Mesa Boogie Walkabout Mega-thread Part 10

[jbravo]

At a recent visit to the Atlanta Bass gallery, I recently found a clean, used 1x15 Powerhouse cab to go with the one I already had. The only problem was that the new(er) one had a black grill while my existing cab was an older silver grill version. The solution was to have both grills freshly powdercoated in black, which was way cheaper than buying a new grill from Mesa. What started out as a WA12 combo now has really big sound with mucho clean headroom.

Seriously sweet!!

 

[sunbeast]

At risk of getting flamed, I can't find my answer, so I'm hoping someone here can help me out.
I have an older Walkabout head with the two input jacks. I would like to mod it so that it functions like the newer model with one input jack and an active/passive switch.
I thought it would be an easy mod, but when I opened up the case, I found three wires to each jack. The red (hot) and black (ground) make sense on the active jack. The white (hot) and black (ground) make sense on the passive jack.
The part that has me confused is the purpose of the white wire which continues on to the other side of the passive jack then continues to the active jack.

Does the active jack feed the passive circuit? Or is this a cut off so that only one jack will work at a time? Or?

If anyone can point me at a thread or even some search keywords I'm not thinking about I would greatly appreciate it.

Thanks!

It sounds like the white wire would be grounded when plugging a standard mono cable into the active input if I am visualizing it correctly. Are both jacks just standard TRS inputs or is one or both a switching jack (where inserting a cable opens a connection)?

 

[gastric]

At risk of getting flamed, I can't find my answer, so I'm hoping someone here can help me out.
I have an older Walkabout head with the two input jacks. I would like to mod it so that it functions like the newer model with one input jack and an active/passive switch.
I thought it would be an easy mod, but when I opened up the case, I found three wires to each jack. The red (hot) and black (ground) make sense on the active jack. The white (hot) and black (ground) make sense on the passive jack.
The part that has me confused is the purpose of the white wire which continues on to the other side of the passive jack then continues to the active jack.

Does the active jack feed the passive circuit? Or is this a cut off so that only one jack will work at a time? Or?

If anyone can point me at a thread or even some search keywords I'm not thinking about I would greatly appreciate it.

Thanks!

Phone MESA tech support, I'm sure they'd help you out. Note the modification doesn't really get you anything other than one less jack to MAYBE / POSSIBLY get dirty from non-use. Unless you have some problem with one of the jacks and you're already going to be replacing them, I'm wouldn't personally bother.

 

[EdwardofHuncote]

I have an older Walkabout head with the two input jacks. I would like to mod it so that it functions like the newer model with one input jack and an active/passive switch...

I have two older silverface WA's - one that has had the jack-to-switch mod, one that hasn't. Ain't a dime's worth of difference... I only ever use that active input or toggle the selector when in my practice room, and only then to keep it used. It's just not a switch I need in a live fire situation.

The un-modded one used to not pad down for active level due to a dirty jack. (probably from lack of use) A couple squirts of DeOxit and a couple pipe cleaners later, it works like a champ. Wasn't worth the hassle of getting it changed. Indeed there are some among us that favor a ban on all "active" inputs.



Obviously, YMMV, and these guys (on this thread) are pros. Good luck either way!

and +1 on Mesa tech support.

 

[agedhorse]

There's no difference in the functional operation, there is a switch inside one of the jacks that performs the same function as the active/passive switch. Unless yuo know how the circuit works, the wiring won't make sense to you.

 

[Jazz4]

I'd be more concerned with the effects loop in the rear acting up. I personally run the WA with the switch on passive at all times no matter what bass I use. On mine the active setting seems to kill the tone somewhat.

 

[bonz - darrell]

Hi,
Thanks for your replies guys! I want to do the mod because I play both active and passive basses. I keep one drop tuned, and switch back and forth as the song requires (we drop tune for our singer).
In order to switch instruments now, I turn down my master volume, and switch jacks. I find the master volume on my WA is a bit touchy -- either just right or way too loud (ie 2 verses 2.5).
If I run my Stu Hamm Urge I (active) through the passive jack, it sounds really bad -- distorted because the signal from the bass is really hot. If I run the '74 precision (passive) through the active jack it's really, really quiet and bland. If I switch plugs, the volume stays pretty constant.

My effects loop came with a patch cord in and out, and the guy I bought it from told me to just leave it there unless I wanted to run effects through it. Since my wireless is set up on my pedal board, it means two less cords to trip on.

I've drawn out how the jacks are wired, and included a picture. Any help would be appreciated. Ugg. Having trouble transferring the image from my tablet. One moment please (hold music).

