X2.5 Preamp —nNo problems other than Sound

what you have of replies being in range of broad generalizations ?

And you can get only that sort of replies if question isn't proper
Fair enough
there is no comparison between "big cap bank" and "shunt"

cap bank, whatever size of it, must be part of rectifier and filtering block
Yes, I understand ac snubber/rectifier/cap bank filter/voltage reg. order of things and where the reg might be shunt or of IC flavor. I will try to pose more specific questions. Possibly we agree a larger number of filter caps after rectifier in front of the reg can lower a PS impedance? And does the voltage regulator have impedance as such? or in less general terms, would a shunt reg circuit have a lower impedance than an 7X15 IC or fancy Sparkos IC reg? When I say impedance of the power supply, I think of it as the speed or transient response of how the dc supply responds to the lower electrical potential of the circuit it feeds. Am I correct ? For X2.5 40v appears to feed the regs. why such a large voltage differential? Possibly this conversation re shunt vs IC is discussed on another thread and would be happy to migrate. I do have an eye to maybe shift some things with what Wayne called a "20 year old" piece of gear. But, maybe not. Peace
Joined 2002
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Wow Wayne. Thanks for your response. Deep respect. I'm an idiot savant who questions everything and builds and rebuilds. The coupling caps are blue and seem really small for 1uf. Polyester? My first thought about this was to short all those blue polyester things and if it worked, put them in a bin. I've ordered a
Bunch of parts from parts connexion and mouser. I know it can sound better. I'm in the mountains listening on battery but will get back on board number. Why are there IRF 610 off the relays?
The input selection uses the TO-220 fets to turn the relays on. Yes those caps can be shorted out.
I will look up the schematic.
What board revision on the main board?
PL62R3 main board and UGS4. Thank you for info on Volume Control! And I have to think Panasonic thin film /shunt would be pretty neutral sonically. I am very carefully considering putting a soldering iron to this board (I have FR-301, but prefer reflow heat gun with flux first). The only thing I'm thinking about now is removing dc caps. My source is solid and my X150.5 (2013) has dc blockers. Would this in your opinion make sense? I don't care about warranty or resale. Just sound. The 15v voltage regs are marked JRC. Thinking Sparkos Labs will have lower noise spec. Or If I listen to the more rational voice in my head, I could put the hood back on, contact Kent, send it to California and we could talk about making some changes. Either way, Thank you Wayne for your response. PS any schematics you are able to share, I will initiate a request separately.
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Joined 2003
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I could put the hood back on, contact Kent, send it to California and we could talk about making some changes.

that would be best, if possible

anyhow, any change I would make on that preamp ..... demands radical changes of parts of circuit, thus impossible on existing platform

and, final result would certainly more feed my ego than I could improve how it sounds

anyhow .... you want better (meaning different)

  • leave X2.5 as is, pair it with some other amplifier to get desired results
  • sell X2.5, buy/build preamp which suits you more