Yes, in our university's industrial consortium, we often "educate" old-school engineers of member companies in more current theoretical
treatments of power converters, electric machines, etc. They are usually either very grateful, or else scared to death.
I am 61, retired at 53. I believe it keeping both body and mind in good shape. I have been an EE and manager of EE for almost 30 years, but electronics is still my passion. I never have a formal education in electronics, my degree was Chemistry. I always feel I am missing something. So when I retired, I decided to study back electronics that I missed. I believe in exercising both mind and body because if you don't use it, you loose it. On top of studying, I exercise 5 hours a week including weight training and kick boxing.
For studying, I started out studying RF since 2000 while I was still working, but after a while, I hit the ceiling because of the lack of knowledge of electromagnetics......which is calculus, differential eq and partial differentiation. So when I retired in 2005, I studied from Cal I all the way to partial differentiation. Then I studied EM. I did that for 7 years until two years ago, 3 hours a day, at least 5 days a week. I corresponded with the professors in college and worked out all the homework, since I self studied, I even did problems of at least two books. After 7 years, I started to feel tired of this heavy duty studying.......and I become forgetful as I get older. So I turn to easier, less theoretical electronics of music electronics. I plan to keep studying and learning till the day I die. I have no interest in crossword puzzle. My crossword puzzle is electronics. I started designing guitar pedals, then to guitar amps. After successful building two, now I am here, decide to build a better amp than my Acurus 200X3. This should keep me busy for a few months. then I have to move onto something else.
I notice people really slow down after retirement. It's like their mind slows down. When I talk to them, it's seem like things goes over their head. My sister is only 1.5 years older than me, but I feel she becomes so slow in thinking.
There is no free lunch, you use it or you loose it, both body and mind. In this modern world, you can't depend on anyone else. Even if you have money, it does not mean anything if you don't have your mind and body.
For studying, I started out studying RF since 2000 while I was still working, but after a while, I hit the ceiling because of the lack of knowledge of electromagnetics......which is calculus, differential eq and partial differentiation. So when I retired in 2005, I studied from Cal I all the way to partial differentiation. Then I studied EM. I did that for 7 years until two years ago, 3 hours a day, at least 5 days a week. I corresponded with the professors in college and worked out all the homework, since I self studied, I even did problems of at least two books. After 7 years, I started to feel tired of this heavy duty studying.......and I become forgetful as I get older. So I turn to easier, less theoretical electronics of music electronics. I plan to keep studying and learning till the day I die. I have no interest in crossword puzzle. My crossword puzzle is electronics. I started designing guitar pedals, then to guitar amps. After successful building two, now I am here, decide to build a better amp than my Acurus 200X3. This should keep me busy for a few months. then I have to move onto something else.
I notice people really slow down after retirement. It's like their mind slows down. When I talk to them, it's seem like things goes over their head. My sister is only 1.5 years older than me, but I feel she becomes so slow in thinking.
There is no free lunch, you use it or you loose it, both body and mind. In this modern world, you can't depend on anyone else. Even if you have money, it does not mean anything if you don't have your mind and body.
Double entendre was intentional but this is not about bedroom performance.. This is about doing the things that made us visit this forum and keep on doing them regardless of our age, whether as a hobby or as a profession. This is about electronic projects and old-age.
I'm nearing mid 30s and so far still blessed with a good pair of eyes and steady hands. Both are unquestionably needed when messing with parts smaller than our finger nails. Lately i've been thinking, perhaps seeing my dad slowly falling apart from getting old has something to do with it, how long will i have them? My mind goes back to decades ago when grandpa was still alive. When he was young, he had the same interest in electronics which was hard to believe since i remember him struggling to hold a spoon whatwith Parkinson's attacking his nerves. I fear the day when i can no longer insert resistor leads to PCBs or read the numbers on ceramic caps, let alone soldering SMD parts! Sitting in a bus for 3 hours and not doing my projects is enough to get me antsy, i can't imagine if age gets the better of me and makes that ride permanent..
