it was up for sale a year or 2 back.

I think it's time for all those old Daly electrolytics to be replaced. I'm surprised they weren't done when the ones on the pc board were done.

If you're wanting to be able to crank it so that it overdrives without destroying your house foundations, I'd look into installing a PPIMV. These amps respond very well to this simple mod.

shaunf wrote: Congrats, enjoy your new old amp. Did you get that from that chap in Kloof, Durbs? If so, I remember having a look at it when it was up for sale a year or 2 back.

I think it's time for all those old Daly electrolytics to be replaced. I'm surprised they weren't done when the ones on the pc board were done.

If you're wanting to be able to crank it so that it overdrives without destroying your house foundations, I'd look into installing a PPIMV. These amps respond very well to this simple mod.

The very same... I'm planning on taking it to JP le Roux some time soon to put in some JJ tubes and just look the amp over... What are the warning signs of those caps having to be replaced? Are they the original (40 year old) parts?
Im very curious as to how this amp spent the majority of its life so far.

psyx wrote:

shaunf wrote: Congrats, enjoy your new old amp. Did you get that from that chap in Kloof, Durbs? If so, I remember having a look at it when it was up for sale a year or 2 back.

I think it's time for all those old Daly electrolytics to be replaced. I'm surprised they weren't done when the ones on the pc board were done.

If you're wanting to be able to crank it so that it overdrives without destroying your house foundations, I'd look into installing a PPIMV. These amps respond very well to this simple mod.

The very same... I'm planning on taking it to JP le Roux some time soon to put in some JJ tubes and just look the amp over... What are the warning signs of those caps having to be replaced? Are they the original (40 year old) parts?
Im very curious as to how this amp spent the majority of its life so far.

My understanding of its recent history is that the previous owner picked it up in a pawn shop for next to nothing a couple of years ago, and has been trying to sell it for quite a while, with the intention of turning a profit. As far as I know, it has seen very little use in recent times, hence me recommending replacing the big electrolytics, which don't like to stand for extended periods, have a tendency of drying out and can sometimes fail catastrophically, even exploding.

I've had very good success with Tungsol Reissue tubes in these amps and have tubed a couple with them now. To my ears, in a back to back test with some JJ's, I felt they sounded a lot better and don't cost a whole lot more than the JJ's.

Thanks for the info!
And the replacement caps? NOS or modern parts?

Looks great. Lovely amp. But I can't even run my 18W with a single greenback at full power at outdoor pub gigs.

You can attenuate the hell out of it. Or run a pedal that simulates the sound of a 100W marshall through it...

I'm sorry to say it, but 100W amp heads belong in museums.

Musee de la Musique, Paris

1969 100W Superlead
1953 Fender Tele
1966 Gibson 335




So hawt.

singemonkey wrote:
You can attenuate the hell out of it. Or run a pedal that simulates the sound of a 100W marshall through it...

I'm sorry to say it, but 100W amp heads belong in museums.

Nonsense. There are other ways of bringing down overall volume, while still retaining that "Big Amp" sound and character that many feel cannot be achieved with a small amp, without attenuating the hell out of it, as you say. As I suggested earlier, a relatively cheap and simple PPIMV fitted to these amps very much retains their tone and character at all but the lowest volume levels, and so while it's not necessarily a good "Bedroom amp" option, it's certainly perfectly suitable for a jam room/gig where you can make a bit of noise.

psyx wrote: Thanks for the info!
And the replacement caps? NOS or modern parts?

Electrolytics have a shelf life. I don't care what some purists say about reforming old or NOS electrolytics, I'd most definitely put a set of new F&T or JJ caps in. I've used F&T's in a couple of Marshalls and my Trainwreck clone is using JJ and both have been fine.

Post a gut shot if you get a chance. It's been a while since I saw that amp's internals, and at that stage anyway it had not been worked on at all and was all original.

shaunf wrote:

singemonkey wrote:
You can attenuate the hell out of it. Or run a pedal that simulates the sound of a 100W marshall through it...

I'm sorry to say it, but 100W amp heads belong in museums.

Nonsense. There are other ways of bringing down overall volume, while still retaining that "Big Amp" sound and character that many feel cannot be achieved with a small amp, without attenuating the hell out of it, as you say. As I suggested earlier, a relatively cheap and simple PPIMV fitted to these amps very much retains their tone and character at all but the lowest volume levels, and so while it's not necessarily a good "Bedroom amp" option, it's certainly perfectly suitable for a jam room/gig where you can make a bit of noise.

