The Tesoro MicroMax Silver, a Technical Review

[olfacere]

Greetings, fellow swingers. First post. I've only had my first detector for about a month now, but I also would like to think of myself as a good researcher. I have something of a technical background and I did/read tons of manufacturer, price, feature, and customer review comparisons before purchasing my first unit: a Tesoro MicroMax Silver. I looked around quite a bit and I was not able to find any real technical reviews for the operation of any metal detectors. So, now that I have my own, I would like to provide everyone else with all that information I wanted to know before buying.

My goal here is to provide a description of how the Silver works that would be useful to someone just getting into detecting, to help know how to space swings and where the discriminator should be set. My secondary goal is to encourage other detectorists to conduct tests such as these and make the information public so that we can, as result of a community effort, compare the real performance of a variety of detectors based on standard measures (presumably inches, coins, and pull tabs). Additionally, the experience of conducting such tests is necessary to develop an ear for the differences between targets and a knowledge of the detector-unique settings that will effect each one of them. Nobody learns to play guitar by attempting "Stairway to Heaven" on a public stage. Likewise, you should learn your detector's uniqueness "in the lab" and then apply that knowledge in the field. Eliminate as much guessing as possible.


"A Technical Review of the Tesoro MicroMax Silver" or "8 +/- 1 Inches"



The field shape chart at the top left is jam-packed with useful information. While swinging, I often will think to myself, "The first 5 inches are free." Even with a little interference, you should be able to detect anything under the full width of the coil for the first 5" down. After that, the field starts to narrow quickly. Notice that, at 6", the detection circle is only 5" wide. Then, at 7", it is only 3" wide. So, if you want full coverage at a depth of 8", you can only move forward by about 2" on each swing. If you were to move forward 6" at a time, then you could cover almost everything down to 6", but you're missing 2/3 of all small targets at 8". So, getting that next few inches of sure depth means pretending to be a ground-scanning robot that misses nothing, moving in the smallest steps possible (or acquiring a double-D coil).

Note that the test just mentioned was intended to establish field shape, but not depth. That chart shows how well an old, copper penny hit on different parts of the concentric coil during an air test. So, it shows the shape of the field, but, in terms of detection depth, it can only tell you about copper pennies. The red O's are the points at which a strong, dig-me-every-time signal started to break up. The red X's are the points at which the signal dropped out entirely. As noted in the image, these tests were done in all metal mode.

The chart at the top right indicates the various distances at which 7 trash items and 9 target items lost their strong, convincing signals. The MicroMax Silver, like most metal detectors, has problems with dimes when compared with other coins. It's just a smaller signal, so it drops out an inch earlier than the others. A silver dollar, having significantly more mass than the other coins, can be hit about an half inch farther. All of our sample target items seem to drop out at 8 +/- 1 inches, depending mostly on the mass and integrity of the target item (the mass of the silver bracelet would have hit farther down if it were one big piece instead of many small pieces; small gold and silver chains are notorious for hiding). Fortunately, however, collectors of bottle caps can hit those at a full 10".

The two dials at the bottom represent where each item lost it's good signal on the Silver's discriminator knob. The minimum and maximum angles reflect those on the real machine. The trash is marked on the knob to the left and the treasure on the knob to the right. Note that nasty, ferrous trash falls out immediately, but higher conductivity trash can totally overlap target items. The small gold band, larger gold band, and silver bracelet all lost their strong signals before the little key, big key, and bottle cap. So, if you want to find jewelery, you're going to be digging a lot of keys and bottle caps. All of the big, silver coins (as well as clad quarters), on the other hand, will produce a noticeable signal at full discrimination (won't discriminate out completely).


The Detector Itself

When the discrimination knob is turned all the way up, about two inches of detection depth is lost. This is because the discriminator circuit chops out the majority of even big signals, so big targets seem to be smaller targets. Therefore, they cannot be detected from as far away. This effect is not so noticeable at lower levels of discrimination. Considering that you shouldn't be walking around with the discriminator set any higher than the noon position anyway, I don't consider it to be a problem. If you're discriminating out nickels, then you're knocking out some small gold. The higher you set the knob from that point, the more gold you pull out of the signal. Because of these tests, I usually keep my discriminator set half way between FOIL and 5 cent (about the 11 o'clock position).

