Lesson #1 Video, Topic: Single Stage Preamp Design

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cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #40 on: 19 Nov 2012, 04:50 pm »
Hi.

(1)  We could do this simple analysis in dB but it's easier to understand in simple voltage gain.

(2. The highest gain triode I know of is the 12AX7.

(3) Given the above I doubt there would be many takers for such a preamp. However, there is no doubt that some sound would be present but I would not call it Hi Fi.

First off, I appreciate you have shown yr due respect to me in this too-simple a phonostage project that has sent so many tube DIYers headscratching. You are not alone, & in fact I was one of them showing extreme skeptism on how one active stage can make a good sounding phono amp let alone it  be theoretically possibe???

Strictly to satisfy my passion for better quality music, I tried it out against all odds. I think I've succeeded to make it an excellent sounding phonostage that beat any, repeat, any multi-stage phonostage respective of makes & prices, sonically, IME. It also sonicaliy beats my already excellent sounding upgraded 50-year stock Dynaco PAS-2 phono-preamp which I virually rebuilt  inside out by chopping out its entire tone-control linestage, + major circuit upgrading. Now it's a 2-stage RIAA phonostage+passive linestage. I dare say I am the only guy ever upgraded a Dynaco PAS-2 in such 'crazy' way so far, 'cause I am a music-maniac!

(1) Please don't go by the conventional wisdom dictated by the textbooks. Anyone who got some audio electronic knowledge should know the gain so called "Needed" for a RIAA phono amp should be min 40dB (@1KHz) for MM cartridge O/P voltage 5mV & 60dB for MC cartridge O/P 0.3mV... becaue of RIAA equalization loss etc etc. My question is - do we need 40dB/60eB so much gain at all???????????????

I've auditioned so many Hi-end brandname phono-preamps tagged for mega bucks matched with TTs, power amps & loudspeakers of similar mega pricing levels in past years.  None of them really impressed me sonically - lacking transparancy, air & music headroom, too pushy due to one common problem, IMO - too much gain!!! The volume control can never go up beyond 9 0'clock. This shows a huge problem, technically & sonically.

So my logic & common sense tell me the 40dB for MM cartridge & 60dB used by the audio industrial in building phonostages is way way too HIGH to reprduce quality music. So why don't we DIYers get out of the box by rectifying such design pitfall??? I've done it & have proved my "less gain for better music" philosophy is correct!

(2) Yes, you are on the right track - we need highest gain triode - 12AX7. A hint - no conventional design!

(3) Yr "doubt" is redunctant as I already built one & have been enjoying QUALITY music for a few years now
      - fast, see-thru transparent, micro-detailedl, airy, dynamic & very quiet background - noiseless at max
      volume pot setting with TT turning. As I already posted earlier, around 2 O'clokc for high level rock/
      pop music & up to 5 O'clock (max volume setting) for some very low level classical music - driving direct
      my brandname tube power amp & SS direct-current power amp

Please get out of the box to think more creatively like what I have done.

I want you to do some more research before I tell you the unconventional design used in this too-simple
phonostage.


c-J


HaViK

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #41 on: 19 Nov 2012, 05:36 pm »
Hi.
(1) But you now know that I know maybe a bit more than you, & many many many others on tubes. I've already been enjoying my LP music, mainly classicals using my DIYed 1-tube stereo RIAA phonostage for a few years now.

     That said, it is NOT my job to babysit whoever wants to know about tubes withOUT making an effort to learn it by reading relevant textbooks first like what I had done. Sorry,  I don't get paid here for babysitting here, my friend.
 
(2) Your such comment should be addressed to someone who started challanging me with foul language.
      Every mother's son can swear, & I can swear back at that character, using the F... 4-letter words.
      BUT I've chosen NOT to as I have at least some "degree of social interaction skills with other human beings".

If any AC readers want to learn how I have done it, then show some genuine respect to make a request to
me like Ericus Rex & Roger M just did.

 If I consider one gets enough tube knowledge & passion for quality music, I surely teach him. Otherwise please don't bother to ask. This is MY call, like it or not.

See how I answered Ericus Rex & how he replied me with a big "Thanks". That is what I called mutual respect.

