New Design, SE 6005 Directly Coupled Audio Amplifier

[RtoR King]

Off topic:
I don't know about this amp design or it's sonic behavior
The plug orientation is important if the component has a fuse, right?
Just to ensure the fuse is on "hot/live" rather than "neutral"

Cheers,
Raghu

No, it doesn't matter for safety. Remember that current flows in a loop back to it's electrical source, in this case your local pole or utility transformer. If there is an internal short or overload, the fuse will still blow. This "flip the AC plug" comes from early tube guitar amps, some of which were hot chassis - very dangerous and now illegal to manufacture. And the use of audio mixers with devices on different AC circuits. There it did make a difference in hum. Many guitar amps even had AC cord polarity reverse switches

 

[Dr.Gary]

Off topic:
I don't know about this amp design or it's sonic behavior
The plug orientation is important if the component has a fuse, right?
Just to ensure the fuse is on "hot/live" rather than "neutral"

Cheers,
Raghu

Perhaps I am missing something, but I don't see why it matters which side of the AC line the fuse is on.

 

[raghupb]

Perhaps I am missing something, but I don't see why it matters which side of the AC line the fuse is on.

I always understood that neutral has a potential of "0" vs live at 120/240V.
So we were taught to put the fuse (if it is a single fuse design) on "live" to make sure the breakout happens before it passes through the component.
Anyways sorry for the diversion, please carry on the amp discussion.

Cheers,
Raghu

 

[RtoR King]

Perhaps I am missing something, but I don't see why it matters which side of the AC line the fuse is on.

Older gear and even new gear sometimes has a capacitor or RC network from the line to ground for conducted RFI attenuation. This could induce hum when components are connected together. Also today you have to use approved X and Y type capacitors if connected across the AC line or to ground which fail open. In the old days they would use a plain 400v or 600v wax paper capacitor which will inevitability short and then you have an unintentional hot chassis. The modern design trend if you do this is to use two capacitors to ground, one on each side of the line. Here it would make no difference in polarity of the AC cord. Today even most two wire gear uses polarized line cords - why I don't know. It really doesn't matter. The polarized two wire plug was introduced in the 70s? to ensure the ring of a lamp socket is the neutral side. But that assumes the wall outlet is wired properly which many are often not.

I always understood that neutral has a potential of "0" vs live at 120/240V.
So we were taught to put the fuse (if it is a single fuse design) on "live" to make sure the breakout happens before it passes through the component.
Anyways sorry for the diversion, please carry on the amp discussion.

Cheers,
Raghu

That would be a concern on hard wired devices but not on stuff with a cord and plug. Still we try to do it anyway just for good engineering practice. And at least North American AC plugs are polarized anyway - even two wire plugs since the 1970s or 80s.

 

[Dr.Gary]

I always understood that neutral has a potential of "0" vs live at 120/240V.
So we were taught to put the fuse (if it is a single fuse design) on "live" to make sure the breakout happens before it passes through the component.
Anyways sorry for the diversion, please carry on the amp discussion.

Cheers,
Raghu

Maybe I wasn't clear, but my comment was with reference to the two leads of a floating transformer primary that are connected to the AC line.

 

[drlowmu]

I am not on HFV to "flip side" ( as you termed it ) discuss the existence of AC polarity with you.

I have been orientating AC plugs on audio gear for at least 55 years . If you do not know about this, and also refuse to take my report at face value. I can be of no help to you in any way. That is OK with me..

My friend told me today, that when he bought his brand new Conrad-Johnson PV-10 phono-line tube preamplifier, and that his Owner's Manual had a page that read like so :

" Your new PV-10 will sound different, depending upon how you plug it into the wall socket. Listen to it in both orientations, and leave it in the position that sounds best to you ".

You very obviously ( to me ) have not read or absorbed my postings in this thread.

I operate ( power dissipate ) most tubes at about only 62 percent of their MAXIMUM ratings, the Golden Ratio proportion. You may not realize this. Also, the 6N23P-EV filament is operating raised 57 VDC above ground, and my 6005 filament is 189 VDC above ground, due to the direct couple voltage, about 225 VDC, on the 6005 cathode. No excess heater to cathode problems should ever exist.

You wrote above this : " Where I come from the ability of an audio system to be "resolving" is mostly dependent on the speakers. ".

Our two personal experiences and our two audio worlds - differ dramatically from each other !!!

