BOSS GE-7 IC Change, yet again

[solarplexus]

Hi,

I want to change the IC's in the BOSS GE-7 and from your last posts there is some confusing information.  I would need to know which is the BEST IC between the TL072 and the NE5532 for noise reduction in the GE-7.  Indyguitarist changes the ICs to TL072s but some people say the NE5532 is better... make up your mind and reply!

Thanks

[cd]

Neither, only vintage JRC4558Ds pulled from old clock radios should be used.

Seriously, either the NE5532 or TL072 will be an improvement.  You'd be hard pressed to tell the difference between either.  Use whatever's cheaper.  Use sockets so you can plug in different opamps.

[solarplexus]

Ok....

So WHY would Indyguitarist sell a DIY kit for IC replacement, as well as Tonejam, when changing IC's (well for the Indyguitarist mod, I don't know about the tonejam one) isn't improving the sound at all (well according to cd)?  If it does not reduce the hum, people out there, (as well as my little person) is being ripped off big time with these mods!

Anyway, any other reply would really be appreciated.

[cd]

Re-read my post.  I said changing the ICs to EITHER chip type will BE an improvement.  Less hum, less noise - well, listen to it before and after.  Or use the search engine.  IME you'll get less noise (I used 5532s myself), but a graphic EQ itself is an inherently noisy device, so don't expect miracles - i.e. if you have things cranked into an extreme V shape and it's noisy, it'll still be noisy no matter what mods you do (well, I suppose you can bash it to bits with a hammer, then it won't be noisy, but you won't get any sound out of it either.)  You'd do better to replace the input preamplifer first, which is pretty crappy spec-wise.

Why are people selling DIY kits?  Do you need to ask?  Even if the mods do nothing (which is not to say they don't), doesn't it make you feel better to know it's supposed to do something when you part with your hard earned $ (especially when it's parts you can get for a fraction of the cost from Mouser, and information you can sift through here for free)?  Use four sockets and buy different types of opamps, then all you have to do is plug in and out (and use your ears, of course).

[TheBigMan]

It depends how you define improving the sound.  Both the TL072 and NE5532 have considerably less noise than either a 4558 or the TL022, both of which are in the GE-7.  NE5532 probably is a little better, but it's generally slightly more expensive than a TL072 (not by very much though) and consumes more power.  I've had good results using TL072s.

[solarplexus]

Thanks cd for the post

that is one reason why I want to mod myself instead of buying DIY kits... I believe there IS a kind of ripping off included... it's easy to make people think the mods does good things.  I have modded many pedals myself and rarely used the same parts as some DIY kits, because honestly, they do not sound as good as they could if you use all the parts included.  I believe people should be more informed on DIY kits and modifications not to get ripped off... cause I had been ripped off in the past... well... we all learn from our errors! I guess

[cd]

I believe there IS a kind of ripping off included... it's easy to make people think the mods does good things.

Ahem.  Let's not open a big huge can of worms here.  Statements like these can get ugly real quick.  Suffice to say, welcome to the forum - use the information you find here in good faith, spread the wealth & knowledge, and help out whenever you can.

[solarplexus]

yeah, well I'm not trying to disrespect DIY kits.  I have bought some that made me very satisfied, others not so much.  Just buy from reliable sources

[Joe Kramer]

Hi!

I don't know what op amps are in a GE-7, but what kind of improvement are you looking for?  What kind of noise problem are you having?  If you are getting hum, that's not likely to be an op amp but rather a grounding problem or an external supply problem: batteries don't hum.  If the problem is hiss, that's the downside of EQs and boosting the high frequency bands.  Besides, a TL072 is not going to beat a 4558 in the hiss department: voltage noise of 13 versus 2, respectively.  A 5532 will be a little quieter than both those and produce a lot less distortion (in the technical sense), but if you are using a battery, 5532's will drink them dry in no time.   The whole circuit might sound worse because 5532's need a lot of current to perform.  FWIW, I would leave the op amps alone.  If you really want to improve the sound of that EQ (or any EQ) replace the filter/signal caps with polypropylenes!

Regards,
Joe

[solarplexus]

yeah, well I'm not trying to disrespect DIY kits.  I have bought some that made me very satisfied, others not so much.  Just buy from reliable sources

[Joe Kramer]

Hi again,

If there's a TL022 in that EQ, there's your noise culprit: a voltage noise of 50!  An op amp like that should never be in the signal path of an audio device.  It was never intended to be.  Change that one to 4558 (or 1458, my fave) and it'll be quieter by 75%.

Regards,
Joe

[solarplexus]

Kramer,

their is no hum from the pedal from bad ground, I just want to improve the over hum from what is found from the parts in the pedal.



Also,

for everyone else out there.... How much IC's can I change to improve some of the hum?? 3?? 4?? 5?? 6?? 56 ??

[Joe Kramer]

Hi,

Remove all the opamps carefully, put in sockets, test as many different  opamp types and combinations until you are happy with the sound/noise level.  Get back to the forum with a report.  Then you'll be the resident GE-7 upgrade expert!

Regards,
Joe

[amz-fx]

The TL022 can certainly be a source of noise...  the TL072 will be better and the TL052 even more so.  The 5532 will be quiet but will likely draw a lot more current.

regards, Jack