The sensitivity knob does not control the power to the transmitter, just the gain on the receiver before the machine interprets the signal. So, it works like the volume on your home stereo. There is a certain level up to which more volume gets more clean sound, but above which brings in a lot of distortion and noise. Both of these devices depend on operational amplifiers; the stereo contains what is basically a bigger version of the same circuit. Set it too high and noise creeps into the signal. On the flip side, because the sensitivity does not control the power to the transmitter, the field does not get any smaller at low sensitivity. The field around the coil is exactly the same. Under normal conditions, if you were to turn your sensitivity down from 10 to 1, you would only lose about an inch of effective detection depth. The higher sensitivity settings (9 to orange) were only ever meant to be used at really high discrimination.

Note to Coin-shooters: I've noticed a point on the discriminator spectrum that I've been calling the "small coin cutoff." Pennies and dimes tend to both drop out right at the "A" in "MAX" and they do so pretty cleanly (very small range of choppy signal). Nickels, of course, drop out earlier, and quarters (even clad) won't drop out completely at full discrimination (unless they are more than five inches deep).


More about the Detector Itself

The MicroMax Silver is made in the USA (as much as is possible for any electronic device at this point) and comes with Tesoro's famous (though not transferable) lifetime warranty. It is everything you need and nothing you don't. It is built well, light weight, has snug-fitting scuff covers for the search coil, has no visual readout to lie to you, holds its resale value well, and has amazing operating time on a single battery (more than 10 hours field time on the generic, alkaline battery that came with the unit and it still reports more than half charge). I believe the discriminator is a pulse width type, but I don't know that for sure. I think this because of the way it chops up trashy signals. It is highly effective, whatever its design.

The Silver has its own language and that language tells you about every conductive thing in the ground. Many new users find a point of epiphany when they realise that their detector has actually been giving them more information all along than they had heard. Many others give up too soon, before really learning to listen to the machine. If you're looking for a solid metal detector for $250, the Tesoro MicroMax Silver is hard to beat. If I ever upgrade to replace this one (not counting specialty detectors on the side), the machine to replace it would cost near $1,000 and would not be a single frequency VLF device.

 

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[Terry Soloman]

I commend you on your efforts to share your experience with your new Tesoro. With only a few hours on the headphones, you have a good handle on its strengths and weaknesses. While I feel you will want to change a few things here and there if you come back and read this a year from now, overall it is a great piece for newbies to read and discuss.

I will argue just one point now with you though. You only need to spend $450.00 to beat the pants off the Silver uMax. The Tesoro Vaquero is much deeper. Keep swinging, keep learning, and keep writing!

 

[olfacere]

Thanks, Terry. There's no argument that the Vaquero can outperform the MicroMax Silver. I counted the Silver as superior because of its price tag. The Vaquero is nearly double the price, but maybe only 50% greater in performance. So, I don't know if I would call the Vaquero a "replacement" for the Silver. Actually, it seems when someone has a Silver and buys a Vaquero, they tend to keep both! So, I suppose what I meant to say was that you would have to spend near $1,000 on a new machine to not care if you lost your MicroMax Silver. I'm sure you're right about having new opinions in a year. We all continually reinterpret life.

I think the Silver is a good representative for Tesoro as a company. Tesoro totally dominates the lower half of the market in terms of quality for price, but the upper half of the market, based primarily on performance, is held by other companies. It's my understanding that a Minelab Sovereign GT will show up most Tesoros, but I don't think that Tesoro even makes a detector that is as expensive as the Sovereign GT when new.

It's all about the balance.

 

[Terry Soloman]

Thanks, Terry. There's no argument that the Vaquero can outperform the MicroMax Silver. I counted the Silver as superior because of its price tag. The Vaquero is nearly double the price, but maybe only 50% greater in performance. So, I don't know if I would call the Vaquero a "replacement" for the Silver. Actually, it seems when someone has a Silver and buys a Vaquero, they tend to keep both! So, I suppose what I meant to say was that you would have to spend near $1,000 on a new machine to not care if you lost your MicroMax Silver. I'm sure you're right about having new opinions in a year. We all continually reinterpret life.

