Putting the Minelab GPZ 7000 to the GOLD test

By Nenad “Gone Beepin” Lonic

 

 

Well, the much anticipated GPZ 7000 has finally been released, and while some users put their name down for one before they really knew any info, others have been waiting patiently for more info to emerge, mainly performance reports from the field. In my opinion, a gold detector should be judged by its ability to find the gold that is still in the ground, so that’s what I did; just put my harness on, switched on the GPZ and went swinging in spots where I have found gold previously. Now, if you are hoping to hear about all the ounce plus pieces I found to date, well then you can stop reading now. It is still early days, and South Australia is generally gold poor, and the Adelaide Hills even more so.  With only 3 public areas available to swing a gold detector, you can imagine they’ve copped a fair hammering, so in saying that, I wasn’t sure what to expect in terms of finds with the GPZ 7000. Fingers crossed that larger nugget with my name on it is waiting for me across the border. But before I get onto the field results, I just want to say a few words about the new Search Modes and the audio.

Gold Mode & Ground Type

In an attempt to simplify the operation of the unit, and allow the user to select the best settings for the conditions, Minelab have done away with having 8 different soil/timings options as found on the GPX5000 and have introduced a new selection method: Gold Mode & Ground Type. The Gold Mode function has three options: High Yield, General, Extra Deep, and the Ground Type has three options: Normal, Difficult, Severe (being a setting of its own). This gives the user seven Search Mode combinations to detect in for different tasks and ground conditions. Here is a brief overview of the various combinations:

High Yield/Normal – For very mild ground, this is what you want to be using!

General/Normal – In mild to Medium soils, this will provide excellent depth on most gold sizes

Extra Deep/Normal – The best depth combination available for very large gold, but only for milder soils

High Yield/Difficult – For finding the greatest number of targets in mineralised soils

General/Difficult – A good all round setting for most medium – high mineralised ground. Runs smoother and provides a slight depth increase over High Yield on larger gold.

Extra Deep/Difficult – This is a specialty setting for maximim depth in high mineralised soils

Severe – Use this on the worst ground conditions, for maximum performance on common gold sizes

Audio

The general audio of the GPZ 7000 is something that I really like. At first I struggled with the often complex target signals, but once you get used to the “Zed” language, it is very good. While larger targets at medium depth sound pretty much like a GPX series machine, the general tone of the audio is more crisp – it seems more closely related to the SDC2300. Identifying ground noises is much the same as with any of the MPS machines, but one thing I have been repeatedly fooled on is when in the Normal ground settings, a deeply buried nugget can sound the same as a charcoal hot spot. The response is broad and mellow but with a definite start and end. By allowing the auto tracking to do its work, by sweeping over the target area a few times you can often identify if it’s a ground noise or not, but as always – if in doubt, dig it out!  Scraping a few inches of top soil off will soon clarify the situation.

So what I have done, is to break up my experiences with the unit in relation to differing levels of ground mineralisation.

Mild/Medium Mineralised Ground

So what would I class as Mild/Medium mineralised ground? If you are familiar with a GPX, you’ve probably come across areas where you are using Fine Gold and Enhance with a mono coil, and the machine is purring along. You “think” you can switch into Normal or Sensitive Extra so you try it, but after 20 mins remember how much you hate digging ground noises, so it’s back to Fine Gold. This is very common for me here in SA, and I know quite a few spots in Victoria that are the same. Pale clays, shale, a sprinkling of iron stone, with a generally mild appearance to the eye, but some nasty stuff going on underneath. In these types of soils with the GPZ 7000, you will want to be in General/Normal for maximum depth, or High Yield/Difficult for really good depth and still excellent sensitivity. Which option you go for will really come down to the exact ground type, the general size of gold in the area, and the EMI levels present. I have found that while the High Yield/Difficult combo will generally run smoother than General/Normal, it can pick up hot rocks in certain areas, and can be more susceptible to EMI.

