Hello.

I've been using the L7660 for bipolar power for a while. Was about to order some when I noticed the company had issued an advisory to a change in the data sheet. The datasheet now recommends adding a Schottky diode between the -ve output and ground to prevent latch-up. It says to so this if the rise rate is > 2V/us.

I've one in my Gristleizer and am wondering if I need to do that - I don't really know how to estimate the rise rate.

I also noticed that it recommends to add a 1N4148...

I am looking to make an isolated power supply to replace my current 'daisy chain' setup.

looks good but i have a few questions:

Locally sourced (240ish v ac) transformers are relatively expensive- around 22 bux for a dual 9v tap or 7-8 bux for single tap 9v.
i want to make an 8 outlet supply and so the cost blows out very quickly into the realms of -'just go buy one' territory.

idea #1 : As a cost saving attempt my first idea i have considered is using a 2 amp transformer (out of the wall...

I have a Maestro Fuzz-Tone FZ-1A.

As you know, it runs on one 1.5v battery, and has no psu jack.

I'd like to mod it to run off my pedalboard power, and was thinking about simply adding a 2.1 mm dc jack, then wiring that to the internal battery leads with a resistor inline.

- But now I'm wondering, would this cause a grounding issue with the rest of my rig? Is the Fuzz-Tone circuit simlar to the Fuzz Face, in that the chassis is positive?

Any ideas on how to accomplish what I want?

-thanks.

hi, im making a tonebender, but i want to use my pedalboard power supply, its possible to convert the power to use the normal supply in this pedal???, im using PNP germanium transistor, plus tonepad pcb layout

Any recomendations for a Bench Power Supply ? dont really want to break the bank, but there is alot of crap out there.
power isnt something you want to f*** with :scratch:

Kind of a n00b question, but why when we use a 3PDT do we use one of the poles to turn on/off the LED? Why not instead turn on/off power to the whole circuit?

Hi all,

I have a T-Rex Fuel Tank Classic power supply that delivers 3 x 500 mA from three sections, 9V DC, 12V DC and 12V AC. I have exhausted the capacity of the 9V outlets (I only buy 9V pedals as a matter of principle), and so I wonder if there is a simple voltage reducing circuit that I can either put inside, or piggy-back on top of the Fuel Tank. I imagine T-Rex would just ignore me if I sent such a request to their customer support (or at best they would recommend purchasing another...

Hi,

I'm looking information about how are supply the effectrode pedals. I explain better: The stompbox have 12VDC input but the valves need 300V HT more or less.
I think that they use a Dc to Dc converter but i would like to know the circuit that they use.

thanks people,

I was hoping someone here could clarify a question about the maximum possible supply voltage to an opamp in a single supply design.

The question:
Via an 18V wall wart brick, or two combined 9V supplies from a Voodoo Power Supply, can I safely supply +18V in a *single-supply* design to the power rails of a TL071 or TL072 op amp?

The application is any homemade distortion / boost / overdrive pedals that utilizes the above opamp. All the capacitors have at least a 35v tolerance, so this...

Hi, I looked quite a bit around the forum to see if this been discussed before but couldn't find any very relevant topics.If I'm mistaken please refer me to the older thread an delete this one :) .

I built a Ge Fuzzface for a friend and he likes it a lot but asked me to make it run with the standard +9V dc supply, if possible.
Of course the circuit is with PNP transistors and positive ground,so I was wondering if there is a standard layout for reversing the polarity from +9V to -9V and add it...

Hi
Anyone know the layout of these types of adapters to isolate an output of a daisy chain?

Regards

People, how are you?

A small query, I have a 9V and 18V source, put it in a box 125A or 1590B, and pierce the box for different outputs, would say 6 and 2 9V 18V, buy it and a source of 20 VDC and depart that for the 9V and 18V outputs filtered to the pedals.

Consumption would have a total maximum of 1A, will that could help me with the circuit?

If you could give me a hand with this, I would greatly appreciate it!

Cheers

I want to merge an old Marshall Lead 12 (3005, schematic ) preamp with Taylor's (from DIYSB) Tiny Giant amplifier ( schematic and info ). What disturbs me is that TG is a single-rail amplifier, and the Lead 12 preamp is designed for dual-supply use. I'll be using this setup with a regulated laptop power supply, because I don't want to mess with transformers and stuff like that. How should I deal with the supply rails difference?