I'm sorry if this post depresses you.. it was not my intentionI notice a lot of members here are from those days when thermionic valve appliances were still the norm.. which is good news for me! (hey, they are still visiting so they must be doing fine!)
In short.. how do you keep on doing what you do? What can we do now that would help us later? Stories and experiences are appreciated.
I'm 28, and have been running/working out for the past 3 years - I already feel better physically than I did when I was 18.
I see it a lot in ham radio, another trending-older hobby; sedentary lifestyles are the beginning of the end. Just causes a cascade of other problems that are very hard to correct once set in motion.
I was fortunate to make it well into middle age before I had to start trying to remain physically fit. It was good that Motorola put in a gym and made it free to employees at about that time. I was 47 years old the first time I set foot in a gym. I went 4 or 5 times a week for 14 years until I left the company at 61. My physical abilities peaked at 50 or 51 years old. I was 205 pounds with 7% body fat, and could bench press a Buick! When I left Motorola at 61 I was about 190 pounds, still low body fat and I could still bench 250 for 10 or 12 reps. Unfortunately the free gym was gone, so I had no gym for about 5 months. During that time I lost about 20 pounds of muscle despite being outside doing physical work for 6 to 10 hours a day. I joined a gym about 6 weeks ago and was surprised how much I had lost in ability, but it is slowly returning. Keep at it....if you don't use it.........
Go to a large hamfest like Dayton and walk around......seeing that should motivate anyone with brain cells to get off their butt and do something....anything...just do it!
I got a job at Motorola in 1973.....that was the crash course! I started as an assembly line tech on the HT220 Handie Talkie and had made it to product engineer in 1984 with no formal education in electronics. After designing circuits that shipped in about 5 different radios (STX, the MTX series, JEDI...) in 1990 they offered to pay for me to go to college. In 1994 they paid for my masters degree. I learned all that fancy math, but never used it. Today, we have computer programs for doing the hard stuff.
YEP, the CPU still has plenty of MIPS, but the DRAM doesn't get refreshed often enough so a few more bytes get corrupted every day. We just don't have control over what gets lost and what doesn't. I can still remember the words to songs I heard on the radio in the 60's that haven't been played since, or vacuum tube numbers that I haven't used in decades, but I have no idea what color shirt I wore yesterday.
Ditto, I spend an hour or two at the computer every day. Most of it is electronics related, just keeping up with the current tech, or gathering ideas for a new project. I think I will always be tinkering with audio, and vacuum tubes since that's where I started in the 60's.
I do not have a lab set up currently since I sold the house in Florida when I left Motorola, and the new house here won't be finished for about 5 more months. I have been planning and outlining several projects for the new place. Tube stuff takes the most physical bench space, so I will start small. Project 1 is an analog music synthesizer using SMD components.
For the last 41 years I have been restricted as to what RF stuff I can do, since anything RF would have belonged to Motorola. That is no longer true, so I may design and build a killer ham radio.....just because I can!
I have seen some of your posts in other threads. Remember that this forum like any other has some members that express their opinions as facts. Back up and look at all the information presented here, and use your engineering judgment to decide what features and circuits are best for your particular needs. If you don't feel like you have the knowledge to make the choices yet, don't rush, just keep digging until you figure it out. Don't be afraid to build something and experiment even if it isn't what you want for the final design.
I hesitated to join in in your other threads since there was already some strong opinion that I did not necessarily agree with and I haven't been around the computer much.....
You keep asking about parafeed. It means parallel feed and just that. Parafeed is usually accomplished by feeding the DC through a choke that is effectively in parallel with the OPT for AC signals. It has quantifiable benefits in a single ended amplifier since it gets the DC out of the OPT, and allows it to be optimized for AC only.
The DC is effectively cancelled in a push pull amp, so true parafeed is not much of an advantage, and is rarely used. Mosfet buffers and current sources can and do offer their stated advantages, but they are not part of the usual parafeed concept, although it is possible to combine all these elements into one design. It is also possible to implement each of these features separately offering more control over each one.