As I have repeated, recently and often in my thread, I believe the biggest turkeys of all in audio are not the speakers at all, but the audio amplifiers. In all of my experience, I concluded one needs a well made about 2 Watt tube amp, two stage, direct coupled, and 100 to 101 dB large radiating surface speakers. This allows the serious audio enthusiast to employ these best sounding small amps, and have the best possible overall sonic result. This has been " my " own audio course, ( non-directly ) , for most of my life.

It is not a question of me being arrogant, when I say I seek to build the world's best sounding amp, ( and that I have been TRYING to do so. ) My audio mentor, the last three decades, has that unique honor in my estimation. But I do try !!! That will put certain people off, but one must realize what my audio background actually is. Equipment I have had, many have not seen, heard, or ever owned. Lets see, nursed in 1944-45 on an ALTEC 604 field coil, then a 604B ALTEC. Outta Graduate school : brand new 15 inch Tannoy Monitor Golds, in GRF enclosures, followed by KLH 9s, single and double pairs. Quad ESL 57s, briefly. Infinity Systems Servo Stat 1s - with all 1-A panels. Fulton Premiere P 10. P-12 and P-22 model speakers, the then-widest band speaker made in audio, 12 hZ to 110 kHZ a seven way. RCA duo-cone 15s, Norelco 9710Ms on open baffles. Professional use RCA UBANGIES, three at one time, used two with MI-9449 double 15 inch woofers, and their famous WW2 era MI-1428 field coil drivers. Most audiophiles have never seen these RCA Ubangies in the flesh, nor heard them, let alone owned and used them.

Presently, I use an audio system which has been 100% gifted to me, by two local Kansas City audio friends I helped. ALTEC 515B woofers, 802D compression drivers came from one friend, and 811 Horns, 825 VOTT A7 enclosures, came from another That is right, a total A7-8 system of ALTEC , ( JUST what I would LIKE to have in a smaller apartment ) obtained for free, by mentoring / helping others.

I am not trying to brag, or be arrogant herein, I am just disclosing the facts.

And by the way, with all the unusual things that me and my mentor do when building SE amps, I really do think I " can and am " building an exceptional amplifier, with a 6005 tube, as shown to all, right in this thread. At age 77, it is about leaving a legacy of sorts. Hari Iyer has built a DC KT88 SE amp in 2020, he might carry it on !! Others may do the same. One of the three DIYers on the 6005 amp, is the same Kansas City fellow who gave me for free the ALTEC 825 ( VOTT ) horn loaded enclosures and the high frequency 811B horn !!

Re read this thread more carefully, with an open mind, but obviously, only if you care to.

P.M. ( private mail ) me through HFV, if you have any questions. I'd be very happy to communicate with you, anytime, that way, or better yet, by phone.

Jeff

PS, Here below is an old picture taken about 1978, of me picking up my ( second ) used pairs of KLH9s, from Bobby Casner, on Venice Blvd, Venice California. " Top down " !!

 

[RtoR King]

I am not trying to argue but rather understand your approaches as even you admit they were not practiced in the golden age of tube audio HiFi. And we aren't talking about modern tube approaches such as solid state CCS and MOSFET interstages either which were not technologically possible in those days. Your circuit is that of the golden age tube amp design, very straight forward as far as the circuit goes.

I am only trying to help and understand for myself as an electronics professional how some of these ideas could work. And if we do discover why, that's just more validation of your technique and prowess.

So not only me but more importantly the people here you are trying to teach how to build world class tube amps should fully understand why you do these unconventional techniques. If you hear a difference, that's great. But I also think other members here should see possible reasons for the phenomena you hear and decide for themselves which if any of these unconventional approaches they should implement.

 

[Dr.Gary]

I am not trying to argue but rather understand your approaches as even you admit they were not practiced in the golden age of tube audio HiFi. And we aren't talking about modern tube approaches such as solid state CCS and MOSFET interstages either which were not technologically possible in those days. Your circuit is that of the golden age tube amp design, very straight forward as far as the circuit goes.

I am only trying to help and understand for myself as an electronics professional how some of these ideas could work. And if we do discover why, that's just more validation of your technique and prowess.

So not only me but more importantly the people here you are trying to teach how to build world class tube amps should fully understand why you do these unconventional techniques. If you hear a difference, that's great. But I also think other members here should see possible reasons for the phenomena you hear and decide for themselves which if any of these unconventional approaches they should implement.

