Modding the mighty DS-5R :-)

[FC Bass]

So I am in the process of modifying my DS-5R.


My unit has been with a pro "rig guru" for a while now, but he has had some personal problems and he had a hard time understanding what I want and how to do it.
We came to the point that he's sending it back without the mods...
He did drill two required holes in the back and included a couple of 1/4 jacks. Including shipping cost totally free of charge. Real nice guy :-)


It will arrive next week and I ordered these:


Meinl MPMGR Merger: https://meinlpercussion.com/en/products/mpmgr-m15444.html
Lehle P-Split Stereo: https://www.lehle.com/lehle-p-split-stereo


Plan is to get these units inside the DS-5R somehow :-)


I'm curious to see how the Meinl works, but apparently it does what I want...


I foresee many problems, so I might need all the help from the experts I can get :-)
If it works flawlessly, this will serve as a "how to" tutorial :-)




I need to have three inputs: 5 pin XLR (summed to "mono") plus 1/4 Jack in the front and 1/4 Jack on the back.
Front input is for my non Series Alembics, back input for my wireless system.


I need three outputs: Clean signal path, Effects signal path (mainly fuzz wah) and a tuner out.


Pics are: Simplified illustration of the DS-5R mods, Complete illustration of the madness in my rig, current state of the DS-5R and my rig with gaping hole where the DS-5R will live plus my basses :-)

[FC Bass]

All that for nonsense like this:

[pauldo]

Seems like a worthy effort.   

[edwardofhuncote]

You have clearly thought this through. I like the whole idea of building-out with a purpose. 

[JimmyJ]

This is the best kind of "madness"! We love purpose-built mods so hope you can put together whatever you are dreaming up.

I'm just a self-taught wire head so bear that in mind as I offer some thoughts.

First thing, that little Meinl summing box must simply be a collection of resistors summing to one output.  No power needed so no "active" components - like for gain recovery.  I believe it's designed to use with line level, or at least low-impedance signals.  So YOU could certainly make your own summing network simply using resistors.  Also obviously the case it's built into will not fit inside your DS-5R so I guess your plan was to disassemble it anyway?

The Lehle piece looks a bit more interesting and does similar things using audio transformers.  Not a bad idea when you have a complicated rig to include some transformer isolation.  Again I'm not sure there is room for the chassis itself inside your DS-5R so you may be on a journey of hand wiring all these components to suit your needs.

The only other concern when you start taking things out of their shielded chassis and putting them together in a single box - is that you run the risk of some induced hum.  Inside your DS-5R you will see that the AC line is not shielded as it runs to the PSU module.  It's purposely designed to have that part of the piece far away from the equally unshielded audio lines in the opposite corner of the box.  So proceed with caution and think about whether the Lehle piece, for example, couldn't be tucked into the rack behind the DS-5R...

Back in olden tymes I built a piece I called the "sumthing" which split the Series bass clean signal sending one pair of outputs directly to the stereo amp rig and the other to the input of an ADA stereo tapped delay/chorus.  That effect was set up to be muted until I switched it on and then it would send the "wet" signal only back to the sumthing where it was added into the clean signal going to the amp rig.  Describing that signal path sounds like it couldn't work because the input and the output of the effect piece were essentially tied together.  But it was all isolated by resistors and a couple active DI boxes in the signal path. It did what I was hoping and sounded amazing. There was one final sum to mono of all those signals so I could send one line to the PA.  The sumthing was a single-space rack piece which was covered with 1/4" jacks looping here and there.  Looked like a recording studio patchbay.

Mods are great, keep coming up with creative ideas.  I'm sorry I can't advise you on exact resistor values but I actually don't think it matters too much.  You just need enough to isolate the inputs from each other so for example when you mute the Series the other inputs will be unaffected.  You can see what the Meinl piece uses and maybe experiment with it before tearing it to pieces.

Carry on!!
Jimmy J

[FC Bass]

See why we love this place? :-) Thanx!


