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RealMarkDeneen

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Everything posted by RealMarkDeneen

  1. The output tube of the preamp is working into a low pass filter where the total capacitance of the connecting cable is shunting the output of the tube. A typical rca cable might have 12pF/ft of capacitance between conductor and shield. Example 1. 8-foot cable @ 12pF/ft.. is 96pF. A 12AX7 in the BBX with zero feedback has an output impedance of say 75k ohms. So using that 96pF cable gives an upper bandwidth of a mere 22kHz. That's not going to give you sharp square waves. If I cut the capacitance down to 40pF I get 53kHz which is better. Example 2. Using a Peach in SuperLoZ mode, the output impedance is 600 ohms. So, I can connect 100 feet of cable @12pF/foot (total 1200pF), and I still get a whopping 220kHz bandwidth. THAT will have sharp square waves. Now you understand the reason for the Peach! Keep your cables short, and use low capacitance cable. Now, whether any of this is audible is a complicated matter and depends on many other variables. So, I'm not making a big deal out of it for SQ. But by measurements it is easily measurable. Cheers Travis, M
  2. Hi Dave, The higher the load resistance, the more the external cable capacitance will interfere with HF response. I like the line out to pass very sharp 10k square waves. Cheers, M
  3. 6H30: Using a 10K 2W plate resistor and 560 ohms cathode and 10k grid resistor you want 100V on pin 1 and 6 plates. Adjust the B+ feed resistor as needed. I don't recall the exact value but it's easy to adjust.
  4. Yeah. That would be Trevor Lees. He was a bright whippersnapper and took our phono section (which was pretty unique at the time) and stuffed it into old PAS3 chassis' without a line stage for maybe $250 bucks? Our Model 10 was selling for $895 at the time. He was a "local sensation" for a year or so. Nice guy. That era - 1970 - 1980- was, IMO, the golden Age of high-end audio in the Bay Area. It was a time of talent, ideas, and fun that is gone forever. I am so happy to have been a small part of that scene.
  5. My first whack at the audio business was Paragon Audio. I started it in 1974 with Bruce Moore (Audible Illusions). We made the Paragon Model 10, Model 12, and 12A as the big preamps, and then I made the System E as an Entry level preamp. The big ones were designed to compete with the mighty Audio Research SP3a. Yeah - wishful thinking, huh? Bruce left in 1975, and I kept it up until 1980 and sold out to ADC where I went and made the B-100, but decided Connecticut wasn't for me, and we moved back to Cali.
  6. Hi Travis, Hmmm....The most difficult was the ADC B-100. However, I haven't heard one since the CES show of 1981! It's overly complicated, but at the time I think it sounded better than the Paragon 12A. According to my current recollections, the Peach II is my "best work. " It is novel, well-built, sounds great, and is pretty reliable, especially after the low-voltage bridge mods. OTOH, the BBX was the most fun - had the killer phono stage and especially the early versions had a look that I really loved. This month is the 20th "birthday" of the BlueBerry. The original prototype chassis shown here.
  7. Hi Dave, Ironically, NOSVALVES just sent me the System E schematic last week. I had lost it for good! Here you go. Cheers Mark Paragon E actual 1.pdf Paragon E actual 2.pdf
  8. Yeah, I ran into that at the Grand Canyon gift shop a couple of years ago. No relation that I know of.
  9. The B100 was part of the ADC "designer series" for 1981 and that scribble is my signature. Yes, I told the guy I was Mark Deneen, the designer. He just didn't answer. Oh well.
  10. @NOSValves This guy hasn't answered any of my inquiries. Weird, isn't it? https://www.ebay.com/itm/154913813046
  11. Right..that makes sense. My memory ain't that great anymore.
  12. Not 100% sure, but I think I changed the input sensitivity to 2V and raised the input impedance to 56k or something like that. I wanted to be able to drive it with a BBX. The sonic change came from the faster OpAmp and boutique caps.
  13. Yeah, really raw beast! Like hand made sheet metal and P2P kind of beast. Somehow we made 100 of them! If I described how we made them you'd split a gut. But the 10 was what got the Cream of the Crop cover story in Sound Advice magazine. A week after that review came out I had HUNDREDS of letters/orders from around the globe--asia, europe, japan, etc. Only TWO units existed, and one was at the magazine! If I had been smart, I would have called the magazine and said, "Hey, it was just a prank." Cheers
  14. Well the only skeleton that hasn't come out of the closet now is the Paragon Model 10 which is to preamps what a Rat Rod is to a Foose hot rod.
  15. OMG! That thing looks mint. And, he says it's working! I can't imagine how he came up with that price. I'm floored. I think I'll contact him to see where he got it. Should be fun! How DO you find this stuff Craig? cheers!