In one gully, that is a perfect example of mild/medium mineralisation, I had tried to use monoloop coils here on numerous occasions with a SD2100, GP extreme and GP3500, without success. Only 1 time when the ground was really dry did I feel it was working well enough, but I still didn’t find any gold. I’d for some reason given up on this area for some years, but decided to give it another look with the SDC2300. In one afternoon, I was rewarded with 6 nuggets for over 3 grams. The nuggets were coated in ironstone and had a smooth waterworn appearance. I made the assumption that they would have been easy to find with the GPX5000 in Fine Gold, so soon returned with an arsenal of coils including a 15×12” Commander Mono and 16” Nugget Finder Mono. The result? The machine performed beautifully with both coils, but I didn’t find any colour.

With a GPZ7000 looking at me, waiting for my decision on where to swing the beast, I decided to go back to the same gully, but my plan was to first use the SDC2300 to see if I missed anything. I worked hard for 2 hrs and was rewarded with two tiny bits. Okay, time to get serious I thought, so put the SDC away and strapped on the Zed. Long story short, the 7000 performed flawlessly in High Yield/Difficult, Sens 8, and I managed 4 nuggets, ranging from 0.2 – 1.4 grams. The 1.4 grammer was literally 40cm away from one of the SDC finds, so must’ve been just out of range for the 2300. I also found several other junk targets at depth which proved the GPZ was seeing targets the other detectors had overlooked.

My gold tally with these two combos gives a clear advantage to the High Yield/Difficult combo, but the finds made in General/Normal (when the ground has been suitable) have been more impressive. I know it is early days, but I predict that the General/Normal combo is going to be responsible for some brilliant nugget finds in parts of NSW, quieter ground areas in VIC, and in generally quieter ground found in New Zealand, Brazil, Mongolia and the USA. There is also the combo of Very Deep/Normal, but I haven’t yet spent too much time in this mode, but if you know of a spot that has produced big gold and the soil is very mild, you should be on your way now!

 

Very Mild Ground

In very Mild ground, High Yield/Normal is the ticket. In the few patches I have gone over with very mild ground, predominantly quartz wash with scattered charcoal and only a sprinkling of ironstone,  High Yield/Normal has been truly impressive. One spot in particular has produced a lot of gold, and has been hit hard with all manner of Minelab PI’s. Taking the “Zed” here was an eye opener. I set it to High Yield, Low Smoothing, Target Volume 11, Sensitivity 6 and began searching. My first 3 signals were nuggets from 0.8g – 1.4 grams and all were DEEP. As night fell I strapped on a head lamp and continued searching and was rewarded with another 4 nuggets, all around the same weight.

On a subsequent trip to the same area I chose a different spot further downslope as it had deeper ground. I first used my GPX5000 with 16” NF mono and Sensitive Extra, trying to maximise depth and sensitivity. After 2 hrs I got 1 nugget. I then strapped on the GPZ, and being a very hot and windy day the EMI was much worse than the previous session, which forced me to use High Audio Smoothing. The unit was now purring, but I did a test on the nugget I found with the GPX5000, and I found that by going back to Low Smoothing and dropping the Gain to 5 gave much better results.  At first I was struggling to get any targets, but I started a loose grid and eventually found a piece of gold directly under a layer of charcoal. 2 m away was another bit, then 3 metres downslope I got a bigger piece and they just kept coming. I ended up with 9 bits of hackly, iron encrusted nuggets. I was sold.

Hot Ground

In really hot ground you have a few options at your disposal: Severe, Extra Deep/Difficult, and General/Difficult. Severe is the most stable, still has surprisingly good sensitivity, but won’t punch very deep. I liken it to Sensitive Smooth on the GPX units. Extra Deep/Difficult is also quite stable depending on the ground, will punch to great depths on larger targets, but Sensitivity to small targets is diminished. My deepest target with the GPZ so far was using the Extra Deep/Difficult  combo, and I was surprised when a blob of lead came out the hole. I wouldn’t use this as a primary search mode, but if you have a suspicion that big gold may be lurking, it is definitely worth a go.

