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View Full Version : Valve Amps - JTM45 Kits



kells80aus
07-01-2015, 04:40 PM
I've been doing a bit of searching for Valve amps and have found quite a few kit suppliers that will supply parts through to complete kits.

http://triodeelectronics.com/jtm45tubeampkit.html $414USD plus P+H

https://tubedepot.com/products/classic-british-jtm45-plus-tube-guitar-amp-kit-head $795USD plus P+H

http://www.tubeampdoctor.com/en/shop_AMP_Kit_PLEXI_HEAD_AMP_Kit_PLEXI_HEAD/Amp_Kit_Plexi45_3442?selected_slave_id=1078 LOT$

http://www.mojotone.com/amp-parts/amp-kits/Mojotone-British-45-Watt-Style-Head-Amplifier-Kit#.VKz-ScnrYkw $577-897 I assume USD

http://www.ceriatone.com/productSubPages/BSJTM45/BSJTM45_Complete.htm $1020 USD complete and working

and there are many more.

Most of these kits are Head only. some do not include the tubes or case. Speaker cabinets are an optional extra.

but it is some where to start. :)

For me it's Finish my gits first then build a JTM45. :)

Cheers PK

TC1600
07-01-2015, 05:48 PM
Some nice looking kits, in reality they will probably all give you a similar end product, it would come down to price (check exchange rates and shipping costs), quality of the instruction manual and customer service. I will warn you now some of the wiring is very fiddly! Luckily with mine the fiddly part came towards the end of the build, so it was a good motivator knowing the end was in sight :) Good luck with the project, I'm sure you will be very pleased with the result!

Edit- don't forget to check it is set up to work with 240V! I don't know if 230V transformers are close enough, definitely something to check.

Mr Fox69
08-01-2015, 05:32 AM
Edit- don't forget to check it is set up to work with 240V! I don't know if 230V transformers are close enough, definitely something to check.

This. Transformers are the most expensive parts of the build. Over $100 in most cases.
The transformer supplied with the JTM45 kit at the top of the list is 240v, but don't forget that the chassis to mount it all to is extra.

I am currently working on a modified Marshall JMP50 design 50 watt tube head. It cost me around $600 in parts.

kells80aus
08-01-2015, 11:23 AM
The Triode Kit Power transformer is set up with multiple coil taps.

"The power transformer has multiple primaries 120/220/230/240V."

they have a downloadable layout which looks much like the one from Tubedepot.

unfortunately it is too large to post up on here. it's 114K.

Tubedepot also have youtube build viseos, but having watched them they go through it too quick and do not always explain whats going on.

I understand the fiddly issues TC. it gets worse when you get older.


Cheers PK

kanelangmaid
08-01-2015, 01:17 PM
There is also any Aussie company selling most of the bits you are looking for. As long as you have a list of what you need they can usually put a package together.

http://www.evatco.com.au/

kells80aus
08-01-2015, 01:39 PM
Tks for that Kane.

I've also had a look on Alibaba and found some there, in fact some of the pics they use appear on other Kit suppliers.
As TC said in his Amps post you need to take care in what kits you buy as you need to get a a full set of Instructions. This is true in my case as the last valve powered unit I built was about 45 years ago, so I am prety sure I wouls like to have a chassis with the holes drilled in the right spots. :)

Cheers PK

TC1600
08-01-2015, 04:06 PM
Yeah I've watched the tube depot videos, they aren't comprehensive but they are a good overview. Their online instruction manual is pretty good though. The good thing about their videos is you get to hear the finished product at the end.

DrNomis_44
09-01-2015, 09:40 PM
There's also Ampclones.com, granted they don't stock JTM 45 kits, but the PCB and Chassis kits they do stock are priced reasonably well.

kells80aus
21-01-2015, 03:26 AM
From the research I have done , not all apples are apples. Most of the Kits have tonal variations dependant on what types of hardware tthey use to build them Mableaudio in China appears as the cheapest, but they use off the shelf modern parts and their amps lack that warm tonal sound that comes from a Classic JTM45. Going through the US based kits the better the components, the greater the costs.

Mableaudio prices range from$358USD to $408 USD for an assembled kit/No case.
there prices are similar for the 5F6A Bassman Tweed on wich the JTM45 is based.
The US kits and Ceiratone kits range in price upto more than $1000USD

The compartive kit types are

JTM45 - British 45Watt. 5F6A Tweed Bassman 40Watt
18 Watt British 18Watt 5E3 Deluxe Tweed 16Watt
5F1 Champ 5Watt

Depending on whether you want to build a Combo Unit or just a Head unit will determin which might be the better amp to build.

With a combo Unit the Bassman and Tweed deluxe represent a more compact unit to build
With a Head Unit the JTM45 offers a more open and manageable design. The issues with putting a JTM45 chassis into a combo unit relates to the fact that the chassis backpanel faces down and is awkward to access, while the Fender Units have the valves facing downwards, and the chassis design is more compact.

Overall the smaller the amps are in power the easier they are to build.

Be aware these amps when operating carry High Voltages that can kill the JTM45 valves operate in the range of around 690Volts.
If you don't have someone that can help set up the tube bios, then maybe get one that is already fully assembled.


Cheers PK