# TL062CN Op-amp first issue

#### maver144

Joined Jul 12, 2020
11
Solved using other op-amp.

#### atferrari

Joined Jan 6, 2004
4,069
Which is a...?

#### Papabravo

Joined Feb 24, 2006
14,250

#### Audioguru again

Joined Oct 21, 2019
1,768
Maybe the opamp that did not work was defective or is a fake?

#### schmitt trigger

Joined Jul 12, 2010
312
This is a very significant problem in this forum and many other forums: beginners purchase unknown-origin components from Alibaba or Ebay, without them understanding the risks.

Many times the problem is compounded by the circuit itself, usually copied from an untested web page.

#### Papabravo

Joined Feb 24, 2006
14,250
Add to that their general lack of interest in relating the full story of what happened and why. A line or two on the actual solution might be appreciated by the next reader of the thread.

#### maver144

Joined Jul 12, 2020
11
I'm still not sure why the first circuit didn't work. There is a risk I have broken it somehow meanwhile testing various configurations. However, I built it again using another op-amp (ne5532). After a little bit of reading, the circuit has been slightly modified. I attach the final schematic.

I also shorten elements legs. Be aware that filter on non-inverting input might need to be adjusted depending on your signal frequency.

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#### atferrari

Joined Jan 6, 2004
4,069
Does it really work with the PSU polarity reversed?

#### maver144

Joined Jul 12, 2020
11
Does it really work with the PSU polarity reversed?
Your right, I didn't pay enough attention while drawing schematic (did it only for future readers, real application had correct polarity). Updated last post with the correct polarity. Thanks for mentioning.

#### DarthVolta

Joined Jan 27, 2015
501
hi 144,
Welcome to AAC.
Is there a DC voltage on the XR2206 output.?
E
I have 1 of the $15 ebay XR2206 gen's, it was single rail, and iirc wasn't exactly centered as I'd expect from 12V, regardless of Pk-Pk. . I'm sure a lot of them are. Mine had a lot of jitter, but it was fine for the$15, and being my 1st 1.

I never tried to quantize the output impedance or anything. I bought a few of the chips to experiment with, as old cheap chips. I look forward to trying to model some of it in LTSpice.

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