I am a solo guitarist/singer with over 35 years of experience performing in Hotels, Restaurants, Bars, Cocktail Lounges, and Private Homes. I play a wide array of styles and types of music from Oldies to Rock, R&B to Country, Ballads to American Standards.
I am available to perform at any and all private parties, birthday parties, weddings, anniveraries, and special events.
Bobby John sang at the Volunteer Appreciation Event which was themed "Breakfast at Tiffany's". He was wonderful. It was great background music while they had breakfast and mingled. They sang along to "Moon River" and everyone left happy. Thank you Bobby John for helping with this event and making it special for the volunteers.
Bobby John was a wonderful addition to our private backyard dinner party. The theme was Latin Chic and he fit in perfectly with a performance including Spanish guitar music and light vocals. He was willing to learn new music for the event and even dressed up! Additionally, he was willing to meet me before to discuss the event and give me a demo. Everyone enjoyed the music and appreciated how he elevated the atmosphere. I would definitely use him again.
A gentleman and a supreme artist. A time of grief is hard on many. He was committed to our family and friends when we needed it the most. I would recommend him to any venue. He made such a sad time comforting, I could only imagine his talent in a happier situation. Thank you Bobby, and God bless you for all you have done.
Bobby John was wonderful to work with and put on an a wonderful performance.
Thank you, Michelle. I was glad to have been a part of your event. I hope I can again be of service to you in the future. ..
wonderful music at the night club -- we enjoyed the music and conversation. I would do it again any time.
I am a true professional. I am very conscientious, punctual, prepared, and friendly. If a client has a certain song request, I learn the song and perform it to the best of my ability. I do not abuse my break time. The performance always come first.
I currently perform at many local nightclubs, restaurants, and hotels; not to mention private parties and events and also at select assisted living facilities.
I have been playing music all my life. I started out playing the accordion when I was 5 years old and took up the guitar when I was 12. My very first gig was a neighbors kid's birthday party. We got paid $5.00 each. There were 6 of us. Wow. We were rich. I fell in love with playing music right then and there.
I got to the point where our band got to be so good that we were hired to back up Dobie Gray ("The In Crowd"), The Drifters ("There Goes My Baby", "Up On The Roof", "Under The Boardwalk"), perform at the Teenage Fair in Hollywood, perform at The Teenbeat Club in Las Vegas, Nevada (every summer for three years), open for "The Ike and Tina Revue" at Pierce College, and many other memorable gigs.
I decided to go it alone and performed steadily ever since in many nightclubs and restaurants in and around Orange and L.A. Counties. I have had the great opportunity to play with many other musicians and singers through the years as a duo, a trio, and as a 4 piece. I still perform with others. Samples are uploaded here on GigSalad.
I perform a lot of 60's, 70's, and 80's music. My set list will follow.
My list is extensive. The Beatles, Rolling Stones, Motown, Blues artists, and some Country acts as well.
The only thing I require is being set up close to an electrical outlet..


What is the PRRT Seminar Bundle?
The PRRT™ Seminar Bundle includes everything that is covered at a live training seminar, packaged in an easy to use, study at your own pace set. We call it the "Bundle" because in addition to all the material you will be receiving, you get FREE access to a live one-day refresher course at your next live training!
How is The PRRT™ Bundle like a live training?
The PRRT Basic Bundle is just like the live training except even better as it's John, the developer of PRRT, teaching you with his 2 decades of experience at your convenience.
I recently purchased Reflex Speed Pain Release™, what is the difference between the two programs?
Reflex Speed Pain Release™ is a great tool for rapid assessment and treatment techniques for 30 different common conditions you see every day. The PRRT™ Seminar Bundle is a must for anyone who is serious about moving forward with PRRT™. It goes into detail about the history, theory, exam and application used in PRRT™. The Bundle includes everything that would normally be covered at a live (Basic level) training.


