I need a suggested DI/PAD to go with my Green Pres, Rec W/Drum Triggs PLZ HLP!!

Please help, if theres any bit or piece or links of info would do for that I'll be Recording via Roland PD5's and or possibly using DDrum triggers as well. 

As far as Mic pres I'll be using Green Pres and so with these Drum Trigger thingies having high Z, I have no clue as far as what kind DI that should be used (need LOTS of headroom!! ;D)


Thanks,

This might help...

http://www.groupdiy.com/index.php?topic=26433.0

ENS Audio said:

Please help, if theres any bit or piece or links of info would do for that I'll be Recording via Roland PD5's and or possibly using DDrum triggers as well. 

As far as Mic pres I'll be using Green Pres and so with these Drum Trigger thingies having high Z, I have no clue as far as what kind DI that should be used (need LOTS of headroom!! ;D)


Thanks,

Click to expand...

No way you can use simple attenuators (pads) because the input impedance would be too low, or the mic pre would see a too high impedance, which is detrimental to the noise figure, or both...
You need some kind of active DI for piezo transducers. A very simple non-inverting amp using a TL07x (71 single, 72 dual, 74 quad), with a potentiometer in the feedback loop should do the trick. No need to balance the output, you can use impedance-balanced output (it just means that the signal from the opamp goes to pin 2 of the XLR, and just a resistor and cap to pin 3).

This is a few less parts and a single supply...
I built a bunch of these and I have piezos stuck all over the studio now, in the piano, under table tops ;D
http://www.scotthelmke.com/Mint-box-buffer.html
Makes a pretty good buffer for carbon telephone mics as well.
Sleeper

Sleeper said:

This is a few less parts and a single supply...
I built a bunch of these and I have piezos stuck all over the studio now, in the piano, under table tops ;D
http://www.scotthelmke.com/Mint-box-buffer.html
Makes a pretty good buffer for carbon telephone mics as well.
Sleeper

Click to expand...

Well if these thingies will do the job for the application that I'll be using them for then you may just have saved me hrs of time and frustration.


Thanks a bunch!!!!  ;D

Sleeper said:

This is a few less parts and a single supply...
I built a bunch of these and I have piezos stuck all over the studio now, in the piano, under table tops ;D
http://www.scotthelmke.com/Mint-box-buffer.html
Makes a pretty good buffer for carbon telephone mics as well.
Sleeper

Click to expand...

About that design (which I will most likely start working on) say if I wanted to have the "buffer" run off of a preexisting Green Pre supply rated at 15v, can I get away with running current through the circuit or do I need to add a few extra parts?? and if option B is my only choice then if you happen to know that is, what would be the few parts that I need would just a LM317 and 337 W/ the right resistor values be all i'd have to put??  Or is it more to it than just that??

Thanks once again for the info....

Sorry I didn't reply sooner... sometimes the notification feature is spotty.
I think you can probably just run this thing on 15 volts and get some extra headroom. the 2n5457 is rated plenty high to deal with the 15 volts.  if not, the current drain is super low so you could just use a little voltage divider or a dropping resistor to lower your supply voltage, I don't see that you would need to bother with regulators. 
Kelly

Sleeper said:

Sorry I didn't reply sooner... sometimes the notification feature is spotty.
I think you can probably just run this thing on 15 volts and get some extra headroom. the 2n5457 is rated plenty high to deal with the 15 volts.  if not, the current drain is super low so you could just use a little voltage divider or a dropping resistor to lower your supply voltage, I don't see that you would need to bother with regulators.   
Kelly

Click to expand...

THNX for the tip!!!! ;D

If you need something that is already pretty completed you can check out Joe's stuff at jlmaudio.com 

His IC DI would do the trick and you can throw in a TL072 to keep the cost even lower.  It will make a pseudo balanced output.  Now, I'm pretty ignorant but I suspect that Piezo pickups want a pretty high impedance - something like 4meg.  I could be wrong.  I think though this could be achieved by swapping some resistors on JLM's DI to make a 4meg pull down on the input.  Joe can advise of the substitutes needed.

CC