Hum is the biggest enemy indeed...
In the dirty channel I had some weird hum/digital noises going on, I traced it down to the Ibanez HD1500
It was present both when the HD1500 was in and out of the signal path (switched with the MGC-6)
It was gone when I removed the plugs of the HD1500 from the MGC-6...
I solved it removing the shield from the plugs on the HD1500 side, so on those plugs only the signal wire (tip) is connected.
Had to do both input and output, but all the weirdness is gone and the unit works perfectly. :-)
(its the delay from the third sample in the vid) Welcome to the world of groundloops... :-)



The Radial SB-6 is sort of the "inline" version of the Lehle, it isolates the connections between the two racks into the two inputs of the Bass 400.
I guess that's kind of the expensive/more reliable way of doing what I did with the HD1500?


I hope to keep the units as intact as possible, maybe even make the mods reversable.
The plan is to desolder the jacks and solder a shielded guitar cable to the pcb's.
The Lehle will fit Hight wise, but the width and dept might be a problem.
I could not find any data on the Meinl online...


If it's not possible I could just keep them external (if it works flawlessly)
Downside is the extra mess it will create, the backside of the rack is no fun place to be :-) (see pics)


Btw: Currently I run this rig with the clean and overdrive channels fed by the main and tuner out from the wireless system, the tuner is connected to the MGC-6.


Reason for the multiple inputs is:
I will use the wireless for gigs, need the freedom :-)
The two inputs on the front are backup for when the wireless fails, I will also use them for practice sessions to save batteries.


Currently I practice with the DS-5, but since I don't have a good "hardwired" option I must use the wireless beltpack to connect to the rig.
If the wireless fails, the only workable option would be to go straight into the Bass 400 (losing all effects, DI and the tuner)

[BeenDown139]

...I solved it removing the shield from the plugs on the HD1500 side, so on those plug only the signal wire (tip) is connected.

sounds like you stumbled upon the dreaded ground loop.  when i had a rack that consisted in part of DS-5, F2-B and mesa stereo power amp, i wound up making a special set of patch cables that were only groounded on one end between all the components in the signal chain.  there are lotsa reasons for this - low impedance ground path from chassis to rack ground paralled with a relatively high impeadance (and reactance) ground path thru the cable shields is one.  throw in a little AC current induction and away ya go.

i useta design medical grade switchmode power supplies back in the hazy days of my youth,  ya oughta see all the wierd phenomena that crops up when ya gots high pulse currents using the the same ground path as logic and signals.  dunno if this is exactly spiderweb ground or holy ground area, but it's close.  good luck with yer endeavor!

[FC Bass]

Ground loops are our worst enemy :-)
The Radial SB-6 is also a ground loop breaking device (with iso transformers) If I don't use it, both clean and overdrive channels hum like crazy :-)

Thomann order is inbound :-) (Meinl, Lehle and Radial JDI)
The DS-5R should have arrived yesterday, but the package got lost somehow. Investigation pending, hope that works out... :-(

In the worst case scenario, I must make this work with the regular DS-5. Then it will all be external, I'm not going to try to cramp all that in the little box :-)
But let's stay positive, I've been looking at some detailed pictures.

I agree that the Meinl most likely is the collection of sum resistors, in that case:
Looks like I have two options to connect the XLR, the "mono" out to the Meinl or:
The individual signal wires each to a separate input on the Meinl.

In the mono option the signal wires will pass through two summing resistors, might be the best option since all input levels will be attenuated the same. Or will the signal passing through two resistors have a negative impact on the sound?

If I connect the signal wires from the 5 pin individually, there will be one resistor inline for each. I guess it will be a bit louder compared to the 1/4 inputs (front/wireless) and the mono wiring?

For the last option, it looks like I have to connect the red and purple wire (coming from the XLR) to the inputs on the Meinl.
Looks like the ground wires are connected to the bass/mono output only (grey wires) One connected to the chassis and one connected to the XLR.
I guess I would have to split those and connect to both inputs on the Meinl, unless there's a solid ground connection between those inputs.

