fernandes sustainer guitar run off of an AC adapter (wall wart)

[petey twofinger]

i got one and it seems to eat batteries . its actually a fernandes , i think its an older model revolver . it doesn't have the harmonic mode , just on off sustainer . i THINK the pu's are active though ... not sure . either way i have a THING about small batteries , and i have a collection of sla 12 volters , 2 deep cell gell cells , 2 reg deep cells , etc . i REFUSE to use small batteries , period . but i am kind of a goof when it comes to knowing the ins and outs of this stuff , i need to learn . always worried about frying stuff , cause i did once 20 years ago plugging a boom box into a cig lighter in my car ...

i made a mini amp with a 12 volt sla in it , there is an automotive phone charger type teansformer that i cut in to get 4.5 volts for the korg pandora that is the amps front end . i also have ac in it with ac adapter , 4.5 volts for at home .

i was thinking , can i do the same thing , get a coupla adapters for 9 volts , one dc adapter , like a phone charger , then a 9 volt say 300 or 100 ma wall wart and have thhose power the sustainiac circuit .

ideally i would figure out a single cable set up , like hack a 3 conductor mic cable , then run the dc on the ring or  something . of course i could blow something , unless i got a proper slow blow fuse or switch (preferably not in the guitar) . i am concerned about audio interference though . dont really want to go thru all the hassle and then find out it wont work .

anyone mess with this idea before ?

what should i do ?

i do have a long length of shielded 4 conducter cable , i could go standard mono 1/4 inch the have lil power wires come outta the back of the jack into some lil 2 conducter clips . something cheesy . but ..

i tried a few power supplys using a 9 volt battery clip tonight with different results . some seemed to make the sustainer too strong , like all the strings were singing loudly . when i had run it , the battery wasnt fully charged and it worked well , but one string at a time . curious about this , is it the milliamps rating or the volts thats gonna make it work harder , it was tought to determine what was going on . some power supplys , the one was a multi voltage , i could set it at the 4.5 volt setting and it still sang , yet the lower voltage 9 volt battery didnt work . also could i lower the sustainer pick up ? it is kinda high . i guess it would be neat to use the adjustable adapter and have different settings , but i do not want to over power or harm the circuit in ANY way !!

anyone ran one of these "hot" like with too much voltage ?


hmmm , i am really outta my league here . i looked around online , didnt find much . the sustainiac page says use a seperate cable to feed dc . it also says NEVER have the auido ground and the dc ground connected . when i used my meter i got continuty between the neg battery terminal and the neg guitar auido jack ... seemed a contradiction , but this is not a sustainiac product , its a fernandes , they are different , correct ?

like i said , i am such a goof , thanks in advance !!!



oh yeah ,  i also sent psw a message .

[ashcat_lt]

This kind of thing keeps coming up, and the big problem always cited is the possibility of a short while plugging.  Can anybody provide a fairly simple current-limited power supply circuit so we can put this thing to rest?  I suppose the sustainer will want more current than most other on-board effects, but...

[gritz]

Yeah, custom leads are a faff, especially if you play live and don't have a spare...

Maybe a rechargeable battery pack mounted on your strap (wireless transmitter style) would be a workable compromise. A 7v2 NiMH and charger robbed from a radio control car / plane perhaps (I have an old radio that I've done this to). Just be aware that these batteries can kick out a lot of amps when shorted, so take appropriate precautions.

Hope this helps.

[FastJunkie]

Perhaps a bit overkill, but would work nonetheless:

Replace your 1/4" jack with an XLR and run that into a box that simply pass the signal through and puts 9vDC through the 3rd conductor.

[petey twofinger]

the rechargable nihm was my original idea . plus i have everything to do it here . got a 9.6 volt nihm and a charger from resale for super cheap . different manufacturer so there is some connector hacking to do .

it just seemed kinda clumsy , also i was concerned about the battery life on the nihm cell . i guess i should start doing this one step at a time . cut the power input into the guitar and go from there . i admit i didnt think about the possability of shorting that battery , good point that i overlooked . any suggestions on that concept ?

i am guessing a fuse , which brings me to the question of what value and type .

the most logical thing at this point is to put a separate input connector for the dc in on the guitar , close to the audio jack .

the nihm cell is a lot larger than a 9 volt cell , but dang is it light weight . i will start here , thanks .

[space_ryerson]

I've had some decent luck with 9V rechargeables (sized like a normal 9V battery) and my sustainer (non fernandes guitar). You could use two 9V rechargeables in parallel inside the guitar to get more time before needing to recharge.

[petey twofinger]

not sure if this nihm cell is dead , but i dont have the legit charger . it read 9.4 when i got it . recharged it , ran it foer 5 minutes and it was 8.44 charging it now at 10.55 volts and i show 13 ma currant running as it charges .

i also built a 809 regulator circuit and put that on the 12 volt sla inside the amp , then got an ac adapter , 12 volts 300 ma , they are on a switch and they run thru the regulator .

i used some xlr cable 3 conductor , and i have 2.1 mm dc connectors that come out of the 90 degree  1/4 jacks . it works , but on high gfain patches i hear a high whistle interferance

surprisingly much less when its runnng off the ac adapter than the sla ...

any thing i could try ?

different cable , ferrite ring on the audio input , filter circuit ?

the 90 connectors i used are really cheep , and i do have some nice switchcraft 90's . the cable looked pretty good shielding . the input jack is an inline one , it doesnt grab too good . i didnt notice till it was done and its a bear to get at it !!

any ideas ?

[petey twofinger]

so i tried using ferrite thingies , i git em off the end of some power supplies . i tried em on the audio input and the dc .

didnt seem to do anything , what did eliminate 99 percent of that problem (high whistling interferance) was cutting the ground wire on the dc out put of the amp . the cable that feeds the sustainer . i cut that ground wire and the whine went away . the sustainer still functions because it gets grounded thru the main audio jack ground .

there is zero hum / whistle or whine when i use the ac adapter that is in the amp , when i run it off the sla battery thru the voltage regulator circuit i made it has LIL interference SOMETIMES , a high whistle / whine . its sporadic , you cant hear it while playing , and it only pops up on super high gain patches . this amp uses a korg pandora going into a ta2024 12 v amp module .

so i can totally live with it .

i charged the 9.6 volt nimh battery i got at 10.5 volts , with an old 9 volt battery charger , and it charged up good this time . i played for a half hour and it only dropped a quarter volt . i just wasnt charging it hard enough before . so i have a battery option too , besides the crap  lil 9volt idea ... i dont care for those lil guys much . they're great in some things but honestly i would rather not , ever .

this wasnt as bad as i thought . gonna make a back up cable and move on to something more interesting .

thanks !!