I would be interesting in getting some batteries, unless it's too much of a hassle to get this small battery buy international.
On the topic of batteries, it seems "9V" NiMH batteries from "reputable" North American suppliers mostly have capacities on the order of 200mAH, with a few topping 300mAH. But there are eBay sellers from Hong Kong selling batteries rated at 400 and even 450 mAH 4 x 9V 9 Volt 400mAH PP3 NiMH Rechargeable Battery uc | eBay and 2 9V 9 Volt 450mAh Ni-MH 6F22 PP3 Rechargeable Battery Cell Block | eBay .
Does anyone have experience with these? Are these for real? For about $5/battery they seem to be offering almost twice the capacity of name-brand batteries.
Does anyone have experience with these? Are these for real? For about $5/battery they seem to be offering almost twice the capacity of name-brand batteries.
Hi guys-
A question for those of you in the US/Canada who have built and are actively testing/using the amp:
Are you all using the recommended Triad WAU12-200 AC adapter?
The reason why I ask is that it seems to me that the listed specs on that particular model are really, really close to the minimum needed to operate the amp. It won't be used with any abnormally high-impedance cans, and will also be used via battery power probably 90% of the time, but I just wanted to make sure that the adapter does indeed work exactly how it should (especially in terms of charging the batteries). I'm giving a couple of these as gifts this year to non-DIYers, and obviously don't want the recipients to worry about the units working correctly.
I trust that NwAvGuy did his homework correctly, but I guess it just makes me a little nervous with only one data point. Is everyone else having good luck with that model too?
Thanks!
A question for those of you in the US/Canada who have built and are actively testing/using the amp:
Are you all using the recommended Triad WAU12-200 AC adapter?
The reason why I ask is that it seems to me that the listed specs on that particular model are really, really close to the minimum needed to operate the amp. It won't be used with any abnormally high-impedance cans, and will also be used via battery power probably 90% of the time, but I just wanted to make sure that the adapter does indeed work exactly how it should (especially in terms of charging the batteries). I'm giving a couple of these as gifts this year to non-DIYers, and obviously don't want the recipients to worry about the units working correctly.
I trust that NwAvGuy did his homework correctly, but I guess it just makes me a little nervous with only one data point. Is everyone else having good luck with that model too?
Thanks!
Very Profound....
Right, I hit nightly maintenance and somehow only posted 1 letter. What I meant to reply with was:
I'd call this 'Creative twisting of the truth', if anything. The difference in capacities often relates to the number of cells in the battery, for 9V you can have lower nominal voltage and more capacity, or higher voltage with slightly less capacity. I recommend something like Maha Powermax - 300mAh, with low discharge. Reasonable capacity and you don't need to worry about them losing power while you're not using them.
Whdemon
please, always post a comment, and not only a quote
moderation
No doubt.
Thanks Mr Demon, but I have already read that section. I'm looking for others' experience. As a colleague of mine used to say: "You can draw a lot of lines through a single data point"
I just received my PCB, so I can't post from a position of experience with the Triad WAU12-200. Personally, if I were buying new from Mouser, I'd probably go with the WAU16-400. I have a couple 5-gallon buckets full of wall warts, and plan to try (in order) three rated at 12VAC 250mA, 12VAC 300mA, and 16VAC 1000mA.
As to working as it should to recharge the batteries, it's only job is to supply power to the cathodes of the Schottky diodes. R1 & R2 do the rest. You could probably use a little bit higher resistor values to limit the current further, at the cost of extending the time needed for full charge. It might not be a bad idea to match the resistor values to the battery used.
As to working as it should to recharge the batteries, it's only job is to supply power to the cathodes of the Schottky diodes. R1 & R2 do the rest. You could probably use a little bit higher resistor values to limit the current further, at the cost of extending the time needed for full charge. It might not be a bad idea to match the resistor values to the battery used.
UK parts kit multibuy
Sorry to cross-post this, but the original post should have gone here rather than in the PCB GB thread.
