The " PFA TRIPLE 6005 "..... DIY tube amplifier of 2022.

05-28-2022................... A Conceptual PRIMER , On SE Tube Amplifier Power Supply Design

The power supplies shown in this and last year's 6005 amp build, each have what is called " L.S.E.S." passive power supplies. This is an acronym standing for " Low Stored Energy Supplies ".

In both the 6005 HFV builds, and in Hari Iyer's 2020 DIY build, we uniquely use L.S.E.S. with the following components :

1) Dual 5U4GB rectifier tubes
2) Dual 6 Ohm DCR Main Power Supply Inductors
3) Film power supply caps, typically just 50 uF or less
4) Bypassing of film caps, with " instantaneous Peak-Current capable " GTO caps, across the C1 and C2 positions

This L.S.E.S. topology, applied to a SE tube amplifier, results in a " Fast Supply", that keeps up with pulsed music information, unlike anything else I have experienced. Essentially, this is a supply that is playing music back " in the time of the music " and not in the time of a large storage reservoir and lagging power supply.

In the last month, my Audio Mentor for the last 30 years, has posted ( on a USA Forum, Audio Asylum ) regarding this concept.

Two of his posts I would like to share with any interested HFV readers. He is " Tube Wrangler or Dennis " :



RE: All feedback is not the same :




  • Posted by 7868 (A) on May 26, 2022 at 20:35:35


    Power supplies are often overlooked as being important. Most do not realize that the power supply is in the signal loop.

Follow Ups:






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

RE: Book operating point seems to sound very good





The above paragraph is an excellent conceptual explanation of why we use a L.S.E.S. supply topology. Yogibear, my friend, this post was authored with you, and many others, in mind. Have fun exploring this. Anyone may P.M. me with relevant questions, anytime.

Jeff
In my opinion, your post entitled "A Conceptual PRIMER , On SE Tube Amplifier Power Supply Design" should be essential reading for anyone who is seriously interested in tube amplifier design. That's because it reflects everything that is wrong with your misguided and seriously-flawed design philosophy. It also documents the fact that your understanding of power supply operation is contradicted by nearly a century of accumulated knowledge and well-established facts in physics, mathematics, engineering and science.
Without getting into the specifics, suffice it to say that your design philosophy does not pertain to amplifier design at all. Instead, it pertains to the design of a musical instrument that contains components that you are able to manipulate in order to produce what you subjectively determine to be the correct sound when used with your speakers.
 
5-28-2022 ................... The Introduction of GTO caps to the on-line AUDIO world, 2017..........................

It looks like I imported the first GTO caps in the USA, from The Netherlands, for audio applications in late 2016. Here is when they were first- ever written up on line. Very much " on the money " description in retrospect, and surprisingly to me, seldom used in 2022.

People are cheap and also - they just don't know !!. For what GTOs alone do, they are worth every penny of their $50.00 cost in a crossover and amp - to me !! I truly have not found their equal, or something remotely approaching them, as to what they do best.

Boli46 in Denmark ( ALTEC VOTT A5s ) knows.

Hari, as in one post referenced below, lift the ground wire from C1's bypass GTO in each monoblock, leaving the C2 GTO intact and operating. ****** HEAR your audio system......... take a huge performance dive !! *******

Here is the GTO's on-line USA introduction :



Has any one in India, other than Hari, experimented with them yet ??

Good luck to all.

Jeff ( Low Ohms in the thread )
 
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5-28-2022 ................... The Introduction of GTO caps to the on-line AUDIO world, 2017..........................

It looks like I imported the first GTO caps in the USA, from The Netherlands, for audio applications in late 2016. Here is when they were first- ever written up on line. Very much " on the money " description in retrospect, and surprisingly to me, seldom used in 2022.

People are cheap and also - they just don't know !!. For what GTOs alone do, they are worth every penny of their $50.00 cost in a crossover and amp - to me !! I truly have not found their equal, or something remotely approaching them, as to what they do best.

Boli46 in Denmark ( ALTEC VOTT A5s ) knows.

Hari, as in one post referenced below, lift the ground wire from C1's bypass GTO in each monoblock, leaving the C2 GTO intact and operating. ****** HEAR your audio system......... take a huge performance dive !! *******

Here is the GTO's on-line USA introduction :



Has any one in India, other than Hari, experimented with them yet ??

Good luck to all.

Jeff ( Low Ohms in the thread )
I look forward to hearing directly from Hari about the sonic effects of GTO capacitors when installed in his amplifiers and crossovers.
 
I look forward to hearing directly from Hari about the sonic effects of GTO capacitors when installed in his amplifiers and crossovers.
I have not done an A vs B with the GTO capacitor in my amplifier and do not intend to do so as it will mean lots of effort and rewiring. My speaker does not have any crossover and is directly connected to my amplifier.
Thanks,
 
06 - 13 - 2022 ....................... PROGRESS REPORT ............................ Photographic

The two mono chassis were returned from Powder Coaters ( " Sure Coat, ", Sedalia, MO ) today. Dropped off 5-18. 136 miles of driving involved. ( 218 Kilometers ).


