Pic's of my pocket amp
Nov 3, 2002 at 3:15 PM Post #16 of 19
JMT. Thank's Joe I would avoid the Glue as you may have to slightly reposistion the Opamp. How i do this is insert the socket into a stack of about 3 sockets so as to absorb the heat and keep the plastic on the socket from melting and distorting the pin locations then stick this stack in some conductive foam to hold the assy and to protect the IC from static damage aligh the IC then solder one of the center pins then carfully solder another center pin on the other side once your sure the IC is placed right then solder the remaining pins quickly to avoid heating. the paper clip method of JMT is a good Idea to move the chip into posistion
 
Nov 7, 2004 at 7:55 AM Post #17 of 19
cool.gif

hi, PPL
I am a diyer in China.
some PPA concepts can be found in this design,cool

but I have the some questions in the schematic:
1. what is the function of the R8 which isolate the input ground path from the virtural ground?
2. what is typical value of the constant current which bias the opa into class A mode? 1ma or 4?
3. According to schmatic, the virtural ground generated from TLE2426 and the output ground derived from EL2001 are tied together at the EL2001's output.
I think it violents the design purpose of the virtural ground.
 
Nov 9, 2004 at 10:59 AM Post #18 of 19
Quote:

Originally Posted by kopfhorer
cool.gif

hi, PPL
I am a diyer in China.
some PPA concepts can be found in this design,cool

but I have the some questions in the schematic:
1. what is the function of the R8 which isolate the input ground path from the virtural ground?
2. what is typical value of the constant current which bias the opa into class A mode? 1ma or 4?
3. According to schmatic, the virtural ground generated from TLE2426 and the output ground derived from EL2001 are tied together at the EL2001's output.
I think it violents the design purpose of the virtural ground.





No the TLE is isolated by the Jfets and 1 mA is fine on the opamp
 

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