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Edit: Sadly with their rise in popularity, smaller clients have been pushed aside.
It has been over 17 days since ordering recently with no response, however larger clients are getting priority on orders.
It has left me quite embarrassed as I got some new buyers to buy up coins for the August 31st batch, all to be left without any response from Canaan so far.
I have covered their loses, but it is still a disappointment.
I also tried ordering from their reseller website, but they declined my order as well and cancelled it.
I would recommend avoiding Canaan if you value time and responsiveness, though I still stand by their hardware.



I first tried out the A721 with their Pi3 controller shortly after they announced it.
They contacted me about payment options, used btc, and had a tracking number the next day, it was already shipped.
I have had 0 issues with this setup.

I then purchased another 2 controllers, one as a backup, another as the main, and very slowly added A741.
There have been 3 MM Firmware upgrades since I got them, never really had any major issues with them, but hash rate does seem to go up pool side with each upgrade so far.
Once summer hit, I learned in my case it was best to set it to -2 or -1 on the voltage offset(easy to set via the controller GUI)
Speaking of which, it's a nice mostly stock cgminer install in the advanced area, I love this and all the advanced options.  The initial GUI front end is very user friendly, but I like the advanced cgminer look.
Poolside rate after rejects is 7.2Ths on the lowest end on the hottest day(as they promised) and 8.4Ths on the high end when it's cool, this is without using +1 voltage (haven't tried it yet).

I had acquired 9 A741 over many months, all within days of payment were shipped very quickly, usually 5 days to my door.
I eventually had one Miner that failed to power on at all very recently.
I tried everything I could think of, but it did seem the Miner was dead.
I reported my findings to their support ticket page.
Showed a few pictures of the Miner, and with no fuss and agreeing it's most likely scrap time, a new miner was sent for free per their warranty.
I've never had that with a Mining company before, or hardly any other company for that matter.

Compared to my various S9 batches, it's obvious the A741 is more durable and more reliable.
All S9 still power on, but currently average 25% dead boards, many during perfect conditions.
Warranty was never valid or within the time frame.

Add on support and warranty, and the A741 is honestly the better ROI.

I am in no way paid, given special treatment or affiliated with Canaan.

How noisy is the A741 compared to the S9?

What is your ambient temperature?
You can use -2 voltage and with 28C intake it will run similar to a 290X reference model at 70% fan, if not less.
Under that temp, it really becomes silent.
You can probably force the fan setting, and also replace it with something more silent, but I have no need for low noise.
I have it hosted so I'm honestly not too good at this, but just checked and 290X at 70% is best I can do.
I could sleep with one in a bedroom, but not 9, though I think heat at that point would be the issue haha.

The s9 is say 75db vs the 741 is 72 db

But the s9 has nasty pitch .

And some times a fucking whistle sound that is really bad.  I suspect it is due to the heatsinks used inside.

Many are offset .

The s9 is pretty much a pos compared to the Avalon 741.

But if you get a good one that does not break they are better.

Of the 11 I have had .four have not had any issues in a year.  The other 7 needed repairs.

Wow,7 out of 11 had problems ??  Kinda like my odds at the Casino  :D

Glad I'm not an ASIC whore anymore,my vid cards rock & with a 3 year warranty,even a free ship label sent to me  8)

I have 10000 sols of Zec and 60th of btc

The Zec earns about 80 usd a day and uses 3333 watts.
The btc earns about. 50 usd a day ands uses 7000 watts

I still stick with Bitcoin, although I have put a few Radeon cards in my PC for mining when i'm not using it. I still enjoy ASIC mining but I fear it's slowly coming to an end for us home miners and the big corporations and farms will centralize the entire mining business (As we can already see with Bitmain and Avalon distributing the only 'effective' ASICs now).

You just realizing this now?? LMAO!!!!!!!!!!!! For the last year or so the diff rise has been a killer,the price rise has helped but not for much longer,unless we're talkin $10,000 BTC by end year  :D

Centralization has been upon BTC & will not let up,enjoy your expensive broke prone ASIC miners LMAO!!!!!!!!!!!  ;)

That is part of what I like about Canaan, so far they have proven themselves to be easier to deal with than Asus, Gigabyte, and Sapphire (All 3 GPU cards died even before mining, only 2 RMAs were passed and it was months of work).
I highly support GPU mining as well, looking into buying something well made and for GPU mining in a more elegant fashion than a rack of GPU raisers dangling and caseless motherboards.

