Recommended Gain Settings for Accuphase Class A amp / Popping noise issue
I have recently purchased an Accuphase A-20V amp and was trying to dial in the Gain settings on the Amp. I am using the A-20 with my tube preamp (Schiit Mjolnir 2 hybrid tube preamp) balanced. The preamp also doubles as my headphone amp and I use the low gain setting on the preamp. Output Impedance on the preamp is 1.0 ohms high gain, 0.3 ohms low gain and 40 kilohms input impedance for the amp using balanced inputs. Gain settings on the amp are -Max,-3db,-6db,-9db,-12db. I usually favored lower gain settings on my preamp when I had my tube ARC preamp. but I no longer have the LS-25, and I have the the Mjolnir gain set at low (0.3 ohms) and the Accuphase at -3db. Any input or experience would help.
I also have a large popping sound in the speakers when the preamp. circuit, slow start, kicks in. I have tried a number of alternate start up sequences but it still happens. I usually turn the REL subs on first to warm up prior to the amp-preamp-dac / phono tube preamp. about 30 minutes prior to music. Is this a ground issue from the amp to the speakers? I never experienced this issue with my previous Class A amp. Any ideas?
@cleeds - Thanks for that input, I thought I tried that sequence before, but maybe not. I tried it again, starting the preamp first, and sure enough "no popping"! I also contacting Schiit about the Mjolnir 2 and they also suggested starting the preamp first. Issue Solved! @fuzztone - I actually find the Schiit Mjolnir 2 an excellent hybrid tube preamp and not looking to replace it anytime soon. I do, however, appreciate your advice on the popping issue. |
Turn preamp on first, then amplifier. Reverse the sequence for shut down. |