I think with the current wiring removed, there should be enough space to fit the Lehle inside the unit. I will put is as far away as possible from the scary AC stuff, looks like I might even be able to increase the distance a bit compared to the original wiring.
I'm pretty sure I need to dismantle the Meinl though, I hope there's a pcb in there. If so, it might fit inside the Lehle enclosure.

Anyways, looking out for the delivery person :-)

[FC Bass]

DS-5R made it back home! :-)
I think I will leave all wiring intact and take the output from the Bass/mono jack. Since all jacks and the switch will be removed from the chassis, I guess I must solder a ground wire between the front bass and treble jacks. Then I will isolate them (wrap it in some kind of plastic bag) and tuck it away to the side.

The Lehle must come out of the enclosure, then there should be plenty of room to fit it in. Most likely I will use some double sided tape on the two transformators and mount it upside down.
Eta of the Thomann order is between Saturday and Tuesday, stay tuned! :-)

[JimmyJ]

Hey Flip,

You're on a roll, keep thinking!  It's not easy to describe audio routing in print so I'm not completely following you, sorry.  But first of all we need to applaud that picture of the factory wiring you posted.  The builds that come out of Alembic HQ are like artwork inside!  Amazing.

OK, so the grey wire is only attached to that one point because the steel chassis serves as a shared ground.  It looks like your DS-5R still has one 1/4" jack on the front panel so why not utilize that the same way and make that the ground lug for all audio?

You won't know until you pop the cover off the Meinl piece but those 1/4" jacks look like they're isolated from the chassis.  However the "aux in" looks like it is not.  So it will be interesting to see the insides (and we hope you'll post a pic when you get it).

It turns out that these summing resistors we're talking about do not drop the signal by much and they will not affect the tone.  I don't totally understand why but I think it's because we are working with active circuitry as opposed to standard high-impedance guitar wiring.  As you see in the pic below, I've made a few variations of mods to my DS-5s over the years.  That bottom one has two mono outputs, one with a mute switch which simply shorts the output to the DI.  Because I have summing resistors (and even an "L-pad") involved in the signal path, I can silently mute that DI output while keeping the Tuner output live.  And vice versa if the tuner output shorts to ground the DI output keeps works.  It's kinda magic.  HA!

Whether you sum the individual pickups to mono right off the 5-pin or use the Meinl to do it, just think of the Series as 2 signal sources.  Your new front panel 1/4" input would be source # 3, rear panel wireless input source # 4, etc...  If you put 20k resistors in line with those signals and connected the other end together ... you'd have a mono clean signal with isolated sources.  Furthermore, if you set up a 2nd set of 20k resistors leading off the exact same points, you'd have another completely isolated sum of all those signals.  And muting your Series bass (which shorts the input) should not affect the other sources. 

Where you want to go beyond that is the part I don't quite understand yet.  FX loop for example and a split back to stereo?  But keep going and please keep updating this thread.  This is good stuff! 

Jimmy J

[FC Bass]

Extremely awesome, thanx for sharing!
No package from Thomann today, looks like we have to wait until Tuesday to see what makes the Meinl tick.
Electronically wise speculations here are most likely true, it's a 49 euro unit so I doubt it's crammed with Iso transformers or elaborate electronics stuff. :-)

Btw: I went with prebuild units because I'm not really good (and good equipped) to make stuff like this from scratch. That's also why I brought it to a rig guru in the first place.

I did some pre-planning in photoshop and am pretty optimistic that the Lehle will fit :-)
There are several options, this one might be the best:
If I remove the left transformer (with the jacks pointing up) the board can slide under the XLR input and will be far away from the scary AC stuff. (in the lower left corner) The removed transformer will get a new spot as close as possible to where it was and reconnected to the board with two short wires.
In this scenario, I think I can use plugs and don't have to modify (destroy in my case) the Lehle further.


