opamp for mini3~~~!
Mar 30, 2011 at 6:35 AM Post #18 of 34

Beftus

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You didn't mention you made a PCB that allows for IC sockets to be use. I thought you modified the AMB Mini3 PCB... PCB looks great. No TLE2426?

Marshall makes guitar & bass amps. They recently issued a pair of headphones.
 
Mar 30, 2011 at 8:21 AM Post #20 of 34

Avro_Arrow

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I don't think you should refer to this as a Mini^3 as it clearly is not one.
Come up with your own name as AMB suggests.
 
Mar 30, 2011 at 11:51 AM Post #23 of 34

Beftus

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You did a great job but it's not a Mini3. The Mini3 owes its existence to the AD8397 opamp. If it doesn't have the AD8397 opamp it's not a Mini3 IMO. I'm sure many will agree. The Mini3 PCB was designed around the AD8397. A more docile opamp might not require such a PCB, and could do with a less elaborate layout (think CMoy). The AD8397 was chosen for its high current output capability, that's why for many it's not needed to practise opamp rolling with a Mini3.
 
Mar 30, 2011 at 11:57 AM Post #24 of 34

cobaltmute

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Quote:
You did a great job but it's not a Mini3. The Mini3 owes its existence to the AD8397 opamp. If it doesn't have the AD8397 opamp it's not a Mini3 IMO. I'm sure many will agree. The Mini3 PCB was designed around the AD8397. A more docile opamp might not require such a PCB, and could do with a less elaborate layout (think CMoy). The AD8397 was chosen for its high current output capability, that's why for many it's not needed to practise opamp rolling with a Mini3.



Really, just the AD8397?
 
I wonder why there is another op-amp option on the Mini3 website....
 
Mar 30, 2011 at 10:33 PM Post #26 of 34

forsakenrider

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Quote:
@forsakendriver : y not ? ?_?



Like everyone else, I thought you modded an original Mini^3 board to accept sockets! I think the sockets are great and I wont why it wasnt like that the true version. I'm sure theres a god reason though.
 
BUT, youre version looks very practical!
 
Mar 30, 2011 at 11:09 PM Post #27 of 34

tomb

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Quote:
Like everyone else, I thought you modded an original Mini^3 board to accept sockets! I think the sockets are great and I wont why it wasnt like that the true version. I'm sure theres a god reason though.
 
BUT, youre version looks very practical!


IMHO, you probably can't plug an AD8397 into a socket adapter and not have it oscillate.  There's a reason it only comes in SMD.  Even then, it was a trick to keep it from oscillating or reduce the offset to acceptable levels.  As others have said, AMB went to great lengths to design a PCB that would run the AD8397 reliably.  He and Morsel built original prototypes years ago that were not usable under all scenarios.  Tangent designed the PINT and eventually took it off the market.  If I remember correctly, AMB came to the conclusion that the AD8397 would never run properly with 2 x 9V batteries and designed the Mini3 with one 9V battery as a result.  (Morsel wanted the higher voltage swing for her 600 ohm Beyers, if I recall, but that version didn't work out.)
 
Some of my recollection may not be perfect about some of this stuff, but the general theme is clear: the AD8397 opamp is not to be trivialized.
 
 
 
Mar 30, 2011 at 11:18 PM Post #29 of 34

forsakenrider

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Very interesting! I love my Mini^3 just how it is (well not exactly, the battery wont hold a charge any more).
 
Thanks for the great history and explanation guys! I feel this DIY forum is lacking some new stuff.... I find myself drifting over to the power amp side of the hobby more and more...
 

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