Hi,
I've been really getting into building circuits on vero board lately and its really the first time I have done anything that doesn't have complete wiring layouts and such. So far so good, but I have a question regarding a power filtering cap and polarity protection diode. I have noticed these in the GGG fuzz face projects and on a few other projects that use fabricated pcbs. I am in the process of building a clone of a colorsound wah fuzz and the perfboard layout I'm following doesn't...

So, I'd like to build the GGG Center Stage Reverb, that uses an actual spring reverb pan.

I'd love to be able to install it into the back of an amp and forget about it. However, it seems the unit would need 18v (or 9v with a charge pump).

My question is this...would it be at all possible to power the reverb using the amp's power somehow? It would be much preferred to running a separate power supply to the reverb in the back of the amp.

I've been eyeing the Pedal Juice (switching adapters create a bad hum for me), but I have a couple of these USB backup batteries around and got this idea. Each one is rated at 5V/1A/5W, so I strung the two together just as a POC.

It is putting out 10-11V, so I should probably add a voltage regulator to be on the safe side (though I did read that the Boss PSA puts out 9.6v...) What do you all think? And is there any low-tech solution for dropping the voltage (diode? series resistor? voltage...

I recently came across some PCB designs of standard old school negative ground germanium TRansistor fuzz boxes wired up with an IC (i believe MAX chips -- can't recall the exact chip part #), but the part of the circuit that filters the power flips the power phase by making a standard positive ground fuzz box like (fuzz face, etc) into a negative ground. Anyone have any thoughts on circuits with this kind of circuit? Do you trade off some quality or any issues with buffering or tone loss? I'd...

Hope this isn't in the wrong forum, if so I apologize.

This is probably one of those 'dumb' questions that will make you question why I'm even trying to hold a soldering iron, but I'm a little unclear about how DC circuits operate with an AC guitar signal.

Since AC is alternating in direction, and DC only goes in one direction, how the heck is it that pedals even work? Wouldn't only the positive part of the signal be amplified/processed, since its alternating directions? How does this keep...

Hi all,

I've finally finished this treble booster and it sounds awesome with a battery but as soon as I plug in my power supply, it makes so much background noise, its unusable. Any clues as to why??

Thanks for your help

I just bought the ModTone PB8 powered pedal board and their power specs don't seem to make much sense. Now, it wasn't my first choice, but I scored one pretty cheap on the bay, so I decided to give it a shot. The wall-wart they included is rated for 450mA at 9v... Fine, no surprises there. The weird thing is that they've given each individual outlet a 100mA maximum current rating. Not sure where that comes from. The outlets are just mounted on a PCB, no extra components besides a resistor and a...

I am looking to combine the two 9vac sources (each have 800mA) from a MC-403 Power Station in order to get a 9vac (1600mA) connection to power my Whammy 5 pedal. I believe if I run this in parallel I will get 9vac (1600mA). Can anyone confirm this for me.

Thanks

Almost every circuit I have looked (if not all of them) have their opamps powered with 4.5v by a voltage divider.

Is there a problem by powering the opamp with 9v?
I mean, for higher thresholds feedback loop diodes (like an LED) it would be better to have 9v on the opamp right? To achieve more signal boost and then reaching the led clipping.

Am I right or this does not work?

Thanks in advance,
Frank

Some time (about a year) ago I bought some regulated 9V adaptors for a very reasonable price. Ideal for stompboxes...I never checked them until I tried to fix a problem with one of my effects while being plugged in to one of those (normally I use a battery when testing) and I got more than 12V from it.

Now I have been using them sometime and none of my pedals seem to be broken or affected by it....but...

What do you think? Can it cause harm using them?

And maybe it's wise to check voltages...

I'm building a fuzz type circuit that'll be powered from an adaptor and a battery, and as the adaptor that i'm using is cheap and noisy i'm going to put the beavis audio 'huminator' type power filter before my circuit. But i want to do it all on one vero board, which means that both the 9V battery and the adaptor will get the filtering. Is there any reason to not do this? like, would it not be a good idea to run a battery through a power filter to power my fuzz or does it make no difference?...

Hello,

I plan on rehousing the preamp board from a Gallien-Krueger 700RB-I to be used as a standalone preamp/DI. (I upgraded to a 700RB-II preamp) Schematic and image of board (RB-I board on top) attached.

I need to feed it 35v and 15v. One thing I'm a little confused about is how the schematic lists the J3 (the connector that feeds the board power) voltages. The -35v and +35v just denote positive and negative right, not some sort of other trickery? If so, why the additional ground?

What...