RealMarkDeneen Posted February 2 Author Share Posted February 2 On 1/31/2024 at 11:28 AM, babadono said: K1 or K2 have less negative FB? I believe on my K2s it is selectable. 26dB gain or 1.4v for full output which is even more gain. My D75s are 26 dB gain. Also I think Mark turned down the gain on the "Duke". 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. Quote Link to comment Share on other sites More sharing options...
babadono Posted February 2 Share Posted February 2 1 hour ago, RealMarkDeneen said: 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. You changed the Zin to 47K. And the gain from26dB to about 17.5dB. All this of course if the list of your changes that I obtained from @Marvel is correct. 2 Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 2 Author Share Posted February 2 6 minutes ago, babadono said: You changed the Zin to 47K. And the gain from26dB to about 17.5dB. All this of course if the list of your changes that I obtained from @Marvel is correct. Right..that makes sense. My memory ain't that great anymore. 1 Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 2 Author Share Posted February 2 @NOSValves This guy hasn't answered any of my inquiries. Weird, isn't it? https://www.ebay.com/itm/154913813046 1 Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 4 Share Posted February 4 On 2/2/2024 at 12:14 PM, RealMarkDeneen said: @NOSValves This guy hasn't answered any of my inquiries. Weird, isn't it? https://www.ebay.com/itm/154913813046 Mark, That is pretty strange since the seller has a lot of feedback and 100% positive. Did you mention you are Mark Deneen? I have a question what is the signature on the upper right side of the face plate? At least it looks like a signature. Craig 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted February 5 Share Posted February 5 I noticed there is a deneen pottery company... Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 5 Author Share Posted February 5 22 hours ago, NOSValves said: Mark, That is pretty strange since the seller has a lot of feedback and 100% positive. Did you mention you are Mark Deneen? I have a question what is the signature on the upper right side of the face plate? At least it looks like a signature. Craig 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. Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 5 Author Share Posted February 5 7 hours ago, Schu said: I noticed there is a deneen pottery company... Yeah, I ran into that at the Grand Canyon gift shop a couple of years ago. No relation that I know of. 1 Quote Link to comment Share on other sites More sharing options...
Salectric Posted February 5 Share Posted February 5 Mark, I just ran across this site and was very pleased to see you are still active and supporting the Juicy Music preamps through your posts here. If you don't mind, I would like to ask two questions: 1. In your conversions to use the 6H30, what B+ are you shooting for? 2. There was some discussion recently about the Paragon 12 and the E preamp. That brought back lots of memories for me. I recall the early days following the initial review of the Paragon 10 and I remember hearing how a certain fellow from Down Under "borrowed" your design. After all these years I would be curious to see what the real circuit looked like. Is the schematic of the E available for posting? Thanks in advance. Dave Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted February 5 Moderators Share Posted February 5 @RealMarkDeneen In light of that ADC Signature Preamp popping up. What do you consider to be your finest work? Paragon System E? Something in the Juicy Music range? Traivs Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 5 Author Share Posted February 5 52 minutes ago, Salectric said: Mark, I just ran across this site and was very pleased to see you are still active and supporting the Juicy Music preamps through your posts here. If you don't mind, I would like to ask two questions: 1. In your conversions to use the 6H30, what B+ are you shooting for? 2. There was some discussion recently about the Paragon 12 and the E preamp. That brought back lots of memories for me. I recall the early days following the initial review of the Paragon 10 and I remember hearing how a certain fellow from Down Under "borrowed" your design. After all these years I would be curious to see what the real circuit looked like. Is the schematic of the E available for posting? Thanks in advance. Dave 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 Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 5 Author Share Posted February 5 25 minutes ago, Travis In Austin said: @RealMarkDeneen In light of that ADC Signature Preamp popping up. What do you consider to be your finest work? Paragon System E? Something in the Juicy Music range? Traivs 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. 3 Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 5 Author Share Posted February 5 36 minutes ago, Travis In Austin said: Paragon System E? Something in the Juicy Music range? 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. Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 5 Author Share Posted February 5 1 hour ago, Salectric said: I remember hearing how a certain fellow from Down Under "borrowed" your design. 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. 1 Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 6 Author Share Posted February 6 1 hour ago, Salectric said: 1. In your conversions to use the 6H30, what B+ are you shooting for? 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. Quote Link to comment Share on other sites More sharing options...
Salectric Posted February 6 Share Posted February 6 Thanks Mark. Much appreciated! 1 Quote Link to comment Share on other sites More sharing options...
Salectric Posted February 6 Share Posted February 6 The E schematic brings back lots of memories. I don’t wish to derail this thread so let me just briefly say that I built the E phono stage back in 1976 or 1977. At the time I knew it as the Trevor Lees design; it was only later that I found out he had copied your circuit. At the time I was a penniless grad student, but a friend saw the ad for the Trevor Lees kit and ordered one. I xeroxed his schematic, designed and etched a circuit board, and built it within a week. I thought it sounded great, much better than my DIY version of the Audio Research SP-3a1 phono. I also remember measuring the RIAA accuracy using an inverse RIAA network, and your design had the flattest response I had measured. In contrast, the SP-3 wiggled and jiggled. Anyway, I owe you a belated thank you for the design. I can understand why people still enjoy the sound of their Paragon preamps. 1 Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 6 Author Share Posted February 6 12 hours ago, Salectric said: Anyway, I owe you a belated thank you for the design. I can understand why people still enjoy the sound of their Paragon preamps. Great story--thanks! Quote Link to comment Share on other sites More sharing options...
Salectric Posted February 15 Share Posted February 15 Mark, I hope you won’t mind answering a question about your preamp designs. In looking over the linestage schematics, I noticed that many of your linestages have a fairly low value load resistor on the output. The original Blueberry and Peach have 47K, and Blueberry Extreme has 100K. Tube linestages typically have a higher value like 470K or 1M which is low enough to avoid a static voltage buildup on the output cap if there’s no amp connected but high enough to avoid loading down the output. I am sure you had a reason for choosing a lower value load resistor. I am just curious what it might be. Thanks in advance. Dave Quote Link to comment Share on other sites More sharing options...
RealMarkDeneen Posted February 23 Author Share Posted February 23 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 Quote Link to comment Share on other sites More sharing options...
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