
Originally Posted by
Co&
I think I did not pay enough attention here. Did you record the desired ESR for each cap? I'd be very interested in the types and values you used.
Boy does my deck sound great now...yet only for the first 60 minutes or if I'm lucky 90 minutes. Then something is warmed up enough to start oscillating and mess up the entire sound. .................
My assumption is that the filter and signal couple caps (around FG, 6680 and 6675) do not play a role in the oscillation and it is all associated to the caps used in the power supply or armature coil decoupling. But I might be mistaken.
Hi, Coen
I didn't saved measured ESR data for old capacitoors, just comparen them with new ones. New capacitors are (AFAIR) mostly CapXon, sseveral Rubicon's and Hitano - I'm don't worried about 'audiofile' caps because of I measure them before soldering and anywhay the final arbithre is sound, any wrong component instantly degrades it.
I agreed with you that FG and PLL filter details can't affect to your issue (at least while both stages are in non-selfoscillating mode). It rather looks like caps or even regulator warming. My 317 has about 50 C temperature after work one hour+. Another (and may be first!) possible weakness is soldering, try to revise all soldering points.
We are deepened into such technical discussion here... is it correct?
Analog: Technics SL-1200MkII (RB300 tonearm, external PSU, separated power supply for all stages, improved bearing), MC Goldring Eroica LX, custom SUT 1:10, Balanced input J-FET DIY phonostage
Digital: Cubietruck (headless Debian server, i2s output, external masterclock from DAC), content on HDD. DAC: Lynx D29v4 (Altera FPGA digital stream separator, 2*AD1853, 2*3 OP42 LPF)
PA: DIY composite amplifier YES-3, schematic by Gennady Bragin
Acoustic: DIY floorstanding 3-way SB Acoustics