Ramadan is the most sacred month of the year in Islamic culture. It is a time for sacrifice and renunciation as well as a period of reflection and spiritual growth. With Muslims around the world fasting simultaneously while bringing family and friends together, it is also symbolizes powerful unity. In welcoming this long-awaited month, The Dharmawangsa is set to celebrate the divine feast of Ramadan with selections of authentic dining and luxurious accommodation experience like no other.
Share an unforgettable Iftar moment with an unparalleled Ramadan spirit over a spread of delectable Indonesian and International cuisines presented on the buffet and food stations. The menu highlights set to take guests on a culinary journey across the archipelago featuring ikan asam padeh, dendeng balado and beef rendang from West Sumatra; ayam tuturuga, daging garorica and udang bakar saus dabu-dabu from South Sulawesi; tahu tek and tahu campur from East Java, nasi jamblang and empal gentong from Coastal Java and many more. While from the carving station, the culinary team presents mouthwatering rendang glazed rib eye beef, kambing guling and traditional braised rib eye.
Price at Rp 595,000++ per person (adult) and Rp 395,000++ per person (4-11 years old child), inclusive of ta'jil, hot tea and Ramadan special drink.
For the month-long series of daily Iftars, the guests are invited to blend in the flavours, aromas and scenes of the Marrakech. The modern function room will be transformed into a Moroccan Ramadan majlis, where an enticing Iftar buffet will be served and Arabic pipe music will be played in the background. The buffet will features an array of Middle Eastern, Indonesian and International delicacies such as assorted cold mezze, shish tawook (grilled chicken skewer), quzzy (slow cooking lamb served with roasted nuts, vegetables and Arabic rice), chicken mandi, lamb kebuli, shawarma live station, iga panggang madu, as well as the signature giant lobster Bunaken and nasi liwet keprabon.
Price at Rp 695,000++ per person (adult) and Rp 495,000++ per person (4-11 years old child), inclusive of coffee and tea.
With the expert team that has been creating great events for more than 21 years; the team of 'Chef at Your Place' provides bespoke events at the outside private venue of your choice throughout the holy month and on the day of Eid al-Fitr.
Price starting from Rp 695,000++ per person for Ramadan Iftar and Rp 195,000++ per portion for the Indonesian specialties stall on Eid al-Fitr day.
The venues at The Dharmawangsa provide the exclusivity where business partners and colleagues can savour in an authentic dining experience. The exemplary culinary and banquet services culminate tailor-made menus with the Indonesian hospitality providing guests with the most memorable experiences.
Price starting from Rp 585,000++ per person.
Cherish the holy month of Ramadan and celebrate the auspicious moment over Eid al-Fitr holiday with our exceptional room program offering suhoor or breakfast for 2 persons, ta'jil at Majapahit Lounge, 10% savings on F&B, Spa and Laundry.
 Ramadan Room Programme starting from Rp. 2,950,000++ per night, valid from May 5th to 31st, 2019.
 Eid al-Fitr Room Programme starting from Rp 2,750,000++ per night, valid from June 14th to 30th, 2019.


Master Techs Auto Repair provides Cooling System Flush & Fill services to West Palm Beach, FL, Royal Palm Beach, FL, Loxahatchee, FL, and other surrounding areas.
Why Should You Have Cooling System Flush & Fill Services Performed at Master Techs Auto Repair?
We proudly service the Cooling System Flush & Fill needs of customers in West Palm Beach, FL, Royal Palm Beach, FL, Loxahatchee, FL, and surrounding areas.


