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Old 8th October 2012, 11:45 AM   #1
jerryo is offline jerryo  Isle of Man
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Default New Sure amps on ebay

Just seen what seems to be a very good deal on eBay from Sure Electronics with 2,4 and 6 channel amps 'with' SMPS for a very affordable price.
Don't know how they can do it for the money they are asking!?
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Old 9th October 2012, 12:48 PM   #2
redjr is offline redjr  United States
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Have a particular link you could share?
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Old 9th October 2012, 04:43 PM   #3
Bare is offline Bare  Canada
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Don't know how they can do it for the money they are asking!?
Counterfeit parts? Child labour .. the traditional methods :-)
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Old 9th October 2012, 04:50 PM   #4
jerryo is offline jerryo  Isle of Man
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hi redjr,
EBay item number ( 110961565832 )
Six channel amp with SMPS
Check out their "other items" for the four and two channel amps.
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Old 10th October 2012, 02:39 AM   #5
redjr is offline redjr  United States
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hi redjr,
EBay item number ( 110961565832 )
Six channel amp with SMPS
Check out their "other items" for the four and two channel amps.
Thanks. I have this Sure amp module and I'm very happy with it. I'm about to finish the build using this module, but want to add a soft-start circuit that I'm waiting on parts for. I'm driving it with a linear PSU @~ +-64VDC. It's not quite as quiet as a class AB amp I recent built, but low enough for my ears.

PS. My thread with a few pics can be found here.
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Last edited by redjr; 10th October 2012 at 02:42 AM.
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Old 10th October 2012, 03:53 AM   #6
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These are not so new... vastly overrated power spec, because they use power at 10% distortion in specs. It's more like a 6x30W amp with some distorted headroom... There are better options, but none as "cheap" as this one! Note that the amp is rated 6x100W but the power supply is only 36V@9.7A. It doesn't add up. Use your money wisely.

