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jvandyke_texas

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jvandyke_texas last won the day on August 21 2020

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    Electrical Engineer

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TO-39 Transistor

TO-39 Transistor (11/21)

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  1. Ar9Jim: If Bob has interest in full cancellation SH, have him send me a PM. I'll dig my schematic out of storage. I have one of my C4000s working with the mods.
  2. It's really stereo side/back channels that create immersion. If it doesn't have time delayed extra channels, it's incomplete.
  3. Ar9Jim, what exactly is being designed and who is doing it? What is the purpose? Lifting the old SH circuit and sticking it into a new box isn't going to cut it.
  4. Listening comparison AK-100 and C-9: https://www.youtube.com/watch?v=qHXQMhvvmKg This is the concept: Clearly issued before USPTO limited claims to 20. https://patents.google.com/patent/US4748669A/en Fake stereo from mono: https://patents.google.com/patent/US4841572A/ Dynamically amplifying sum and difference: https://patents.google.com/patent/US4866774A/en
  5. How does the Hughes AK-100 effect compare to the C-9? I would very much like to read the owner's manual. I doubt a service manual is available.
  6. There was a fad of 3 dimensional audio processors in the late 70s. Even Radio Shack had their Realistic version. Most were ham fisted and over the top. Boomy and way overmixed. Carver made his musical and was the winner. It's time he rearranges the delays to cancel cancellations. You get more auditorium reverberation.
  7. 4krow, result will be highly dependent on frequency shaping and injection ratio. So can't bulk dismiss that full cancellation sounds bad. There's a lot of artistry to this.
  8. Forget tubes. The tube sound comes from the amplifier output stage. This is a signal processor. The problem with the SH generator is that it's designed to cancel only the 1st arrival of the opposite channel. I redesigned mine to cancel 1st arrival and all subsequent arrivals. That is, it cancels the cancellation signals. It has quite a different sound, and I had to shape the frequency response differently. It's part of my C-4000 redesign project. Unfortunately the project is on hold since I sold my house.
  9. Very early versions of C4000 (typically under SN#1000) had sonic hologram A board which did not use the Pade delay lines. There was a factory upgrade to fix early C4000 bugs for $67. I know BillD sent his in, because I fixed and modded his C4000. SH upgraded to version B was the biggest fix. Upgraded early units have a "C" written in black felt pen in front of the serial number. The champagne units (and I think some of the early anthrocite units) used 4136 op amps in the phono stage, and were not as quiet as higher serial numbers which had transistor front ends. Units with 35/50 ms rear channel delay most likely will have the delay ICs burned out. They were fragile chips, and low serial number C4000s had a higher voltage power supply in them to give the rear channel amp higher power. But that higher voltage caused reliability problems. Later versions use a lower voltage power supply board. Anthrocite units (gun metal) usually have working rear delay channels. The champagne units are beautiful. You can read the faceplate, unlike the dark anthrocite units. There were many changes vs serial number, and I have cataloged all of them. I have not looked at the notes in years, and they are in storage. Any C4000 with MM phono input will have most of the latest fixes. All versions have a not great correlator design, and the balance control does not work with SH. I redesigned my C4000s to fix all those problems. I'm working on another multi-year project but when finished will resume my C4000 project. The C4000 is by far my favorite preamp. It is the Swiss Army Knife of preamps. My latest changes blink the correlator LED when the gates open and shut. I've also reconfigured the SH unit to cancel the cancellation signals, not just the first arrivals. It gives a very different open sound. That automatic threshold for the correlator is a lie. It's a fixed resistor voltage divider. The problem with the 4000t is the SH is stuck on wide mode, which does not image as well. And Carver deleted the dynamic range expander and substituted the time lens gimmick. The rear amps are missing, but you can use external amps. The correlator is better, though.
  10. Phase Linear 4000 preamp with joystick has a quadraphonic decoder chip and 4 channel output.
  11. Low serial number C-4000s like #0773 do not have the quiet phono stage. There was a factory bulletin and a replacement upgrade to the SH unit for low SN. For $67 you sent the preamp in, and Carver Co. performed the upgrade. If you did not do that, then there isn't a "C" written after the serial number on the back.
  12. It's worth it to set up rear channels of C-4000 with an external amp. Sonic hologram + rear channels gives the illusion you are in a club or orchestra. Much better than SH alone. I modded Bill D's C-4000, and we communicated regularly about the upgrades. Some of the changes went into his C-1 mod. What serial number is your C-4000? Silver or anthracite?
  13. They look sharp. This is why my long term C-4000 will have aluminum face plate, rather than anthracite.
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