Difficult/General is the happy medium setting. It handles most mineralised spots very well, still has the capability to ping nuggets down to 0.2 gram, and will go surprisingly deep. I used the Difficult/General mode in a heavily worked area of diggings in Victoria and spent 3 hrs digging plenty of bullets and lead shot, a few 2 ft holes (unfortunately for junk) and also picked up 3 nuggets for my trouble. What impressed me the most was the sensitivity and depth I was achieving at the same time – the GPZ 7000 will prove to be a fantastic patch hunter.

 

Warts and all?

Okay, well no review is ever taken seriously if it is all peaches and cream, so there has to be some negatives……doesn’t there? Yes, as always, one thing can’t be the best at everything. Here’s a couple of downers:

– The coil is a touch heavy. The unit does balance nicely, and the Pro-swing takes a lot of the weight, but this doesn’t help you when lifting the coil over obstacles or doing side walls etc. On flat open terrain it’s very comfortable. If you are working undulating terrain, then the supplied swing arm is a massive plus. The only problem I have here is where to put your pick, as the GPZ will detect it if it’s anywhere below chest height!! Probably a good time to mention – leave the baby picks at home!

– The DOD configuration of the coil is good for getting extra ground coverage at depth like a conventional DD coil, which is fine in open terrain where you can swing left to right (did I mention this is going to be a great patch hunter :) ). However, the beauty of a round monoloop coil is that it has equal sensitivity around the rim of the coil, so you can swing it left and right, push it under a stump, guide it around tussocks etc. and you don’t have to think about the search pattern.

Considering I do a lot of my detecting in harvested forest areas, as well as overgrown old diggings, I won’t be offloading my GPX just yet, as the ability to select the right coil for the task is still a big plus. With this in mind, and the fact that most of the gold here is well under the 2 gram mark, I will be eagerly awaiting some coil options for the GPZ 7000. In the meantime, I have plenty of spots to revisit that are nicely suited to the 14” Super D.

In Summary

So how would I summarize the performance of the machine? Well, if you’ve used a SDC2300, try to imagine it with a 14” DD coil without any loss in sensitivity. It is great on the porous, prickly, ironstone encrusted and specimen gold at greater depth, but the GPZ’s field is still tickling the ground at a deeper level looking for the bigger lumps. Yes everyone likes to find big gold, but the thing I hate is coming home empty handed. The SDC2300 proved that you can find gold on a regular basis, even if the pieces are quite small, at the end of the day gold is gold and it all adds up. The GPZ 7000 has also proven to have the capability to find gold regularly, but the general size of the pieces are a lot bigger, and judging by the size of some of the holes I have dug, it will prove to be quite capable on larger lumps at depth.

Well I hope this review has given you some useful information, and I will be keeping you up to date with any tips & tricks as I get more time behind the wheel.

Happy Beepin’

Nenad

 

Minelab GPZ 7000 with gold nuggets
A selection of nuggets found with the Minelab GPZ 7000



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  • bob flitton

    nenad
    great review mate my gpz should arrive soon reading your review just supports that I made the right decision .
    I think you have to put the price tag of the gpz on the back burner because we all know its going to find gold just depends on what effort you put in to go out and get it.
    just my two cents

    cheers bob

  • Peter Rob

    Thanks for the review Nenad, every bit of information helps.
    Will be sitting on the fence a little longer mainly because of such a large outlay on a product that hasn’t as yet lit the goldfields.
    There is talk of additional coils (at no doubt extra cost) which by rights should have been included with the original purchase. A little like buying a car and the spare tyre, jack etc which aren’t included, all very well until needed.

    Regards
    Peter

  • Dustin - online innovation

    Great writeup and great tips weve all been waiting for a decent review of the 7000 i myself had my name down to grab one at first release but am waiting for feedback like this. My hope was the performance and clarity of the sdc2300 in a deeper punching detector and it sounds like were on a winner. Thanks again mate

    1. Nenad

      Yes, in High Yield it has the performance and clarity of the SDC 2300, but to find the tiniest pieces you need a slow and controlled sweep speed. I dug a tiny bit of gold that didn’t register on my scales, and this was in General/Difficult, so it still has plenty of grunt and sensitivity even in areas where you can’t use High Yield.