text:
Students, community rally for Augsburg professor facing deportation
MINNEAPOLIS (KMSP) - A beloved Augsburg University professor, who is facing possible deportation, is receiving a groundswell of support from students and community members.
Humbled by the crowd waiting for him, Dr. Mzenga Wanyama thanked dozens of supporters as he stepped out of his latest meeting with Immigration and Customs Enforcement Friday.
"Even if they had detained me, your presence here would have made me happy right in there," said Wanyama.
Wanyama said this is roughly his third so called "flare up" with ICE, but it is the first time he has not hidden meeting with agents from his close friends and colleagues.
After coming to the United States from Kenya in 1992 seeking political asylum, Wanyama received a doctorate from the University of Minnesota and later taught in St. Cloud. He now teaches African-American literary history and postcolonial theory and literatures at Augsburg University. He has no criminal record and has not missed a single supervised check-in with immigration agents, but has now over-stayed his visa.
"I must admit one of the reasons I didn't talk about it is because I feel embarrassed," said Wanyama. "I feel embarrassed to think I have problem like this."
In a statement, ICE clarifies Professor Wanyama does not have legal status. He entered the U.S. several times on nonimmigrant visas between 1992 and 2005. He overstayed his most recent term of admission by several years.
In 2010, a federal immigration judge granted him voluntary departure, requiring him to leave by mid-June 2010. He did not and instead appealed the decision. In December of 2011, the Board of Immigration Appeals dismissed his case, granting him 60 days to leave the country. Again, he did not follow the court order.
In 2012, the U.S. Circuit Court of Appeals denied Wanyama's petition to review the case and since he did not depart by the court ordered deadline, he automatically becomes subject to the final order for removal.
"You can't want to be a part of this great nation and not respect its laws," said ICE Deputy Director Thomas Homan in a statement in part. "When that due process is over, that final order from a federal judge needs to mean something or this whole system has no integrity."
"I think diversity is under attack," said Gabriel Benson, one of Professor Wanyam's students.
Wanyama will meet with ICE again next month and was instructed to make concrete plans for his departure back to Kenya.
To show their support for the professor, students and community members started an online petition, which has more than 7,000 signatures.
"I really don't know how to say thank you, because I don't think I've done anything to deserve this, so this is not about me," Wanyama said to the group. "This is about you and what you can do to make things move."
The president of Augsburg University and Minneapolis Mayor Jacob Frey say they are working to help Dr. Wanyama get to an immigration status that will allow him to stay.
Augsburg University President Paul Pribbenow full statement:
"We are relieved for the moment that Dr. Mzenga Wanyama has additional time to pursue options to stay in the United States long term. We support him and intend to vigorously work toward an immigration status that will allow him to stay. Augsburg's mission embraces people from a diversity of life experiences, and Dr. Wanyama has been a respected friend, teacher, and peer. Dr. Wanyama's scholarship in postcolonial theory and literatures and in African-American literary history plays a critical role in Augsburg's undergraduate curriculum. His expertise is unique and would certainly be very difficult to replace. We are grateful for the thousands of people who've voiced their support for Dr. Wanyama to remain in the United States."
Minneapolis Mayor Jacob Frey full statement:
"Dr. Mzenga Aggrey Wanyama is a pillar in his community. For over two decades he's helped shape future leaders in Minneapolis and beyond. Our city and our region are better for his work. No President, no federal agency will deport Dr. Wanyama without a fight from me, from our partners in the state and federal delegations, and from the thousands of people in Minneapolis who share our values."
ICE Deputy Director Thomas Homan full statement:
"You can't want to be a part of this great nation and not respect its laws. So when you violate the laws of this country -- and the taxpayers in this country spend billions of dollars a year on border security, immigration court, detention. And they go through a process. They get a decision from the immigration judge -- most times will appeal to the Board of Immigration Appeals, then to a circuit court. When that due process is over, that final order from a federal judge needs to mean something or this whole system has no integrity."

redpajama_set_name: RedPajamaCommonCrawl


text:
KTM's 2020 Enduro Lineup Is Full Of Podium-Winning Performance
Chris West
Category: Rides
After bringing a handful of exceptional, enduro-oriented machines to market each year, KTM has once again set the bar for the motorcycling industry in terms of power, performance, and innovation. The Austrian manufacturer recently unveiled its plans for the anticipated 2020 EXC line — outfitting a wide range of two-stroke (and four-stroke) platforms with the company's upgraded architecture.
Standing atop the podium of the enduro world isn't a new experience for the brand, and with the introduction of seven new variants for the upcoming season, it seems that KTM's outdoor division won't give up the crown so easily. The company's powerful two-stroke offerings will be bolstered with the addition of two new bikes — the KTM 250 EXC TPI and KTM 300 EXC TPI — outstanding machines that have found their stride with the addition of more efficient engine capabilities, a re-developed chassis, and improved handling thanks to the implementation of the company's WP XPLOR suspension system. Alongside these two-wheeled rompers, the company has announced a handful of four-stroke upgrades, including the KTM 250 EXC-F, KTM 350 EXC-F, KTM 450 EXC-F and KTM 500 EXC-F — all of which boast the same upgrades we've referenced above. Aside from the inclusion of these beneficial improvements, NEKEN handlebars, Brembo brakes, No-Dirt footpegs, CNC milled hubs, and revised cooling/exhaust systems will also find their way onto the new bikes this June — proving, once again, that KTM is a force to be reckoned with when it comes to hardcore enduro.
More From Rides
The 20 Most Expensive Motorcycles Ever Sold At Auction
The creme-de-la-creme of the vintage two-wheeled realm.
Ares Design Honors The Defender With A Bespoke Carbon Fiber V8 Build
The exterior has been stripped of adornment -- even its rivets.
Sony's 149MPH Vision-S Electric Car Is Now A Bonafide Road-Going Prototype
Power will be sent to all four wheels by a pair of electric motors.
Polaris Unleashes A Heavily Upgraded, Best-In-Class 2021 RZR Trail SxS Lineup
With updated styling, new interior amenities, and greater trail-ready performance.
This Retro-Themed Street Bike Started Life As A No-Frills 2006 Ninja 650 Moto
Cowboy's Chopper turns a Kawasaki commuter bike into a vintage-flavored standard.