In addition to your obvious technical knowledge, you appear to be somewhat skilled in the art of diplomacy. Unfortunately, your diplomacy isn't going to bear fruit when dealing with Jeff Medwin. For starters, he does not have the technical knowledge that is needed to answer the types of questions that someone with your technical knowledge is inclined to ask.. More importantly, he only cares about the end result, which is what he hears or believes that he hears, and has no interest whatsoever in trying to investigate and discover what currently-unknown phenomena are behind the multitude of seemingly preposterous, nonsensical and absurd assertions that he pontificates.

 

[drlowmu]

I am not trying to argue but rather understand your approaches as even you admit they were not practiced in the golden age of tube audio HiFi. And we aren't talking about modern tube approaches such as solid state CCS and MOSFET interstages either which were not technologically possible in those days. Your circuit is that of the golden age tube amp design, very straight forward as far as the circuit goes.

I am only trying to help and understand for myself as an electronics professional how some of these ideas could work. And if we do discover why, that's just more validation of your technique and prowess.

So not only me but more importantly the people here you are trying to teach how to build world class tube amps should fully understand why you do these unconventional techniques. If you hear a difference, that's great. But I also think other members here should see possible reasons for the phenomena you hear and decide for themselves which if any of these unconventional approaches they should implement.

Very reasonably, nicely stated. But you have to understand this, I am not a very technical person at all. There are many things I do, where I do not worry too much - about the reasons. I concentrate more on the listening result, a different " r ".

You know, my corny / cute joke, " Don't tell me about the pregnancy, just SHOW me the baby ".

Some of you will enjoy this, my recent true story.

A few weeks ago, I pulled out my TEK Dual 100 MHZ scope and probes, and started to try to measure AC Phase on two 6005 amps' XFRs.

Guess what, I forgot how to use my scope, how to turn all the knobs and dials on the front face !! I said to myself, " to hell with this scope ". I reminded myself, " in 2019 I easily heard every AC phase relationship inside my 12BZ7-KT88 DC amp. " I'll just do these two 6005 amps the same way, after I get each running.

( AC Phase polarity optimization was done two days go, as reported, by ear on Page 12, Post # 235, using " Solo Drums " ). So my friend, I can not satisfy you, or any E.E. trained person, with good explanations, and I will usually TRY to avoid them. I build intuitively, and by listening mainly. Serves me well !!

Another great example, who would think to use a 1,500 AMPERE ( peak , 64 A. RMS ) GTO 5 uF capacitor in a 0.120 Ampere circuit ?? No E.E. would ever try it. It was me and my DIY supplier in the Netherlands, who tried it - and listened. Him first, in this entire world ( 300B amp, uck ) and me second in the USA . I DO have reasons why I THINK it works so well, but I am far more concerned about its' results, and being sure to use a GTO, because of what I know, and hear what it does for the music's playback !! Nothing I know, gets close. Boli46 , a DIYer who owns A5 ALTECS ( !!! ) heard it too.

Thank you for your careful and thoughtful post, very nice !!

Jeff

 

[Dr.Gary]

Very reasonably, nicely stated. But you have to understand this, I am not a very technical person at all. There are many things I do, where I do not worry too much - about the reasons. I concentrate more on the listening result, a different " r ".

You know, my corny / cute joke, " Don't tell me about the pregnancy, just SHOW me the baby ".

Some of you will enjoy this, my recent true story.

A few weeks ago, I pulled out my TEK Dual 100 MHZ scope and probes, and started to try to measure AC Phase on two 6005 amps' XFRs.

Guess what, I forgot how to use my scope, how to turn all the knobs and dials on the front face !! I said to myself, " to hell with this scope ". I reminded myself, " in 2019 I easily heard every AC phase relationship inside my 12BZ7-KT88 DC amp. " I'll just do these two 6005 amps the same way, after I get each running.

( AC Phase polarity optimization was done two days go, as reported, by ear on Page 12, Post # 235, using " Solo Drums " ). So my friend, I can not satisfy you, or any E.E. trained person, with good explanations, and I will usually TRY to avoid them. I build intuitively, and by listening mainly. Serves me well !!

Another great example, who would think to use a 1,500 AMPERE ( peak , 64 A. RMS ) GTO 5 uF capacitor in a 0.120 Ampere circuit ?? No E.E. would ever try it. It was me and my DIY supplier in the Netherlands, who tried it - and listened. Him first, in this entire world ( 300B amp, uck ) and me second in the USA . I DO have reasons why I THINK it works so well, but I am far more concerned about its' results, and being sure to use a GTO, because of what I know, and hear what it does for the music's playback !! Nothing I know, gets close. Boli46 , a DIYer who owns A5 ALTECS ( !!! ) heard it too.

