Ironsounds Loop findings

[greiswig]

I installed an Ironsounds loop in my D'Lite chassis, to work in tandem with a TC Electronic reverb/fx unit. I installed in initially the way they described to: between the MV output and the PI.

The result was okay, and got better after I replaced the TO72 chip with a Linear Audio chip. But it was pretty noisy.

The FX unit I have doesn't display db at the input except in terms of one LED lighting up when -60db is reached. But my ears were telling me that a lot of the noise I was hearing was because the input level was too low.

I rewired it to go before the MV control, so the FX unit is seeing the full volume at all times. This seems to work much better: much less noise, and programs like the "Dynamic Delay," where the echo is ducked under input signal, actually work where before they did not.

Just FYI...

[Structo]

Interesting.
I haven't really noticed too much noise with mine.
What kind of noise were you getting? Hash, 60 Hz?
Could you describe a little better where exactly you connected the send and return in the amp?
Thanks

[greiswig]

Interesting.
I haven't really noticed too much noise with mine.
What kind of noise were you getting? Hash, 60 Hz?
Could you describe a little better where exactly you connected the send and return in the amp?
Thanks

White noise...the kind caused by A/D converters that are operating too close to the lower limit to be completely happy.

Basically, the MV has an "input" on one lug, the wiper is the output, and the other lug is ground. Ironsound wants you to put it between wiper and PI. I just put it in before the input to the MV.

[Structo]

Thanks.
What chip did you use for the improvement?

[greiswig]

Thanks.
What chip did you use for the improvement?

Can't recall, and the amp is actually in the chassis for a change. I had a bunch of Burr-Brown and Linear Audio op amps sitting around that I've used for other studio equipment upgrades, and I used one of those. Almost anything is going to be less colored than the TLO72 that was in it.

BTW, if you do this, you'd be wise to put a socket in instead of a chip.

(EDIT: Okay, it's a Linear Technologies LT1469 chip)

[candh]

Interesting, I put one in my D'lite and it is quiet as can be. I tried putting another one in an 18 watt TMB just for fun but I got terrible white noise which I couldn't track down a cause so ripped it out.

[Structo]

Yeah, mine came with a socket.
I haven't played the amp in a few days but I don't recall any unusual noise.

[ampedup]

that's wierd, mine is quiet as can be.

[Deric]

This thread made me curious. I thought mine was very quiet but I thought I'd double check. First with nothing in the loop, I turned the MV to about 2 o'clock. Switched the loop in and out and could hear no difference in noise levels (on clean or OD). Put a Boss RV-5 in the loop and tried again - this time I could hear a very slight increase in noise only when on OD.

I am not using shielded wire to/from the loop. I do have send and return pots instead of the pad switch or internal trimmers. They are adjusted to get unity with the loop engaged.

I do like the idea of putting the loop before the MV though.