Aesthetix Io - Manual (Page 4)

GAIN ADJUSTMENT:
Important note: Io with volume controls has no internal gain adjustment. Use volume
controls.
1. Ensure that the power cord is disconnected from the Io preamp.
2. To ensure proper capacitor discharge, wait a minimum of 20 minutes before removing top
cover.
Inside an Io main unit there are two circuit boards, one for the left channel and one for the right.
Each of these circuit boards contains two jumper blocks, which are used for setting the gain.
Please refer to figure 3 for block locations.
A block adjusts the gain for one phase of the balanced signal. To properly adjust the gain, both
blocks for each channel must have the same jumper settings. There are two jumpers per block.
Both jumpers on each block, need to be positioned for the same attenuation amount. Therefore
changing the preamp gain means 8 jumpers on 4 blocks must be set.
There are five possible gain settings which are represented as ATT 1, ATT 2, ATT 3, ATT 4 and
ATT 5. The chart in figure 2 indicates each of these settings as a decibel (dB) range.
Jumper
Attenuation
Amount
Overall
Gain
ATT 1 0dB ~80dB
ATT 2 -6dB ~74dB
ATT 3 -12dB ~68dB
ATT 4 -18dB ~62dB
ATT 5 -30dB ~50dB
Figure 1: Block Identity Figure 2: Jumper Settings
On each circuit board, only ATT 2, ATT 3 and ATT4 are marked, and only on one of the blocks.
Therefore please refer to the ‘block’ diagram above for the complete ATT positions.
Important Note: If using ATT 5, tubes V5 and V6 must be removed.
3. Set all 8 jumpers for the desired gain, according to the information above and in figures 1-3.
4. Replace top cover and screws.
5. Test
unit.
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