Chalumeau TL071 instead of LM386

[falco_femoralis]

Hi all, I'm combing over the schem for the Chalumeau and I'm wondering why the design doesn't use a TL071 rather than the LM386? All the other delay designs use a regular op amp before the delay chip, what is different about this one?

I intend to lift pins 1 and 8 and set the internal gain of the chip to the lowest setting so that I can bypass the fuzz entirely.

After reviewing the data sheet for the LM386 and TL071, it appears that enough of the pins interchange that I may be able to install a TL071 instead of an LM386 with some minimal tomfoolery, with the goal being a cleaner tone with less distortion. Does this make sense?

 

[jesuscrisp]

They are not interchangeable at all

 

[falco_femoralis]

why not?

 

[jessenator]

They are not the same type of chip.

The 386 is an audio amplifier, while the TL071 is an operational amplifier (op-amp), and they perform different functions. "Amplifier" being in their name isn't indicative of identical properties.

 

[falco_femoralis]

From what I've read on the LM386, it's an audio amplifier meant to drive a speaker, and in this case it's driving a PT2399. Various other analog delays use a TL072 to drive a PT2399, so why is this one different?

 

[JTEX]

The 386's output drives an LED directly in this circuit. Maybe the extra current drive it's capable of was needed for this purpose.

BTW, I wouldn't think that the cleaner tone with less distortion you're after would happen with a TL071. PT2399 is a pretty low fi/noisy/dirty chip at longer delay settings.

 

[neiltheseal]

Hi all, I'm combing over the schem for the Chalumeau and I'm wondering why the design doesn't use a TL071 rather than the LM386? All the other delay designs use a regular op amp before the delay chip, what is different about this one?

I intend to lift pins 1 and 8 and set the internal gain of the chip to the lowest setting so that I can bypass the fuzz entirely.

After reviewing the data sheet for the LM386 and TL071, it appears that enough of the pins interchange that I may be able to install a TL071 instead of an LM386 with some minimal tomfoolery, with the goal being a cleaner tone with less distortion. Does this make sense?

If reducing gain is the goal then you can sever the connection between pin 1 and 8. A swithc is a good way to do this to allow you to switch on and off. Alos can use a pot.

 

[Feral Feline]

One of these things, is not like the other, one of these things DOESN'T BELONG ...




...in the Chalumeau.


OFFSET NULL — NOT CONNECTED

Further discrepancies can be found in their respective datasheets.