  • Fred

    Hey Nenad, probably the best review I have read so far on the GPZ 7000! I run the 4500 and still happy with it. I hunt in California and what I found most helpful from your review is the fact that the 14″ is a bit heavy for scanning side walls and in general terrain that is extremely rough. A smaller coil would help in those situations. I suppose for flat land like you have in Australia and some parts of the the southwest like in Arizona and Nevada the 14″ would work fine. I for now will wait and keep using my trusted old Minelab as it continues producing ,,,and perhaps one day I may have a GPZ 700 to go over my old patches.

    1. Nenad

      Thanks Fred, yes I’m eagerly awaiting some more coil options for the GPZ.

  • John Williams

    Thankyou Nenad, that is the best, most informative and helpful review on the 7000 I have seen and I am indebted to you.
    I hope you are richly rewarded.

    Best wishes,
    John

  • Ashley Cowley

    Many Many Thanks Nenad for putting this out there. Brings a bit more clarity to the Zed’s potential

    Cheers
    Ashley

  • Nenad

    Thanks everyone for the feedback. Much appreciated

  • paul

    Great review Nenad!!!!

    Thanks for a well laid out presentation that can be used as a field manual for some of us..

    paul

    1. Nenad

      Cheers Paul.

  • Tim

    Hi Guys

    Having used the GPZ 7000 for two days now I’m deeply disappointed to say the least.
    Currently I am running GPX 5000 ,
    SDC 2300 & xterra 705.
    Let’s start with the coil on the GPZ
    It’s heavy cumbersome and uncomfortably so…
    It’s no where near as clear or stable on audio as the SDC 2300 on hot ground not even close…
    Truely I had expected it to be very quiet running on hot ground but it is not.
    Running the GPZ 7000 in settings as followed.
    Sensitivity 6
    High yield
    Audio stabiliser low
    Difficult Ground mode
    Auto balance
    Even dulled down I was digging ground noise all day very frustrating for $10,700.

    The SDC outperforms it on everything but outright depth period.

    After using the SDC for one day I grew completely confident it was better than a well tuned GPX 5000 with an eight inch coil.
    With the GPZ 7000 I’m not as confident that says a lot.

    Having found large ferus targets at depth with the GPZ 7000 today I’m guessing yes it will eventually find bigger nuggets but it’s just so cumbersome to use with the heavy stock coil and to stop it being noisy you have to dull every setting down thus eliminating any perceived depth advantage you are expecting.
    I’m not trying to bash the product just giving my honest opinion,
    being a minelab fan at heart I can say the GPZ is packaged nicely but I can honestly say it didn’t live up to my expatation considering the price,
    perhaps minelab could have packaged it with an optional eight inch coil or made the price more realistic.
    Looking into the future I’m not sure this machine is going to be remembered as fondly as the GPX series.
    7/10

    1. Nenad

      Hi Tim,

      The GPZ 7000 surely is a different beast. You are going to need a lot more that 2 days to get used to it, explore the different setting options, and understand how to get the best out of it. I really feel it’s more closely aligned to the SDC2300 in terms of the audio, running both in Tracking, slow sweep required for maximum sensitivity, internal batteries etc etc. However, due to the DOD coil and new unique technology, the GPZ definitely has a different language. Some target signals will sound exactly like on a GPX, but others will be a double beep, some will be a broad dip, then deeper targets can give you a wobble. Many users may be dismissing these bizarre responses as ground noise. The same old rules of gold detecting apply: 1. Any repeatable signal, then start digging, and 2. If you are not 100% sure, scrape an inch or two off the surface and re-check.