Six faculty members are recipients of Excellence in Teaching Awards at the University of North Carolina School of the Arts for 2018-19, Provost David English has announced. They are Trish Casey from the School of Dance, Kate Douglass from the High School Academic Program, Janine Hawley from the School of Drama, Eric Rimes and Jason Romney from the School of Design and Production, and John Roberts from the School of Filmmaking.
At UNCSA, recipients are chosen each year from those current, full-time members of the faculty who are nominated by students, alumni and peers to receive an award. They will be honored at the University's annual Celebration of Excellence in April.
The Excellence in Teaching Awards were established by the University of North Carolina Board of Governors in 1994 to encourage, identify, recognize, reward and support good teaching at each of its 17 constituent institutions. In the spring, one recipient from each campus will receive a System-wide teaching award from the Board of Governors. That award includes a $12,500 stipend, a commemorative bronze medallion, and recognition at commencement exercises.
Trish Casey is an Associate Professor in the Contemporary Dance Program.
Trish Casey joined the faculty of the UNCSA School of Dance in 1989 and currently serves as an Associate Professor in the Contemporary Dance program. She has a joint faculty appointment in the Division of Liberal Arts. As a proud alumna of both the high school and undergraduate programs at UNCSA, Casey has a long-standing relationship with the school spanning more than four decades. She declares herself to be "shaped by the wisdom, vision, practices and aesthetic values of beloved teachers along the way," and in turn, she continues to inspire students who will impact the field for years to come.
Characterizing herself as a "lifelong learner with an insatiable curiosity" in her Philosophy of Teaching Statement, Casey has undertaken a Lincoln Center Education Summer Immersion Workshop, a Gyrotonics Pre-Certification Teachers Course, and work as a Level 4 Apprentice of Healing Touch, among numerous other studies. "I want students to be inspired by seeing that I am inspired, motivated because I am motivated, searching because I am searching, passionate because I am passionate, and discerning because I care to be discerning," Casey said.
Casey earned a High School Arts Diploma and a Bachelor of Fine Arts in Contemporary Dance from UNCSA, and a Master of Fine Arts in Modern Dance from New York University's Tisch School of the Arts. Prior to joining the faculty of UNCSA, she was a member of the Pauline Koner Dance Consort in New York City and the faculty of Southern Methodist University. She is a previous winner of the UNCSA Excellence in Teaching Award in 1997 and the UNC Board of Governors Excellence in Teaching Award in 2005.
Kate Douglass teaches Social Studies in the High School Academic Program.
In 2015, Kate Douglass joined the Social Studies faculty in the High School Academic Program, where she currently teaches Advanced Placement U.S. Government and Politics, Civics and Economics, and Advanced Civics and Economics. This past December, she earned her National Board for Professional Teaching Standards Certification, the most respected professional certification available in K-12 education.
Douglass earned her Bachelor of Arts in History with minors in Classical Studies and Political Science from Virginia Tech University, and her Master of Arts in Secondary Social Studies Education from Wake Forest University. Prior to joining UNCSA, she served as a Social Studies teacher at North Brunswick High School in Wilmington and Hanes Magnet School in Winston-Salem. She is engaged as an Advanced Placement Reader for the AP Exam in U.S. Government and Politics.
Janine Hawley teaches singing in the School of Drama and is the founding director of Acting Out! community outreach program.
Janine Hawley joined the School of Drama as a faculty member in 2013, moving from a 2001 position as guest artist to adjunct status before assuming her appointment. She currently teaches singing in the School of Drama, leads the Acting for Singers course in the School of Music, and is founding director of the vibrant Acting Out! community outreach program through UNCSA's Community Programs.
Hawley holds Bachelor of Music degrees in Voice Performance and Choral Music Education from Indiana University, and a Master of Arts in Voice Performance from Columbia University Teachers College. Her students regularly place in the top three in the National Association of Teachers of Singing Musical Theater auditions for the Mid-Atlantic Region. Former faculty appointments include the Hartt School, Greensboro College and Wake Forest University. She has soloed with opera companies in Washington, Philadelphia, New Orleans, New York City, Miami, Boston, and Fort Worth, among others, receiving critiques that praise her lush quality, dark timbre, technical facility and charming stage presence. Concert performances are an equally important aspect of Hawley's art; she has performed in such venues as Lincoln Center's Alice Tully Hall, Carnegie Hall and Weill Recital Hall.
Eric Rimes is Professor of Lighting Technology in the School of Design and Production.
Roberts attended UNCSA before earning a Bachelor of Arts in Art History from University of North Carolina-Wilmington. Prior to joining the faculty at UNCSA, he worked as Picture Editor on film and television projects including "Designated Survivor," "Code Black," "Sleepy Hollow" and "Glee." He was engaged as a member of the Duke Talent Identification Program (TIP) faculty in Filmmaking at Chapman University from 2008-2012.
Jason Romney is Director of Sound Design and Assistant Dean of the School of Design and Production.
Romney earned a Bachelor of Fine Arts in Theatre Design and Technology from Utah State University and a Master of Fine Arts in Sound Design from UNCSA. He has designed sound professionally at Children's Theatre of Charlotte, Imagination Stage, Triad Stage, Playmakers Rep, Alliance Theatre Company, Piedmont Opera, Weston Playhouse Theatre Company, Utah Festival Opera, and others. He is also a self-taught computer programmer, developing software solutions for sound designers and engineers. His programs are used by professionals in the theater, film and music industries and in educational institutions across the country. He recently published a book, co-authored with Jennifer Burg and Eric Schwartz, entitled "Digital Sound and Music: Concepts, Applications, Science." He was Co-Principal Investigator for a National Science Foundation Course, Curriculum, and Laboratory Improvement research grant from 2008–12.


