Waveforms in motion

Fred,

When I use the Lexicon MX200 as a parallel insert effect to the ART tube-preamp (the pre-amp has an out/in for this) I see this funny shape on the Main output of the Pre-Amp. When I insert the other reverb unit instead of the Lexicon, its gone.

Rich

Real strange, Rich!

But I have watched the videos and dont have a clue.. Your comment that the Lexicon "cuts the gain" may be a clue - some loading issue.. I would drive the input to the Lexicon from a signal generator via a 10k resistor, and monitor the input at the Lexicon to see what voltage drop occurred across the resistor, and change the sig-gen voltage and frequency etc to narrow the problem down (if it appeared)..

Have had the above kind of problems myself a couple of times over the years- usually though its at a live gig, and someone has connected two outputs together!

Fred.

Fred,

I just sent the note and video to Lexicon. Heck. Let them figure it out.

Sweetwater (where I bought it) is scratching their heads.

Rich

Fred,

Lexicon figured it out instantly. Turns out I had the input to the MX200 set too low - pre-amp gain was too high for the unit and MX200 clipped the waveforms. When I raised the input a bit the waveform started to quickly look as expected. There's some input threshold I have to be aware of using this unit.

Basically operator error. I should have expected that.

Rich

"There's some input threshold I have to be aware of using this unit." - Rich

Ok - Must admit this is a new one for me! - IMO, the input stage to any pro audio gear should be able to accept any standard line levels and present its specified impedance- for an input stage to actually present  low-z clipping on the output of the stage driving it....   :-(   ----- I wonder if my MPX1 does the same ?

The whole industry is going down the pan!

But thanks - its worth knowing about these sort of issues.. I am starting to feel really old though - What with audio inputs presenting active loading, and digital 'standard' supply voltage dropping to 3.3V or lower - I want a time machine to take me back to the days when inputs were passive 10k, logic ran on 5V, and the amazing 741 op-amp cost £1 and one was tempted to buy a cheap tube instead!

Oh - nearly forgot.. the days when manufacturers gave a way comprehensive printed data books, one could get full specifications on new products before you even dreamed of parting with your money, service manuals were available before the product was, and one would laugh at any audio manufacturer who forgot to put a ground terminal on the back of their audio kit!

;-)

Fred.