how to use a dual I/O op-amp?

[kit102]

first, thx for looking at my thread. any respond are appreciated.

looking at the data sheet, I found that TL072 has 2 input+, 2 input-,and 2 outputs. In a circuit we always use setof I/O only (the triangle thing).
So, if in a circuit it need 2 triangle things, can i use one TL072 instead of two?

There is the same for TL074CN, but TL074 got 4 set of I/Os. Would that cause any problem if I use up the 4 sets of I/O? (May be not stable? or low output signal?)

another question: what's means dual op-amp?

PS: I am Malaysian, hardly can find anyone has the same interest in building stompbox 
a stompboxe does cost a lot of $$

[Dave_B]

Yes, a TLO72 is two complete op-amps on one chip.  Look at some schematics an you'll see things like "IC1A" and "IC1B."  Those two 'triangles' are on a single chip.  A TL074 has 4 complete op-amps on one chip. 

When you see "dual op-amp" they're talking about chips with two op-amps. 

Does that help?

[kit102]

Yes, a TLO72 is two complete op-amps on one chip.  Look at some schematics an you'll see things like "IC1A" and "IC1B."  Those two 'triangles' are on a single chip.  A TL074 has 4 complete op-amps on one chip. 

When you see "dual op-amp" they're talking about chips with two op-amps. 

Does that help?

yes it does help. thx.
So, the dual op-amp is something like the TL072 IC?

[moosapotamus]

Welcome to the forum, kit!

Yes, a TL072 is a dual opamp.

So, if in a circuit it need 2 triangle things, can i use one TL072 instead of two?

Yes. That is what they are for.

There is the same for TL074CN, but TL074 got 4 set of I/Os. Would that cause any problem if I use up the 4 sets of I/O? (May be not stable? or low output signal?)

No problem. Again, that's what they are for.

You did not say what you are building. But, it can sometimes be better to use separate opamps. For example, if you are using one of the two opamps in a TL072 to buffer the power supply, it might be a good idea to NOT use the second opamp in your audio path... could get some unwanted noise. So, you would use a second TL072.

But, if you are using all of the opamps for audio, the above is not really a concern. A quad opamp like a TL074 is a great choice for a small mixer circuit.

another question: what's means dual op-amp?

TL072 is a dual opamp... two (2) triangle things.
TL074 is a quad opamp... four (4) triangle things.


~ Charlie

[kit102]

You did not say what you are building. But, it can sometimes be better to use separate opamps. For example, if you are using one of the two opamps in a TL072 to buffer the power supply, it might be a good idea to NOT use the second opamp in your audio path... could get some unwanted noise. So, you would use a second TL072

But, if you are using all of the opamps for audio, the above is not really a concern. A quad opamp like a TL074 is a great choice for a small mixer circuit..[/quote]


Hey, Charlie, nice to meet you! I am building Shred Master now, but in a planning stage. I am actually newbies in DIY. I built electra distrotion and MXR Disotrtion + in the last week but I am not satisfied with the ouput of these two effects so I try the shredmaster, a more power full one . It  is a complicated circuit to me, so a planning must be done before solder on board.

[Mike Burgundy]

While we're picking nits, let's not forget it's often easier to do layouts for dual opamps than for quads, even if an equel number of opamps (4, 8, etc) is needed.

Kit, welcome to the DIY community. There's a wealth of information here, read all the beginners sections, work through the links, perhaps do a search on the forum for electronics basics and tutorials to get you started. Good luck, and happy building!

[Dave_B]

So, the dual op-amp is something like the TL072 IC?

Yes, that's correct.