The maximum diameter at the central wire for a 5-7mm diameter cable is AWG16 (1.3mm). 5m of cable will have a cumulative resistance (round + return) of about 0.13Ω, which for an 8Ω speaker is a lot. To the high resistance of the cable is added the enormous capacity, which leads to instability for the amplifier.Coaxial cable for speakers?!? One of the worst ideas ever.
I suggested a test a few days ago but was completely ignored. It seems that if I don't give audiophile suggestions, no one listens.
@sesebe, it's not because I don't give feedback to your post that I didn't read it! It's just that I don't have these kind of ferrite core in stock for the moment.I suggested a test a few days ago but was completely ignored. It seems that if I don't give audiophile suggestions, no one listens.
Well noted!When I lay a PCB out I always do the output stage power transistor traces (V+, V-, output rail, 0V and decoupling) first. After that the feedback resistor and gain resistor plus HBR then after that, everything else.
You should observe how much it is crowd.
Three - four turns made of a ferrite tor with the signal input cable solved much more serious problems than the ones you encountered here.@sesebe, it's not because I don't give feedback to your post that I didn't read it! It's just that I don't have these kind of ferrite core in stock for the moment.
I bet I am one of the guy here who read everything!
The 100nF is connected between the Input RCA ground lugs via the white #14 gauge wire, and the screw of the bottom panel HQG ground. This bottom panel HQG is the star point of both Amplifier modules HQG (on each pcb) and the HQG of the Power Supply PCB.Is the 100nF cap joining the signal ground to the PSU/ chassis ground? I can't quite see exactly what the opposite end is attached to. Should the signal ground not be entirely isolated?(actually connected back at the pre amp)
As this is a Modushop chassis why not remove each side heatsink with the amp attached and swap them over?
Question... Where did you read something about coaxial cable for speaker in this threads? I can't find it.Coaxial cable for speakers?!? One of the worst ideas ever.
In your layout, you show a central ground track going to the input circuit. This is the correct way to do it, with the following caveats. This signal ground track must run under the feedback and gain setting resistors - again, to keep the loop arwea as small as possible. The gain setting resistor is returned to the signal ground trace through the HBR and the input signal; ground connects to the other side (ie not the signal ground trace side) of the HBR. Again, keep the input circuit loop areas as small as possible. Do not connect any other components to this signal ground trace. If you put your decoupling capacitor returns, you will cause excess noise.
Question... Where did you read something about coaxial cable for speaker in this threads? I can't find it.
"Speaker" is written there...I can also interpret pictures, it doesn't have to be explicitly written somewhere.
Any cables suggestions?it's still one of the worst ideas. 253pF/m