Constanta, Romania, European Union – March 19, 2020 – Following additional testing with the new CompIQ TWAIN Dual Band / Stacked Compressor used with a wider range of “hot” instruments and higher input signal levels, we found some scenarios in which the pedal may have a limit on the headroom on the Dry-line only, which may lead to premature clipping. The Wet line is not affected.
This is not a fault in the circuit, it is the result of how the internals was set for processing. Because the signal on this path always passes through the Saturation module, clipping may occur on either the Lows band or the Highs band even with the SAT control at minimum, depending on the input’s frequency characteristic (as it originates from different sources) and/or the position of the Crossover separation point. Lows band is susceptible to clip earlier, because of a lower-set threshold in the Lows saturation engine. This was intended to better serve the warm bass instruments that have passive or low output pickups, but it limits the headroom for other instruments.
How can this be noticed
If the compressor is used with bright instruments like Strato’s or Tele’s, this will hardly be noticed. Hot pickups, brighter or darker, may trigger this behavior, regardless of the instrument – bass or guitar. Strong flat output signals like synths may be affected as well. Again, this happens only in the Dry line, so as long as you don’t use the MIX knob to blend more dry signal over the wet signal, this may pass unnoticed.
Who is affected
CompIQ TWAIN’s delivered before March 13, 2020, including products sent for reviews have this issue.
There are several ways to fix this. First of all, we want you to know that for all those affected we offer the possibility of sending us the pedal for the fix, at our expense – we will Paypal reimburse the cost of mailing it to us. We will also send back the fixed pedal at our expense. This may take a while, but it is the best and safest way to have the Twain at proper specifications.
1. Increase DC power voltage
The CompIQ TWAIN can be powered at 18V to have the saturation engine’s headroom increased. The pedal is prepared to support this voltage. This alone might not be enough, though.
Note: The PEAK detection is calibrated for 9-12VDC power supplies. If the pedal is powered at 18V, the PEAK indication LED may stay lit.
2. Adjust the clipping thresholds in the Lows saturation engine
This can be easily done by removing two components on the board. This raises the clipping threshold on the Lows saturation engine.
Note: If you wish to do this on your own care must be taken when removing the SMD components so that the board is not affected.
- D24, D25 – remove the shorting Zero Ohm resistors on top of diodes; leave the diodes in place.
3. Restructure the levels on the internal signal path
This is more labor-intensive and sensitive work and should be done by us. In that respect, it is best if the pedal is sent to us for the fix.
Note: If you are tech-savvy and wish to do it yourself we can mail you the four needed 0805 SMD 1% thick film resistors.
- R108 – remove; no replacement needed
- R110 – change to Zero Ohms (shorting resistor)
- R117 – change to 4.9K
- R120 – change to 33K
- R129 – change to 33K
We acknowledge that this issue is not something you would like to live with. If you feel disappointed and want to solve things fast, we will issue a full refund first, and then we will expect the pedal returned.
We feel sorry for not catching this bug before delivering the first products. Please accept our apologies.