aion QUARK 매뉴얼 - 페이지 5
{카테고리_이름} aion QUARK에 대한 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. aion QUARK 10 페이지. Vintage overdrive
BUILD NOTES
EQ switch
The original OD-880 uses an op-amp low cut arrangement similar to the Tube Screamer. The EQ switch
changes the resistor (which sets the gain ratio) and capacitor (which sets the low-cut frequency) for
alternate values. The values in the parts list work well as a starting point, but you can tweak if you want.
• For more available gain in the modded EQ mode, reduce the value of R9 (e.g. 2k2).
• For more bass cut (i.e. less bass), reduce the value of C4 (e.g. 100n or 220n).
• For less bass cut (i.e. more bass), increase the value of C4 (e.g. 470n or 1uF).
Make sure to use an on-on toggle switch for this since there is no center-off mode as with the other two
toggles. The center position of a center-off switch would cut out the signal.
Treble switch
The original OD-880 has a steep treble cut after the clipping diodes and no discrete tone control. The
default treble cut works pretty well, but you may find you need more for certain guitar & amp combos.
Or, you may want more treble on tap so you can turn it up and down directly from the guitar.
The stock capacitor value is 4n7. This has been modified so that it has 1n2 and 3n9 capacitors in parallel
with an always-on 820pF capacitor, which creates 3 different settings: 4n7 (stock), 2n2 (less treble cut)
and 820pF (least treble cut).
By tweaking these three values, you can end up with different modes. For example, by using a 4n7
capacitor instead of 1n2, you can have one mode with more treble cut, meaning there is one setting
above and one setting below the stock mode.
C5 capacitor
The original OD-880 does not include a feedback capacitor in the op-amp gain stage. This capacitor is
found on nearly every similar drive circuit that came afterward and is seen as best practice to limit the
bandwidth of the op-amp for better stability. It's extremely subtle and has nearly no impact on the audio
frequencies except at higher drive settings.
QUARK VINTAGE OVERDRIVE
5