Well if the op amp(gain stage) is designed well then it should be tollerant to capacitive loading from the output stage internal capcitances. Poorly designed op amp then I'd agree that it may be a plorbem with highly capcitive output stage.
I'm using half fake Chinese tip41c as my head amps output stage(takes only 32W max), also tried tip3055 2955 fake transitors which both case I get same frequency response and slew rate.
My amps gain stage not excatly tuned for high frequency but with 90 degree phase margin slew rate is arround 15v/us.
If I was to convert to power amp All I would be doing is resetting resistor values to suit higher voltages or use parallel transitors for my op amp stage to stand higher voltages without reducing bias current.
What do you mean by opamp gain stage? You use IC opamp or you mean type opamp design in discrete form.
No, power electronics is nothing at all this simple. I thought is simple too before. It is not simple like you described by just scaling up. It described in Cordell's book about input capacitance of transistor proportion to current. When power goes up, capacitor loading the front end change drastically. You get into conditional stability problem. Amp don't oscillate that easy in small signal, only in large signal. You see oscillation riding on part of the sine wave!!!
Power electronics is really a separate topic. I used to think how hard can it be in audio frequency after years of designing RF, ultra low noise high speed analog, analog IC design and all other analog circuits. I was surprised by how power electronics different. That's where simulation models fail big. They cannot account the change of characteristics accurately.
Look up the thermal derating of TO220, when temperature is up, you don't get 20W or anything close. That's the reason people use many pairs of big transistors that rated 250W each and they still burn transistors if not careful.
I actually thought of using many pairs of TO220 as output stage, it did not pan out at all. The reason I thought about it is I want fast transistors of over 100MHz to get better stability. Long story short, I need like over 20 pairs or more. Can you imagine the work to drill holes and mount the transistors with isolation pads. Let.s just say, I spent the last night mounting my 9 pairs on the pcb and heatsink. Just one amp, hours. I spent one night drilling and tapping hole on the heatsink. Imagine triple the amount of transistors.
TIP42 is too old, too slow. It's not easy to find good transistor. I use 2SC4883 and 2SA1930 TO220 for pre-drivers, over 100MHz, high beta 150V. They are all discontinued, I bulb buy 100 each as I use 2 pairs only for each amp. The faster the transistors, the easier to tame the stability.
It is not that simple, that's why I take on power amp as a challenge.
You have the book by Bob Cordell? It's a very good book. I talked to him a lot on the forum before. We both were analog IC design engineer before ( power amp is like a big discrete opamp inside). We both have a lot of insight in this subject. He talked a lot about these subject in the book.
I go on a separate post as it gets too long.
We only talked about the theoretical amp design so far. There is the real world. When you run like 10A signal, a wire is not a short circuit, the grounding and power distribution becomes a big problem. The ground becomes a design by itself, so is the power distribution. You need to think like the current, where does in go. Designing the power supply and distribution is a separate subject. I have to say, there are still things I cannot explain in the power amp. I thought I've seen enough electronics. But when you are pushing to 0.001%THD, it's like RF, nV level of noise, High voltage etc. There comes a point of time it's hard to explain.
Imagine the simple bridge rectifier gave me problem, the turn off is too slow and it affect THD reading. I have to resort to pay $25 each of the bridge rectifier to lower the THD and make the wires less sensitive to where it rest. I can explain it now, but that alone took me like 2 or 3 days. It's like voodoo that I can change the THD reading by waving my hands on top.
When you get down to 0.001%THD, everything matters. To get 0.1dB flatness to 20KHz, you need an amp that response way into hundreds of KHz. To prevent large signal distortion, you need like slew rate of 30V/uS.
I have not looked at the book by bob cordell.
Further more all I had talked about is what happens in my real life testing, as said before I do not belive in circuit simulators nor use them.
I had emphasied head amp able to drive 8 r headphones to be same as power amp, becase mainly what made most of my head amps have cross over like distortion was from a large load like 8 or 4 r.
I think this is because of the current drawn out of the op amp when voltage swings it reduces gain and causes it to mailfunction.
Fruther more when there are multiple output devices normally the predriver handles the capcitance at ease.
This is becasue its low output impedance and has high current sink source capaciblity, this allows like 10 pairs internal capacitance to charge up quickly, therefore 10 and 1 pair should hair fairly simliar response.
I've not tried more than 3 pairs yet on scope, but I would be making a class a amp with 8 pairs of output when I have time I already have the case.
I normally not chose high frequency and low capacitance capacitors because japanese transitors 2sa 2sc 2sb 2sd has poor sound quality compared to just a geniune tip3055, pre drivers are also worse than a tip41c.
I like mj14003 14002 and tip36c and 35c +3055. I like mpsa06 or mpsa42 for small dudes.
MJ14003 has arround a BE BC voltage at 0.45v measured on meter BE voltage is also like 0.02 0.03 volts higher than BC voltage, this kind of high power transitor really had improved my lisetning expreience.
Small signals to-92 I find fairly simliar to non japanese ones however I still prerfer to stay away.
Just every time I test japansese transistors they give me poor sound quality. Its hard and mid range sounds distorted like mp3.
I've got like 10pairs or so of diffrent japanse transitors from geniune broken down yamaha and luxman machine, amplifier board was fortunate enough to not be dead. Just sound quality not up to standards.
Normally cross over like distortion and higher order harmonics are at higher frequencies, its not auditable theoriotically. I gave one of my audiphilie mates a amp with oscillations, he couldn't tell the diffrence.