010 edited.jpg




004 (2) edited.jpg



006 edited OK.jpg



14 Gauge steel, with welded corners.

Jeff
 
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7-11-2022 ............................ Stay in TOUCH, a mini UPDATE

The " TRIPLE 6005 " SE build has been stalled a bit more, last few weeks. My computer's download of PSUD2 power supply simulation software became unavailable to me. Software conflicts. On 6-29, I downloaded ( for free ) a new PSUD 2 version, to allow me to assist another HFV F.M. with his 1/2 6FQ7 - F2a SE DC design

This past weekend, I applied the latest PSUD 2 software simulation program, to my own 6E6P-E - Triple 6005 amps' needs. I have just developed a very precise build plan of action.

A two stage tube Directly Coupled circuit is a bit tricky. When you typically change one resistor value, the entire circuit is inter-related. Simultaneously, ALL operating points must be thoughtfully taken into account - towards optimization.

This is the ONLY amplifier topology and design that interests me.

Thankfully, I have specialized on this for about 15 years, after hearing it for the first time at Denver's RMAF Audio show, in 2007 at the Serious Stereo demo room, all weekend !! Then, ten more weekend show visits over the next dozen years.

The use of PSUD 2 is so helpful. I no longer have to breadboard to get the tube operating parameters I have in mind.
In a Direct Coupled amplifier, everything must " balance out " VDC - wise. Doing a third PSUD 2 iteration over two days, I was able to get a main B+ of 459.62 VDC to simulate and balance out ( on the Direct Couple ), to within 0.06 VDC. This was accomplished while selecting " in - stock / available " high-performance resistor types, which historically, have long proven themselves to be favorites, sonically.

Everything is operated conservatively, and designed for long term reliability. I am willing to spend money on parts solutions. " Delicious sounding " resistors are four times over-rated in their Power rating VS : Dissipation level. Tubes operate nicely at Golden Ratio proportions ( 61.8% ) of their maximum plate dissipation rating. This results in producing an ultra long service life, while also sounding fine.

Now I can order all the needed resistors, mostly of German manufacture, ( as are many of the amps' film caps ) . I shall proceed - while also being highly confident as to the ultimate outcome.

Fun stuff !!

Jeff
 
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7-16-22 ............ Photo UPDATE................................

001  7-13 gto.jpg

ABOVE : I typically avoid use of plastic "tie wraps" - around wiring and capacitors. In the case of three inch diameter GTO bypass caps however,, an exception is made. Notice how the cap is pre-positioned AWAY from direct contact with the chassis' bottom and side steel surfaces. This lessens magnetic chassis - fields and also extreme heat from chassis-heat-sunk power resistors. This planned positioning lengthens the life of film capacitors, by keeping them cooler.



008 edit.jpg
010 edit.jpg012 edit.jpg
018 edit.jpg


013 edit.jpg

Jeff
 
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7-17-22.......................Dual FILAMENT BIASING STRING............

This is a dual-voltage resistive divider string, powered from the 458 VDC main B+ at C2, to ground. It applies two differing VDC potentials, to two differing center tapped Filament Transformers.

One transformer energizes the 6005 Filaments. It is raised above ground to about 201 VDC, at the 6005 filament transformer's center tap. The 201 VDC potential is needed in a DC amp, when the cathode is over 220 VDC above ground, so as not to exceed the 6005's suggested Heater-to-Cathode maximum voltage differential rating.of 90 VDC.

A second "tap" on this single resistive divider string places the second separate Filament Transformer ( for the Input/Driver 6E6P-E tube ) about 50 VDC above ground. This 50 VDC of Input/Driver tube Filament Biasing often makes for a SLIGHT and minor sonic improvement on a top-notch system.


..............................................................................Filament BIASING String, Dual.JPG................................................................................

+++++++++++++++++ ( 458 VDC divided by 377K Ohms total is 1.21 mA. to ground ) +++++++++++++++++



Today, I made both Resistive Voltage Divider strings, one for each monaural amplifier.

I also fashioned from a Keystone #817 terminal strip, an AC attachment terminal strip, that will allow me to attach an amp's multiple power transformers to either phase of the 120 VAC power feed. This will allow for an unambiguous and safer-to-execute process, when optimizing Internal AC Polarities by ear. Power wiring and phase selection will not be crowded or difficult to access.

Here is what the new circuits looks like, a 6-32 single bolt to install, and 4 hook up wires. ( B+. Ground, +201 VDC, and +50 VDC ).

010 edit.jpg


Some other Keystone Terminals , handy for DIYing, point - to - point :

014 edit.jpg018 edit 2.jpg

Jeff
 
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07 - 21 - 2022 .......... Started Soldering in Parts.........


Below, installed hash chokes for the Driver tube's 6.3 VAC filament activation. Cleans up the feed.

004 USE EDITED.jpg




Below, RAISED both the 120 VAC main power attachment points, used for all three Power Transformers. Employed 2.5 inch long HEX standoffs, internally threaded.

This provides very EASY " in your face " ACCESS........... to optimize Internal AC PHASE Polarities better.


006  USE edited.jpg
.

Jeff
 
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07 - 23 - 22............................. EQUAL length Wire Build Detail ........

