http://waltjung.org/Classic_Articles.html
line driver artcles in walt's "Op Amp Applications" book lower half of page
Walt's recommendation of the AD811 maybe a little dated - no doubt he has a a bunch on hand and they are OK but now I would look to TPA6120, LT1795, AD8397 - if you can deal with surface mount
line driver artcles in walt's "Op Amp Applications" book lower half of page
Walt's recommendation of the AD811 maybe a little dated - no doubt he has a a bunch on hand and they are OK but now I would look to TPA6120, LT1795, AD8397 - if you can deal with surface mount
the LM4562 could be used as the input op amp in Walt's composite line drivers, the op amps I suggested would be used in the output buffer amp position where Walt uses the AD811
The LM4562 is faster than most input op amps shown in Walt's composite driver circuits so you may need to add some frequency compensation at lower gains
For the output buffer amp the AD811's main advantage to diy types is the DIP package which is also its weakness - power dissapation is limited, the plastic package shouldn't be used at the full supply V rating
Walt points out the Pdiss problem with the AD811, his suggestion of adding a clip-on heat sink is generally not that effective with plastic packages so you need to use the ceramic part to get to the rated Vsupply for large output swings and low impedance loads
the SMT parts I mentioned have provision for conducting heat to the gnd/power planes on the pcb and can handle several Watts to more than 5W per package for the TPA6120
The AD811 is OK in applications where it's power limitations don't come into play
The LM4562 is faster than most input op amps shown in Walt's composite driver circuits so you may need to add some frequency compensation at lower gains
For the output buffer amp the AD811's main advantage to diy types is the DIP package which is also its weakness - power dissapation is limited, the plastic package shouldn't be used at the full supply V rating
Walt points out the Pdiss problem with the AD811, his suggestion of adding a clip-on heat sink is generally not that effective with plastic packages so you need to use the ceramic part to get to the rated Vsupply for large output swings and low impedance loads
the SMT parts I mentioned have provision for conducting heat to the gnd/power planes on the pcb and can handle several Watts to more than 5W per package for the TPA6120
The AD811 is OK in applications where it's power limitations don't come into play
Hi there!
I have build a preamp with the LME49710 (single version of LM4562). The sound is very rich of details but has a lack of warmth and deeper frequencies (under 1KHz). So, voices seem to be a little bit to thin and a bass guitar vanishes often of the sound spectrum.
So, does anybody have a well working preamp circuit for the LM49710? Mine is too thin.
Thomas
I have build a preamp with the LME49710 (single version of LM4562). The sound is very rich of details but has a lack of warmth and deeper frequencies (under 1KHz). So, voices seem to be a little bit to thin and a bass guitar vanishes often of the sound spectrum.
So, does anybody have a well working preamp circuit for the LM49710? Mine is too thin.
Thomas
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juergenk said:
Hi Jürgen,
you are right. On the original circuit they are grounded but because I am no electrician but a business man I haven't seen the mistake but funny, it works although!
The drawing is exactly how I have connected the parts so the mistake is in my circuit, too!
What will be the effect when grounding correctly? More bass? With OPA604 there is enough bass!
Regards and thanks
Thomas
Tolu said:
Please look at the diagram on here (Noninverting amplifiers) and compare your schematic:
http://ourworld.compuserve.com/homepages/Bill_Bowden/opamp.htm
That might help you to see where your schematic is incorrect.
Regards
Simon
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