Hot-rodding my amazing

[Martin Jonas]

As I've mentioned in another thread in passing, I'm now getting serious in hot-rodding my Amazing e-mando. #At the moment, it's a solid-body, but with only a piezo pickup. #That sounds cool, but very agressive and not very versatile. #I love the playability and the design, and I think it could be a truly great e-mando if I add a humbucker so that I can mix the two.

I've decided on a pickup and a wiring diagram and have all the parts together, so now it's just down to figuring out how best to install them.

Here is the mandolin as it is now:





I've decided to go for the GFS Lil Puncher. #This is a narrow rail-type humbucker designed to swap like-for-like with a Tele neck pickup. #Looks like this.

I reckon this will look pretty good if fitted a few centimetres down from the end of the fingerboard. #If anything it'll improve the looks as the mando at the moment looks strangely empty there without visible pickup. #It's not much longer than the string spacing, either, so I don't think it'll look disproportionate.

However, I need to decide how to carve out a new cavity. #Two options: through the body, or a pocket from the top.

Going through the body would mean I can have the cutout in the top exactly the same size as the business end of the pickup, no need for a pickup ring or similar. #Downside is that I might weaken the stiffness of the body, I'll need a cover for the cavity on the back, and I'll only have about a centimetre of wood thickness for the mountin screws.

Going for the top pocket means I'll have to oversize the hole in the top in order to get the base of the pickup in, which in turn means I'll need some sort of pickup ring to hide the gap between pickup and wood. #I suspect a Tele pickup ring will look far too chunky, so I'll probably make a skinnier rim out of ebony.

At the moment, I'm inclined towards the top pocket approach, mostly because I fear the body will become unstable if I cut all the way through. #However, I'd be most grateful for any thoughts on the matter before I start.

Martin

[Martin Jonas]

Regarding the electrics, I want to go for the wiring shown here, with the signal wire then soldered together with the existing piezo pre-amp output at the jack. # That would give me the option to tap into both single coils as well as in-phase and out-of-phase dual coils. #With the independent piezo and magnetic volume controls I can mix the signal. #Can anybody think of a reason why this wouldn't work?

Obviously, I need a new pocket for the two pots and the rotary switch. #With a body as minimalist as this one, there's only one place where that pocket can go: next to the existing control plate with the jack and pre-amp volume control at the edge of the mandolin:



Plenty of wood there to carve a pocket into.

What I still need now is a nice-looking control plate and knobs, ideally matching the existing brass plate and black knob. #I'd need a three-hole brass control plate (tone, volume and pickup switch). #Tele plates are a bit large, and have a slot instead of a third hole. #Similarly, Tele knobs are much chunkier than the small black knob on the existing pre-amp control. #Can anybody recommend a source for a suitable control plate and knobs, or should I resign myself to making one from scratch from a brass sheet?

Martin

[Martin Jonas]

a hot, sensitive pickup should work at a 3/8" distance below the strings don't you think?
..
is there enough wood left around any potentially thru cut hole?

a stacked Pot, 2 in one, would allow tone and volume to share
the same hole so fabricating a new plate is optional.

Thanks, Mandroid.

Not sure about keeping it below the wood: the string height is rather higher than 3/8" and this pickup is really nice-looking so I don't think I'll mind having it show. #From what I hear, it's not all that hot, either, so I'd rather install it height-adjustable so I can play around with optimum distance from the strings.

On an initial inspection, I think there is enough wood for a cut-through, but not a massive amount. #I'll have to do some precise measuring to see how much exactly. #As it's such a small body, I'm really reluctant to cut through, so I don't think I will.

I've thought about a stacked pot but decided against it: with those you can only adjust either tone or volume, but not both independently. #I think I have enough space to fit both pots in.

Martin

[Antlurz]

Looks like the pickup will be about as wide as the whole body is at the point you intend to install it. Have you actually measured widths and compared them?

Ron

[jefflester]

Looks like the pickup will be about as wide as the whole body is at the point you intend to install it. #Have you actually measured widths and compared them?

Ron

That was my initial reaction.

[MandoBen]

Because the pickup is long enough to span six guitar strings, it might fit on a diagonal like a strat bridge pickup.