Thank you for your careful and thoughtful post, very nice !!

Jeff

Thank you for confirming EVERYTHING that I just posted. Specifically........
"In addition to your obvious technical knowledge, you appear to be somewhat skilled in the art of diplomacy. Unfortunately, your diplomacy isn't going to bear fruit when dealing with Jeff Medwin. For starters, he does not have the technical knowledge that is needed to answer the types of questions that someone with your technical knowledge is inclined to ask.. More importantly, he only cares about the end result, which is what he hears or believes that he hears, and has no interest whatsoever in trying to investigate and discover what currently-unknown phenomena are behind the multitude of seemingly preposterous, nonsensical and absurd assertions that he pontificates"
.
"

 

[drlowmu]

( 1 )

( 2 )


AND of course, we also have the Conrad - Johnson PV-10 Preamplifier OWNER'S MANUAL pages to address,

........................................................." plug it in the way it sounds best " ....................................................................


- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -

Do my above two ( 2 ) AC Polarity topic entries right above sound reasonable ...... OR - Dr.Gary : " seemingly preposterous, nonsensical and absurd assertions that he pontificates ".( from Post 254 right above )

How about from Post 242, a little bit higher up on this page ?? ........ Dr.Gary : " You really need to get off the drugs and stop lying. "


- - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - -- - - - - - - -- - - - - - - - - -- - - - - - - ---- - --


Please also, review my own history, 14 months at H.F.V. " Reaction Score ", TOTAL reactions ( 476 )

...........Likes : ( 461 ) .......... Loves : ( 2 ) ............ Ha Ha : ( 12 ) ...........Angry : ( 1 )

Won't someone please stick up for me now, and my work ????

Can't someone act to end this mess he alone is creating ? It pollutes this thread, and anything I try to share.

Thank you F.M.s.

Jeff

 

[drlowmu]

1-1-2022 ................................ Wire Management of your own AUDIO SYSTEM......................................................

Several times in the last 14 months I have been on H.F.V., I have enthusiastically referred F.M.s to Mapleshade Audio's web page entitled " Wire Management ". Excellent advice there. Look it up and follow along as much as you can.

Sadly, the person behind Mapleshade, the capable and brilliant Pierre Sprey, died in late 2021. We do not therefore know, how long his web pages will be kept intact on line. Absorb it now !!

I just today found one additional web page, that mirrors my experiences - and makes MUCH sense to me. Pierre, R.I.P, was right on the money, in every way .

I would like to also share this wire information with the appropriate interested audio enthusiasts. Here it is :

Mapleshade Audio Products

Copy it and save these notes on your hard drive !!

I also want to show people the first 2022 audio purchase, I made - just one hour ago. It is 100% related to wire management !!



Just enough glass insulators ( 4 ) for the positive and negative polarities, not to ever touch each other, nor the floor or carpeting, ... and for both channels. A new, permanent DIY solution, .............is coming up !!

Jeff

PS : Ohh my goodness, Pierre nailed it ....... wonderful reinforcement .......... 9.52 feet in a speaker lead, and ALSO in an AC Power cable, sounded better to my audio mentor Dennis, than a single ( 4.76 feet ) Robert Fulton length !!!!!

 

[Dr.Gary]

( 1 )
View attachment 65763
( 2 )


AND of course, we also have the Conrad - Johnson PV-10 Preamplifier OWNER'S MANUAL pages to address,

........................................................." plug it in the way it sounds best " ....................................................................


- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -

Do my above two ( 2 ) AC Polarity topic entries right above sound reasonable ...... OR - Dr.Gary : " seemingly preposterous, nonsensical and absurd assertions that he pontificates ".( from Post 254 right above )

How about from Post 242, a little bit higher up on this page ?? ........ Dr.Gary : " You really need to get off the drugs and stop lying. "


- - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - -- - - - - - - -- - - - - - - - - -- - - - - - - ---- - --


Please also, review my own history, 14 months at H.F.V. " Reaction Score ", TOTAL reactions ( 476 )

...........Likes : ( 461 ) .......... Loves : ( 2 ) ............ Ha Ha : ( 12 ) ...........Angry : ( 1 )

Won't someone please stick up for me now, and my work ????

Can't someone act to end this mess he alone is creating ? It pollutes this thread, and anything I try to share.