I think the Silver is a good representative for Tesoro as a company. Tesoro totally dominates the lower half of the market in terms of quality for price, but the upper half of the market, based primarily on performance, is held by other companies. It's my understanding that a Minelab Sovereign GT will show up most Tesoros, but I don't think that Tesoro even makes a detector that is as expensive as the Sovereign GT when new.

It's all about the balance.

I believe a lot of new hobbyists tend to base their initial opinions on marketing and branding hype. The top selling brands have the largest advertising budgets, and tend to “own” the online forums because more members own and use their machines. In many cases there is no empirical evidence that one brand is any better than another. In even more cases, the same engineer has designed basically the same machine for several companies, who then argue over which “brand” will go deeper or find smaller targets.
I am an Arizonan, and I have personal friends at Tesoro in Prescott, including Vince Gifford, Rusty Henry, and Robert Martensen. I will be the first to admit I do have certain biases and opinions about their machines, but I have to disagree with your assertion that, “Tesoro totally dominates the lower half of the market in terms of quality for price, but the upper half of the market, based primarily on performance, is held by other companies.”

My opinion, is that when you have more experience and are more knowledgeable about metal detectors, and individual company philosophies when it comes to design and marketing, you will probably want to amend your statement. In terms of gross sales, the big five are Minelab; Garrett; Whites; Fisher; Tesoro.

I think Jack Gifford had a very different philosophy when he began Tesoro. Unlike Garrett and Whites, he didn’t want to have a “New Release” every 18- months, or gimmick up his machines with lipstick and lights so he could charge $1,400.00 for a $700.00 machine. Unlike other manufacturers, the Gifford’s designed their machines to last the hobbyist a lifetime, and set their prices at the factory so that dealers could never gouge a new hobbyist at the retail level. To this day, Tesoro is the only manufacturer to offer a lifetime warranty.

Tesoro’s VLF technology is just as up-to-date (or better in some cases) than all of the other single frequency VLF machines being offered today with their supposed “improvements,” or “leaps forward” in technology. I own two Minelab machines, the GPX 4000, and GPX 5000. I own five Tesoro machines as well Tejon, Vaquero, Compadre, Sand Shark, Lobo Super Traq.

The bottom line is you need to find the right machine for YOU. Right now it is the Silver. When you get tired of being outhunted by a Cibola or Vaquero, your opinions will begin to morph, and you’ll understand that the more “clubs” you have in your bag, the better your score will be.

 

[olfacere]

Well, I did say, "not counting specialty detectors on the side." I totally agree that limiting oneself to only one machine would miss most of the available advantages. What I was trying to get at is the fact that the MicroMax Silver has the best bang for the buck among single frequency, fixed ground balance, VLF type machines in this price range. I'm also thinking of detecting in a goal-oriented way. If what you want is to spend as little money as possible to go coin-shooting in the park, so you don't ever want to dig deeper than a few inches anyway, then the smartest choice would be the Compadre. If you want to do everything the Compadre can do, but with the flexibility of a sensitivity knob, then the Silver is the way to go.

As you said similarly, it's all about getting the machine that will do what you want to do. Gradually, as one wants to cover new types of ground or seek new kinds of targets, the parametres of what one wants will change. The Silver still holds its own ground, though. Technical reviews are meant to establish exactly that; what the machine will do, what it will not do, and how much it costs to make it do what it does.

I suppose I could have been more impartial, but that's what the numbers are for. I'm not actually impartial!

 

[cokat7]

I have had the vaquero and silver both. I would say that the vaquero beating the pants off the silver is an over statement. I sold them both and now own a compadre and a fisher 1265x.
The only circumstance where the vaquero truely beat the pants off the silver was when searching in vco for the deep and tiny stuff. And it is only because I learned a coupe quirks with the v that I will say : it was the best coin cherry picking machine I have or may ever own.
The vaquero as well as the rest of the hot machines have an audio that can't come close to comparing with that of the silver. The audio on the silver is easily learned and is a discrimination circuit in itself.
As far as depth in the disc mode, the silver was not far behind the vaquero, howbeit, it was very slight with the 10x12.
For old homesteads, yardsites, playgrounds and certain types of relic hunting, I truely believe the silver would give any $1000 machine a run for its money.


Exellent review, especially for someone relatively new to metal detectors.