From contiuous and precise listening though, high frequencie distorions are actally slightly heard, the oscillations or cross over like distortion are at high freq, the high frequency noise some how is able to get distortion into the 20-20khz range.
I do have some of douglous self amp books, only found it slighlty usefull when I was still a noob. I don't find it usefull anymore though because I am getting into pro range.
I think the main plorbem with self is that he trust and uses the circuit simulators too much. Where my real build has different from sim a few times or even not work I stayed away from sims.
Virtually everything is talked with reference to circuit simulators, it needs more parcticall and more verbal therotical explnantions on whats going on.
I personally don't think transistors make any difference to the sound. I choose transistor for stability. I don't like book by Doug Self at all.
I was on DIYaudio, I was talking with Cordell, Self joined in and got into big argument between the two. Cordell and I both design analog bi-polar IC, we see eye to eye in a lot of things. Power amp is just a big discrete IC. I don't agree with Cordell 100%, they are all human, nobody is perfect. I just look at his explanation and think about it. I did verify a lot of his writing with the IC design book by Grey and Mayer, and from my own experience of designing opamp, I agree a lot with Cordell. I think Self is a little full of himself.
I think for small signal like preamps, simulation should be quite accurate as devices are working in linear mode. LTspice is quite good and is free. Just download from Linear Technology site. It just not accurate with large signal that device becomes non linear.
Ha ha, when you add more drivers and predrivers, that's when trouble starts.
When you said you use 20 transistors with the tube for preamp, are you trying to shape the sound, frequency response. That's the reason that got me curious. Because normally, all the circuit I saw in preamp are just straight pass, no tone circuit, no shaping the response. I just don't see how you need all the transistors to do a straight pass.
I found all the tone control, presence, loudness control contaminate the sound. I always put them on bypass. total passive preamp with just a volume pot gives the most fidelity. I am at the process of finding room in the power amp to put in the motorize volume and remote control to put the volume pot close to the power amp so the short coax won't load down the volume pot to get the best frequency response.
Yes, crossover harmonics are higher order, but remember it down mix and get right back into the audio band.
For my pre amp zero eq control, just direct input and pot on pre amp output.
I personally not like eq either, thats why all my stuff is zero eq.
This is the first amp I designed and built. It is Blameless design ( single LTP input stage). Here are the 3 pages schematics.
First page is the OPS section with SS output relay for speaker protection. I use 9 pairs of output transistors, total bias current is 0.9A ( 100mA per pair) to give the first 13W of pure class A into 8ohm. I have 0.1uF and 10uF right at the collector of all the emitter follower transistors. Together with ground and power plane, this minimize the parasitic for better stability. I use triple EF output stage to increase open loop gain ( avoid loading the VAS stage).
Page 3 is the IPAS section. IPS is Blameless design. I have the page number for the Power amp book by Bob Cordell labeled in different section. They are described into the book on reasoning of using the circuit. The design is very standard, the only difference here is I put ALL the bells and whistles in. I have never seen any amp on the market that put everything in. Even the high end amps like Krell and Mark Levinson leave out a lot of the features. Only thing I can think of is the more complete it is, the higher the open loop gain and the harder it is to tame and make it stable. I worked on a lot of closed loop feedback system, so I put in the time to tame the amp. I found LTSpice simulation is not accurate at all. Simulation might show a lot of phase margin, but the real amp oscillate and I have to tame it by feel. The difficulty is the transistor model is not accurate for large signal. Took me over a week to tame the amp.
This is picture of the filter caps. I have about 2.5F of capacitors using a lot of smaller 10,000uF capacitors to lower the ESL and ESR. I have 100uF, 10uF and 0.1uF in parallel to cover full range of frequencies.
BW of about 330KHz, slew rate of about 30V/uS. THD of 0.001%@1KHz, progressively increase to 0.0035%@20KHz at 46Vpp or 66W@4ohm or 33W@8ohm. Because I use 25V-25V power transformer, the rails are +/-34V only. This is a low power amp of only about 55W@8ohm. But it can drive low impedance. 110W@4ohm and 220W@2ohm.
Last edited by Yungman on 04 Jul 2018, 04:59, edited 1 time in total.
I have to put this in the second post as I can only upload 6 files max.
This is the TOP layer of the main pcb, I have complete ground plane for OPS section and power planes for the IPS/VAS section. Care was taken to make sure the planes are not accidentally cut up by through holes and vias.
This is the bottom layer, I have power planes for the rail voltages. The output has it's own plane instead of a trace.
It feels like a grounding problem, but I have no idea why as one channel works perfect. The grounding design is proven in the other two amps to be solid. It's a cookbook at this point. The pcb is very much the same as the first amp above that you can see the ground plane( blue) is one very solid piece with no cut up. It's 2oz copper, very beefy. AND it was tested and passed on the bench. Only other thing I can do is take it out of the amp and run it on the bench again. I have a suspicion it's going to test out good. I measure all the voltages inside the amp and are all good already.
Strange. There are things that I still discover and learn all the time. On the spectrum analyzer ( on the laptop), things are very sensitive, you literally breath on it and things change, Still have no explanation for all this. Put it in the system, sounds fine ( not a real test, just listen to it at lower level, big boss is sleeping). I am stumped.
Sorry about the ranting, I just run out of idea.


