I might try to reformat my BF862 quad pair SE class A headamp to squeeze into an Altoids. Even though SMT, running four pairs and two for input stage with ancillary resistors adds up in real estate.
I will need to shrink this 5x in area to fit in Altoids 1/3rd space. Maybe 2 small boards top and bottom sandwiching the 3.5mm jacks?
I will need to shrink this 5x in area to fit in Altoids 1/3rd space. Maybe 2 small boards top and bottom sandwiching the 3.5mm jacks?
PM - and resistors - sent.
But good question, other folks building the Super CMOY and using Digikey will run into the same issue. I used those 0.1% just because they happened to be cheap at Mouser (likely an overstock) and the extra precision actually is useful in that particular circuit. The voltage divider sets the point at where the power management circuit cuts off the batteries. But I made the BOM really based on Mouser. Some of the parts are not available at Digikey (3.3uF film caps, volume pot) and that 100K resistor winds up pricey, at least in the 0.1%.
By the way, if anyone building the Super CMOY finds a part out of stock at either Mouser or Digikey let me know, I can probably come up with an alternate part number. If all else fails I probably have the part too.
Nice homemade PC board in your post above! Very impressive.
Please do post on your listening impressions between your class A amps and the Super CMOY's OPA1688.I agree that this Super Cmoy amp is fun to build, the hard part was soldering the TPS3701 chip...and cap.....I managed to do two boards and they both worked!!! I was surprised! Getting a ready to go board here is the way to go.
Its a small but dynamic package and everyone I show it to smiles....
Alex
Its a small but dynamic package and everyone I show it to smiles....
Alex
I'm far from an expert, but I've not seen any mounted upside down either. My only other experience with an Altoid tin resulted in a lid that did not close well, so for this go-around mounting the board "the right way up" was the only choice for me.
Alex - you soldered up a couple of those! Your tape idea helped tremendously.
xrk971 - I've never heard of magnifying binocular googles! I'll look into that. Sounds like just the ticket. None of the desk magnifiers I've found come anywhere near being high enough magnification.
mlackey - right side up definitely works too!
xrk971 - I've never heard of magnifying binocular googles! I'll look into that. Sounds like just the ticket. None of the desk magnifiers I've found come anywhere near being high enough magnification.
mlackey - right side up definitely works too!
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Alex - yeah you soldered up a couple of those! Your tape idea helped tremendously
xrk971 - I've never heard of magnifying binocular googles! I'll look into that. Sounds like just the ticket. None of the desk magnifiers I've found come anywhere near being high enough magnification.
mlackey - right side up definitely works too!
Essential for SMT work.
https://www.amazon.com/SE-MH1047L-Illuminated-Multi-Power-Magnifier/dp/B003UCODIA
PM - and resistors - sent.
But good question, other folks building the Super CMOY and using Digikey will run into the same issue. I used those 0.1% just because they happened to be cheap at Mouser (likely an overstock) and the extra precision actually is useful in that particular circuit. The voltage divider sets the point at where the power management circuit cuts off the batteries. But I made the BOM really based on Mouser. Some of the parts are not available at Digikey (3.3uF film caps, volume pot) and that 100K resistor winds up pricey, at least in the 0.1%.
By the way, if anyone building the Super CMOY finds a part out of stock at either Mouser or Digikey let me know, I can probably come up with an alternate part number. If all else fails I probably have the part too.
Nice homemade PC board in your post above! Very impressive.
I am listening to my BF862 SE Class A amp in "portable" mode now using 5v USB battery and my Aurvana 3 IEM's. Listening impressions here:
http://www.diyaudio.com/forums/head...class-headamp-without-heat-4.html#post4925265
Class A makes a difference vs direct output from my iPhone earphone out. Even on 112dB/wW headphones.
Can't wait to make my Super CMOY 1688 and do same test.
I'm old (school) and have no experience with hot air stations. Do you flow solder on the pads and then push the part in place, like "tack soldering"?
Well,I'm to cheap to buy solderpaste (and honestly, I'll never use one tube within its shelf life), I just tin each pad a little bit with a regular iron (with a fine-ish tip) using good lead solder. Then I just place the part on top and just push it into place when the solder melts (yup, its basically tack soldering with a fancy blow dryer ). The part just kinda slides right into place with no bridges. If you're using lead free, it might be a little dangerous for the part as it take much longer to melt (in my experience anyways).
). The part just kinda slides right into place with no bridges. If you're using lead free, it might be a little dangerous for the part as it take much longer to melt (in my experience anyways).
The video of that hot air station is absolutely AWESOME!! I am very impressed...looks like a really neat tool for DIY'ers..
The Super Cmoy you did really looks great in the soldering of the small devices!!
Great Job!
Note I got a set of 600 ohm Beyer T1's from Santa and this Super Cmoy drives them to very high sound levels!! The volume is cranked up to 70-80% but its really a great little amp to make these cans play well!
The Super Cmoy you did really looks great in the soldering of the small devices!!
Great Job!
Note I got a set of 600 ohm Beyer T1's from Santa and this Super Cmoy drives them to very high sound levels!! The volume is cranked up to 70-80% but its really a great little amp to make these cans play well!
Yeah, here's the one I use: https://www.amazon.com/YOUYUE-Rework-Station-Soldering-Digital/dp/B00P8Z4RPG/
They sell them allover ebay. Just check the wiring when you get on to make sure its done correctly. There are reports of bad wiring jobs, but luckily mine was fine
They sell them allover ebay. Just check the wiring when you get on to make sure its done correctly. There are reports of bad wiring jobs, but luckily mine was fine
Thanks - through hole soldering is hobby fun. SMT is when steady hands matter.
. Although with solder paste and an oven maybe anyone can make good SMT.Good that it can drive 600ohms - my DT880's are 250ohms so should be fine.
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