Boss GE-7 Mods

[Voxin]

Hello all, are there any Boss GE-7 mods out there that will make it a bit quieter?  I have noticed a mod on eBay from Monte Allums...any thoughts?  Thanks!

[Voxin]

The more and more I read the more confused I am...I understand that changing the Op-Amp chips will make a difference but I've also read that changing the capacitors to higher quality caps won't make an audible difference.  Is this true?

[Thomas P.]

maybe, but I guess "higher quality" is often mixed with "high-priced mojo"!

But I don't see what's confusing you? Because changing opamps can make a difference doesn't tell anything about capazitors.
Changing the opamps could make a difference - there are very fine devices out there with incredible specs (and prices!), but one has alway consider the use!

[Voxin]

Sorry about that, I was confused about Caps.  I've just read that in order to do a mod to this pedal, the op-amps need to be changed along with the caps.  I was just thinking of changing the op-amps to lower the noise level but was wondering whether or not changing the caps would make a difference. 

[wampcat1]

Sorry about that, I was confused about Caps.  I've just read that in order to do a mod to this pedal, the op-amps need to be changed along with the caps.  I was just thinking of changing the op-amps to lower the noise level but was wondering whether or not changing the caps would make a difference. 

There should be a TON of threads about this (see search button). An opamp change will do a little, but won't perform any major miracles. Changing the caps...I wouldn't mess with it.

bw

[Meanderthal]

 True, if ya go around changing the caps in an eq you might wind up equalizing frequencies far different than the ones marked on the sliders... Unless they're really old and rotten the caps most likely are not the sole cause of noise anyway.
I'd love to get a peek at the schematic of the old 6 band mxr blue eq with no switch... I had one of those many moons ago, and it was silent, and one single battery lasted me about 2 years. Whatever those things used worked very well.
I use an old Ibanez series 10 bass eq that adds no noticable noise. When I opened it up I noticed it was full of jrc4558 opamps, and they're not known to be particularly low noise. That's why I say an opamp change might not fix it...

[Mark Hammer]

There is a nice article about op-amp choices in here: http://hammer.ampage.org/files/Device1-8.PDF

Now, keep in mind the article is from 1979, so the choices available were vastly different.  Still, some of the choices THEN are current choices, and the basic principles still apply.

[petemoore]

  I got an EQ700, seems like it's less noisy than the Boss...Was...never did I A/B...I read that somewhere and it seems' like it too.
  I used power supplies back then, since then I've upgraded that componentry to a VS One Spot, and this reduces, or eliminates HuM...*large noise reduction in hum, *because I had alot of it W/other adapters.

• Eq's are 'naturally' a source of noise, because there is multiple gaining up and 'filtering out' of the signal.
    Whether opamp choice will reduce it is questionable, I would guess Boss puts modern 'fairly low' noise OA's to begin with...maybe there's a "little bit of noise reduction modding room in these components, probably very little...one way to find out for sure...if you have two 'nearly same noise level' GE7's and 'modd trash' out of one, then compare. 
    GE-7's are not known to be low noise effects, so there is room I guess to improve..but again
• .
    This EQ noise issue has come up here before, I remember reading similar posts on the matter...but don't remember reading any 'schizzaammm-sure-fire' noise reduction post[s.
   

[Voxin]

Thanks for the article.  I think the more I read about this topic the less I want to mod the pedal.  I don't know if I would notice a huge difference with swapping the op-amps out because the EQ only bothers me when I use a heavy distortion, other than that the EQ is fairly quiet.  How are you liking the One Spot?  I have a signalflex adapter box on my board and it's quieter than using wall warts, but i've always been curious about the One Spot.

[petemoore]

How are you liking the One Spot?
  I'm liking the very low/no noise 1700ma of power supply the one spot supplies,
  Bill then bought one, at that time having plenty of noise to contend with, and offered this: "Best money I've ever spent on a power Supply".
  ...Very 'quiet'...I can barely tell it from batteries with an 8-10 circuit daisy chain.
  The sheet from VS purports the 1spot as capable of powering Line 6 ToneCore pedals, IME it is not.
 

[Mark Hammer]

Keep in mind that the intrinsic noise properties of an op-amp start to matter more as:

1) the gain you try to squeeze out of it is higher

and

2) the bandwidth requirements are greater

So, if you don't expect to apply much gain (e.g., x3), and you're happy with 8khz usable bandwidth, then noise specs don't matter that much since the brunt of the noise will be from either what you feed that circuit with or from what you do to it after the circuit in question, or both.  If you have some sort of low-gain stage that you are expecting to deliver a full flat 20khz bandwidth so that you can process lute/harpsichord duets and get every finger gliss and string pluck during the quiet parts, then you'll want to be sure that the op-amp does not contribute much hiss to contaminate that silence.

If you expect to make a mic preamp for sampling sound sources in the field, and you will need to produce 40db of gain with at least 16khz bandwidth, then will want to make damn sure the op-amps are as quiet as they can be because you can't squeeze any more input signal out of the mic than it can produce, and maybe you can't get the cricket to move in a little closer to the mic to help out.

If you are making a high-gain distortion unit, and will be trimming a lot of the upper treble fizz to get a warmer sound, you will also be trimming back a lot of hiss at the same time, so low-noise op-amps will not make that big of a difference in what you end up hearing.

In the case of EQ pedals, it will depend on how you expect to use them.  Some people try to use their EQ pedal as a selective booster and situate them early on in the signal chain where and hiss they contribute is magnified many times over by later stages.  Others prefer to use their EQ pedals as room-resonance control, primarily in the cut mode, much farther along the signal chain where the signal is already hot, plenty noisy, and unlikely to be further boosted before hitting the amp.  IN the one instance I can see a greater need for lower-noise specs than the other.