Adult-sized pillows might not be the best for your child. Our specially designed pillows give children the proper positioning they need for a good night's sleep. Made from 100% latex for a healthy sleeping environment, you can rest easy knowing your child is resting on quality pillows.


Image Credit: NASA/Ames Research Center.
NASA's Kepler space telescope may be retired, but the discoveries continue to rack up for this historic planet-hunting mission. Kepler rang in the new year with several new planet discoveries, including a previously overlooked planet of unusual size, as well as a super-Earth and a Saturn-sized world orbiting a Sun-like star.
In the meantime, the Kepler mission has released its final record of the spacecraft's full field of view before the depletion of fuel permanently ended its work. NASA retired the spacecraft on Oct. 30, 2018, to a safe orbit.
The "last light" image taken on Sept. 25 represents the final page of the final chapter of Kepler's remarkable journey of data collection. It bookends the moment of intense excitement nine and a half years earlier when the spacecraft first opened its eye to the skies and captured its "first light" image. Kepler went on to discover more than 2,600 worlds beyond our solar system and statistically proved that our galaxy has even more planets than stars.
This is Kepler's view of the TRAPPIST-1 system, an ultra-cool red dwarf star with seven rocky planets, at least three of them believed to be temperate worlds.
For this final field of view, Kepler's last observation campaign in its extended mission, the telescope was pointed in the direction of the constellation Aquarius. It caught a glimpse of the renowned TRAPPIST-1 system with its seven rocky planets, at least three of them believed to be temperate worlds. Another target was the GJ 9827 system, a nearby bright star that hosts a planet that is considered an excellent opportunity for follow up observations with other telescopes to study an atmosphere of a faraway world.
Here are videos of some of Kepler's last targets as these stars brighten and dim. In addition to the static snapshots, Kepler routinely took of its full field of view, the telescope's camera also recorded selected targets at 30-minute increments. These continued for other several hours after the "last light" image before data collection ceased. The target data is obtained to measure the change in brightness of the stars, essential for discovering planets as they transit the faces of their stars and for understanding other aspects of stellar behavior. The motion of the stars in the videos are due to decreasing thruster performance caused by near fuel exhaustion.
NASA's Ames Research Center in California's Silicon Valley manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operated the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.


