JTM board, tranny's w/JMP component parts okay?


Senior Member
I recently purchased a JTM 45 100 board and chassis, pre assembled from Ceriatone. I'm on a shoe-string budget and wanted to get the rest of the parts locally, here in the USA. I tried Weber and Marsh amps but they told me to get a list of individual components together since they would not merely subtract the parts I already have and provide a partial kit. That's fine except I haven't a clue what I need, part by part. I had assumed I could just ask for everything needed for the output stage of the amp, also not knowing what parts besides the tranny's would be JTM exclusive. I figure most of the stuff is JMP guts before the tranny's but hey, it's my first build. Also if anyone knows what company besides Weber or Marsh could fill my order without taking it personally, that would be great.


You still need to know what you need for them to supply the parts.Most people don't have the time to figure out what extra parts you will need without seeing the schematic and layout.
This amp for a first build is a little optimistic if you don't understand what you are doing.
You need to know what each component is and what it does unless you are a 'paint by number' sort of builder.
The parts also need to fit the Ceriatone chassis,so whay didn't you order from Ceriatone?

What do you mean by 'taking it personally'? They don't have time to figure it out for you.


Planning ahead sounds like a pretty good idea right now doesn't it?

You will have to assemble a list of components you'll need, I don't think anyone will fill that order. Ceriatone MIGHT because they supplied the board, so try there first.

You can assemble said list by looking at a layout of the amplifier and eliminating the components you already have, and making a list of what is left. Don't forget tube sockets and shields, jacks, wire etc.

Good Luck!


Senior Member
Not a big deal really. Actually sounds like a lot of fun. Like WesKuhnley posted, go to Ceriatone site take a look at their layout for the amp and make a list of everything you don't have.

I'm guessing you will need all the chassis hardware - input jacks, speaker jacks, switches, etc. Be sure to make note of the differences in things like the pots for the tone stack some are linear, some are audio. All the stuff you need are common amp building parts, you may be able to order it all from the same place, depending on you choice of PT, OT and choke (people speak highly of the iron from Metro Amps). Don't forget the power cord, hookup wire and solder.

If you don't want to deal with Marsh or Weber, contact Hoffman. He should have most if not all of what you need. Also with Hoffman your order will ship quickly.

One other thing be sure to measure the holes in the chassis to make sure the parts you order will fit!
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I guess I just didn't realize what I was getting into. Dumb.

Hi. I'll try to give a fresh perspective (although experienced techs
have already posted), as I have completed my first amp project. It wasn't a kit, I started from a schem. and layout, had an old SS Crate cab and chassis and went to it. It has been a rewarding experience, maybe first time luck.. but I'd like
to think that good preparation and confidence in my building/ soldering/assembling skills gave me a higher percentage of success. And not to mention, a project that is not overly complicated... because if you have to trouble shoot, you won't be overwhelmed. Just don't give up! Follow it through to completion, no matter how long it takes.

And, this forum is full of helpful folks that are willing to share their knowledge. I've learned a lot from reading, I haven't asked a lot of technical questions but the info is in here.

Before you start a project like this, it is important to study and
plan ahead. In turn, that will boost your confidence that once you
start, you can finish. Although, there's nothing wrong with diving in
(so to speak) and learning/making mistakes as you go (I have taught
myself many things this way), but be prepared to run into problems
and potential dangers from doing it this way. I don't recommend it,
especially considering high voltages can and will be present. That
brings me to my first real suggestion...

Learn how to properly discharge caps. Understand and respect that
there are potentially deadly forces within. There is a lot of info on
this out there, so read up and experiment when the time comes. Second, its
easier to learn this type of stuff on an existing amp. I did.. and I first
tinkered around with my vintage traynor ygm-3 and got it running, and
also an old peavey. That's part of the confidence building, because
you're learning and trouble shooting- using your creativity.

Study your layout and schematic. A layout is obviously easier to
comprehend, and as you study it - cross check it with the schematic
and follow what's going on. This will help your understanding, and
I'm just now beginning to feel confident about reading a schematic,
and translating that into a layout. There are so many good layouts
and schematics available out there, with component values and all.
Essentially, as mentioned above, you can 'paint by numbers' if need be. Copy a known layout, go over every capacitor/resistor value, write them down and the rest of the parts you will need. If you can't get to that point, then maybe you're not ready to start building one yet... If you can, then get the parts you need and get started.

If this is something you're interested in doing, which I'm sure it is since you posted here, then take time to learn all you can. Be patient, because going into it blindly could be overwhelming. Good luck! Don't give up! You'll be hooked once you get it right, I promise you.

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