Volume control for acoustic guitar with K and K Pure Mini?

smigeon

Hi all,

As I reported in a recent thread, I've just installed a K&K Pure mini pickup in an old dread of mine. I'm very pleased: it already sounds good simply plugged into my Roland JC40, and even better via a Joyo American Sound into the Roland's loop return!

But I'm looking for a setup that gives the best possible results when I plug straight into the PA.

I think I've decided that I don't need a preamp. From what I've read, I'm persuaded it's best to go straight into the mixer via a suitably impedance-matched active DI (such as this: http://orchid-electronics.co.uk/micro.htm), and to use the mixer for EQ.

But then, as the pickup has no onboard controls at all, the only means I'd have to kill a bit of encroaching feedback, or to tweak the volume a bit, would be to rely on someone manning the mixer, or to stroll over to the mixer myself! Not very realistic.

Looking for a solution, I came across this: https://schatten-pickups.myshopify.com/collections/volume-controls-thumbwheel-controls/products/bb-03-black-box-volume-control. And also this http://www.jjb-electronics.com/Voljack.html: These look like nice solutions, albeit a bit expensive.

Anyone got any experience of these? Any similar products anyone is aware of (ideally in the UK)?? Can anyone, such as @Danny1969, make me one :-)?

Danny1969

I can make you the Voljack  for £28 but need to know the output impedance of the pickup ?  I had a google but can't see any specs for it .... 

smigeon

Hi @Danny1969, I can't find a definitive statement of the output impedance of the pickup. The manufacturers state that the input impedance of a preamp that the pickup plugs into should be in the range of 500 KOhm to 1 MOhm - as opposed to the 10 MOhm input impedance of many preamps. Does this help? If not, I'll keep digging. 

How small could you make the box??

Danny1969

That is useful actually that tells me what value pot to use without excessive loading. I could make it slightly smaller than the commercial one but it needs to be a certain size for the jack plug to slide into it. 

smigeon

Thanks, @Danny1969. Sounds good. I'll have one for £28, then, please. A couple of things:

- I'm assuming the volume control would work such that it turns right down - i.e. so it's safe to leave the guitar on a stand with the vol turned down and there's zero chance of feedback starting??
- How quick can you do it? Quickish hopefully?? I have a festival coming up soon and would ideally like to get in in time for that.
- I think you already have the info you need to determine the resistance of the pot - but please shout if a DC resistance measurement would help - I have the technology :-).

Assuming all is OK, I'll PM you the address and PayPal you the cash and as soon as I hear...

Teyeplayer

Note to self: must save this thread and contact Danny when I install a k&k in my acoustic!

camf

Bookmarked!

ICBM

smigeon said:

Hi @Danny1969, I can't find a definitive statement of the output impedance of the pickup. The manufacturers state that the input impedance of a preamp that the pickup plugs into should be in the range of 500 KOhm to 1 MOhm - as opposed to the 10 MOhm input impedance of many preamps.

For anyone else needing to know this, that means that the pot should be 1M ohm. That way if you're plugged into a 1M input impedance (normally the lowest for an acoustic amp etc) the load will vary from 1M down to 500K, depending on how far up the volume control is.

Danny1969

smigeon said:

Thanks, @Danny1969. Sounds good. I'll have one for £28, then, please. A couple of things:

- I'm assuming the volume control would work such that it turns right down - i.e. so it's safe to leave the guitar on a stand with the vol turned down and there's zero chance of feedback starting??
- How quick can you do it? Quickish hopefully?? I have a festival coming up soon and would ideally like to get in in time for that.
- I think you already have the info you need to determine the resistance of the pot - but please shout if a DC resistance measurement would help - I have the technology :-).

Assuming all is OK, I'll PM you the address and PayPal you the cash and as soon as I hear...

Yeah it will work exactly as a normal volume, turned full down is off and safe to leave on a stand. I'll post you one out Monday or Tuesday and see what you think

smigeon

Thanks, Danny - I’ll PM you now...

crunchman

Teyeplayer said:

Note to self: must save this thread and contact Danny when I install a k&k in my acoustic!

Just buy it with a volume control:

https://www.thomann.de/gb/kk_pure_mini_volume_control.htm ;

You can get the volume control and retrofit it as well:

https://kksound.com/products/volumecontrol.php

smigeon

Yes, the K&K retrofit volume control is an option. Downsides for me, though, were that it seems to add a lot of extra stuff permanently (or at least semi-permanently) to the innards of the guitar (additional endpin jack, which is quite bulky and heavy; two 3.5mm jack plugs), and also the tiny thumbwheel is less good than a knob.

The thing that Danny is making can be removed trivially - and has a proper knob :-).

Horses for courses...

smigeon

Just received said volume control from @Danny. In case someone is reading this who hasn't read the whole thread (what??), we're talking about a tiny box with a jack plug sticking out of it, and hosting a volume knob and a jack socket into which you plug your normal lead. You plug the little box into the endpin jack socket of your passive-pickup-equipped acoustic guitar, and the volume knob gives you a modicum of control over the guitar, despite the guitar having no electronics apart from a passive pickup (e.g. K&K Pure Mini, in my case). You plug your normal lead into the little box.

https://www.dropbox.com/s/9ajz6uqoi1yj8oe/vol.jpg?raw=1

Have only had a quick play so far, but the concept works really well for me - it's easy to feel the volume control and it's nicely controllable whether you want to quickly kill feedback or make subtle adjustments like going from strum to fingerpick etc. It doesn't affect the quality of the guitar's sound at all (not tried it through a proper PA yet, though).

There's also a nice side benefit: if you accidentally stand on your lead while playing, it will tend to only tug the lead out of the unit as opposed to breaking the guitar.

As well as a normal lead, I also tried plugging my Boss wireless bug into it (Boss WL-20) and this works great too. The combined vol control and transmitter bug are quite big together, but they are well out of the way and pretty invisible. 

I'm really happy with it so far! 

TimmyO

Looks neat