Simple Chip Amp for P to P wiring

[coldcathode]

AND the CAPS were a little backwards too!! DUH

[coldcathode]

The trannies are actually 25.2VCT @ 2A so that is 50VA?

So 100VA with 2 trannies per Channel.

You have to forgive me because I rarely work with Bridges and dual supply circuits, all my other stuff is TUBEs and I work from B+ to ground using Full Wave tube rectifiers.

As re-drawn it should be OK?

[coldcathode]

Assuming I work out the PS issues.

I revised the schematic on that project removing the bridging and SIM optional components.

Couple of questions

#1 Feedback resistors and caps are they R5,R4 and C3??

These determine overall gain and LF cutoff correct?

#2 How to increase Input Impedance (to about 50K min) and assuming I have no DC from the source and the source is cap coupled to prevent DC back into it can I remove C1? and what is the purpose of C2?

#3 Notes say that C4 determines HF responce this will be a SUB amp so what components determine that POLE so I can lower it?


Any help to a "Bottlehead" would be greatly appreciated!!

[MJL21193]

How did you go from P2P chipamp to ESP 3A?? And why?

[Fenris]

Leave out the CTs. You're defining ground level after the bridge.

[danielwritesbac]

Originally Posted by MJL21193

How did you go from P2P chipamp to ESP 3A?? And why?

Hi MJ!

Methinks he wants high-current design like his tube amp.

As to function, my only guess is that maybe the discrete design will make for an easier time with a unified volume control, since the discrete design is easier to mod because it isn't sealed inside a chip.

[MJL21193]

Originally Posted by coldcathode

Assuming I work out the PS issues.


#2 How to increase Input Impedance (to about 50K min) and assuming I have no DC from the source and the source is cap coupled to prevent DC back into it can I remove C1? and what is the purpose of C2?

#3 Notes say that C4 determines HF responce this will be a SUB amp so what components determine that POLE so I can lower it?


Any help to a "Bottlehead" would be greatly appreciated!!

Power supply looks correct (oops, bottom bridge is upside down!) .

Input impedance: Change R2 to ~50K, change R5 to match and adjust R4 to get the same ratio (22:1). C2 is part of the input low pass filter, it's a good idea to maintain this.

Lower C4 (NO!) or lower the HF response?

[danielwritesbac]

Originally Posted by danielwritesbac

Well, then, are these decent examples?:

Page 9 http://www.st.com/stonline/products/...60/tda2040.pdf

Page 10 http://www.st.com/stonline/products/...85/tda2052.pdf

Page 10 http://www.st.com/stonline/products/...9/tda2030a.pdf

Originally Posted by AndrewT

which parts of pages 9 & 10 show that you understand how it works?

Those three links are all different files with different examples. Funny question, and the answer is that they show usage, but not especially good at showing why. Given several examples, with all different crossover points, it becomes more clear on what makes function.

Originally Posted by ratza

Actually I have a better question: is that a passive or an active filter?

They are passive filters. Those designs really do need a unity stable quad op amp as a buffer instead of too-much reliance on those resistor mixers.

Now, THIS is an active filter (photo):

[ratza]

Originally Posted by danielwritesbac

They are passive filters. Those designs really do need a unity stable quad op amp as a buffer instead of too-much reliance on those resistor mixers.

Nope, those filters are active. Passive filters are made with passive parts. This is my last post here. I'm sorry for the offtopic, but I cannot help when I see electronics engineering being insulted by those who do not understand it.

[danielwritesbac]

Originally Posted by ratza

Nope, those filters are active. Passive filters are made with passive parts. This is my last post here. I'm sorry for the offtopic, but I cannot help when I see electronics engineering being insulted by those who do not understand it.

Clarify please. Putting an amp at the output of passive filtration makes an. . . active filter? Wow, there are unexpectedly vast differences in quality of active filters.