Substituting semiconductors

[Breke]

I was thinking about building two of Craig Anderton's projects from Electronic Projects For Musicians; the "super tone control" and the "practice play along". The problem is that the IC that is required, RC4136 or XR4136, aren't available on the sites I'm going to order from (www.banzaieffects.com and www.trimlog.se). Are there any good and common ICs that could be used instead? I was thinking about the LM324N, TL074 or 74136 TTL. (The first two were discussed in similar contexts in earlier threads, and the third simply contained 4136 ) Will one of these work or are there any better choices? And are there any relatively easy general guidelines to follow when you have to substitute, or to you have to study the datasheets and actually understand All the values to know that?

Oh, and MPSA64 transistor used in the Bear Face (http://www.smallbearelec.com/Projects/BearFace/BearFace.htm), could you replace that with an ordinary PNP Si transistor?

I'm still in the phase where I can manage to assemble a few not to complicated circuits, but as soon as it comes to the theory behind it, it is far above my head  A few suggestions would be appreciated

[The Tone God]

Welcome to the forum.

The function is your friend.

http://www.diystompboxes.com/smfforum/index.php?topic=33320.0

http://www.geofex.com/FX_images/anderton.gif

Andrew

[John Lyons]

Mouser has the 4139 chip...
I'm putting one of these together right now.

[Breke]

Thanks!

The embarrassing thing is that I spent about a hour looking through old threads about 4136 (missing the one that you tipped of, I might add), and I didn't even think about searching for the STC project I think I will just buy a few of the ICs mentioned and try them out, it will be interesting to see what difference there can be between them.

The problem ordering for me is that I live in Sweden and my choices of places to order from are somewhat limited. The shipping cost can get really nasty if you order from somewhere outside Europe, and if you're unlucky you might get additional fees from the customs... I suppose there have to be SOME benefits in living in the US instead of in a country which total population measures up to about the same as an average American city;)

[The Tone God]

No problem. Opps I forgot to add the search criteria. I did use "4136" but then I ran another search using "super tone control" and came up with a collection of nice threads. You might want to give that one a shot for some usefull info.

Good luck.

Andrew

[Mark Hammer]

Any pair of decent low-noise dual op-amps or a quad op-amp will do just fine.  At the time the original circuits were published, the 4739 presented the best bang for the buck in duals, and the 4136 the best bang for the buck in quads.  These days it is easy to find topnotch duals for half the price of what a 4739 cost even at its lowest, and4136s can be easily ound in the buck-a-piece range.

A TL074 will do just fine.  An LM837 (the quad version of the LM833) will also do a nice job.

Just keep in mind that the pinouts on the 4136 were, and continue to be, different than those of the 324 package (which is shared by the TL074/64/84, LM837 and a bunch of other quads).  The most dangerous confusion is that of the power pins.  They are NOT AT ALL the same.

Before you build it, be sure to check out the mods for it in DEVICE (hammer.ampage.org).

[Breke]

I will do that, thanks a bunch!
I can't imagine how people were able to learn stuff like this in the days before internet. Sure, there are a few nice books like EPFM about the subject, but it just can't be compaired to all the information on the net and all the experienced veterans who are willing to share their hard-earned knowledge It is highly appreciated!

[smallbearelec]

Oh, and MPSA64 transistor used in the Bear Face (http://www.smallbearelec.com/Projects/BearFace/BearFace.htm), could you replace that with an ordinary PNP Si transistor?

The high gain of the darlington is wanted there to keep the base current minimal and so avoid switching pops. That entire section of the circuit is just an in-use LED driver, and it can be worked-around several ways, as you will discover in your research.

The shipping cost can get really nasty if you order from somewhere outside Europe, and if you're unlucky you might get additional fees from the customs. I suppose there have to be SOME benefits in living in the US instead of in a country which total population measures up to about the same as an average American city;)

Yes, the 200+-year tradition of relatively low duties and a Customs union among the States have been very important to our prosperity. As an importer and exporter, I have to hope they last. Note that shipping rates are not too bad for small, light air mail packages, and SBE policy has always been to declare the lowest reasonable value on the Customs sticker.

Regards
SD