Unfortunately not many people can be so civil. We have just seen one here, being totally ignorant yet arrogant & BAD mouthed.

c-J

I think it's funny how your making such a big deal because I said "asshole". It's not like your younger then I am, again if your going to act "mean", then expect to get treated "bad". You disrespect Roger and other people here, but yet you want people to treat you like a saint. Sorry, it's not going to happen. You don't have the best audio system in the world, so calm your ego.

Ericus Rex

Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #42 on: 19 Nov 2012, 06:26 pm »
Cheap Jack,

With each of your posts I'm left shaking my head more and more in disbelief.  The only conclusion I can come up with is that you have no idea who Roger Modjeski is or what he's done to further the design of valve circuits.  Here are some links so you can get acquainted with him and what's he's accomplished.

Bio:

http://www.ramlabs-musicreference.com/bio.html



Latest Stereophile review of his RM-200 amp (pay close attention to the measurements section).

http://www.stereophile.com/content/music-reference-rm-200-mkii-power-amplifier


6 Moons review of the RM-10.  Pay attention to the fact the Roger has coaxed 35 watts out of a pair of EL84s when everyone else can only get 17 watts, all the while achieving an expected tube life of 10k hours.

http://www.6moons.com/audioreviews/musicreference/rm10.html


There is much  more out there.  Please spend some time getting to know Roger.  If there is anyone who thinks 'outside-the-box' or 'unconventionally' about tube design, it's Roger Modjeski.

cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #43 on: 19 Nov 2012, 06:56 pm »
Hi.
Cheap Jack,

With each of your posts I'm left shaking my head more and more in disbelief.  The only conclusion I can come up with is that you have no idea who Roger Modjeski is or what he's done to further the design of valve circuits.  Here are some links so you can get acquainted with him and what's he's accomplished.


Please be more polite like me to start with a "Hi".

This is a public forum of electrical/electronic technolgies. I don't have to know beforehand however a big shot whoever could be.

I am talking about design/build of a one-tube one-stage stereo phonostage which I built & have enjoyed using a few years NOW.

While I am communicating with Roger M on this project, you or whoever are welcome to comment positively on it. I am listening. BUT, but I don't need to entertain whoever who comes up with anything irrelevant.

c-J

PS: Please don't challenge me with electrical science unless one's is very prepared as I am an EE, engaged in the electrical engineering industres for decades till now.

HaViK

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #44 on: 19 Nov 2012, 07:08 pm »
Hi.
Please be more polite like me to start with a "Hi".

This is a public forum of electrical/electronic technolgies. I don't have to know beforehand however a big shot whoever could be.

I am talking about design/build of a one-tube one-stage stereo phonostage which I built & have enjoyed using a few years NOW.

While I am communicating with Roger M on this project, you or whoever are welcome to comment positively on it. I am listening. BUT, but I don't need to entertain whoever who comes up with anything irrelevant.

c-J

PS: Please don't challenge me with electrical science unless one's is very prepared as I am an EE, engaged in the electrical engineering industres for decades till now.

Ericus Rex is probably the most polite person here, and just because you start off with hi, doesn't not mean you are. Cheap Jack, you say you don't need to know if someone is a big shot, but yet you won't stop talking about how great and godly you are when your not. You are not respected by any means in this field, but yet Roger is one of the most respected in this field. You are not a good teacher at all, no teacher would go into a forum and start fights with people. I don't see Roger doing that, and he is a better teacher then you will ever be. Again, go away with your ego. And by the way, its JOAN SUTHERLAND, not Joe Sutherland, just throwing that out there just in case you didn't know.

Ericus Rex, thanks for putting up those links.

Rclark

Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #45 on: 19 Nov 2012, 08:49 pm »
It appears that unbeknownst to all, Cheap Jack is an elder Will Hunting of tube design. Capable of abstract, never before seen circuits, yet happy to sit back humbly and watch it all go by. Do not challenge this! I say, dare to challenge..at your extreme peril.

Ericus Rex

Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #46 on: 19 Nov 2012, 08:52 pm »
Havik, my sincerest apologies.  Your assessment of cheap-jack's character seems to have been spot-on.


Now, back to the video....

Roger, if someone wanted to use another twin triode in place of the 12AX7, would the only differences be to the values of the components?  I.E. same exact parts layout for 6DJ8, 6S*7, 12A*7?   And what if someone wanted to use something a bit more exotic like a DHT like the 45?  Would the component list and arrangement look much different?  (of course other than the lack of separate heater supply).