I did some experimenting with the DS-5R, some optimistic findings:
Initially the rear mono output had some added noise (hiss) compared to the front output... However, I tightened all nuts and now they're both equally silent.
With all jacks and switch removed from the chassis it is still dead quiet when plugging into the front mono output. :-)
So with a plug in the front mono output and all the wiring isolated in a plastic bag, I should have a good signal from the XLR input. (leaving all original wiring intact)

I also did some tests moving the signal wires close to the scary AC stuff. Somehow I'm happy to say I was not able to introduce noise/hum to the signal.
I did the test with all jacks and the switch removed from the chassis, very promising :-)


Don't try this at home btw, AC line voltage is scary stuff! Can cause serious harm, or at least will hurt a lot when mishandled! (do NOT ask me how I know!)


Trying to explain the madness a bit better:

There are three outputs, one for the tuner (which is always on) and two separate channels.
Channel one is the dirty channel and has all the effects (Overdrive Wah etc.)
Channel two is the Clean channel

Channel one goes into the lexicon after all "external" effects are added.
Channel two goes directly into the Lexicon

The Lexicon MX-400 is used as two totally independent (mono) effect processors, one for each channel.
So when the signals leave the Lexicon, they are still separated and go through the stereo DI. (which is used as two separate DI's)
Now the foh has the two channels separate and the desk won't explode in their face when I switch to the overdriven sounds. :-) (which are mostly way louder than the clean sounds)
I also have some presets where I combine the overdrive and clean sounds, this setup gives foh total control over the mix.

The "through" connections from the DI go the the Mesa Channel one and two input, so from there the signals are combined. The inputs on the Mesa both have a gain control, so it's easy to set levels for the desired stage mix.

With the Lexicon I can mute both channels separately (dead silent) So I mute the channel that is not used and mute both channels for silent tuning.



Everything Alembic makes is a work of art, I feel a bit bad messing this one up... :-)
But I endeavor to make the mods as reversable as I can.

Picture of the unit in original state (though with most cable ties removed and two jacks added to the back) and pic of the sound test setup.
Plus the two options for Lehle explored in photoshop, one with the trafo removed and one mirrored for upside down installation.

[FC Bass]

Well... The Meinl was a bit of a disappointment... Just all jacks daisy chained together, only the aux in had two resistors.
But it did have two pcb's, let the slaughter begin! :-)


I tried to make some kind of summing resistor device, I used some 15K resistor I got from Mica a couple of years ago.
I soldered the three inputs to the pcb with a resistor in the signal line, the last wire is the output.
I tested it with two inputs, the XLR 5 and the wireless.
I'm starting to realize I start almost all sentences with I :-)
I suspect there is some volume loss and maybe some added noise, did seem to work good though. (no weird stuff happening when turning volume controls of the basses etc.)


Lehle works great and fits :-)
Next project will be the connections to the Lehle, I'm going to use plugs for those. (as you can see with the output on the pcb, which wil go to the input of the Lehle)

[JimmyJ]

Hey Flip,

That's a good use of those Meinl PCB.  I don't think you should experience any noticeable volume loss, and it should be dead quiet because I don't believe passive components can add noise.  Keep in mind that the output of your wireless receiver is always present in the summed signal so you might test to be sure it doesn't have any "idle" noise.

Keep going, you're on a roll.

Jimmy J

[FC Bass]

It works! Previous "failure" was user error which I will never ever do again, I don't like extreme loud feedback :-)


Anyways, works!
No problems with three basses at the same time, no weird interactions encountered thus far.
I will do extensive testing this week and tidy some wire mess up.


I will also reuse the red box from the Meinl, it will become the new connection box on my pedalboard.
But that's a project for later in this year. :-)


Thanx for the encouragement! Helps a lot!

[pauldo]

I really don’t understand much of the details involved with all of this but do find joy in your success!