Post by Deleted on Sept 11, 2020 14:50:03 GMT -5
I have built myself a 5E3 from parts. I acquired a partial MOJO kit some years ago in a private deal and had to buy the rest of the missing components individually over the years as well as a few extra tools to complete the build.
I finally completed the build earlier this week and have been enjoying my new toy up until I tried placing a jumper between the bright and normal jacks. I had been using only the normal jack. It was when I did this and was experimenting with the individual volume knobs that I started noticing something was amiss. The first thing I noticed is that there was no sound when plugged into the bright jacks. The MOJO drawing I downloaded and used to build the amp showed 3 out of the 4 input jacks using the chassis as ground and I wondered about that while building it. I went ahead and wired up a ground to the other 3 jacks and then there was sound from the bright jacks but only at half volume compared to the normal jacks. The second thing I noticed is that the bright volume control does very little when plugged into the normal jack, almost nothing when plugged into the bright jack and shuts off all volume if dialled past 11 regardless of which jack. Using a jumper between normal and bright does not seem to have the same affect as it normally should. In fact, it almost seems as though it's not even there.
This is the MOJO drawing I used as my reference to build the amp.
I did not follow the drawing to the letter. There were two deviations.
One, I wanted a mute/standby switch and saw no need for a ground switch. I facilitated that by eliminating the cap, connecting the red/yellow from the PT to one side of the ground switch and the other side to ground. The third contact at the other end of the switch is unused.
Two, I did not get the MOJO 768 OT shown on the drawing and instead used a Mercury Magnetics FTDO-59 so the wire colors are not exactly as shown.
I've been around forums for a long time so I know people will want more information.
I will try to provide whatever I can.
I appreciate any help I can get.
I am not an amp tech, I am an amateur.
Simple language is preferred.
Thanks
I finally completed the build earlier this week and have been enjoying my new toy up until I tried placing a jumper between the bright and normal jacks. I had been using only the normal jack. It was when I did this and was experimenting with the individual volume knobs that I started noticing something was amiss. The first thing I noticed is that there was no sound when plugged into the bright jacks. The MOJO drawing I downloaded and used to build the amp showed 3 out of the 4 input jacks using the chassis as ground and I wondered about that while building it. I went ahead and wired up a ground to the other 3 jacks and then there was sound from the bright jacks but only at half volume compared to the normal jacks. The second thing I noticed is that the bright volume control does very little when plugged into the normal jack, almost nothing when plugged into the bright jack and shuts off all volume if dialled past 11 regardless of which jack. Using a jumper between normal and bright does not seem to have the same affect as it normally should. In fact, it almost seems as though it's not even there.
This is the MOJO drawing I used as my reference to build the amp.
I did not follow the drawing to the letter. There were two deviations.
One, I wanted a mute/standby switch and saw no need for a ground switch. I facilitated that by eliminating the cap, connecting the red/yellow from the PT to one side of the ground switch and the other side to ground. The third contact at the other end of the switch is unused.
Two, I did not get the MOJO 768 OT shown on the drawing and instead used a Mercury Magnetics FTDO-59 so the wire colors are not exactly as shown.
I've been around forums for a long time so I know people will want more information.
I will try to provide whatever I can.
I appreciate any help I can get.
I am not an amp tech, I am an amateur.
Simple language is preferred.
Thanks