You keep asking about what the high end companies do....as stated previously they dress up the same old designs, maybe throw in some expensive parts, and hire some high powered copy writers and marketing people. Your engineering abilities should be able to beat their marketing budget!
I must offer the same advice I offer a newcomer to the tube amp hobby every few years or so. It would be cool if you could dream up some fancy whiz bang 200 WPC tube/mosfet parafeed hybrid, draw the circuit, buy all the right parts, wire it all up, plug it in, flip the switch and listen to great music on the first try. The probability of success in that endeavor is very low.
I make an amplifier design I call the Simple Single Ended, or SSE. I publish the design and sell a PC board for it. It has been a success because the probability for first time success is virtually 100%. This is because the engineering, layout, and parts selection is already done, the amp is relatively low powered, SIMPLE, and easy to understand.
Any time you take one of these constants and vary it, the probability of success goes down. This is not a problem IF you have the knowledge to understand and fix any issues that arise from deviations from the proven formula. The probability of first time success goes down as the power level goes up AND the magnitude and costs of minor issues goes UP!
I usually urge newcomers to start with a proven design, understand it, build it and get it working before going on to something bigger. Nothing kills a hobby quicker that spending big bucks on a project and then watching it smoke when you turn it on.
As stated by others the output transformers in a tube amp are the most important component in the design. They are responsible for 90% of the amps sound capabilities. If you are careful, you can use the same transformers for several projects if you decide to upgrade later, or redesign. There are two schools of thought here, buy a cheap pair now and then buy the final pair once you have designed the final amp, or decide how much power you want, and what types of tubes will get you there, and get the good transformers now. Possibly the tubes too.
You have asked about high end. I don't pay attention to what other companies make since I have always designed and built my own audio equipment (except for a 5 year period when I was first married). I have no idea what an Acurus 200X3 is, but I got the impression it is fairly powerful, so I will recommend two long and involved threads. These are for learning by example if you are interested, although both are excellent amps that could be built at several power levels and could hold their own against any so called high end push pull tube amp.
This thread is about an amp designed by Pete Millett, an engineer who works for Texas Instruments. I took his conservative 18 WPC design and stretched it as far as it would go....beyond 250 WPC, then backed up to a reliable 125 WPC design, published the details and at least a dozen people built it. I built 3.
http://www.diyaudio.com/forums/tube...p-p-power-amp-design.html?highlight=6L6GC+AB2
This thread started out as a question, and turned into a cooperative effort with me designing circuitry, and Chris building an amp on the other side of the world. Both of us got amps, and everyone who paid attention learned something, including both of us.
http://www.diyaudio.com/forums/tubes-valves/133034-6l6gc-ab2-amp.html?highlight=6L6GC+AB2
Thanks Tubelab ( I don't know your name). Your post is the most useful so far for me. That's what I think about the parafeed. I just feel if I balance both the AC and DC, parafeed is irrelevant. From experience, if the circuit looks too complicate, chances is it's too complicate. I am new in this and I don't want to pretend I know and offend someone, so I ask in a round about way.
I am planning to buy a pair of expensive OT to start. Cross my fingers, I don't think I would burn them( again cross my fingers). I don't want to spend money on OT that I know I am going to replace. I have enough OT for guitar amps already and those are not designed for 20KHz. Do you have any suggestion on good OT for push pull about 40 to 50W? I am planning to do a Class AB with a little higher current so in most case, I use it in Class A anyway.
I always like RF, for quite a few years, I studied very hard in EM. I think it really help even in audio. Signal travel as EM wave and EM theory still govern in grounding, crosstalk and signal integrity in audio frequency. I just troubleshoot an OT that gave me squealing in my new guitar amp design and I based a lot on the theory EM radiation.
I am not as strong as you, My best before was only benching 1 rep of 245. I am over weight but my frame is not that big, I pushed too hard and now I have shoulder problem. I am using only 80lb dumbells for press. Something about 55 years old was the magic number for me, seems like I started getting all sort of injuries right after my 55 birthday. But I still do weights 3 times a week, then two days of cardio.
