Hi Guys so over the weekend i built the EQD Chrysalis. I have to say it's the best overdrive I have heard so far and when I plugged it into my old Fender Champ Clone, I just went ARRRRRRRR, that's the sound I have been looking for.
I have ordered the parts to build another one this time I am hoping to tweek. As I am quite new to the hobby I was hoping for some help.
I have found the layout and schematic on tagboard effects...
From what I have learnt so far:
The circuit looks like an electra drive going into an LPB 1 style boost stage with a tone shaping in the middle.
So looking at the schematic I think C1 is a decoupling cap and is there to remove any DC from the guitar signal. Is this right?
If C1 is a decoupling cap then I do not know the function of C2. Guessing I would say it is some sort of tone shaping and would shave off some bass.
P1 is the drive pot but I don’t understand how drive can be set here. I thought the guitar signal would be too weak to really have any effect but obviously I am wrong. Any help explaining how it works would be appreciated.
Again I am at a loss as to how R1 affects the circuit, help or pointing me in the direction of a good resource to help would be appreciated.
I believe R2, R3, form a voltage divider and that is Vout= 4.5. This is the bias for the first Transistor?? And goes to the base.
I get the Transistor it amplifies the signal??
R4 is to bias the Transistor at this stage if you decrease the value it will add more gain and decrease less gain?? This goes to the collector. R5 sort of does the same job and the value changes will have the same effect but joins the emitter to ground.
I have no clue what C4 does. I may be thinking feedback but i don’t know.. Please can you help.
C3 is again a coupling cap and is there to remove any dc?
The diodes clip the signal and placing different diodes will clip the signal in different ways. Like the switch in my Rat Clone. Asymmetric, Symmetric, and so on.
The next stage is the tone control. I am not sure of the function of R6. The capacitors C5, C6 affect the cut of the tone pot. Changing the cap values will alter the tone like upping the values will roll off more highs.
Does anybody have a suggestion for a good mid boost value in this circuit???
C7 is a coupling cap and is there to remove any DC picked up from the diodes and tone control. But does this also work by shaving off some highs.
I am not sure why R5 is connected to R7 my guess would be they share the 9v supply as R7 forms a voltage divider with R8 form a voltage divider to Bias the second transistor.
The voltage works out at Vout = 0.818. I am thinking that the second transistor turns on a 4.5 volts as it's the same MPSA 18 as the first Tranny, so the remaining voltage is coming from the first transistor?
R10 and R9 do the same job as R4 and R5..
The Last cap C8 is there again to remove DC and slightly shape the overall tone.
The Last pot is just volume control.
Thanks guys in advance for the help
