xeawr
Well-known member
Dear GroupDIY fellas,
I have a quick request. Could you smart people out there be so kind as to have a quick glance at my schematic and tell me if it makes sense to you? Here are my issues:
a) I'm not sure about the H-pad, in the ReAmp signal path . Is it really necessary? Did I even get the correct values for the H-pad; is this a reasonable attenuation factor?
b) Doesn't the transformer do all the impedance matching, or do I really need a resistor in parallel with the transformer?
Maybe I do, since
1. Jensen included an impedance matching pot in their design (notes) - see attachment. For simplicity's sake I don't want such a potentiometer. However
2. the popular LINE2AMP also shows a resistor in parallel with the transformer.
c) Will this schematic (work well :). I know there are some other schematics around, I studied them carefully and tried to understand them. Mine varies in a number of points:
1. No Z pot for more simplicity (unless you convince me it is ABSOLUTELY necessary )
2. XLR input/output is split into TRS input for line level (for reamping) and XLR mic level output (for DI purposes).
d) Do I (really) need a pad in the unbalanced part of the schematic? I think basically all guitars have a volume control, so I'd rather turn that down (to not "overdrive" the x-former), instead of engaging a pad at the DI box. Makes sense?
e In the data sheet (attached) it says "Do not pass DC through the windings." Would I pass DC through the windings if I engaged the 48V at the XLR output? If yes - how to block? (caps?)
f) Any further, hints, insights, caveats?
I can't believe I made such a simple thing so complicated, ;D but there is simply so much I don't know, hence the myriad of questions...
Thank you SO MUCH (!) for your help. I can't wait to build this thing so I'm really really curious to hear what you will say!
I have a quick request. Could you smart people out there be so kind as to have a quick glance at my schematic and tell me if it makes sense to you? Here are my issues:
a) I'm not sure about the H-pad, in the ReAmp signal path . Is it really necessary? Did I even get the correct values for the H-pad; is this a reasonable attenuation factor?
b) Doesn't the transformer do all the impedance matching, or do I really need a resistor in parallel with the transformer?
Maybe I do, since
1. Jensen included an impedance matching pot in their design (notes) - see attachment. For simplicity's sake I don't want such a potentiometer. However
2. the popular LINE2AMP also shows a resistor in parallel with the transformer.
c) Will this schematic (work well :). I know there are some other schematics around, I studied them carefully and tried to understand them. Mine varies in a number of points:
1. No Z pot for more simplicity (unless you convince me it is ABSOLUTELY necessary )
2. XLR input/output is split into TRS input for line level (for reamping) and XLR mic level output (for DI purposes).
d) Do I (really) need a pad in the unbalanced part of the schematic? I think basically all guitars have a volume control, so I'd rather turn that down (to not "overdrive" the x-former), instead of engaging a pad at the DI box. Makes sense?
e In the data sheet (attached) it says "Do not pass DC through the windings." Would I pass DC through the windings if I engaged the 48V at the XLR output? If yes - how to block? (caps?)
f) Any further, hints, insights, caveats?
I can't believe I made such a simple thing so complicated, ;D but there is simply so much I don't know, hence the myriad of questions...
Thank you SO MUCH (!) for your help. I can't wait to build this thing so I'm really really curious to hear what you will say!