      The GPZ7000 likes to be pushed a little, and when the machine is slightly chattery is where you want it to be, as target signals will still stand out. High Yield won’t work in all areas, and a lot of guys I know are mainly using General / Difficult as the unit still has lots of grunt, but is less reactive to hot rocks, hot spots, charcoal etc. Also, you need to train yourself to the GPZ7000 in Low Smoothing, and then when you feel comfortable go to Smoothing Off. This really unlocks the power of the Zed, as there is no “filtering” in the audio, so you are hearing every response the coil/detector is picking up. Again, as with High Yield, you may not be able to use Smoothing Off in every location you visit, but in my experience, I’d rather have Smoothing Off with a lower Sensitivity setting, compared to Smoothing Low with a slightly higher setting.

      Also, if you are in highly mineralised soil and struggling with High Yield and General, Severe is a very good setting that still has plenty of sensitivity on offer, but runs very stable so Smoothing Off and a increased Sensitivity setting can usually be used. But if you’d rather concentrate on the larger bits, then Extra Deep / Difficult is the ticket.

      Hope this gives you a few things to try as you’re learning the new detector.

      Best of luck!

      Nenad

  • Rick Jobs

    Hi Nenad,
    2 week owner of GPZ7000…I traded my GPX5000 and I got a veterans discount. This week I put it to its first test…in Oregon on dredge tailing piles up to 30 feet high…I am a disabled vet ..so I can’t do steep area but nonetheless with the new harness with the inserts and the adjustable bungy, I was able to get in 6 long GeoHunts a day about 1/4 mile long each…although the detector is heavy…I found it much easier to understand and tune than the GPX5000…I was interested to hear your post above about a double bleep…I heard several of those and since I am learning…I failed to dig them. The tailing piles are much like Australia in that there are massive amounts of ironstone and the dredge finishing screens were 1 inch. My settings started out using deep mode and sensitivity of 12 or more…the reason is that their are no real small nuggets since that’s what the dredges in 1880’s were after…instead I am looking for specimen grade quartz at depth. One feature I really like is I can be in deep mode and touchpad back and forth between high yield and deep…that helps me to discern trash. My first find was a very rare silver and platinum nugget with just a sprinkling of gold…which a gold dealer ran a spectrum gun on…17grams about the size of a US quarter….found about 24 inches down in deep mode. I would appreciate any setting suggestions for this machine…..Thanks for your info

    1. Nenad

      Hi Rick,

      Sounds like a cool spot! If you’re after large specimens at maximum depth then High Yield Normal is the way to go. If ironstone is a problem, then flick to Difficult, have Smoothing Off, and Sensitivity as high as you can handle. Depending on the type of gold and ground minerals, General could be the magic setting. It can have a little more punch on larger or more solid gold, yet much more sensitivity compared to Extra Deep. So that would definitely be worth a try, especially if you can run it in Normal Ground Type, even if it means dropping the Sensitivity setting right down. Looks like you’re off to a great start anyway – nice work!

      Nenad

      1. Rick Jobs

        Can I send you some pics of this piece…its…very unique…you have my email…if you mail me I can reply….the more I clean it off…the weirder it looks

  • norman velez

    me gustaria ke alguien me dijiera como se puede controlar en donde puedo ponerlo en la mejor opcion para poder tener el mejor rendimiento ya ke no dice en el manual tiene ¡¡ muchas opciones pero si alguien me podria ayudar me encantaria lo e calado el lugares ke hay pero no me a ido bien por eso pido ayuda ojala me pùedan ayudar vivo en sonora mexico

    1. Nenad

      Hola, si usted me deja saber las condiciones del terreno , y qué tipo de oro son sus expectativas de encontrar, yo estaría encantado de sugerir algunos ajustes.

  • sami

    Haw match gpz7000

    1. Nenad

      $10,700 here in Australia, but get in touch with your nearest Minelab dealer for latest pricing and promotions etc. http://www.minelab.com/aus/consumer/where-to-buy/where-to-buy

  • adnana

    Haw match is the max depth of it?

    1. Nenad

      The depth you will achieve depends on a lot of variables: target size, shape, density, how it is sitting in the ground, soil mineralisation etc etc. In milder soils you can use Normal ground type and General gold mode and punch very deep on most target sizes.

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