I have recently received a TT JTM45 chassis made from galvanized steel. While checking the std cutouts against the TTshop ordered pot.meters(Alpha) and impedance selector switch I noticed the following:
1. The holes for the pot.meter are 8mm while the Alpha pots need at least a 9,5mm hole. Also the small 3mm hole to prevent unwanted rotation of the pot.meter housings are missing.
2. The hole for the imp.selector switch is 11,4mm while a hole of 10,2mm would do the job. Also here the small 3mm hole to prevent rotation of the switch housing is missing.

Question: Is the aluminum version facing the same issues??? I guess most clone builders will use the aluminum version, as Jim Marshall used this material too. I went for the steel version because of better conductivity for the grounding.

Because the chassis are all produced by laser cutting it would be a small mod to add the 3mm holes and correct the other holes to accept the shop avalable parts

Hi,

I guess you are talking about the PX45 Chassis, Item number tt-ch045-15s.
On the product page you can download a pdf file , which is the datasheet of the chassis. Scale is 1:1, so you can e.g. import it into inkscape and measure all cutouts you want.
For the PX45 and the other amps which are using this chassis we use the 16 mm alpha potentiometers, so the drills will fit if you use this potentiometers. If you want to use an other kind of potentiometer you must enlarge the drill by yourself.

This chassis is not designed to be a common JTM45 chassis, it is designed for your kits and products.

Best regards, Dirk

Yes indeed, I ordered a PX45 chassis. Í'll use this to build a special JTM45 custom designed clone. To my opinion the 24mm will do for the channel volume pot.meters when turned 90 degr. However in this case for the bright channel I will use a push/pull version to select an option in the tone control. I can still use the ordered 24mm pots for all controls.

Which dimensions are for the pot.meters are provided in your std JTM45 chassis. I can download the faceplates but are unable to print these to scale nor can I measure the holes

BTW, the 24mm Alpha potmeters I've ordered are 8mm drilling versions so no problem

I have been mislead becuse the HiWaii chassi I ordered has 9,45mm holes for the potmeters

The ordered chassis is the extended version. To my opinio it is designed to build both the JTM45 or the PX45 amplifiers. This due to the hole patern in the front part of the chassis. It is recomended to indicate in the item description that the holes for the potmeters are designed for std 8mm version of the controls.