Nonsense? Your solution still gives you only preamp drive which is even worse than attenuation or a pedal for getting the sound that these amps built their reputation on. You'll sound more like Zeppelin live running a Marshall-in-a-box pedal into the clean amp. Of course it would do the same to any clean amp.

singemonkey wrote:

shaunf wrote:

singemonkey wrote:
You can attenuate the hell out of it. Or run a pedal that simulates the sound of a 100W marshall through it...

I'm sorry to say it, but 100W amp heads belong in museums.

Nonsense. There are other ways of bringing down overall volume, while still retaining that "Big Amp" sound and character that many feel cannot be achieved with a small amp, without attenuating the hell out of it, as you say. As I suggested earlier, a relatively cheap and simple PPIMV fitted to these amps very much retains their tone and character at all but the lowest volume levels, and so while it's not necessarily a good "Bedroom amp" option, it's certainly perfectly suitable for a jam room/gig where you can make a bit of noise.

Nonsense? Your solution still gives you only preamp drive which is even worse than attenuation or a pedal for getting the sound that these amps built their reputation on. You'll sound more like Zeppelin live running a Marshall-in-a-box pedal into the clean amp. Of course it would do the same to any clean amp.

So what you're saying is that if you fit a PPIMV, all you're ever going to get is preamp drive? Ok. 8)

To any guys out there who have big amps, you heard it here first. Your 100w Marshall is not suitable for anything except gathering dust in a museum.

Please be so kind as to donate it for display purposes to Shaun's Museum of Old Marshalls (and other oddities):

Pedals definitely do work. They hit the front end of your amp and drive your power tubes if I am not mistaken.

However it is different for every amp. My Boss DS-1 might be have certain characteristics but it won't sound the same hitting the front end of a Fender Bassman as it will a Marshall plexi. You will get distortion but the distortion will sound very different, with only the characteristics of the pedal being the same.

Each amp has its own tone that nothing can ever change, pedals will bring out the amps overdrive/ distortion sound although the ability to turn the amp up will change the characteristic of that once again. This is why you have to try an amp before you buy, if you don't like its tone you can't change it short of modding it.

Haha guys, cool your guns! Its very much the same as saying that a Ford Mustang belongs in a museum, since it uses too much fuel and you will never be able to use it properly
Modern cars are way better in terms of living with them and the same goes for these amps. Yes, this is an outdated behemoth, but its beautiful and it sounds even better.
I realised that it would be too loud to get natural drive from it, but thats why i intend to use it with fuzz pedals etc to utilise the bottom end. I have my Orange for the overdrive sounds at tolerable levels.

Maybe i will end up passing it on to a better musician someday, but for now i am proud to have her as a beautiful centrepiece.

refuogee wrote: Pedals definitely do work. They hit the front end of your amp and drive your power tubes if I am not mistaken.

However it is different for every amp. My Boss DS-1 might be have certain characteristics but it won't sound the same hitting the front end of a Fender Bassman as it will a Marshall plexi. You will get distortion but the distortion will sound very different, with only the characteristics of the pedal being the same.

Each amp has its own tone that nothing can ever change, pedals will bring out the amps overdrive/ distortion sound although the ability to turn the amp up will change the characteristic of that once again. This is why you have to try an amp before you buy, if you don't like its tone you can't change it short of modding it.

Pedals work but they don't hit your power tubes hard. Different amps do sound different if you drive them with a boost pedal but that is because the preamps / tonestacks are different.

There is absolutely no way to get power tube distortion without loads of volume or loads of attenuation (with anything but the smallest amps). You can install Variable Voltage Regulators to decrease the headroom of certain tube stages in amps but with amps like these Marshalls, with fixed bias, the VVR doesn't sound that good if you turn it down below about halfway, which still results in massive volumes. This is practically only useful with cathode biased amps where you can turn the VVR down much further.

So yes and no. You can get a big amp to sound lekker at a reasonable volume with pedals and the amp clean, or you can do it at massive volume with the amp driven. The difference comes in at how the amp responds to pick attack and volume changes on the guitar. Most pedals just don't respond the way an amp would i.e. they don't clean up at all, although, things are changing and you get some that will clean up.

Still, if you go with pedals, you may as well get a smaller amp because carrying around a 25kg head and a 40kg 4x12 is a sucky business at best.

Knowing all this though, I still look at these big old Marshalls and want one haha.

I think I'll just leave this over here...

=

Hi Shaun

Do you have a circuit for a good PPI MV?

I was looking at the version at the bottom of this page.......
http://areyouexperienced.net/Marshall-JTM45-Reissue-Mods.htm

Thx
Peter