Is there anyway to make the dd3 less susceptible to noise using non boss adapter

[Belanger]

So I have my friends old dd3 here and he thought there was something wrong with it because it made a really high pitch sound everytime he engaged it.  Through the forum I figured out it was the adapter that was cAusing the problems and having it plugged in here(I have a boss branded adapter) everything works fine.  Is there anyways I can make it so he can use other adapters with it and not have this problem.b he uses a power supply to power his pedal board and wants to avoid having to carry Around a wall wart

[Mark Hammer]

I am guessing it is a switching power supply - i.e., a small thing that puts out a lot of current in a fairly small and light package?

Such PS use a clock internally to "switch".  That can interact with the clock in the pedal, and create a certain kind of buzz.  Other non-Boss wallwarts can probably do the trick, as long as they provide the right voltage and current and the plug is oriented the right way (outside pos).

That doesn't mean that ANY such supply will be quiet.  Inside those black blocks of plastic can be many different degrees of regulation.  Heck, sticking a single diode in series and running a 47uf cap to ground from the positive side of the diode can technically count as a "DC supply" though it clearly won't provide nearly smooth enough power for audio purposes.

So, what you will want/need is:

• something meeting the voltage/current needs that is well-regulated enough to not provide any hum
• something that will not heterodyne with the clock in your DD3

[Transmogrifox]

If you're into hacking into the cable then you can help it with
1)  Put a common mode choke inline with the cable.
2)  Add a series inductor for differential rejection.
3)  Low ESR capacitor bank of something like 3x470uF caps on the side of the filter feeding into the DD3.
4)  470uF cap upstream the filter to soften transient current hits from the DD3.

Inductors and chokes can be cannibalized from most consumer electronics that plug into AC outlet (wall) power as you might find at goodwill...like a cheap boombox or a printer or something.

Another thing that can cause switch-mode power supplies to create audio-frequency noise is control-loop instability or transient response.  A digital effect like the DD3 will act like a hammer that keeps ringing the bell and the 2 loads make noise together.  It's not the digital circuits in the DD3, but if it gets 9V in it has some kind of switching buck converter to convert the input 9V to levels that the DSP chip uses.  This translates to relatively low frequency pulses (low frequency < 1MHz)

If the power supply is unstable you might be able to stabilize it by adding a dummy load (resistor) and/or extra load capacitance.  Often a large load capacitance acts to form a dominant pole in the loop gain response while the additional (resistive) load adds some damping.

If you want to just build a clean power supply box, then use a 12V -15V wall wart and regulate that with a linear regulator and a good-ish sized capacitor bank (470uF min).  That would probably help quiet things down.

You could go to Goodwill (or similar) and get a pile of 9V regulated supplies and start trying them until you have something that doesn't cause the noise.

The question is -- do you want to spend money or time?  The easy route is to buy the Boss supply and a power strip so the other power source can be used with pedals where it doesn't matter.

[Belanger]

Ok so I'm going to run all of this past him and let him know the possible options and see just how bad he wants to avoid this boss adapter.  I don't mind putting in the work because it's fun for me  , but seriously. I don't think it can be that bad having to carry around a extra wallwart with your pedalboard. I would probably not of purchased a boss delay to begin with but eh, that's just me.  At this point personally I'd sell the thing and put the money towards a dispatch master from EQD or any of the other countless great pedals out there

If he wants it done then I'll update the post and let you know how it turned out

[R.G.]

I run into similar issues a lot.

Digital pedals that use a lot of current also generate a lot of current noise on the ground lines. It is very common for this to cause interactions with other pedals and amps.

Sometimes filtering helps. However, it is **very** difficult to filter a ground wire.

[Mark Hammer]

Can't a choke on the ground line help? (he asked naively)

What do any of the power conditioners like we see from Furman and others do? (i.e., what sort of general strategy do they use?)

[slacker]

Whats his power supply? Does he have the problem if he uses the DD-3 on its own with his power supply, or only when using it with the rest of his pedals? What are the rest of his pedals?
With the info we've got so far there's not enough evidence to say whether or not the problem is with the DD-3 itself.

[R.G.]

Can't a choke on the ground line help? (he asked naively)

It depends on where you want to get your noise from; it's all about which wire carries the pulses, and how it's connected up.

If you have a power supply connected to two things, one of which is quiet, but amplifies, and another thing that doesn't amplify much, but puts lots of noise on its local "ground", you have an issue if you then connect the quiet thing to the noisy thing with a cable that has a "ground". If they both share a wire going back to the power supply, the power pulses cause voltages on the ground wire that they both get. That may be a problem or not, depends on whether and how much they reject their own ground noise.

If the "ground" between the two carries noise pulses and you put an inductor between them, the inductor causes the noise to pile up on the generator side, being impeded from crossing the inductor. Whether this makes the noisy thing noisier, the quiet thing noisier, or the combination noisier depends on which side of the choke is connected back to the presumably quiet power supply.
If you fence the noise pulses out on the power side, then they can still get to the quiet side by coupling through the signal ground.

The real answer is to make there be a nice, tight loop inside the DD3 (or other noise generator) that lets the noise circulate in a loop inside it, instead of being forced out on shared ground lines. Forcing the noise to stay on one side or the other of an inductor may not be much help, depending on where the other things contact the noisy ground.

What do any of the power conditioners like we see from Furman and others do? (i.e., what sort of general strategy do they use?)

Not much. If it's the Furman I'm thinking about they're trying to keep noise from the AC power lines out. That's a bit different. There is a transformer of one kind or another between the power lines and the end user unit. So AC line conditioners tend to use capacitors between the two AC lines and between both lines and safety ground. That's an attempt to shunt noise between the wires before it can get across the transformer. They then use a common mode choke to impede noise from getting into the powered equipment's transformer, and often another stage of each capacitors and common mode choke. They usually have three or more MOVs to each high-voltage transients as well. Some few of them will use isolation transformers with a grounded shield between primary and secondary.

There is a good answer to isolating AC power line noise, but it's not popular. It's the ferroresonant, or constant voltage transformer. These use the AC line to pump up a big resonant circuit, then power is taken out of the resonance to the secondary. They're deadly effective for line noise - but heavy and expensive.

[PRR]

> What do any of the power conditioners like we see from Furman and others do?

Cut the crap from elevator and A/C relays, fluorescent ballasts, etc from the AC power wave. As R.G. says, caps, maybe chokes, and the heavy ones add isolation transformer to cut-loose from some ground crap.

Ideally they deliver a pure 60Hz sine. Which is of course an audio (bass) note. And subject to re-mangling by rectifiers and switchers on "our" side of the Furman.

Looking broadly: the history of technology has been for many years the history of Power. From man to horse to water to steam Diesel turbine. Electric delivery of Power opened many new fields. Short-sighting your power system may not be the best path.

[Tony Forestiere]

Honest suggestion: Have your buddy drop the $40 or so bucks for a One Spot Combo Pack. 1700Ma of very clean power. I am running two power hungry digital delays (one being a DD3), a DS-1, and the two 1/8" adapters allow me to use my Rev. J Small Stone and my old BMP. My "studio" is over the main garage which is filled with florescent lights. I have no issues with noise, high frequency squeals, nor hum.

This is not shameless ass-kissing, but a strong recommendation of a well executed and value driven product. Heck, even Wally World carries it for around 30 bucks: http://www.walmart.com/ip/24191956?wmlspartner=wlpa&selectedSellerId=12&adid=22222222227018322627&wl0=&wl1=g&wl2=c&wl3=52320814215&wl4=&wl5=pla&wl6=79420939815&veh=sem