I've just looked into getting the parts from Mouser, problem is that there is a 20 Euro delivery surcharge for orders under 75 Euro.
If I were to buy enough components for 5 units, would there be any interest (UK only) for a kit of parts for £23 (including postage and Paypal charges)?
Only 4 kits would be available so please PM me if interested, first come, first served. (sorry but I don't have time to organise a bigger GB)
Kit would be all parts on the BOM - no case, no front panel, no PCB, just electronic components. I can't give exact dates because Mouser have some of the parts on back order, but I'd certainly reship asap after getting the parts.
Update - one kit reserved, 3 still available. No payments yet please!
Sorry to cross-post this, but the original post should have gone here rather than in the PCB GB thread.
I've just looked into getting the parts from Mouser, problem is that there is a 20 Euro delivery surcharge for orders under 75 Euro.
If I were to buy enough components for 5 units, would there be any interest (UK only) for a kit of parts for £23 (including postage and Paypal charges)?
Only 4 kits would be available so please PM me if interested, first come, first served. (sorry but I don't have time to organise a bigger GB)
Kit would be all parts on the BOM - no case, no front panel, no PCB, just electronic components. I can't give exact dates because Mouser have some of the parts on back order, but I'd certainly reship asap after getting the parts.
Update - one kit reserved, 3 still available. No payments yet please!
Whdemon
please, always post a comment, and not only a quote
moderation
I sent the quote by accident but couldnt edit it because of the Check thing.
He used the WAU16-400 for all testing.
Further update - 3 kits now reserved, one still available. I have placed the order with Mouser, but as several parts are currently on back-order, I have asked them not to ship until the order is complete - no idea how long they will take to get everything together, hopefully not more than a few days.
They normally will list the lead time next to the part description. Some of the original parts on the BOM had 10+ week lead times, so I ended up using some of the alternatives that were listed. It shipped late last week, so it all should arrive today or tomorrow.
'Still not sure about the AC adapter, although I suppose I should just suck it up and pay the extra ~$5 for the 16-400. The specs listed on the datasheet for the 12-200 are just a little too close to the design minimums for my taste.
It would be nice to hear from more people on what they're using, but I think we're all just getting ready to build, so there's not a lot of info out there yet.
Thanks Sofaspud for your response.
My PCBs arrived today from the round 2 group buy. Thanks for the quick shipping Olli and also for organizing the group buy, I really appreciate it. Now the fun begins
O2 Op Amp PCBs by schmidtc89, on Flickr
O2 Op Amp PCBs by schmidtc89, on Flickr
In the European GB, we went for the alternative route and ordered a custom transformer. We had trouble finding a suitable transformer, but now we have one that simply ticks all the boxes, including not being a wallwart but having a real mains lead. Would that be an option to consider for the US?
Thanks for letting us know. I'm guessing it must have some kind of box though, right? Something similar to the transformer that you get with a laptop computer?
I think the 16-400 will work great, I just had hoped to save a little money.
I have a LOT of unused wall-warts sitting around, but they all output DC voltage, so they won't work.
Thanks again for your response. I'm glad you found something that works well!
If a basement full of junk counts as a box... Yes. But indeed, in my case, most of them put out DC. BTW, laptop adapters also put out DC. The only suitable adapter I had was already earmarked for something else. I could also just slap a transformer in an enclosure (it will be in a living room where a little kid is playing too), but that would probably be more expensive and not as nice as the ones we have now. The Mouser wallwarts are quite a bit cheaper though.
For us in europe:
FISCHER AMPS 9V NIMH ACCU - 270 MAH - Thomann Cyberstore Sverige
Maybe old news but I'm waiting for mine to arrive.
Brgds
FISCHER AMPS 9V NIMH ACCU - 270 MAH - Thomann Cyberstore Sverige
Maybe old news but I'm waiting for mine to arrive.
Brgds