Built-in Preamp.

I've wanted a booster of some description for my guitar for some time, and finally found this on eBay. For £13 +£5.50 shipping I thought I couldn't go wrong! I had actually bought parts to build a preamp that cost about a tenner, but this was going to save me a lot of headaches.

s-l1600
Currently on sale here: https://www.ebay.co.uk/itm/Active-Onboard-Guitar-Preamp-G-501/272909922087
Sold by Gandalf Electronics
Made by AnalogWorkshop.freecluster.eu

It really was that simple to install. Follow the instructions, which amount to where to solder the wires (ie there are no modifications as such) and you're away.
Of course, I wanted something a little different, so I wired in a push-push pot to turn it on and off and a stereo jack to turn off the battery when unplugged.

On offer is up to 21db of gain which you can set with a PCB-mounted pot.

And it sounds GREAT!
21db is a LOT of gain, so I dialled it down to about 12-15db, which is about right to "push you over the cliff". It goes WAY past 11, but then you could turn it down further to act like a small nudge of gain.

Overall, I'm super impressed. The customer service was fantastic as I got several emails offering help with installation, which I did take them up on. They were very helpful and friendly.

There are two other models for sale : 6db and 28db, just in case you need just a nudge, or you want to "blow the bl**dy doors off."

Comments

  • Kevin PeatKevin Peat Posts: 3,034Member
    What's the red thing and the thing marked EOS ?
  • Kevin PeatKevin Peat Posts: 3,034Member
    edited April 1
    My guess is this. The red thing is a resistor to protect the IC or use one of the caps as a timer with reactance (I think protect the IC.) The thing marked EOS is a pot to wind in/out current. The integrated circuit is where all the gaining takes place through micro transistors.

    I'm still at the kid's electronics kit stage at the moment, I'm afraid. (I know NOTHING, John Snow !)
  • nicholaspaulnicholaspaul Posts: 839Member
    The EOS is indeed a pot. I have it set like in the picture so it's not too loud.

    You're way beyond me. I'm barely an electronics twinkle in my fathers eye.
  • Kevin PeatKevin Peat Posts: 3,034Member
    My guess is that the capacitors are there for smoothing things out.

    Electronics engineers have my total respect.
  • nicholaspaulnicholaspaul Posts: 839Member
    It all looks like sorcery to me. I just don’t get it!
  • Kevin PeatKevin Peat Posts: 3,034Member
    edited April 1
    What looks like sorcery to me is my smart phone. I may as well be a member of a lost tribe in a rain forest as far as techno goes.

    My son said I looked like a monkey with an abbacus when I first got it.
  • Kevin PeatKevin Peat Posts: 3,034Member
    Microchips are made in Israel.

    Happy Easter.
  • nicholaspaulnicholaspaul Posts: 839Member

    Microchips are made in Israel.

    Happy Easter.

    Nice one!
    Happy Easter, Kevin :)
  • Screaming DaveScreaming Dave Posts: 777Member
    Where did you put the battery? I assume it takes a standard 9V?
  • nicholaspaulnicholaspaul Posts: 839Member
    It does. Oh the cavity is big enough to sleep a family of four, so I’m not short of room. All the guitars I built have lots of space for expansion. Strats can be a pain when it comes to hiding 9 volts, but I did take a tone control out in one that left enough room.
  • Kevin PeatKevin Peat Posts: 3,034Member
    I have a *battery* of children.

    The energy comes from all the fighting. Enough to power an army of Duracell Bunnies.
  • Screaming DaveScreaming Dave Posts: 777Member
    I have piles.

    (Joke for all you French speakers)
  • DaveBassDaveBass Posts: 3,311Member
    The chip's an NE5534 low-noise high-speed op-amp. An op-amp is basically a chunk of gain (typically 100 dB or so). You wrap passive components (resistors, capacitors) around it to define what you want it to do.

    The blue things are electrolytic capacitors and the red thing looks like a plastic dielectric capacitor of some sort. On the underside of the PCB are various surface-mount passive components, probably mostly resistors and small capacitors.

    A Google translation from Polish says "The moment has come to slightly refresh the designs of miniature guitar preamps and to reduce them a bit, so that they can be easily placed inside the guitar. Details of projects G-501 and G-201 can be read on the entries dedicated to them, and below I insert a gallery of photos of new versions of preamps."

    There's more Polish info here if anyone wants to follow it up!
    analogworkshop.freecluster.eu/2016/12/24/preamp-g-501-aktywna-elektronika-gitarowa/
    No circuit diagram unfortunately. :-(
  • Kevin PeatKevin Peat Posts: 3,034Member
    I hadn't considered the Dark Side of the Chip. Woooah !

    Still voodoo to me.
  • Kevin PeatKevin Peat Posts: 3,034Member
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