And thank you for your thorough answer to my last query about bias voltage.  I'll need to read it a couple more times before I've digested it thoroughly.

cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #47 on: 19 Nov 2012, 09:26 pm »
Hi.

...And thank you for your thorough answer to my last query about bias voltage.  I'll need to read it a couple more times before I've digested it thoroughly.

No pain no gain. Why don't you spend some time to read up some tube textbooks to learn tube basics, like bias voltage, as I suggested you to read.

Then you don't need to ask basic tube ABC, like tube bias.

OR you simply want to stage a show here to promote yrself or whoever here? You're a genuine tube learner or an 'actor' with hidden agenda???????

Sorry being so upfront on you.

c-J

rbwalt

Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #48 on: 19 Nov 2012, 09:28 pm »
you have to remember most engineers have no social skills to speak of nor do they know how to dress. i wonder how many pens C-j is able to get into his pocket protector.

lets move on guys. this whole thing is getting a bit tiresome. one last thing i know EE's and Me's that for the love of things can not figure out why or how a simple upgrade to a better set of speaker wires or power cord can make a difference. nor are they willing to try.seems like they love being stuck in the box.

HaViK

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #49 on: 19 Nov 2012, 11:55 pm »
Hi.
No pain no gain. Why don't you spend some time to read up some tube textbooks to learn tube basics, like bias voltage, as I suggested you to read.

Then you don't need to ask basic tube ABC, like tube bias.

OR you simply want to stage a show here to promote yrself or whoever here? You're a genuine tube learner or an 'actor' with hidden agenda???????

Sorry being so upfront on you.

c-J

You say you read tube textbooks, and you tell people to read them, but in your earlier messages you say that you don't follow the textbooks as you try to do your own thing (paraphrasing). So why are you contradicting yourself. First you are saying we don't read the handbooks and saying we are uneducated, but yet you clearly state "I am an EE but I don't go by the conventional wisdom laid down by the textbooks as I always think "out of the box" So if this is true, you are also uneducated, because you don't go by the books. How about you read your own writing and see your contradicting yourself before you post.

Roger A. Modjeski

Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #50 on: 20 Nov 2012, 01:45 am »
My father was a professor of Dentistry and materials researcher at Virginia Commonwealth University. I spent many hours in his lab and he got me started in electronics. Around age 10 I surpassed his knowledge but he had a friend who was a Ham Radio Operator. This man introduced me to the Radio Amateurs Handbook and I bought my first one when I was 12 and I still have it. Its in the picture below which includes three other books that I suggest in the order presented from left to right. The Red Radiotron Designers handbook that Jack recommends is far too complex for a beginner, whereas the Radio Amateurs Handbook is written for one who knows nothing about electronics. It is published yearly and the lessons in the first 50 pages are identical, however the construction projects changed every year... to get people to buy the latest. These projects cover power supplies, speech amplifiers (preamps) and modulators (power amps) that are very much like what we have in our homes. Single ended, push-pull, biasing, impedance matching and many other things are explained in simple terms. One purpose of the book was to teach a person who wanted to be a Ham Radio Operator how to pass the electronics part of the test to get his licence. The other puropse was to assist operators in making their own equipment. Although some Hams buy or build kits, many collect parts and build their own on the Cheap. Anyone interested in my story can read it at. http://ramlabs-musicreference.com/bio.html  Thats me in the treehouse and my cat on the walkway.

As a  teacher I welcome students of all levels. I have taught at several community colleges, guest lectured at several universities and had the pleasure of being a Lab Instructor for Ralph Smith at Stanford University. He wrote the text we used at University of Virginia for EE 101 and I highly recommend. The title is Circuits Devices and Systems.







G Georgopoulos

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #51 on: 20 Nov 2012, 02:31 am »
Hi Roger, you are truely a legend, I cant wait for your next video... :)

Kind Regards

George

cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #52 on: 20 Nov 2012, 03:08 pm »
Hi.

... one last thing i know EE's and Me's that for the love of things can not figure out why or how a simple upgrade to a better set of speaker wires or power cord can make a difference. nor are they willing to try.seems like they love being stuck in the box.

