Op Amp assortment

[SparkyCal]

I am looking to utilize Op amps to build guitar pedals (distortion, overdrive- things of that nature).

I bought some through Amazon and they seem to be defective.

Preferably looking for an assortment, and preferably through Amazon. Does anyone have a recommendation/link to such an assortment on Amazon?

Thank-you

 

[davenn]

I bought some through Amazon and they seem to be defective.

Ohh ? and how did you come to that conclusion ?

which OP-AMP ?
have you downloaded the data sheet for them to make sure you have connected them correctly ?
what is the circuit you are wanting to use them in ?
Show us the circuit

 

[Audioguru]

Maybe the opamps you bought from Amazon the clothing and shoes online store are fake? Amazon and their sellers know nothing about electronic parts.
The JRC4558 opamp was made by New Japan Radio Corp and is a old copy of a very old American MC4558. The American ones with pins are obsolete but surface-mount ones are still available.
The circuit you posted on the other thread is fine and copies of it also work fine.

 

[hevans1944]

I am looking to utilize Op amps to build guitar pedals (distortion, overdrive- things of that nature).

I bought some through Amazon and they seem to be defective.

Preferably looking for an assortment, and preferably through Amazon. Does anyone have a recommendation/link to such an assortment on Amazon?

Thank-you

Why don't you select just ONE op-amp type and learn how to use it? Here is an assortment of op-amps available from Amazon, but I have never bought this particular assortment. Caveat emptor, but might be worth risking forty bux.

 

[bertus]

Hello,

As @hevans1944 said, you could try some of the opamps in the assortment he showed.
I have used the NE5532 several times with success:




If you want to be sure you get genuine parts, buy at farnell / newark, mouser , digikey or arrow.

Bertus

 

[SparkyCal]

Thanks to you both. I have been trying to learn how to use op amps. I don’t think anyone can say it is for lack of effort or good advice. It is so simple , which makes it really difficult to understand why I can’t get it to work. I don’t give up easily and I have not given up. But sometimes a break from a problem can bring some needed perspective. One day, I’ll lick this problem but for now, I am parking it. I will revisit this thread and carry on at some point soon, I’m sure. I have just begun to fight

 

[Audioguru]

The Amazon opamp assortment includes TDA7052A that is obsolete and has not been made for many years (fakes?).

 

[SparkyCal]

I have these arriving today. Any thoughts?
Robojax LM741 UA741 Operational Amplifier 8-DIP OP AMP 741

I had ordered them for another schematic I found a few weeks go

 

[SparkyCal]

The Amazon opamp assortment includes TDA7052A that is obsolete and has not been made for many years (fakes?).

I don’t know what is fake and what isn’t but I do suspect that at times old inventory is dumped, or sometimes, factory seconds are sold. I have had this experience with other products on amazon. 99% of the stuff I buy, I am happy with but the odd time, there is some weird stuff. Minor example but once I bought some brand name guitar picks. Great deal for so many. They arrive and many of the had little plastic shavings hanging from them, as though the cutting tool at the factory did not quite do a clean job. To use them, I had to scrape off the excess, which proved annoying to the point that I threw them out

 

[bertus]

Hello,

Read the following pages about counterfeit parts:
https://www.aeri.com/counterfeit-electronic-component-detection/
https://atadiat.com/en/e-introduction-counterfeit-ics-counterfeiting-detection-avoidance-methods/

I have a lot of documents on the counterfeit subject, but the files are to large to post here.

Bertus

 

[Audioguru]

I have these arriving today. Any thoughts?
Robojax LM741 UA741 Operational Amplifier 8-DIP OP AMP 741

I had ordered them for another schematic I found a few weeks go

The 741 opamp is 52 years old and its performance is horrible compared to modern opamps. Its datasheet shows only a 30V supply so many will not work when powered from a 9V battery.

 

[Audioguru]

I bought my car from a car dealer, not from Amazon. I buy my groceries from a name Brand grocery store, not from Amazon.
I buy electronic parts from Digikey or Newark (Farnell in Europe), not from Amazon.

 

[SparkyCal]

Lesson learned. The counterfeit article Bertus posted is a real eye opener

 

[SparkyCal]

What would be good op amps to buy?

 

[Audioguru]

Most modern audio opamps have extremely low distortion and noise. But you WANT lots of distortion and noise!
I have used thousands of TL071 (TL072 dual and TL074 quad) which are the audio version of the general purpose TL081 (TL082 and TL084). Today I use OPA134 (OPA2134 dual and OPA4134 quad) for hifi audio.

Many people use LM358 dual and LM324 quad opamps. They produce crossover distortion, noise and have a poor high frequency slew rate so they are not used for hifi but maybe are used for acid rock noises. I think old telephones are used for RAP "music".

 

[bertus]

Hello,

Have a look at this thread on the AAC forum wich opamps are used, started by @OBW0549 :
https://forum.allaboutcircuits.com/threads/which-op-amps-do-you-use.142355/

Bertus

 

[AnalogKid]

Guitar pedal people love the 741, and really love the even older 301 and 308. From a pure audio performance view, none of these are good. But a guitar pedal is not about pure, clean audio, and the coloration these parts add to the signal is considered classic. Some pedals from the 60's fetch very high prices.

ak

 

[Audioguru]

Many guitar circuits use antique germanium transistors and vacuum tubes.

 

[Martaine2005]

Regardless of age (tried, tested), don’t shy away.
They work and will continue to work for decades.
Cheap doesn’t mean crap. Likewise, expensive doesn’t mean perfect either..
We don’t all have a budget for top shelf, best parts. This is a hobby and not commercial!!.
Buy 10 for the price of one good one. You’ll get 7 good ones.
But stick to one type rather than assortments. Buy sockets for each too, easier to replace a rogue.

My advice...... Get one circuit working first. You have more experts helping you on this forum than I had at college in two years.
Use an IC socket (always). Swap in two seconds.
You sound like my son “don’t work”.
Give us all a break and stop starting different threads about the same thing.
Continue with your first pedal, don’t change anything until asked to. Have your multimeter ready.
Make sure you ‘bridge’ your breadboard rail lines.
All I have said is from reading your posts.
The worst is you have changed or swapped out without waiting for a responcse.

Martin

 

[AnalogKid]

Many guitar circuits use antique germanium transistors and vacuum tubes.

For the same circuit topology, clipping percentage, etc., I prefer the germanium sound over silicon. Made both for a cousin for an A-B test - clear tonal difference.

ak