IC replacement, need help

[solarplexus]

Hi,

I am a newbie here but I've been looking on this site for about a year now, so I know the basics of electronics, made many mods to my pedals and now want to mod my amp.  So... I am looking at my amp today and see that there is many IC's in the circuit.  I would like to replace them all with a quieter model.  The first one has these written on it:

0720
   JRC
 30468

And the second one:

0720
   JRC
 30148


I don't know if you recognize any of these IC's but anyway, just wanted to ask you to see if they can be replaced with quieter IC's to clean my amp signal.  The amp is a SGH, a copy of a marshall head, which sounds pretty amazing for the price, but is quite noisy.  Anyway, thanks for any suggestion you may have!

[ninoman123]

Looks like the basic 072 package.  As for making it quieter....you might want to elaborate on where ur getting noise...are u getting like a buzz while ur not playing on the clean? If its humming thats a problem but usually with all amps there is some background noise when not playing.  If you are using a single coil pickup those tend to be noiser. You could also shield your guitar.  I dont think changing op amps would make much change at all. Maybe some others would know better than me.

[solarplexus]

Hi,

I don't get any noise from my guitar, I have a pretty noiseless setup.  I use a single coil on my fender strat 75, and a seymour duncan on my godin.  Even with the single coil in my other amp is pretty noiseless.  The hum is from the distortion channel in general, but I thought that maybe if I changed all the IC's in the board, I could increase the overall tone.

Anyway, if anyone has any other suggestions, please go ahead.

[niftydog]

they are both the same type of chip. The 072 op amp is already a reasonable quality op amp. In fact, they are called "Low noise J-FET dual op amps" in most data sheets.

The distortion channel is noisey because it's high gain. I feel that there's not much that can be done to improve that.

[Steben]

A better quality guitar (or even better: pickups!) can make a lot of difference too. Don't blame it always on the amp, nor single-coils. Humbuckers tend to sound more noisy in fact, but less humming. Don't mix up hum with noise.

[ninoman123]

Make sure you arent playing close to any monitors. TV or computer, they cause noise. Also those florescent (i think thats spelled wrong) lights can cause noise. Also my brother uses this machine to help clear out his lungs. If i play while thats turned on it picks up some background noises too.  Tons of stuff causes noise. I dont think its your amps problem...Maybe buy a boss noise suppressor. I have one and it makes my distortion channel nice and quiet, but you lose sustain in the process too.

[Joe Kramer]

Hi,

I don't get any noise from my guitar, I have a pretty noiseless setup.  I use a single coil on my fender strat 75, and a seymour duncan on my godin.  Even with the single coil in my other amp is pretty noiseless.  The hum is from the distortion channel in general, but I thought that maybe if I changed all the IC's in the board, I could increase the overall tone.

Anyway, if anyone has any other suggestions, please go ahead.

Hi!

I have a cheepee s-s Peavey that improved in tone when I put in 1458's (JRC, FWIW).  They sound a bit thicker in the midrange and not so scratchy on top.  The overall gain is a tiny bit lower.  No problem with noise.  To my ear, the 072's sound thin and scratchy in everything for guitars.  Just my two cents!

Regards,
Joe

[ninoman123]

I had a bass amp that had 3 072s in it that I replaced with low noise fet opamps from TI. Opa2111kp or something like that. Made no difference in sound to me.