Thanks for your detail answer. this is of most helpful.
I am planning to buy a pair of expensive OT to start. Cross my fingers, I don't think I would burn them( again cross my fingers). I don't want to spend money on OT that I know I am going to replace. I have enough OT for guitar amps already and those are not designed for 20KHz. Do you have any suggestion on good OT for push pull about 40 to 50W? I am planning to do a Class AB with a little higher current so in most case, I use it in Class A anyway.
I always like RF, for quite a few years, I studied very hard in EM. I think it really help even in audio. Signal travel as EM wave and EM theory still govern in grounding, crosstalk and signal integrity in audio frequency. I just troubleshoot an OT that gave me squealing in my new guitar amp design and I based a lot on the theory EM radiation.
I am not as strong as you, My best before was only benching 1 rep of 245. I am over weight but my frame is not that big, I pushed too hard and now I have shoulder problem. I am using only 80lb dumbells for press. Something about 55 years old was the magic number for me, seems like I started getting all sort of injuries right after my 55 birthday. But I still do weights 3 times a week, then two days of cardio.
Thanks for your detail answer. this is of most helpful.
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Can be a mechanical problem, in which case working out will not improve functionality of your arm/shoulder.
(if you strained the ligaments of your shoulder, exercising with 20-30lb max is a better way to get them back into shape)
I had MRI, doctor said it was cartridge wearing thin from years of exercise. Sad thing is when you exercise, you build up muscle and ligaments, but you wear out cartridge and it will not regenerate. Doctor said there's nothing wrong with my shoulder, it's just the cartridge is wearing thin!!!!
Yes, I am doing minimum 10 reps instead of high weight low reps now.
Here is a little paper that I found of interest. Realy I have read several such papers all with one common theme that is as we get older we need substantialy more protein. But one paper did prepose a work around for that. They found that by consuming 80% of your protein at one meal you got a lot more out of it than spread out through the day. This may
not be mentioned in this paper, Amino Acids and Muscle Loss with Aging
not be mentioned in this paper, Amino Acids and Muscle Loss with Aging
Been told that you can use supplements, for example high dosage vitamine-c ?
(cartilage)
I have spent the past 15 to 20 years figuring out what works for me. This paper hits most of it.
When Motorola open the free gym, about 10 of us started going regularly as a group. All males, I was the oldest, everyone else was from 6 to 27 years younger. I had already been working out in my backyard, swimming and bike riding a lot. Whenever a bunch of guys get together and do something, there will be some competitive spirit, so the "how much can you bench, squat.....stuff started early. The young guy had played soccer in school, so he was always the king of leg exercises, but within a couple of years I had become king of the bench. Part of this must be genetic, some people can gain muscle easier than others, and some people keep it with less maintenance work than others. I can gain it quick, but lose it quicker! It also helps to figure out what works for you personally. Understand these things:
You don't build muscle in the gym, you break it down, causing microtrauma to the muscle cells. You body will then repair the damage, and attempt to build the muscle bigger to survive the next occurrence. This is called recovery. Recovery takes time, and the time increases with age. If work a muscle hard enough to reach failure, or near failure, do not hit the same muscle at that level again for a while. 2 days for a twentysomething, 3 or 4 for a sixtysomething.
During recovery your body needs raw materials, and sleep to do it's repair work. Proteins especially the BCAAs are the raw materials needed for rebuilding, and calories are the fuel for the rebuilding engine. If any of the 3 are missing, or insufficient, especially in an older person, repair will not be optimal.
Immediately after hard exercise your body begins repair work. Muscles are thirsty, and hungry (glycogen depleted). There exists a window of opportunity to "force feed them" that lasts for an hour or two. I mix a scoop of BCAA powder with half a scoop of Gatorade powder in a 16 ounce bottle of water and drink it on my way out of the gym. The BCAA's are raw material for repair, and the sugar in the Gatorade helps restore glycogen, and raises your insulin levels, which directs the extra blood sugar into the muscles....all of this is mentioned in the above paper.