  16. I did rent an IBM Selectric typewriter though. At that time it was almost as expensive as our Sound Technology Distortion Analyzer. I had young tech who was building IMSAI computers and told him no one would ever care for their own computer. That's how dumb I was.
  17. Hi Craig, I just saw this. I haven't been checking much lately as the traffic slowed to a crawl. Yeah, System E docs would be cool to have. Just send them to aroadrunner@protonmail.com. I would guess that i drew them, but I haven't seen those things in 50 years! I get a Paragon question about once a year now. Not many left in service i think. How's life treating you, Craig? Still doing it? 🙂
  18. Zen, There have been several phases in my 23 years here and so many guys that have gone missing over the years. There was a speaker building phase, vintage Tube Amp phase, arguing over analog v. digital phase, a couple phases, the Juicy phase, the really bad phase and now a retirement phase--🥸. I hope i make it to 25 years before the lights go out! Hope you and yours have a wonderful new year!
  19. Bruce, David - - Thanks for letting me know your "Juices" are still flowing! Nice setup David. The Duke still reigns! Duke Spinner - People Chow was a project I worked on in the 90s. It occurred to me that most people feed their dogs the exact same food every day. I thought if that worked for dogs, maybe it would work for humans too. Why not have the "perfect nutrition" every day instead of monking around with a million different foods - many of them bad for you. So, I began concocting ingredients into a mix that could be stored easily, carried easily, and eaten without utensils - aka People Chow. It was of course 1/2 joking, 1/2 theater for my friends, and 1/2 serious attempt at simplifying my life living in an Airstream trailer on the beach in Half Moon Bay. Happy New Year to you all! This begins my 23rd year on the K-forum. Ha Ha, I don't know what to think of that.
  20. Hey Babadono--- I turned 75 last October. Yup, still out in the desert where I imagine I will someday just walk out into the 120-degree heat and become part of the landscape of bleached bones in the Mojave Preserve. People Chow is still a dream - HOWEVER, I do eat incredibly simple foods in very modest amounts. My menu has about 12 - items on it, which is in some way consistent with the People Chow idea. But when I first worked on P.C. it was 1993 and I was mostly using "carbs" to make the mix. UGH! I am almost a zero-carb guy now. "All you need is meat!" I'm hibernating for the dang winter here. I'm freezing in this 50-degree weather. Can't wait for that 100-degree mark which usually comes in early May. Keeping busy with speaker projects and my very newest "entertainment" of restoring 70's era receivers. Little damn jewels they are! Happy New Year, Amigo! Mark
  21. WOW---I am amazed! I loved the System-E. We sold those for about $495 and they were insanely great sounding. It has the same phono section as the Paragon Model 12, but we simplified the line stage greatly and got rid of the tone controls. Every now and then I hear from a Paragon owner - usually they are in Europe. So glad to hear you are enjoying it. I have not seen one with my own eyes since 1980. The System-E was the first commercial preamp I designed. If you ever find a "BlueBerry Xtreme", I'll be happy to restore it for you. Look for the later model in black metal chassis. Cheers, and Happy New Year! Mark
  22. I live in an area with lots of casinos. On any particular weekend, one could go see any number of 1950s - 1970s rock/pop stars. Last week was Frankie Valle supported by a troupe of 20-year old "backup singers." 🙂 Tony Bennet sang well into his 90s. I guess what I'm saying is that I think this is just the very beginning of the Stones' "goodbye tours" - -you still have another dozen years to catch them somewhere!
  23. Last August I purchased a new pair of RP-600M for my office/lair. They arrived with no visible box damage and seemed ok when I hooked them up. I've only run them with a couple of little restored vintage receivers - no big amps or anything dangerous. A week ago, I started hearing distortion - especially in upper midrange and especially on vocals and cymbals. I've spent a week changing out amps, sources, switches, other speakers, and so forth to no avail. It's in the speakers - one more than the other. I've sent a request to Support today. But while I'm sitting here waiting over the holiday, I want to see if there were any "recalls" kind of known problems. Although I bought them in August '22, I believe these are from 2018 or so production. Cheers! Happy New Year!
  24. Doctors receive about 2 hours of education on nutrition. It's forgotten before they get out of residency. The USDA, which produced that ludicrous food chart is tasked with promoting and expanding agriculture, and that means they are never going to stop promoting sugar, grains, corn, soy, and polyunsaturated vegetable oil. They are still (the last of) the believers in the lipid hypothesis of the 1970s. Agriculture and pharmaceuticals go together like a hand and glove. Look at this chart for statins - the most useless drug on the market:
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