Converting positive ground pedals to negative ground...pros and cons?

[skiraly017]

Really just starting to dig into Tonebenders. Are there any drawbacks to converting to a negative ground? Also curious about RG's +/-9v from the same battery using a MAX1044. Any and all feedback, suggestions and general input would be greatly appreciated. Thanks.

[FlyingZ]

I recently converted my Tonebender to NPN because of strange volume drops even when bypassed. It lost some of the sweetness when rolled way down but otherwise the same. I used ECG103 transistors.

[Processaurus]

Using the Max 1044 is an excellent (and amusingly hi-tech) solution to externally powering ancient PNP fuzzes.

[R.G.]

Really just starting to dig into Tonebenders. Are there any drawbacks to converting to a negative ground?

Yes. Sometimes this works great. Other times there are intractible hum and noise problems which can only be cured by converting it back to positive ground.

The fact that sometimes it works is what keeps the people who have been lucky suggesting it to people who haven't tried it yet.

Do a search here on "positive ground" postings by me.

Also curious about RG's +/-9v from the same battery using a MAX1044.

Works just fine.

[Paul Marossy]

I built the negative ground version of the "Boutique Fuzzz Face" that was available at GGG at one time - it works and sounds great!

Too bad it's not the same story for some other positive ground pedals... 

[petemoore]

  Make floating supply voltages like the Spyder. Lifting the ground connections in this way supports most of your power supply needs and defeats [most/all] effect PS problems.

[liquids]

It's easy to get an LT1054 and just convert the +9 to -9.  The LT1054CP is cheaper than MAX1044, is available from smallbear (etc.) for $1.70, does not whine due to it's frequency being way above audio, and it's easy to use.  The MAX1044 will do here too, if that's what you have already.  'Ground' then stays the same, but is now more positive than the voltage supply....best of both worlds.  You only need to look at the datasheets for each to find out how to keep ground as ground and turn +9 into -9.  Easier than doubling voltage, even.

No drawbacks to speak of.  Only 'negatives' are the added space the chip and caps, and the minor cost, which is actually still cheaper than the cost of one or two 9v batteries. Space on a Fuzz Face or Tonebender board is usually in abundance since the circuits are so simple, so that's negligible.  And being able to run off the same wall supply is priceless to me, and means either one less wall wort to manage, or fewer batteries purchased and disposed of. It will yield more consistency to your tonebender tone than using a battery.  If you do like experimenting with  'sagging' voltages, you can always add a 'devolt' type control....which means you can even cget that lower voltage consistently. 

I was really avoiding fuzz faces, germanium, and anything PNP in general, until I realized how easy and reasonable in cost this solution makes it, once R.G. confirmed things will work quite simply this way.  It makes working with PNP less problematic, and now I can effortlessly enjoy tinkering with germanium.   Cheers to that!   

[skiraly017]

It's easy to get an LT1054 and just convert the +9 to -9.  The LT1054CP is cheaper than MAX1044, is available from smallbear (etc.) for $1.70, does not whine due to it's frequency being way above audio, and it's easy to use.  The MAX1044 will do here too, if that's what you have already.  'Ground' then stays the same, but is now more positive than the voltage supply....best of both worlds.  You only need to look at the datasheets for each to find out how to keep ground as ground and turn +9 into -9.  Easier than doubling voltage, even.

No drawbacks to speak of.  Only 'negatives' are the added space the chip and caps, and the minor cost, which is actually still cheaper than the cost of one or two 9v batteries. Space on a Fuzz Face or Tonebender board is usually in abundance since the circuits are so simple, so that's negligible.  And being able to run off the same wall supply is priceless to me, and means either one less wall wort to manage, or fewer batteries purchased and disposed of. It will yield more consistency to your tonebender tone than using a battery.  If you do like experimenting with  'sagging' voltages, you can always add a 'devolt' type control....which means you can even cget that lower voltage consistently. 

I was really avoiding fuzz faces, germanium, and anything PNP in general, until I realized how easy and reasonable in cost this solution makes it, once R.G. confirmed things will work quite simply this way.  It makes working with PNP less problematic, and now I can effortlessly enjoy tinkering with germanium.   Cheers to that!   

Power supply compatibility was my biggest question. I've been reading articles about how sometimes converted positive ground pedals may not play well with others when using the same power supply but it sounds as if the LT1054CP/MAX1044 may be the solution to that? Thanks for the input guys.