hi, new here.

into some hobby electronics. so, im sure i will not be a good "community member" here, as i dont have much ability (knowledge) to answer many questions. (my main hobby is gun collecting/smithing, so if you have any questions on that....... )

any how, i have just started building a small guitrar amp and distortion circuit from some old plans, and while searching for a lm383 and a rc4739, which apparently dont exist any more, came across a few electronics forums (this, obviously being one of them) and found out what i needed to know (the current prod substitutes)

so any way, i decided id join up, and, here i am!!!

 

Hi and welcome to the forum.

I have some advice that might help you in the future. When asking questions on a forum, use a descriptive tital and give as much information as you can.

What do those ICs do?

Do you have the datasheets?

What circuit are you planning to build with them, could you please post the schematic?

I found using Google that the LM383 is a 7W audio amplifier IC, how about replacing it with the TDA2003? I probably isn't a direct replacement but it'll probably do.

I found that the RC4739 is a low noise op-amp, what about using the TL070/71/72/74 etc?

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no questions, just introducing myself

found the answers i needed in past posts.

yup, i found some tda2003's to replace the 383's, and found some 4558's to replace the 4739. turns out i already had some of these lying around

the 383 was for a small amp im looking to put together. the current living conditions have me with attached neighbors, wouldnt appreciate me using the big guy. the 4558 is a dual op amp, it for a selectable distortion cuircut inside the amp, it an, iirc, "ultimate fuzz" plan.

like i said, im not too knowledgeable on the design front, so i dont know if an op-amp is called for in a cuircut, if i can replace it with just any, or what parameters to look for. most of this kind of info is over my head, for what im doing. thats why i was searching on the net!!

 

Most NOOBs make amplifiers with extremely high distortion. I guess that is how GEETAR fuzz circuits were born.

I like to make amplifiers with distortion so low that it cannot be heard.

The Fuzz Face circuit is popular in Google. There are old ones with old germanium transistors and new ones with new silicon transistors. They both sound horrible.

The LM386 is a little amplifier IC that is still made.

__________________
Uncle $crooge

 

What's an fng?

 

Go for the TL072, it's pin compatable, lower noise, has a larger bandwidth and a faster slew rate and is probably easier to get hold of than the 4558.
http://focus.ti.com/lit/ds/symlink/tl074.pdf

__________________
I also post at the following sites:
http://www.stop-microsoft.org http://www.heated-debates.com
Screen name: Aloone_Jonez
And http://www.silicontronics.com, same screen name as here.

 

f***ing new guy

 

i plan on having the distortion circut by-passable, so it can go clean too.

looking at the info now. the distortion is the "ultra fuzz" it dosent use diode clipping like most, and one of the op amps is set up as a comparator, so when the input falls below a certain level, it cuts out, eliminating excess noise.

its stated in the info as a circut that actually transforms the wave rather than applying distortion to existing waveform.

 

actualy had a few 4558 in the parst box. the distortion cuircut is actually the only part thats done so far. i breadboarded it and it sounds diffrent, thats for sure, hooked it up to the smaller amp i have to see how it sounds. it need a little tweaking, but i added a pot and put a cap in 2 unused slots in the ic socket, these are the fixed parts that the troubleshooting says may need to be changed out to achive optimal performance.

waiting on my 7watt anps (the 2003's) from ebay to try out the amp circuit.

 

Oh....so it is what I thought it was lol.

 

Yep, have used them myself to re-create my own version of the Ibanez Tube Screamer, substituted silicone diodes to germainium to get a better "crunch" but
you have to be careful with shielding, track spacings etc.

TL072's are also cheaper than 4558's!

There is no substitute for a valve guitar amp!