Please hold yr generalization as I don't think you really know what you are talking about

Sorry, I can easily detect sound changes by changing loudspeaker cables or power cords or interconnects.
That's why I modified my KEF 2-way bookshelvers to bi-wiring using #12 oxygen-free pure copper cables.

All my 6 pairs of interconnects for my rig & the power cord for my tube power amp are DIY-built with 99.99% pure solid silver wires from Germany. I hear the difference big bigtime. I had to build them as silver sounds far better than the best copper & no such pure silver cables available in the marketplace.

For those scratching their head about Ag vs Cu, silver is the metal of best electrical & thermal conductivity & lowest contact reisistance on this planet.

I know why they sound different technically as I am an EE.

c-J


stevenkelby

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #53 on: 20 Nov 2012, 03:13 pm »
I had to build them as silver sounds far better than the best copper & no such pure silver cables available in the marketplace.

I know why they sound different technically as I am an EE.

c-J


If you know technically why silver and copper cables sound different, could you share that explanation with us? :)

cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #54 on: 20 Nov 2012, 03:15 pm »
Hi.
If you know technically why silver and copper cables sound different, could you share that explanation with us? :)

Plese read my post above. Already explained.

c-J

stevenkelby

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #55 on: 20 Nov 2012, 03:21 pm »
Hi.
Plese read my post above. Already explained.

c-J

Well I'm disappointed but not surprised.

Your edited post there reveals the well known fact that silver is a better conductor than copper but not how better conductivity confers an audible difference.

Keep on trollin'! :D

cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #56 on: 20 Nov 2012, 03:23 pm »

..one last thing i know EE's and Me's that fordifference the love of things can not figure out why or how a simple upgrade to a better set of speaker wires or power cord can make a . nor are they willing to try.seems like they love being stuck in the box.

So you seem to tell us YOU know "why or how". Please explain it.

c-J

cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #57 on: 20 Nov 2012, 03:28 pm »
Hi.
Well I'm disappointed but not surprised.

Your edited post there reveals the well known fact that silver is a better conductor than copper but not how better conductivity confers an audible difference.

Keep on trollin'! :D

Who is trolling, YOU or me?????

I already point out the key physics between Ag & Cu. IF YOU still can't figure it out, read to learn more about it.

It is not my job for babysitting here as I am NOT got paid to do so.

Enough said.

c-J

cheap-Jack

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Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #58 on: 20 Nov 2012, 03:55 pm »
Hi.

 and you tell people to read them, but in your earlier messages you say that you don't follow the textbooks as you try to do your own thing (paraphrasing).So why are you contradicting yourself. First you are saying we don't read the handbooks and saying we are uneducated, but yet you clearly state "I am an EE but I don't go by the conventional wisdom laid down by the textbooks as I always think "out of the box" So if this is true, you are also uneducated, because you don't go by the books. How about you read your own writing and see your contradicting yourself before you post.

I have decided NOT to answer any of yr posts as you don't seem to know what you are talking about. & wasting bandwidth here.

Sorry to say, you post for the sake of posting. You talk like a child - so childish, sorry to be so blunt.

You can't even read & understand English properly & start talking nonsense.

Let me explain to you being the last time posting back to you;-

One needs to read & learn. Once one really learns it, then one should digest it & EVOLVE one's idea from it. Don't quote blindly whatever books tell you - this is what I call it :- common or conventional wisdom.

Basing on one learns from the basic principle taught by the books, then uss yr own thinking to do better.
That what I mean to say - evolve from what one learns from the books, but don't be dictated by them.

That what led Newton to discover gravity - creative thinking. Likewise for tube.

Enough said with YOU.

c-J


Roger A. Modjeski

Re: Lesson #1 Video, Topic: Single Stage Preamp Design
« Reply #59 on: 21 Nov 2012, 03:04 am »
Here is a table of conductivity that uses copper as a reference at 100. http://www.eddy-current.com/condres.htm

Pure silver is 108 or 8% better. When silver oxidizes it is still a good conductor where copper is not. Copper oxide forms a rectifier.  However this is usually not a problem with good plated connectors.  Given that the resistance of most cables is almost nothing then 8% less than almost nothing is still almost nothing. One could just make the copper 8% larger and get the same effect.