Thank you F.M.s.

Jeff

The comments by Just Walking are from a two year old thread in a Steve Hoffman Forum entitled "Does Electrical Polarity Really Matter". Unfortunately, the title doesn't specify "Matter to What". And that enables someone like you to cite comments of context and to misrepresent what the comments and the thread are actually talking about. Fortunately, the entire thread still exists. and it is clear that the thread as well as the comments by Just Walking pertain to hum, noise and ground-loop issues, and do not pertain to any alleged effects of line polarity on the sonic purity of an amp or preamp. Likewise, common sense suggests that the statement that is made in the owner's manual for the Conrad Johnson PV-10 also pertain to hum, noise and ground loop issues and does not pertain to any unspecified effects of line polarity on the sonic purity of the preamp.

 

[drlowmu]

I don't understand this at all. Your B+ is no doubt from a center tapped rectifier topology. Your filaments are hopefully either center tap grounded or have a phantom center tap made from two 100 ohm resistors to ground or a hum pot centered to ground.

Either way you will still have a 180 degree difference from either winding end to ground?

What difference does it make in reality? I think that's the reason why the classic manufactures, current manufactures, and DIYers don't bother with it. The only time I worry about POWER transformer winding phasing is when I parallel dual primaries or secondaries. There it matters and can destroy the transformer if wrong.

But if you think you hear a difference, I guess going through all this extra work this doesn't hurt anything either.

Dear RtoR King:

You concluded by saying " But if you think you hear a difference, I guess going through all this extra work this doesn't hurt anything either. "

Well, I just want to say, I didn't "think" I heard a difference. I A-Bed back and forth, and on EVERY winding aurally testing each individually. I "knew" I heard a difference, on each winding !! I could tell which 180 degree orientation sounded best, on my ALTEC VOTT A7-8s, consistently.

There were four internal-to-the-amp AC winding orientations I tested. The sum combination of having all four AC feeds operating ideally, was easily, subjectively, perhaps an 8% improvement in the amplifier's performance, overall, versus the haphazard non-checked original build connections.

Three AC orientations for sure were " 180 degrees out of whack", and I lost track on the fourth one, VS from how I started to listen. But I certainly DID find the right orientation, for the one " lost track " AC winding. " Solo Drums", Steven Clarke .

Thanks a lot for you open attitude and comments, 'appreciated. Helped the thread and people's understanding of this topic.

We now clearly know, from"Just Walking's" most lucid post, the mechanisms (inside any AC power transformer ) that are in play here.

I have suspected something like this was happening, since 1968. ( Tannoy 15" MGs / McIntosh C-22 / Dyna ST-70 ).

Jeff

 

[RtoR King]

Dear RtoR King:

You concluded by saying " But if you think you hear a difference, I guess going through all this extra work this doesn't hurt anything either. "

Well, I just want to say, I didn't "think" I heard a difference. I A-Bed back and forth, and on EVERY winding aurally testing each individually. I "knew" I heard a difference, on each winding !! I could tell which 180 degree orientation sounded best, on my ALTEC VOTT A7-8s, consistently.

There were four internal-to-the-amp AC winding orientations I tested. The sum combination of having all four AC feeds operating ideally, was easily, subjectively, perhaps an 8% improvement in the amplifier's performance, overall, versus the haphazard non-checked original build connections.

Three AC orientations for sure were " 180 degrees out of whack", and I lost track on the fourth one, VS from how I started to listen. But I certainly DID find the right orientation, for the one " lost track " AC winding. " Solo Drums", Steven Clarke .

Thanks a lot for you open attitude and comments, 'appreciated. Helped the thread and people's understanding of this topic.

We now clearly know, from"Just Walking's" most lucid post, the mechanisms (inside any AC power transformer ) that are in play here.

I have suspected something like this was happening, since 1968. ( Tannoy 15" MGs / McIntosh C-22 / Dyna ST-70 ).

Jeff

Anything an animal mind senses is a thought. One person's reality may not be another's. We all have different perceptions based on our body chemistry plus external experiences and influences.

I'm quite sure you can find support for these unconventional electronics theories on audiophile forums. Ditto that for literature from manufactures who sell in this market.

Now see if you can find any papers published in accredited engineering journals or university research verifying this phenomenon in HiFi audio. That will get my attention. I'm sure there are some highly precision instruments where this may occur but for HiFi audio the only known problems AC line or mains produces is hum.