-Charlie
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Old 11th October 2012, 08:02 AM   #7
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Wonder how those SMPS compare to Connex...
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Old 11th October 2012, 12:16 PM   #8
Cristi is offline Cristi  Europe
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Depending what you want to compare. price ? they are definately cheaper. built quality ? ask someone who have both of them, efficiency ? well, the moneywell (meanwell clones) are at least 10% below connexelectronic power supplies, EMI, at least 10dB above.
The surprisingly low price is achieved by using some "Cxinese innovative solution" like aluminium wire instead of copper in the transformer and inductors, and often complete transformers and inductors salvaged from distmatled similar power supplies. second-hand parts for almost everything but the cheap resistors, and unqualified labor in some hidden corners mostly in non-urban areas, villages, wherever someone would accept to work for 3-4$ per day.
All the electronic shops in china have booths selling such knock-off power supplies, at prices starting ~10 usd for a claimed 350W, yet the original meanwell ones cost at least 3-4 times than anything which look similar and claim similar performance with them. Once I was curious and bought one for tests and dismatled to see what parts they use and how can they sell them so cheap. surprisigly the complete parts BOM would cost ~15 usd each in 1000 pcs quantities. I hope that some of you won't come to tell me that they produce them in quantities of tens of thousands, hundreds of thousands or even millions and they get much cheaper price, because: 1. they are produced in quantities of maximum hundreds or few thousands except if someone place a bigger order and pay in advance full quantity, because nobody here is crazy enough to invest the money in products, especially garbage, where they know that they market is sluggish and the can lose them at the first complain when police come and confiscate them. (they focus their investments into overpriced real-estate market for long time specu.... i mean investment) and 2. the price drop from 1000 to 10.000 pcs for parts is insignificant most of the times. so the question remains how they fill the gap from 15$ BOM of parts plus labor to 10$ selling price.
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Old 13th October 2012, 06:38 AM   #9
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Originally Posted by Cristi View Post
Depending what you want to compare. price ? they are definately cheaper. built quality ? ask someone who have both of them, efficiency ? well, the moneywell (meanwell clones) are at least 10% below connexelectronic power supplies, EMI, at least 10dB above.
The surprisingly low price is achieved by using some "Cxinese innovative solution" like aluminium wire instead of copper in the transformer and inductors, and often complete transformers and inductors salvaged from distmatled similar power supplies. second-hand parts for almost everything but the cheap resistors, and unqualified labor in some hidden corners mostly in non-urban areas, villages, wherever someone would accept to work for 3-4$ per day.
All the electronic shops in china have booths selling such knock-off power supplies, at prices starting ~10 usd for a claimed 350W, yet the original meanwell ones cost at least 3-4 times than anything which look similar and claim similar performance with them. Once I was curious and bought one for tests and dismatled to see what parts they use and how can they sell them so cheap. surprisigly the complete parts BOM would cost ~15 usd each in 1000 pcs quantities. I hope that some of you won't come to tell me that they produce them in quantities of tens of thousands, hundreds of thousands or even millions and they get much cheaper price, because: 1. they are produced in quantities of maximum hundreds or few thousands except if someone place a bigger order and pay in advance full quantity, because nobody here is crazy enough to invest the money in products, especially garbage, where they know that they market is sluggish and the can lose them at the first complain when police come and confiscate them. (they focus their investments into overpriced real-estate market for long time specu.... i mean investment) and 2. the price drop from 1000 to 10.000 pcs for parts is insignificant most of the times. so the question remains how they fill the gap from 15$ BOM of parts plus labor to 10$ selling price.
So the ones they say are Meanwell are actually fake?
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Old 13th October 2012, 12:07 PM   #10
Cristi is offline Cristi  Europe
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Not all, just those which are sold at a price below the Meanwell originals selling price, except very few sellers anywhere else than here which really do have some NOS, but they usually offer documentation and some of them the original purchasing invoice. But don't expect to buy the same on fleabey from "hapypappynicedoll", "profosionel making prodcuts" or whatever scrambled string of characters which designates their ID. I'm sure most of you found at least one similar funny names.

You can find a close reference for prices on Mouser and other distributors. Then take the price of an average quantity of 20 or 50 pcs to make an idea of the minimum real price for which you can get an original unit. All what cost below that price are made on the knees as explained in the previous post. If you're searching on fleabey you will see tens maybe hundreds of sellers selling each single unit for 15-25 usd while the original one cost at least 2-3 times in quantities of 1000 or more. I don't expect to learn that all of them aford to buy such quantities to resale them on fleabey while the history shows that they sold 17 pcs in the past 6 months and still have 20 pcs available.

Of course there are many other power supply brands which are ripped-off. but by far meanwell is the most frequent because they offer low price power supplies, allowing them to spread easy and be popular, thus easy to sneak out the knock-offs on the market, then, the extreme simplicity, which offered the oportunity even for the less trained sanitation worker turned into "sower pupply bisuness manager" to copy-paste them without any special skills, even more, on some forums, can find complete projects of such power supplies, schematic, pcb gerbers, and information where to buy the parts, some of them including phone numbers and price list for most important item.

Meanwell original power supplies bricks are using half-bridge topology, bipolar transistors, and switching frequency in 20-30 KHz range, similar with 90% of the cheap ATX power supplies. This is a mature technology, from mid '80s and the only advantage is that is relatively simple and can use cheap bipolar transistors. but the efficiency is within 80-85% range for 24V and up and even below 80% for <24V and <150W. And of course a lot of EMI, being hard switched.

My advice is: except trying to convince anyone to buy from me dedicated power supplies for audio amplifiers, which have clear advantages, but might look expensive for one who compare them with the fakes, they can also seek some server power supplies, telecom, or even industrial ones sold on the internet for prices lower than their weight in copper and iron. I'm sure that any of them is far better than a knock-off sold for similar price.
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