some general metropoulos amp questions

[Celluloid]

sorry, i am a nub in this department.

i just wanted to know a few things about these amps before i purchase a kit

im looking for the sound from Are you Experienced and Disraeli gears specifically, and was led to believe that the amps used were the same type, wondering if you could tell me which replica is the one for getting that kind of sound (i know i need a certain guitar, pedal, etc, just wondering what amp)

also, looking throught the forum i see a lot of posts mentioning a JTM 45/100, but i only see a pre-built amp of that type. are they any kits for the JTm45/100? i only see JTM45....

i have looked throught many threads and couldnt find the answer i needed exactly, so just decided to ask.

[Flames1950]

Metro has all the parts available for a JTM45/100, just not as a complete, one-click kit. (There's only so many kits poor George can offer, as tech support time is not easy to come by for supporting all the kits.)

That said, head to the JTM45/100 build log section of the forum and you'll find the complete bill of materials, as well as mucho advice for building these amps. There is no step-by-step instruction set though, for the same reason as above.

If you do need a kit with step-by-step instructions to get close to those sounds, the '69 kit (ordered as a Super Bass) will serve you very well indeed. The Super Bass circuit remained truest to the old 45/100's and early Super Lead/Bass amps, up through the mid-70's.

[Celluloid]

just want to make sure i understood

so a jtm45/100 is the ideal replica for those sounds even if its not in kit form
but the '69 super bass is the next closest thing in kit form

ill have to check the build log

so what exactly is the difference between a jtm 45 and a jtm45/100? Wattage?

[Loganp]

yes. JTM45 is in the area of 45 watts. and a JTM45/100 is 100 watts.

http://metroamp.com/store/product_info. ... cts_id=491" onclick="window.open(this.href);return false;

[Flames1950]

The '69 Super Bass in closest in kit form with instructions.

There is a complete '67/'68 kit option if you look at the '67 steel chassis in the store.....but once again, no step-by-step instructions due to the amount of support time available.

[Celluloid]

what exactly is missing from the 45/100 kit listed here? besides instructions?

http://metroamp.com/store/product_info. ... cts_id=491" onclick="window.open(this.href);return false;

assuming you order all the options

[thousandshirts]

what exactly is missing from the 45/100 kit listed here? besides instructions?

http://metroamp.com/store/product_info. ... cts_id=491" onclick="window.open(this.href);return false;

assuming you order all the options

Quite simply, LOTS is still missing, even if you take all those options. It's a starting point for people who want a lot of DIY options. Off the top of my head, the resistor package doesn't include all the resistors you'll need for the entire amp. You'll need capacitors. Potentiometers, power/standby switches, an impedance switch, a voltage selector switch, power cord (strain relief/socket), fuse holders, input and output jacks, tube sockets, lots of mounting hardware, lots of wire. . .and so on! If you look in the 45/100 Build Journal section, you'll find a Bill Of Materials Thread

I think the Super Bass is a great suggestion. The 45/100 and the Super Bass are very closely related.

[Billy Batz]

Basically you can just get the 69 Super Bass kit and swap for the JTM-45/100 output transformer and KT66s tubes. If you wanted to go further use smaller value filter caps as well. Like use 32/32 cans throughout instead of 50/50. Theres maybe 2 other spots where theres some different value resistors. 270k's in place of the 470ks on the board and a 27k in place of a 47k. Thats nearly everything. It would be identical at that point accept for a small power supply variation.

AFAIK Disraeli Gears would be mostly JTM45. The live stuff is where clapton uses the JTM45/100 stacks. Also Hendrix may have used that amp for live shows at this time but how much he uses it on the actual albums is in debate. Theres lots of talk of Fenders and even Voxes. Either way its an awesome amp and using the 69 kit with some substitutions would get you 99% there.

You could use the bill of materials and get the JTM45-100 kit and use the 69 kit instructions but youd have to be able to improvise a bit because the amps are layed out a good deal differently even tho the basic design is the same. I would only recommend it if you have a good basic sense of signal flow and electronics.

[Celluloid]

alright, i think i have a better understanding now

if wanted to match the JTM 45/100s tone but not wattage, would the JTM 45 do the job?

i would probably not use all 100w and i really would prefer the instructions

[Flames1950]

I think the tube rectifier in the JTM45 is going to influence the sound more than you'd like compared to a 45/100. I'd consider the 50 watt Bass.

Volume difference between these amps may be less than you think too, so if you're hoping the 45 or 50 will be substantially quieter you may be surprised.

[Celluloid]

thats about all the info i need for now

thanks everyone