I thought we were done with this topic. You hear it, you trust what you hear, you work to correct it, and you post your findings. If someone else here wants to investigate, they have your postings. But all these subsequent redundant posts trying to legitimize what you believe to hear are unnecessary.

 

[Dr.Gary]

Anything an animal mind senses is a thought. One person's reality may not be another's. We all have different perceptions based on our body chemistry plus external experiences and influences.

I'm quite sure you can find support for these unconventional electronics theories on audiophile forums. Ditto that for literature from manufactures who sell in this market.

Now see if you can find any papers published in accredited engineering journals or university research verifying this phenomenon in HiFi audio. That will get my attention. I'm sure there are some highly precision instruments where this may occur but for HiFi audio the only known problems AC line or mains produces is hum.

I thought we were done with this topic. You hear it, you trust what you hear, you work to correct it, and you post your findings. If someone else here wants to investigate, they have your postings. But all these subsequent redundant posts trying to legitimize what you believe to hear are unnecessary.

 

[drlowmu]

Anything an animal mind senses is a thought. One person's reality may not be another's. We all have different perceptions based on our body chemistry plus external experiences and influences.

I'm quite sure you can find support for these unconventional electronics theories on audiophile forums. Ditto that for literature from manufactures who sell in this market.

Now see if you can find any papers published in accredited engineering journals or university research verifying this phenomenon in HiFi audio. That will get my attention. I'm sure there are some highly precision instruments where this may occur but for HiFi audio the only known problems AC line or mains produces is hum.

I thought we were done with this topic. You hear it, you trust what you hear, you work to correct it, and you post your findings. If someone else here wants to investigate, they have your postings. But all these subsequent redundant posts trying to legitimize what you believe to hear are unnecessary.

Hello RtoR King:

I agree, I was redundant with that last post to you.

I was only attempting to reinforce my position, and real-life findings of over half a century in audio, to make-up of for the thread's dilution, caused by others, ( people with much education, and with a university background. )

Besides personally adhering to, and divulging optimized polarity of any and all AC feeds, .........here are a couple more things, that you may not have caught on to :

a) The amp's main power supply filter ( L1/C1/L2/C2 ) does not use a " Critical Inductance " choke. Look carefully, L1 and L2's Hammond 159ZA labels says 300 mHY. vs. a 117 mA. total draw.

b) Amplifier uses a TETRODE operated output tube, and by design, has ZERO negative feedback.

I am "not 100% sure" you realized either ( or both ) of those above ( a & b ) things.

Ever wonder WHY .......one would ever do those things ???? ............Ponder that !! There is a good reason, and a long history !!!

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I am sorry, but as I sensed from your numerous comments ( beginning in your early post - orange drops, electrolytics ) I do not believe we two people are on the same page in audio !! ( No electrolytics inside the SE DC amps ).

Here is WHY I say this : Frankly, in all my years of following audio, I found VERY FEW degreed E.E.s. or university - trained people, coming up with fantastic sounding audio amplifiers. ( And, I have met and personally known numerous famous amplifier and audio designers, over the decades. )

I would imagine, the nice lady who owns and runs MBL, out of Germany, hires German graduate E.E. amplifier designers. Anyone have a million dollars for one of their Radialstrahler EXTREME 101 MBL system ? Sure sounds nice to me. Heard it twice briefly at Denver's RMAF shows, when she personally visits the USA. See them here : Poland's 2019 show :

How about this - I have recently been wondering, ....... was Wm. Z . Johnson ever a graduate E.E.?? I don't know. What school, graduation year and degree?? Can anyone tell us ? I was friends with him, we always met and talked at CES shows, him and Mrs. Nancy.Johnson.

Overall, I would guess 90% of the amplifier builders and designers I have met and known over the years, do not come from University Research or E.E. degreed backgrounds. In fact, like some of this thread's very recent posters : most EEs and university people are at a distinct and VERY OBVIOUS disadvantage, compared to say, me, with a degree in Business Administration.

A great example, superb - follows :

Would they ever think to TRY a GTO 5 uF cap in any 1.5 Watt amp, or in any loudspeaker crossover. Why of course not !!

How about this, as we can see from this thread, some of these seemingly " ultra educated people ", do not even know HOW to best plug an audio amplifier, or an audio preamplifier, .................into the wall socket !!!!!!!

