Hello. I'm new here. I will go introduce myself as well. I mostly write music for my bands, play guitar , do luthier work and build guitar amps, but I Iove recording and have built some simple tube pres, upgraded microphones etc.
I've done some Akai Roberts conversion in the past and haven't been happy with the12ax7 circuit so I built a NYD one bottle pre with the 12ax7 circuit(I'm using a 12AT7 as I don't have any 12AV7s seems to work with 12AU7s and 12AX7s as well)
I really like it's a huge improvement and I thought I'd add the pad. It works well ,seems to be more like a 23DB pad but that's okay.
However when the pre is turned up past halfway with the pad on I get some hum/buzz. I don't get it with the pad off and the preamp at half, or even cranked. What could this about? Pad toggles are just below the phase switches. It's pretty cramped in the chassis but If there was overall noise in the circuit you'd think you'd hear it more without the pad on . I built 2 of these units and they are both reacting the same way.
Thanks
I've done some Akai Roberts conversion in the past and haven't been happy with the12ax7 circuit so I built a NYD one bottle pre with the 12ax7 circuit(I'm using a 12AT7 as I don't have any 12AV7s seems to work with 12AU7s and 12AX7s as well)
I really like it's a huge improvement and I thought I'd add the pad. It works well ,seems to be more like a 23DB pad but that's okay.
However when the pre is turned up past halfway with the pad on I get some hum/buzz. I don't get it with the pad off and the preamp at half, or even cranked. What could this about? Pad toggles are just below the phase switches. It's pretty cramped in the chassis but If there was overall noise in the circuit you'd think you'd hear it more without the pad on . I built 2 of these units and they are both reacting the same way.
Thanks