Eating your major protein meal about 2 hours later will put that protein where it is most needed.
I was chasing the young guys around a mountain bike trail that I was somewhat unfamiliar with, when a tree stepped out in front of me. My right shoulder has been messed up for about 10 years. All my gym friends were laid off over the years, so the competition is gone, I just go now to keep from withering away.
I would find a set of them that match, and are close to the desired impedance, and big enough power wise, but not too big. Use them to experiment with. I have a lot of guitar amp OPT's too, and some of them work quite well for HiFi when driven with the right tube / circuit. The Pete Millett amp with big sweep tubes works great with guitar transformers.
I was under the impression that you wanted over 100 WPC. All the amps I build are budget limited, so I tend to pick good quality budget transformers. My latest design is 120 WPC and uses Edcor 100 watt transformers. They are about $100 each. I also used these in my 125 WPC version of Pete's amp. You will need to figure out how much power you want, what tubes you will use, and what B+ voltage you want before you can choose the primary impedance. There are better transformers out there, for more money, but I have not explored any of them except for the 400 watt Plitrons that I got cheap.
https://www.edcorusa.com/cxpp100-ms-3_3k
Toroidal Audio Transformers
How do you "do" physical chemistry without a dozen credits in calculus and statistics? PChem was a bone-crusher at my alma mater, but I survived!
I opted out of the advanced inorganic course which was required for ACS certification, and took a couple advanced organic classes instead.
The calculus and diff equations started to become important when I started building financial models for bonds of companies in bankruptcy.
I was in biochem major which gear for pre-med or pharmacy. I did have to take some calculus, which is equivalent to Cal I of today. I did so bad that I almost learn nothing. When I started studying in 2007 I had to start from page 1!!! No, I avoid the ACS major that require more physical chemistry and calculus.
I am taking 500mg a day minimum, I do eat apple and orange also. I also take glucosamine also.
I am the hard gainer type. I have been doing weights for over 20 years and only have a 16" arm to show for. I am over weight but being a Chinese, I am only 5'6".
I have 50gms of combine soy and whey every day in the morning before going to the gym. On the day I go to the gym, I do drink another 50 gm within 1 hour after working out. I keep about 150 gm of protein intake a day. I learned this years back, it's only because of the protein that I got to 16"!!! Before that, it was sad!!!
Hi Geoge
What is WPC? I am new here, I don't understand a lot of the terms. My goal is 40W to 50W with two EL34. That would bring the primary impedance to about 3.4K to 4K.
WPC is Watts Per Channel an old term.
EL34's were common in HiFi amps of the past. Some would call them guitar amp tubes, but you can make a good HiFi amp with them. I tend toward a tube with a lot of peak cathode current capability since this improves the transient dynamics of the amp. The EL34 is far better than the 6L6GC family in this respect but I would use a KT88 or a TV sweep tube. It is possible to use EL34's and KT88's in the same amp with adjustable bias. Look at the 6L6GC in AB2 thread that I linked. I think I tried just about every tube possible in that amp EXCEPT the 6L6GC although I didn't document all of them.
EL34's were common in HiFi amps of the past. Some would call them guitar amp tubes, but you can make a good HiFi amp with them. I tend toward a tube with a lot of peak cathode current capability since this improves the transient dynamics of the amp. The EL34 is far better than the 6L6GC family in this respect but I would use a KT88 or a TV sweep tube. It is possible to use EL34's and KT88's in the same amp with adjustable bias. Look at the 6L6GC in AB2 thread that I linked. I think I tried just about every tube possible in that amp EXCEPT the 6L6GC although I didn't document all of them.
My hat is off to you! (Seriously). In my era, only premeds took biochem. We had 8 guys in our suite, 3 pre-meds -- they spent every evening on this course, to the detriment of all else. Of course, there was no molecular biology at the time either.
My wife, late in life, decided to get her PhD in bio -- she did extremely well in biochem and biostat -- but hasn't prepared dinner in many years.
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