NOS-style JTM 45/100 on Metro chassis

[emmjaydubya]

I've been chomping at the bit to build one of these for a long time now and I got excited when Valvestorm offered up aluminum Metro 45/100 chassis recently so I picked one up with a really excellent engraved and back-painted back panel with a SERIAL NUMBER! Pretty damned cool if you ask me. Robert went the extra mile and got the holes for the vintage-style selectors just right!





These selectors are the crazy expensive ebay ones from France but I said why not, this amp will be the one. The impedance selector has the 100v instead of the 4ohm which is not so much 45/100, but I'll just put the 4ohm secondary tap on the 100v. Also Belling-Lee fuse holder and drilled the hole for a Bulgin socket 'just in case I ever want it' and put in a trick IEC that fits in a Bulgin hole.





Sparky front panel with orange indicator and knurled switch nuts:



Found these cool NOS Elco pre sockets sealed in original 1961 packaging:



Starting in with the Pihers:

[emmjaydubya]

Used 18 ga. topcoat on the McMurdo power tube sockets, kind of overkill but it's what I did on my 12,000. Scoured the planet for Radiospares 1k 5watters for the screen grids but never could get any. Settled for the trusty Welwyns. Piher 5k6 for swamp resistors. Also opted for orange wire here instead of yellow because I was finding mostly orange in this era on Amp Archives.

[Strat78]

Great work! I like the orange wire look for the power rails as well, guess I'll have to switch out my yellow ones. The Bulgin sockets are pretty easy to come by Those selectors look really great, as soon as a sell off a bunch of stuff, I'll grab a couple. Are you going for the Dickinson spec or just a nice classic 45/100?

[axeman]

Great work

[emmjaydubya]

Thanks guys, hey Art, how did that 132 OT work out?

How you been Phil? How's that knee doin? Funny about the power rail, that right-angle routing is ripped-off from your 12,000 builds!

It will be stock except for 470k mixers, although I could probably be convinced to try 270ks. I've got several Bulgin sockets but I don't like dealing with them playing out live. Keeping the cords from eventually pulling out of the plugs is a nightmare, I'll just stick with IEC till I'm too old to lift my amps. Then I'll put in Bulgins and stare at the vintage-ness at home, haha!

I really want it to be as traditional as possible, I like the 250pf/56k in the tonestack on my JTM45. I've been pretty inspired by these two vids for the 45/100 sound lately:

http://www.youtube.com/watch?v=bozMjxiWdTY

http://www.youtube.com/watch?v=YZJTXoOvzhY

Of course they are both George's amps! The cabinet in the second vid sounds SO SICK! Scumback 20 watters in a tall Hendrix cab! I don't play this kind of music in my band, but I love to noodle this kind of stuff all the time. I think a 45/100 would be useful for any situation I'm in though and I can't wait to finish and play it...

But I have to, because it's nine weeks and counting waiting for my Marstran trannies.

[axeman]

I haven't used the OT bought it because of the good price. I'm actually finishing up my 68 with a C1998, I'll use it for a while then try the 132. Do you have the 3 prong Bulgin sockets?

[emmjaydubya]

Funny, I've thought about pulling the 132 in my 12,000 and trying out a C1998.

I have one Bulgin on hand, I see the sockets on ebay all the time, not that rare. The straight plugs that go into the sockets you find from time to time, sometimes you'll see a set. What are rare, are the right angle plugs! These are what you want to keep the cord from pulling out of the plug.

[Strat78]

I've switched most of my 132's out for 1998's OT's, just because that's how the wind was blowing last Fall, think I still like the 132's better, though the difference is small (nicer low E feel with the fatter tranny). As far as the knees, my range of motion could be better, but I am almost back to normal activity wise, I was able to load a half stack into the care all by myself today!

[emmjaydubya]

Glad to hear it! You been on that block end build at all?

[Strat78]

Nine weeks and still waiting! Thats brutal. I guess business is good for these guys, because I've been waiting ten weeks so far for a custom head cab from mojo. Hey, I just added a link to pics of my 45/100 at the end of my thread. It's been done for a while and does everything these monsters are supposed to do.

[maxwedge572]

Fantastic work there!

[Xplorer]

very cool ! this amp looks great

[emmjaydubya]

Thanks guys, still waiting on iron...

Got some brown Paxolin material from England and split turrets from Mouser, time to start on the boards this weekend! I'm going with a solid board for the pre and a perfed board for the power board. I've seen several of this configuration on Amp Archives,looks pretty cool.

Got a question, still need a choke and I was wondering about the 114, I think it's a 3H? Can you get one from George or Heyboer? All I'm seeing offered is the C1999. Differences?

[neikeel]

Funny, I've thought about pulling the 132 in my 12,000 and trying out a C1998.

I prefer the C1998 in those

I have one Bulgin on hand, I see the sockets on ebay all the time, not that rare. The straight plugs that go into the sockets you find from time to time, sometimes you'll see a set. What are rare, are the right angle plugs! These are what you want to keep the cord from pulling out of the plug.

's ok as I try to buy all the right angle ones that I see - the straight ones are no good live

BTW - really nice work. I have a similar project in kit form with one of Robert 7026 panels, Marstran chassis and trannies just waiting for time, I have all the NOS stuff (inc the RS 32uF caps and the Dickinson spec replaced caps and resistor types - how sad is that ?). Can't decide whether to relic the chassis and cap board too!

[neikeel]

Funny, I've thought about pulling the 132 in my 12,000 and trying out a C1998.

I prefer the C1998 in those

I have one Bulgin on hand, I see the sockets on ebay all the time, not that rare. The straight plugs that go into the sockets you find from time to time, sometimes you'll see a set. What are rare, are the right angle plugs! These are what you want to keep the cord from pulling out of the plug.

's ok as I try to buy all the right angle ones that I see - the straight ones are no good live

BTW - really nice work. I have a similar project in kit form with one of Robert 7026 panels, Marstran chassis and trannies just waiting for time, I have all the NOS stuff (inc the RS 32uF caps and the Dickinson spec replaced caps and resistor types - how sad is that ?). Can't decide whether to relic the chassis and cap board too!

Correct is -114 but C1999 is same 3H spec.