[Martin Jonas]

Yes, I have measured it, and it's quite a lot narrower than the body. It's really not all that wide a pickup even if installed at a right angle to the strings (I might angle it slightly). Also, as it's designed to slot into the Tele bridge pickup place, it has the same size as a single-coil pickup, and thus also the same as a stacked humbucker, which means it won't look as huge as a full-sized humbucker.

Mandroid -- with the stacked pots I've seen put, when you pull them to get the tone control, the volume automatically goes to 100%. Maybe I need to look at some more specs to see if there are other models that don't do that.

No need for a Fishman or Schatten -- there's already a piezo with pickup in the mandolin.

Thanks for all the comments.

Martin

[Martin Jonas]

After quite a delay while real life (a young family and much work-related travel) interfered with progress, I got around to carrying out the mods I had planned over the Christmas break.

In brief, I did the following:

1) Rout a pickup cavity from above using a Dremel with 4.2mm router attachment. Of course, this had to be slightly larger than the top of the pickup and the edges looks a bit rough at the moment, but I'll cover that up with an ebony pickup surround which I'll make.

2) Drill a connection from the new pickup cavity to the existing piezo pickup cavity, and from the piezo cavity to the underside of the tailpiece for a ground wire connection.

3) Rout a control cavity into the side of the mandolin, next to the much smaller existing control panel.

4) Make a new brass control panel, and load it with two 500k pots, a tone capacitor, and a five-way rotary switch.

5) Wire it using the diagram linked above. I needed to modify that somewhat, as the pickup has north-start hardwired to ground, which messes up the grounding envisaged in the diagram. No biggie, though.

6) Solder the resulting humbucker signal wire together with the piezo signal wire.

7) Ground everything with copper shielding on the pickup and control cavities.

8) String it up with Optima stainless steel polished ball-end strings.

All of this worked pretty much as planned; more straightforward than I was expecting for my first electric mod.

Result: an absolutely wonderful smooth full humbucker tone, sounding much like recordings from a vintage EM-200. Looong sustain because of the solid-body construction. Switching to single coil configuration works fine, although there is not much difference between the north and south coil (not surprising seeing that they are so close together). Having the two coils in parallel gives a tone somewhere between humbucker and single coil. The final mode, both coils in series out-of-phase, is pretty useless as it gives virtually no volume, again probably unsurprising as the two coils just cancel each other. Still, there are four successful tones from the magnetic pickup. I expect to spend most of the time playing with this warm powerful humbucker tone, but it's nice to have the options for something spikier.

Of course, I still have the piezo as well. I found that the volume from the piezo element alone, without pre-amp, is much the same as the magnetic volume, so I've taken the existing pre-amp out. This does actually improve the piezo tone, somewhat surprisingly, but it's still a thin spiky beast. Useful to have for some contexts, though.

What doesn't work yet is to blend the two tones. The piezo runs through a switched volume pot. With the pot in the "off" position, I get the magnetic signal, but in the "on" position the magnetic pickup signal just drops out of the circuit and I have the piezo tone on its own. That's not quite what I was expecting, but I'll try replacing the existing mini-pot for the piezo volume with a 500K blender pot. In theory, this should allow me to blend smoothly from all-magnetic to all-piezo and all points in-between. As the tones are so radically different, blending them should be really interesting, so I hope I get this to work.

Other than that, there's just a bit of cosmetics to take care of. I need to make a pickup ring to mask the edge of my routing, and I need some control knobs. I've ordered three black Tele-style metal knobs, which should fit well with the look of the mando.

I'm really pleased with the results: this has always been an amazingly playable instrument with smooth action, great radiussed fretboard and fast neck, and now it has the tone to go with the looks and the playability.

Having a decent electric mando now, I guess I need to think about the amp side of things. I'm currently playing it straight into an Orange Crush 15 practice amp, and that sounds pretty good, but I think I'll probably get myself a modded Epiphone Valve Junior amp for some extra vintage warmth.

A couple of photos: here is the mando with the new pickup and the as-yet-unknobbed control shafts at the side.

Martin

[Martin Jonas]

Here is the new pickup. I think this is a really sleek-looking pickup which fits in well with the overall concept of the mando. Also, for a guitar pickup, it's not all that wide so it doesn't look too oversized for mando string spacing. The ragged cavity edge won't be visible once I've made the pickup ring.