text:
from __future__ import unicode_literals

import sys, traceback
from django.utils.translation import ugettext_lazy as _

class LatLngError(Exception):
    def __init__(self, value):
        self.value = value

    def __str__(self):
        return self.value

    def __unicode__(self):
        return self.value

class InvalidCoordinateType(LatLngError):
    def __init__(self):
        super(InvalidCoordinateType, self)
        self.value = "%s"%_("Values are not coordiates type.")

class IncompatibleCoordinateType(LatLngError):
    def __init__(self, val=None):
        super(IncompatibleCoordinateType, self)
        self.value = "Cur Type:%s (%s)"%(val, _("Values aren't coordinate compatible format. String must is '-xxx.dddddddd,-xxx.dddddddd' (lat,lng)") )

class StringTypeError(LatLngError):
    def __init__(self, msg):
        super(StringTypeError, self)
        self.value = "%s"%_("Values is type %s. It must be a string object."%msg)

class LenArgsError(LatLngError):
    def __init__(self, msg):
        super(LenArgsError, self)
        self.value = "%s"%_("Values are %s. LatLng wants max 2 values in args."%msg)

class KwargsError(LatLngError):
    def __init__(self):
        super(KwargsError, self)
        self.value = "%s"%_("LatLng want keys 'lat' and 'lng' in kwargs")

class OutOfRangeLatError(LatLngError):
    def __init__(self):
        super(OutOfRangeLatError, self)
        self.value = "%s"%_("Lat is must between -90 and +90 degrees")

class OutOfRangeLngError(LatLngError):
    def __init__(self):
        super(OutOfRangeLngError, self)
        self.value = "%s"%_("Lng is must between -180 and +180 degrees")

class NELatLngObjectError(LatLngError):
    def __init__(self):
        super(OutOfRangeLngError, self)
        self.value = "%s"%_("NE value must an LatLng object instance")

class SWLatLngObjectError(LatLngError):
    def __init__(self):
        super(OutOfRangeLngError, self)
        self.value = "%s"%_("SW value must an LatLng object instance")

class FloatError(LatLngError):
    def __init__(self, value):
        super(FloatError, self)
        self.value = "%s"%_("%s. Coodinate must be type '-xxx.dddddddd'"%value)

redpajama_set_name: RedPajamaGithub


text:
Publisher description for Three stations : an Arkady Renko novel / Martin Cruz Smith.
A passenger train hurtling through the night. An unwed teenage mother headed to Moscow to seek a new life. A cruel-hearted soldier looking furtively, forcibly, for sex. An infant disappearing without a trace. So begins Martin Cruz Smith's masterful Three Stations, a suspenseful, intricately constructed novel featuring Investigator Arkady Renko. For the last three decades, beginning with the trailblazing Gorky Park, Renko (and Smith) have captivated readers with detective tales set in Russia. Renko is the ironic, brilliantly observant cop who finds solutions to heinous crimes when other lawmen refuse to even acknowledge that crimes have occurred. He uses his biting humor and intuitive leaps to fight not only wrongdoers but the corrupt state apparatus as well. In Three Stations, Renko's skills are put to their most severe test. Though he has been technically suspended from the prosecutor's office for once again turning up unpleasant truths, he strives to solve a last case: the death of an elegant young woman whose body is found in a construction trailer on the perimeter of Moscow's main rail hub. It looks like a simple drug overdose to everyone—except to Renko, whose examination of the crime scene turns up some inexplicable clues, most notably an invitation to Russia's premier charity ball, the billionaires' Nijinksy Fair. Thus a sordid death becomes interwoven with the lifestyles of Moscow's rich and famous, many of whom are clinging to their cash in the face of Putin's crackdown on the very oligarchs who placed him in power. Renko uncovers a web of death, money, madness and a kidnapping that threatens the woman he is coming to love and the lives of children he is desperate to protect. In Three Stations, Smith produces a complex and haunting vision of an emergent Russia's secret underclass of street urchins, greedy thugs and a bureaucracy still paralyzed by power and fear.
Renko, Arkady (Fictitious character) -- Fiction.
Police -- Russia (Federation) -- Moscow -- Fiction.
Moscow (Russia) -- Fiction.
Kidnapping -- Fiction.