Canaan took me about 5 minutes of work and not a satoshi out of my wallet.
Is this sustainable? I hope so, because I plan on sticking with them with this customer satisfaction.

A741 on 6.5cent electric is pretty nice, especially on a pool paying out transaction fees.

My failure rates with the S9 were about as bad as Philipma, and I know they take good care of their miners with lots of experience.
That's not good for clearing 100% ROI.

Out of 10 Canaan miners, 1 failure, (and before Bitmain has even responded to my delay PSU shipment which is another story), the replacement was shipped by Canaan.
I'll be out a PSU for them crazy enough, wasn't expecting it to be so fast.
Will power down a bad S7 for it.

Someone else may be better about sound mods, I know it could be better than an S7 or S9 with ease, but I don't care about noise.  Though I have had an S4 before drive me almost insane with this ear piercing whine.
I replaced the fans in it just for safety, cooled it off a bit, maybe bad internals.
I bet the 721, if they have any more, would be amazing for whisper quiet operations, it runs very cool on stock settings.
In a 70F house, I bet with -2 volt you could make it idle at 30% fan, no more than a normal PC sound.
Add a quiet fan or dual fan setup, done.

Agree with all except:
Speaking as a person who designs/builds high power electronics for a living, *why* do folks constantly seem to think they can make a better decision about cooling/fans than the OEM did?

Canaan did even more research into that than Bitmain (who just went for brute force) did. Read the bit on Canaan's site about it then look at the innards of your 721/741 miner to find out how they reduced the noise.

That said, as with Bitmains s7 on up and applying equally to the Avalon's, IF you are going to play with fans at least make sure they are rated to work against high static-pressure. Most lower noise ones are not and will not deliver enough or at best will deliver only barely enough airflow even with a miner throttled down. In short - expect marginal performance....

I've known this for a long time if you track my posts (who would?). I'm still profitable as my electrical cost is right around six cents per kilowatt and I probably will be for a long time. POW change is an option but with centralization Jihan will make some chess pieces move and block that out. My mining rigs haven't broken down yet and I still actively buy miners and use them, GPUs also have risk involved, albeit much less.

I agree they designed these things by default perfect for my setup and anyone who can tolerate expected fan noise.
As stated I have no need for silent operations so don't have any first hand experience, but I do see people constantly underclocking/downvolting units, some for a living, for home mining and basically costing performance in exchange for lower fan noise, at almost any cost.  I assume the openness of the Avalon compared to current options could dominate TH/Sound DB with some modding, software and hardware.
R4 was meant to fill this void, but didn't do so great, high failure rate, and low supply.  Still a market for it, just one I'm not really needing right now.

So in summary probably still too noisy to run in a dorm but it might be OK in an apartment if you can keep it in the next room. In other words, there's a reason why college students have moved on to altcoins years ago.

I would second that. I was Bitmain customer before, went through all series, but after we got A741's, would never buy anything else. Build quality is amazing, cooling designed more efficiently due to angled board, noise is less, super reliable. Fantastic miner.

So far using a mixture of the 1600watt PSU batches from bitmain back during the S7 and S9 era, on 220v.
Zero issues it seems, and able to get amazing rates with them, 7.2TH is indeed the floor with the A741.

Anyone powers 2 x 741's per APW5? is that a good option?

Well it's a bit late to ask i have that ordered and practically shipped, but still would be nice to know opinions.

Personally that would be right at or maybe above the limit even at 220V and I would not do that.

If you had an A741 and A721 setup that would be pretty good though two A721 would be overly safe.

1600watt PSU seem to handle the A741 even at full blast with a good overhead left over.
Personally I like to overkill the PSU so it has max efficiency, but hard to beat the 1600w PSU deal and has yet to cause an issue.

APW5 specs say it provides 2600w@220v (so its kinda 1300 per 741 in my case, and i have access to 230-235v voltage, so 220 is guaranteed) while A741 requires approx 1150w, isnt that enough?

I also have some APW3's on the way, though somehow APW5 for 2x741 seemed a nice option for tests.

My 1600watts are reading around around 1300 usage when they are running around 8TH.  With -2 voltage via their setting, it drops around 8% but still has variation.
From the specs: ≈ 1150W, +0% ~ +15% So at +1 volt and 8.2TH+ it will be closer to 1355.

I'd ask them about it, they most likely have a solution.

Thanks for detailed info! Ill get in touch with'em and see what else can they suggest.