Martin

[Martin Jonas]

Here is the new control panel, still without knobs. If I were to do this again, I would use 1mm thickness of brass plate, rather than 2mm, as this was unnecessarily difficult to drill and shape. I may still replace it for a slightly smoother look, but for now this works well.

Martin

[mandroid]

Too bad about the chip out around the pickup hole,
Sharp chisel cut outline may have been a way to anticipate and prevent that,
but thats monday QB'ing of sunday's game.

[Martin Jonas]

It would have needed a pickup ring anyway, so the chip out doesn't matter much: as the pickup had to be inserted from the top, the hole had to be oversized, so there would always have been a gap of between 2mm and 5mm between the pickup and the edge of the hole which needed masking. It'll look much tidier once I've done the ebony rim.

Martin

[mandroid]

my Lace pickup install got plugs of cork to fix an inset from the top situation,
covering the Ears.
adjustments mean digging out the cork plugs,
then finding a bottle that doesn't use a plastic cork to replace them

Brass surround, esthetically, would go well with the Tail and control plates .
and it wont Split along the grain.
nor would black plastic pick guard stuff

made the FM61's new plate out of that stuff
with slow hand tools.

... have some [stew mac] black sheet left over...

[thistle3585]

Thats a great looking design. Are the controls easily accessible and adjustable being on the bottom side?

When I look at the body I think I think of a gunstock. It would look classy if you inlaid the control plates and pickup cover into the body. Then you could engrave some designs on the brass. A simple binding channel router could create a ledge for them to sit on. I'd suggest scoring the lacquer and maybe using some tape before making the cut.

I have .060 brass if you need some. Definitely an Amazing project.

Andrew

[thistle3585]

For what its worth, there is a short blurb from Mike Zimmerman, the designer of the Amazing, in the December issue of American Lutherie. He said that one of his instruments is in the Museum of Modern Art in the Industrial Arts exhibit.

[Martin Jonas]

Interesting -- I'd like to see that. I've found very little about the company or their instruments on the net.

I've now made an ebony pickup ring, which looks fine and goes well with the look of the wooden bridge next to it. I may also make a brass pickup ring, just to see which look I prefer -- easy enough to make and to switch around. I suspect, however, that I will stick with the ebony. Also got the control knobs today.

I think I have figured out why the piezo won't blend with the magnetic pickup, and will try a remedy this weekend.

Martin

[Joel Glassman]

There are special pots available to blend magnetic with piezo pickups. You can buy them from the Stewart McDonald catalog or online.
http://www.stewmac.com/shop....ts.html

[edit]
You may want to call them. This page on the site doesn't seem to have the correct electronics. I'm sure they have what you want.

[Martin Jonas]

Joel --

Thanks for the link. I had already bought a blend pot, but I got it sorted now without using it. The problem was that the pre-existing volume pot on the piezo side was a switched 25k pot and the magnetic signal was simply lost to ground as soon as I switched the piezo into the circuit, regardless of the piezo volume. I've now replaced the piezo volume pot with a 500k one, and it works fine now, with the output of both volume pots soldered together to the tip of the jack. Independent volume control for both signals gives control over the blend and overall volume.

I also have got the knobs and the pickup surround sorted -- I'll post more pictures later this weekend if I get around to it!

Martin

[Martin Jonas]

As promised, here are some photos of the finished project. I have made an ebony pickup surround, which nicely echoes the beveled base of the bridge next to it. I think I will stick with this rather than try it in brass. The control knobs are heavy solid-brass, painted black, intended for Telecaster. I like the chunky look, and they are nicely accessible when playing.

There are now four control knobs: piezo volume (pre-existing), magnetic volume, magnetic tone and humbucker configuration (both coils in series, single coil, both coil parallel). With these controls, I have a pretty wide range of tone options. What I particularly like is that the piezo signal has much less sustain than the humbucker signal, more like an acoustic mandolin. That means that where the pure humbucker gives a pretty guitar-like tone, mixing a bit of piezo into it makes the attack much more distinct and renders the entire tone more mandolin-like. So, this means that I can successfully play fiddle tunes, or tremolo, on this which never sounds quite right on a conventional solid-body mandolin. I took great care in shielding and star-grounding, and it's a very low-noise mandolin whether in humbucking or single coil mode.