Yes, I will work on improving the redundancy , thanks. If there is no continuing thread dilution, there becomes no more of a need for it. If you have additional questions, kindly contact me through HFV's messaging system. You will get my immediate attention, or, telephone me if you would like to have a serious audio conversation. I would surely enjoy that.

Jeff

 

[drlowmu]

1-2-2022.......................................Early, Earliest - Audio Research Corporation - History .........................................

I knew Bill Johnson owned a Hi Fi store in Minneapolis, early on, and lived above it. I believe, the attached history would have mentioned if he graduated from College as an E.E., or whatever. But no mention is made at all.

SEE : https://audioresearch.com/our-story

Oh my goodness, I just realized, EXACTLY like Bill Johnson, my first amplifier self-design was a three chassis mono amplifier ( a pair, or six chassis for stereo ). Remember the " Triode Music Amplifier " photos?? Never knew this .....until this evening. An amazing coincidence. SEE:

New Design, SE 6005 Directly Coupled Audio Amplifier

Thank you for posting your work (and in such detail). This will take more time for me to think about. While I am here, one question if you have time: I can not tell if the star ground itself penetrates the powder-coating to earth the chassis as well (presumably to the green included in a...

www.hifivision.com

His SP3-A1 preamp ( we all owned one ) set the audio world on it's ear back then. Most people then ( and today ) use a mediocre sounding 150 VDC to 165 VDC on the plate of a 12AX7 Input tube. Bill used on his " V1 " plates 206 VDC and 208 VDC respectively ( dual triode ), with lowered current. WHY ?? So the tube would SWING and do something, sound superior to all other products. He "knew" ( what to do, was a listener) back then. We "know" to do this today...some of us.

The 6N23P-EV Input tube ( in the new 6005 amp ), is design centered to run above 200 VDC also on the plate ( and the direct couple ) - at 211.5 VDC . It's been designed to SWING and do something !!! Only 4.5 mA. of current is this tube's design center. The Input tube is thus operating at only 51.2% of it'sMaximum ( 1.8 W. ) power rating,............ conservative designing . Somewhat close to 62%, the Golden Ratio.

( SEE this thread's page 1, Post #18 !!! Looks like I did about 15 voltage changes ( upwards mostly ) early on - to determine what sounded the absolute best !! Very interesting circuit development :

https://www.hifivision.com/threads/...ly-coupled-audio-amplifier.82963/#post-927796 )

In 2022, we hope to be able to apply things, ( some things learned in 2021- with this 6005 amp ) to a new all-out Passive RIAA tube phono - line preamplifier. Premium parts and execution throughout, for my personal use. I simply love hearing good analogue !!

Tube rectified, SHUNTING, double Dennis Fraker Final Filters ( for each triode tube and plate resistor / Ra ), all film capacitors, a two 12AX7 phono EQ, and a 12B4 for line, with the phono EQ tube stages Directly Coupled.

In 2022, there exists a new 6005 DC power amplifier, and a record collection, to justify this new phono preamp. Ohh boy . BTW, LOL, I am no Bill Zane Johnson . May he R.I.P.

Jeff

 

[RtoR King]

Hello RtoR King:

I agree, I was redundant with that last post to you.

I was only attempting to reinforce my position, and real-life findings of over half a century in audio, to make-up of for the thread's dilution, caused by others, ( people with much education, and with a university background. )

Besides personally adhering to, and divulging optimized polarity of any and all AC feeds, .........here are a couple more things, that you may not have caught on to :

a) The amp's main power supply filter ( L1/C1/L2/C2 ) does not use a " Critical Inductance " choke. Look carefully, L1 and L2's Hammond 159ZA labels says 300 mHY. vs. a 117 mA. total draw.

b) Amplifier uses a TETRODE operated output tube, and by design, has ZERO negative feedback.

I am "not 100% sure" you realized either ( or both ) of those above ( a & b ) things.

Ever wonder WHY .......one would ever do those things ???? ............Ponder that !! There is a good reason, and a long history !!!

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

I am sorry, but as I sensed from your numerous comments ( beginning in your early post - orange drops, electrolytics ) I do not believe we two people are on the same page in audio !! ( No electrolytics inside the SE DC amps ).

