Thoughts on Audio Research D70

These caps are huge and made by the company that makes them for ARC.

Hifikeek1 and Johnsonwu, IF you had an unlimited budget for cap replacement, which caps would you use in the D70 or the D115? and why?

@HifiGeek1: Audio Research seems to source caps from The Reliable Cap company (Audio + Rel) and TRT (which some think is sourced from ASC). I will pass on big sized caps for now. Even the 0.47 I have I couldnt find anything to fit them in.

@DaveyF: For coupling caps I would say V-cap Teflon TFTF or Mundorf Silver Gold Oil. Tried/have them on many friends'gear as well as my own. Never tried the Duelunds, no I didnt win the megamillions lotto. Jensen ceramic caps, maybe, too expensive still.

@Hifigeek1: I was trying to do some final checks on the regulated voltages to the first stage B+ and regulated screen grids and I found an ultrasonic oscillation of about 20mV peak to peak. My mistake for not turning the horizontal dial of my scope all the way to look at ultrasonics. Thought the 20mV was just hash or the probe.

This was traced all the way back to the plate of the 12AT7, and then back to pin 6 of the TL071 (U1) which was sending 100mV of sawtooth.

I'm leaving this for another day now but am curious if you think I should replace the 3 0.22 caps surrounding the input pins of the TL071 opamp.

Much appreciate any guidance.

@Hifigeek1: Never mind, the relcap 2.0uF bypassing the cathode (regulated B+) output of the regulator 6550C has deteriorated enough that when I paralleled in another 1uF all is good. Time to replace them bypass Relcaps too I guess.