Sunday, April 3, 2011

Reamp Box Curves

update on the reamp box here is the frequency response of the xlr cable run direct into MOTU 896HD. Test was done using sine wave sweep 20 to 20k 20 sec duration. 

This is the response of the reamp box inline with MOTU 896HD In passive mode.


  1. interesting... did you determine the ratio on the primaries to secondaries on the input transformer?

    was it 1:5 -ish?

    looks like kinda harsh low frequency roll-off if that plug-in analyser is an accurate way to test.

    thanks for posting this info. Wanting to use this input trafo for a moving coil pre-pre.

  2. for the tetrad 106A its a 2:1 or 1:1 depending on how you hook it up and the 106B 6.89:1 or 3.4:1 depending on how its hooked up as well.

    The top graph shows the response of the cable so compare that to the response of the reamp they seem fairly similar.

    I may have access to higher quality test equipment this summer to do some more in-depth response plots.

  3. ah, I thought you were using the Lear #91881 T102-A input transformer. I see in your Flickr pics a T102 with another part number... don't have either that or the 106A/B. Thanks though. I wish I could figure out how to measure this transformers' step up. Apparently I have to feed it a live voltage/signal. Novice obviously... thanks.

  4. I dont have a signal generator so i just used the Test oscillator from logic. Adjusted the volume till i was reading 1v out then hooked that up to the secondary and then read the voltage there. remember your multimeter is going to need to be in ac voltage not dc when you do this test. I think i did a test on the 102 that i have if i remember correctly its 1:6 or 6:1 or right in that range. hope that helps you out.