Here is WHY I say this : Frankly, in all my years of following audio, I found VERY FEW degreed E.E.s. or university - trained people, coming up with fantastic sounding audio amplifiers. ( And, I have met and personally known numerous famous amplifier and audio designers, over the decades. )

I would imagine, the nice lady who owns and runs MBL, out of Germany, hires German graduate E.E. amplifier designers. Anyone have a million dollars for one of their Radialstrahler EXTREME 101 MBL system ? Sure sounds nice to me. Heard it twice briefly at Denver's RMAF shows, when she personally visits the USA. See them here : Poland's 2019 show :

How about this - I have recently been wondering, ....... was Wm. Z . Johnson ever a graduate E.E.?? I don't know. What school, graduation year and degree?? Can anyone tell us ? I was friends with him, we always met and talked at CES shows, him and Mrs. Nancy.Johnson.

Overall, I would guess 90% of the amplifier builders and designers I have met and known over the years, do not come from University Research or E.E. degreed backgrounds. In fact, like some of this thread's very recent posters : most EEs and university people are at a distinct and VERY OBVIOUS disadvantage, compared to say, me, with a degree in Business Administration.

A great example, superb - follows :

Would they ever think to TRY a GTO 5 uF cap in any 1.5 Watt amp, or in any loudspeaker crossover. Why of course not !!

How about this, as we can see from this thread, some of these seemingly " ultra educated people ", do not even know HOW to best plug an audio amplifier, or an audio preamplifier, .................into the wall socket !!!!!!!

Yes, I will work on improving the redundancy , thanks. If there is no continuing thread dilution, there becomes no more of a need for it. If you have additional questions, kindly contact me through HFV's messaging system. You will get my immediate attention, or, telephone me if you would like to have a serious audio conversation. I would surely enjoy that.

Jeff

You are missing the point. I don't think I ever made a comment on degree'd EEs versus non-degree'd EEs. There are many highly competent and well compensated EEs that have little to no FORMAL education in Electrical Engineering. Note I said FORMAL. While it certainly takes longer, some people can learn complex engineering theory without a formal classroom and lab environment. People on the Autism spectrum fit this mold very well. Howard Vollum, founder of Tektronix, was notable in the 1960s for hiring non-degreed engineers based on ability. And of course he had many degree'd EEs as well. He wanted results, not just sheepskin.

Therefore saying people who are EEs, either by degree or experience, "are at a distinct disadvantage" is ridiculous! They do understand the fundamental science of electronics. That's why they don't even think of using a GTO cap in a 1 watt audio amplifier to a sonic advantage. It's special attributes offer no advantage in this application. They don't have to "try it" because they know established and well proven electronic theory. This "Drum Solo", "capture the leading edge" demonstrates this idea is just wishful placebo effect. If I want to determine the slew rate of my amplifiers I use a calibrated pulse and study the results. Then I may play the Drum Solo to hear it. But lack of test facilities or knowledge of how to use them does not make all the engineering problems just go away.

Example: Do you realize how slow in electrical terms the rise time of a drum or cymbal beat is? I don't know the exact number either but I can assure you, it's slow in electrical terms considering the entire electromagnetic spectrum. Audio is at the bottom end of that spectrum not to mention the acoustical risetime attenuation caused by our atmosphere to the recording microphone.

 

[Dr.Gary]

You are missing the point. I don't think I ever made a comment on degree'd EEs versus non-degree'd EEs. There are many highly competent and well compensated EEs that have little to no FORMAL education in Electrical Engineering. Note I said FORMAL. While it certainly takes longer, some people can learn complex engineering theory without a formal classroom and lab environment. People on the Autism spectrum fit this mold very well. Howard Vollum, founder of Tektronix, was notable in the 1960s for hiring non-degreed engineers based on ability. And of course he had many degree'd EEs as well. He wanted results, not just sheepskin.

Therefore saying people who are EEs, either by degree or experience, "are at a distinct disadvantage" is ridiculous! They do understand the fundamental science of electronics. That's why they don't even think of using a GTO cap in a 1 watt audio amplifier to a sonic advantage. It's special attributes offer no advantage in this application. They don't have to "try it" because they know established and well proven electronic theory. This "Drum Solo", "capture the leading edge" demonstrates this idea is just wishful placebo effect. If I want to determine the slew rate of my amplifiers I use a calibrated pulse and study the results. Then I may play the Drum Solo to hear it. But lack of test facilities or knowledge of how to use them does not make all the engineering problems just go away.

Example: Do you realize how slow in electrical terms the rise time of a drum or cymbal beat is? I don't know the exact number either but I can assure you, it's slow in electrical terms considering the entire electromagnetic spectrum. Audio is at the bottom end of that spectrum not to mention the acoustical risetime attenuation caused by our atmosphere to the recording microphone.