I'm now playing it through a hot-rodded Epiphone Valve Jr combo. What a great tube amp at that price! Not very loud, but just right for playing at home.

Martin

[Martin Jonas]

Here is a closer look at the pickup surround. I'm reasonably happy with the way this has come out.

Martin

[Martin Jonas]

I've also now exchanged e-mails with Mike Zimmerman, using the e-mail address given in the American Lutherie article (thanks, Andrew!). There is another almost identical article in the December issue of 20th Century Guitar Magazine, with photos of their mandolin, violin, bass and guitars. Mike is very excited to hear from owners his instruments, and glad to hear that mine has a new life with a more versatile pickup configuration.

What is interesting is that the violin and bass guitars were both headless, with tuners at the body end. By sheer coincidence, this means that the control knobs I've added to mine now precisely echo the look of the tuner buttons on the violin and bass versions. Here is the best photo I've found of the violin -- unfortunately, it's a black-and-white scan (as indeed are the photos with both of the recent published articles).



On Friday, I also found a site with very nice photos of the bass guitar version. The site is here, but strangely, the photos that were there on Friday don't show up today. The body of this particular bass is exactly the same shape and colour as my mandolin, just rather larger, with the tuners situated where I have the control knobs. Interestingly, the bass (unlike the violins and mandolins) did have two magnetic pickups in addition to one piezo, with the magnetic ones inserted from the top much like I did on mine.

The Amazinol mentioned on this site is also mentioned in the two articles: it was a synthetic ebony substitute developed and patented by the company. On the later violins and mandolins (including mine), the fingerboard was made from Amazinol (the neck is more traditional maple), whereas the bass guitars had the entire neck made from it. The Amazinol does look very nice -- I thought it was a particularly well made ebony fretboard until I read the article and until Mike Zimmerman confirmed that most mandolins had Amazinol fretboards.

Martin

[Martin Jonas]

Further to my previous message, the image of the Amazing bass guitar body was still in the browser cache on my work PC, so I'm attaching it here.

Martin

[Martin Jonas]

Reviving this old thread for another update: a few months ago, I decided to have another go at getting a useable piezo tone out of the Amazing. The old piezo simply never sounded at all right, regardless of what post-processing was thrown at it, and regardless of whether I used the existing preamp or not. After I learned from the maker, Mike Zimmermann, that the pickup and preamp that were installed when I bought it weren't the original ones anyway, I had very little qualms to ditch them.

Instead, I bought an Artec mandolin undersaddle pickup, sold on Ebay as a package with a preamp with three-band tone controls for 30 Pounds ($45). This is the same pickup and preamp as used on the ubiquitous Crafter mandos, which usually get good reviews for their electric tone (although more variable for playability, build quality and acoustic tone). The plastic preamp unit was intended to be inserted into the side of a guitar (or guitar-shaped mando like the Crafter) and was far too big for the tiny body of the Amazing. However, opening the back showed that it was mostly air and by cutting away the battery compartment (battery can sit loose in the cavity) and shortening the depth of the case, I managed to make it small enough to fit into the existing cavity at the back of the body. I then made a new bridge, with a slot to house the pickup and a new bone saddle above it. I briefly experimented with blending the passive magnetic signal with the active piezo signal, but even with various attempts ot match impedance, it never worked properly and compromised the tone of both pickups (I think because of a phase mismatch which I can't correct without completely rewiring one or the other of the pickups). So, in the end I went for simply having two mono jacks: one for the magnetic pickup and the other for the piezo. If I want to blend them, I can patch them separately into a mixing desk, where matching impedances and phase is much easier.

At the moment, I simply play either/or, depending on which jack I'm plugged in. Both pickups sound very nice, just completely different from each other, and that was after all the point of having two pickups.

Some photos: the new bridge, the magnetic pickup controls at the side of the body, and the piezo preamp controls at the back.

Martin

[Daniel Nestlerode]

Hey Martin,
Does the piezo pickup's control panel ever contact your body and inadvertently change settings?

Daniel

[Martin Jonas]

Daniel: No, there's a raised rim around the edge of the control panel which is higher than the tone control sliders and keeps them away from the body. Also, they are quite firm and do not move on slight contact. No problems so far.

Martin