Source Audio Programmable EQ

[Lord of the Badgers]

Thinking about maybe getting one of these to match up my mandolin/cbom/tenor guitar & uke & save inputs on the desk in our band, and save our sound chap some hassle.

http://www.sourceaudio.net/products/...ammable_eq.php

will that idea work? or am i being optimistic?

+1 Daft question:
can i use the gain on it as a form of preamp -?

[Tavy]

+1 Daft question:
can i use the gain on it as a form of preamp -?

No, sorry. A pre-amp isn't about gain, it's about impedance matching, so unless the box has a high enough input impedance to function as a pre-amp as well as an EQ, then not only are you out of luck, but it would likely sound terrible without a pre-amp in the signal chain first.

[Tavy]

Update: found the manual... 1MOhm input impedance and true bypass switch means this is definitely intended for electric guitars not piezo's. If you go direct from a piezo to this it really will sound bad.... sorry!

[mandowilli]

If you have a DI such as the Baggs Venue or Para DI you can insert it into the effects loop and it will work just fine.

[foldedpath]

Just a word of caution about this approach. There was a time when I wanted to do something similar, with programmable EQ that I could quickly switch between different instruments as I swapped them during a gig. Back then, I was swapping between mandolin, octave mandolin, and guitar, each with their own EQ and volume needs.

I tried the idea with a TC Electronics G-Natural pedal, which had 3 programmable EQ bands (along with other goodies like delay and reverb, tuner and mute). Patches could be called up instantly with the press of a footswitch.

Sounds good in theory. But the problem I ran into was being locked into those programmed EQ settings. Every venue is different, and a "standard" setting just doesn't work everywhere. To make any change in the EQ, I had to bend down to the floor and start fooling with menu pages. Just the difference between playing an outdoor stage vs. indoors is enough to throw off your EQ settings in a fairly major way.

So I reverted to using a small mixer nearby, with each instrument plugged into a different channel with its own EQ. I just muted the instruments I wasn't using. This made it much easier to quickly fine-tune things during the gig.

I don't know how easy it is to fine-tune patches on that digital EQ pedal, but I suspect it's not something you'll want to be doing very often for sound check, or (worse) in the middle of a performance. One of the new compact digital mixer would let you use one input for all the instruments and store "scenes" with different EQ for each one, but you might just find it easier to use a compact mixer like I've been doing, where you can see the EQ knobs and quickly grab them for a change.

[almeriastrings]

Update: found the manual... 1MOhm input impedance and true bypass switch means this is definitely intended for electric guitars not piezo's. If you go direct from a piezo to this it really will sound bad.... sorry!

Sorry - but that's not entirely correct. There are a few more complex issues involved.

This unit does have a 1M input impedance and this is absolutely fine for many piezo transducers. In fact, it is the recommended input impedance for K&K's. In some applications, and for some transducers, a higher input impedance may be suitable (particularly with string bass where extended LF response is important), but this is not so with mandolin or violin (where excessive LF response can result in increased handling noise/pick noise without any useful 'musical' content). It is a question of the load presented to the transducer and the effect this has on the roll-off knee. Quite a lot of really very good buffer preamps and DI's for piezo's have a 1M input impedance (the superb Orchid designs, for example, and the Red-Eye). What matters as much as the input impedance is the peak-to-peak voltage handling. This is where many fall down...in fact, the Source Audio unit has a really good spec here accepting 2.2V without protest - this is higher than the Red-Eye (1V) but not quite as high as the Orchids. 2.2V peak-to-peak is very, very good though if you are sending a piezo to it.... especially on a hard-driven mandolin.

Also.. there are two modes of bypass on this thing. Hard-wired (relay driven) - ideal for magnetic pickups, and buffered, via the Hi-Z input, specifically intended for use with passive piezo transducers. The concept that you need 5 or 10M input impedance with all piezo transducers on all instruments is simply wrong.

Really, the main concern with this unit is the EQ is rather limited (only 7 bands in a graphic format) and those bands are far from 'surgical'. It is also worth noting that units like this are obsolescent, if not yet obsolete, as the onwards march of low cost digital consoles gives musicians access to unlimited snapshots of very sophisticated true parametric and various other forms of multi-band EQ.

[Lord of the Badgers]

Cheers all. My desire was to cut the amount of cables as I predominantly use wireless with the mandolin as we are a "get out in the audience" sort of band. Thanks for helping me save money!

[Flame Maple]

Thanks to you all, to me its education,very helpful .

[almeriastrings]

Just a general observation here... but all this heavy duty EQ'ing is almost invariably associated with instruments with piezo transducers. The contrast between what you need to do on the desk end of things between "plugged in" instruments vs. say, a DPA4099 or ATM350 is substantial (or indeed, any really high grade stand mounted instrument mic). With these, you just need to roll of a bit of low end, high end, and sometimes scoop the mids a bit (not always), but once you have done that you can leave it essentially flat and can change instruments with no further messing. That's what I do. I switch between flatpick guitar and mandolin in a set, and I don't need to change any EQ settings at all.... I find this easier with a stand mount mic, as I can vary distance and position on the fly to get the dynamics and tone I want, but with a really good, accurate clip on you can get similar results. So much effort (and money) ends up getting thrown at pickups in an attempt to get them to even approach the quality you can get with an old SM57, never mind a really top class mic.

PS: I do realize there are times when you may have to use a transducer, for reasons of stage volume, etc... but even so.. a sobering thought when you directly compare the two and what they need to sound good.

[Lord of the Badgers]

PS: I do realize there are times when you may have to use a transducer, for reasons of stage volume, etc...

that's me

[Tim Griffin]

I use the Source Audio EQ to preset switching between a K&K in a D-18 and a K&K in a Guizouki. I have it in the effects loop of a Red Eye Twin. It works well for onstage instrument swaps. D-18 is in Channel 1 of the Red Eye with gain down, flat EQ on Source.
Guizouki is in Channel 2, Of the Red Eye with gain at max, the Source EQ is preset to boost gain and adjust EQ for the Guizouki. A Boss TU2 tuner mutes the signal when switching. Gain settings cover the disparity in output between the instruments and allow me to match them. I don't have to change anything on the board so the level is the same when I switch back to guitar from zouk. It works great for me. One note-batteries won't last for an entire night so you need outboard power for the Source EQ. The Red Eye is phantom powered from the mixing board. Switching instruments at gigs is very easy for me. It requires a little tap dance but no real distractions as the sound is consistent.