I’m building a poweramp for my frfr guitar cabinet. I’m using the QuadCortex modeler as a preamp. Currently I’m using the Harley Benton GPA-400 as a Poweramp, but I don’t like the sound, it gets harsh as soon as you turn the volume up.
As far as I know Seymour Duncan is using Icepower modules for Powerstage amps. So I was thinking why dont I just build an Icepower 700AS1 module into my cab. One device less to drag around.
I was expecting this to be easy but the result was not what I expected. It sounded good when I had the QC volume at half, but when I turned it up the sound got all distorted and wasn’t as loud as I would expect.
The dealer explained to me that the output voltage of the QC was too high for the Icepower amp.
From the QC manual:
Analog Outputs 1-2
• Connectors: (2) XLR-M with Ground Lift
• Impedance: 560 Ω
• Max Output Level: +9.5dBu
Analog Outputs 3-4
• Connectors: (2) TRS
• Impedance: 560 Ω
• Max Output Level: +15.5dBu balanced, +9.5dBu unbalanced
“Quad Cortex 4.6V (calculated from +15.5dBu). For the 700AS1 the max is 3,3V.”
Basically I have two questions.
Thanks!
As far as I know Seymour Duncan is using Icepower modules for Powerstage amps. So I was thinking why dont I just build an Icepower 700AS1 module into my cab. One device less to drag around.
I was expecting this to be easy but the result was not what I expected. It sounded good when I had the QC volume at half, but when I turned it up the sound got all distorted and wasn’t as loud as I would expect.
The dealer explained to me that the output voltage of the QC was too high for the Icepower amp.
From the QC manual:
Analog Outputs 1-2
• Connectors: (2) XLR-M with Ground Lift
• Impedance: 560 Ω
• Max Output Level: +9.5dBu
Analog Outputs 3-4
• Connectors: (2) TRS
• Impedance: 560 Ω
• Max Output Level: +15.5dBu balanced, +9.5dBu unbalanced
“Quad Cortex 4.6V (calculated from +15.5dBu). For the 700AS1 the max is 3,3V.”
Basically I have two questions.
- How do I fix the Voltage/ Ohms mismatch issue?
- What would be a good 3 band eq solution to add?
Thanks!
From the manual:
Input Stage
The balanced input buffer has an anti-
aliasing filter and a DC blocking capacitor. 220R The input impedance of the signal input
section is minimum 8 k ohm over the audio
bandwidth, which is an acceptable
loading condition for pre-amps, active
crossover outputs etc
Input Stage
The balanced input buffer has an anti-
aliasing filter and a DC blocking capacitor. 220R The input impedance of the signal input
section is minimum 8 k ohm over the audio
bandwidth, which is an acceptable
loading condition for pre-amps, active
crossover outputs etc
Output impedance doesn't matter in this scenario.
The preamp will easily drive the 8kOhm input impedance of the power amp.
Input divider will have similar effect to turning the volume down.
Speaker details please.
How many, impedance & how are they wired?
Do you have another preamp or signal source to try?
Narrow down if the distortion is from the pre or power.
If your power amp will play clean and loud from another source then the problem lies in the pre.
The preamp will easily drive the 8kOhm input impedance of the power amp.
Input divider will have similar effect to turning the volume down.
Speaker details please.
How many, impedance & how are they wired?
Do you have another preamp or signal source to try?
Narrow down if the distortion is from the pre or power.
If your power amp will play clean and loud from another source then the problem lies in the pre.