Passive, Active and Ground wires come from the circuit board. The question I have is what the passive wire is doing crossing the passive jack then connecting to the active jack.

darrell

 

[agedhorse]

You need to consider the switches inside the jacks for any of this to make sense.

 

[bonz - darrell]

You need to consider the switches inside the jacks for any of this to make sense.

I think I'm beinng dense (and I'm certainly not an electronics guy!)... Are you saying that I can safely pull the cord out and switch from active to passive without turning down the volume?

 

[sunbeast]

I think I'm beinng dense (and I'm certainly not an electronics guy!)... Are you saying that I can safely pull the cord out and switch from active to passive without turning down the volume?

I think he's saying that one or both of the jacks incorporate some sort of switching mechanism that connects or disconnects two of the three used terminals when a plug is inserted. To test you could use an ohmmeter to see what happens between the three connections at each jack when you plug or unplug a cable. My novice guess is that plugging into the active input grounds the input wire from the passive input...

 

[bonz - darrell]

Phone MESA tech support, I'm sure they'd help you out

I tried emailing them with this question, but I got back the politically correct response that I should take it to an factory authorized tech and have him/her do it.
In this case, I kind of want to be hands on, and understand my amp a little better. I solder new pickups,pre-amps, etc into my basses on a regular basis, so I'm not exactly a total neophyte, but as I said, I'm certainly not an electronics tech...

 

[nemo]

Hi,
Thanks for your replies guys! I want to do the mod because I play both active and passive basses. I keep one drop tuned, and switch back and forth as the song requires (we drop tune for our singer).
In order to switch instruments now, I turn down my master volume, and switch jacks. I find the master volume on my WA is a bit touchy -- either just right or way too loud (ie 2 verses 2.5).
If I run my Stu Hamm Urge I (active) through the passive jack, it sounds really bad -- distorted because the signal from the bass is really hot. If I run the '74 precision (passive) through the active jack it's really, really quiet and bland. If I switch plugs, the volume stays pretty constant.

My effects loop came with a patch cord in and out, and the guy I bought it from told me to just leave it there unless I wanted to run effects through it. Since my wireless is set up on my pedal board, it means two less cords to trip on.

I've drawn out how the jacks are wired, and included a picture. Any help would be appreciated. Ugg. Having trouble transferring the image from my tablet. One moment please (hold music).

Passive, Active and Ground wires come from the circuit board. The question I have is what the passive wire is doing crossing the passive jack then connecting to the active jack.

darrell


View attachment 455660

Why don't you just use passive input when playing passive bass and active input when playing active bass? Why do you need the switch? Did I miss something?

 

[Chef]

I never used the active switch, even with my hottest basses.
They didn't clip in passive, and active seemed to really change the tone in ways I didn't like.
This also applied to my 400(+), and M6/9....

 

[bonz - darrell]

Why don't you just use passive input when playing passive bass and active input when playing active bass? Why do you need the switch? Did I miss something?

Yup. I do switch, but I have to turn my volume down first. It doesn't seem like a big deal, but it drives me crazy because I struggle to not be too loud... (wow, did I just say that?)

 

[EastCoastThump]

The point of the mod was to remove the jacks as a point of failure in the older design (the input jacks and the FX loop jacks were prone to short).

 

[nemo]

Yup. I do switch, but I have to turn my volume down first. It doesn't seem like a big deal, but it drives me crazy because I struggle to not be too loud... (wow, did I just say that?)

Why would you have to to turn volume down? Are you afraid that unplugging cord from first input and plugging the cord again in second input would cause loud pop? It will not.

 

[D.A.R.K.]

Hello Walkabout people-
I got a sweet walkabout head in a Mesa hard case (thanks Chef it rocks!) but would rather have a soft bag than case-
so i'd like to sell the hard case.
Listed here:
http://www.talkbass.com/threads/walkabout-head-hard-case-by-mesa.1094518/

 

[Rickles]

Looks like a lot of folks here like JJ's for V1. Can anyone tell me if the JJ ECC83-S or ECC803-S is preferable? I read that the 803 is a long-plate version of the 83, but I wonder if that makes a difference for V1 and which is best. The 803 seems to be a few dollars more.

While looking at the JJ ECC83S description on Doug's Tubes site, he noted they are also known as a GroveTubes ECC83S.

 

[sunbeast]

The long-plate ones are supposedly more prone to microphonics, so I probably wouldn't use one in a combo Walkabout. I use the standard JJ personally and love it in most every application I've tried it in.

 

[Rickles]

The long-plate ones are supposedly more prone to microphonics, so I probably wouldn't use one in a combo Walkabout. I use the standard JJ personally and love it in most every application I've tried it in.

Thanks; exactly what I wanted to know.