5E3 Deluxe interactive volume (or lack thereof)

[DavidP]

I recently hauled out my Mission 5E3 "Tweedy Deluxe" clone I'd mothballed for the past couple of years (for you-know-what reasons). This was my first build back in 2003 so I figured it may be time for some filter cap maintenance given age and recent inactivity.

After some twiddling, I find no discernible change as I increase the normal channel volume control while plugged into the bright channel set around 6 (my sweet spot)...

To re-familiarize myself with the volume controls, I viewed the great in-depth demo by RecProAudio (). At 14:40 he zeros the bright channel and brings up the normal channel, while plugged into the bright channel 1, resulting in increasing amp volume. Hmm, nothing like that occurs on mine...

So... fellow 5E3 owners, before start troubleshooting this in depth, I'd love to hear back from others when doing this manipulation.

 

[schmee]

Is that the scheme that you need to jump the channels with a patch cable for?

 

[dan40]

Some of the Mission Amp mods involved separating the channels to remove the interactivity between the two. Any chance you did that mod and forgot about it?

 

[archetype]

Some of the Mission Amp mods involved separating the channels to remove the interactivity between the two. Any chance you did that mod and forgot about it?

^Good question. In standard config a 5E3 has interactive controls. Either a mod has been intentionally performed, or it's miswired.

 

[DavidP]

Some of the Mission Amp mods involved separating the channels to remove the interactivity between the two. Any chance you did that mod and forgot about it?

Nope... Guess its time to open up the hood and revisit the schematic and layout...

 

[ReverendRevolver]

Yea, the circuit has interactive volumes (like it or not) unless modified out of it.

 

[King Fan]

Faint hope: You may not notice the interaction a ton in the middle of the dial. Keep the active channel low to start -- and keep the tone in the 3-4 range too. Sure, 6 is a nice full-Deluxe sweet spot, but try 2 to 4 on the volume -- set it to go into dirt only with harder picking. Now try turning the non-active channel up thru 9-10-11-12. It should gradually act as a muffler or squelch.

But TBH some interaction should be audible even with the active volume at 6. I'm thinking you may be right about a wiring issue.

 

[2L man]

Perhaps you did not follow schematic strange way to wire potentiometers, which are not typical voltage dividers? It might have happen if you are used to use potentiometers normally

When potentiometer is turned CCV it shorts more pre amp output signal to ground and perhaps interaction functions when it result more B+3 voltage fluctuation? I recall reading that it is essential for 5E3 sound to wire volume potentiometers like that.

 

[Ricky D.]

I run my Mission 5e3 (standard circuit) in the bright channel, tone 12, volume 5-6, and control the loudness at the guitar. Volume control interaction begins from 9-10 on up to 12 on the other volume. Very noticeable.

 

[DavidP]

Thanks @Ricky D. for the info. Please do me a favour -- what sound do you get when you plug into the bright channel w volume set at zero, and then turn up the normal channel volume? Similar to what happens in the RecProAudio video? That would help me alot at this end, given you have the Mission build (which IIRC follows the 5E3 circuit pretty closely).