Avoid " dog - legging " in S.E. builds, etc, when possible, employ EQUAL wire lengths .

FINALS stage , three 6005 tubes wired in parallel. 19 AWG " Wonder Wire " used.

G1 and G2 circuit wiring details photographed. Unique .


003 edited.jpg




04 edit.jpg



012 edited.jpg



ANODE and CATHODE triple EQUAL wiring not yet ready to execute. Not shown.

The desired 1% tolerance Cathode power resistors, used for the three 6005 tubes, are not arriving until 08-26-22 . 5% tolerance resistors simply will not do in that circuit location.

Jeff
 
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7-17-22.......................Dual FILAMENT BIASING STRING............

This is a dual-voltage resistive divider string, powered from the 458 VDC main B+ at C2, to ground. It applies two differing VDC potentials, to two differing center tapped Filament Transformers.

One transformer energizes the 6005 Filaments. It is raised above ground to about 201 VDC, at the 6005 filament transformer's center tap. The 201 VDC potential is needed in a DC amp, when the cathode is over 220 VDC above ground, so as not to exceed the 6005's suggested Heater-to-Cathode maximum voltage differential rating.of 90 VDC.

A second "tap" on this single resistive divider string places the second separate Filament Transformer ( for the Input/Driver 6E6P-E tube ) about 50 VDC above ground. This 50 VDC of Input/Driver tube Filament Biasing often makes for a SLIGHT and minor sonic improvement on a top-notch system.


..............................................................................View attachment 70695................................................................................

+++++++++++++++++ ( 458 VDC divided by 377K Ohms total is 1.21 mA. to ground ) +++++++++++++++++



Today, I made both Resistive Voltage Divider strings, one for each monaural amplifier.

I also fashioned from a Keystone #817 terminal strip, an AC attachment terminal strip, that will allow me to attach an amp's multiple power transformers to either phase of the 120 VAC power feed. This will allow for an unambiguous and safer-to-execute process, when optimizing Internal AC Polarities by ear. Power wiring and phase selection will not be crowded or difficult to access.

Here is what the new circuits looks like, a 6-32 single bolt to install, and 4 hook up wires. ( B+. Ground, +201 VDC, and +50 VDC ).

View attachment 70698


Some other Keystone Terminals , handy for DIYing, point - to - point :

View attachment 70699View attachment 70700

Jeff
 
7-17-22.......................Dual FILAMENT BIASING STRING............

This is a dual-voltage resistive divider string, powered from the 458 VDC main B+ at C2, to ground. It applies two differing VDC potentials, to two differing center tapped Filament Transformers.

One transformer energizes the 6005 Filaments. It is raised above ground to about 201 VDC, at the 6005 filament transformer's center tap. The 201 VDC potential is needed in a DC amp, when the cathode is over 220 VDC above ground, so as not to exceed the 6005's suggested Heater-to-Cathode maximum voltage differential rating.of 90 VDC.

A second "tap" on this single resistive divider string places the second separate Filament Transformer ( for the Input/Driver 6E6P-E tube ) about 50 VDC above ground. This 50 VDC of Input/Driver tube Filament Biasing often makes for a SLIGHT and minor sonic improvement on a top-notch system.


..............................................................................View attachment 70695................................................................................

+++++++++++++++++ ( 458 VDC divided by 377K Ohms total is 1.21 mA. to ground ) +++++++++++++++++



Today, I made both Resistive Voltage Divider strings, one for each monaural amplifier.

I also fashioned from a Keystone #817 terminal strip, an AC attachment terminal strip, that will allow me to attach an amp's multiple power transformers to either phase of the 120 VAC power feed. This will allow for an unambiguous and safer-to-execute process, when optimizing Internal AC Polarities by ear. Power wiring and phase selection will not be crowded or difficult to access.

Here is what the new circuits looks like, a 6-32 single bolt to install, and 4 hook up wires. ( B+. Ground, +201 VDC, and +50 VDC ).

View attachment 70698


Some other Keystone Terminals , handy for DIYing, point - to - point :

View attachment 70699View attachment 70700

Jeff
Because the 458.76 Vdc is unregulated, the bias voltages that are derived from it using a high-impedance resistive divider are going to be affected by changes in AC line voltage as well as by larger dynamic voltage fluctuations on the B+ line which result from the use three paralleled 6005s in the output. It therefore seems to me that the use of low-impedance zeners to provide the needed filament bias voltages would be a much better choice than the use of a high-impedance resistive divider.
 
As I was a very late comer to this forum and the 6005 diy amp thread created by Jeff Medwin was closed for comments, I hope you guys don’t mind me sharing my findings on the 6005 amp here !


Audition of 6005 Power Amplifier - Subjective Opinions


Background

Being an audiophile for over 40 years in Hong Kong, I consider myself very fortunate in the sense that I have full access to almost ALL successful high-end audio products, all within an 88 square kilometres area ! Years ago I stumbled into one of Jeff Medwin's Audio Forum articles, my understanding of Jeff’s overall design direction “ less is more, shortest signal path, small output amplification and high efficient speaker system ” matches mine tightly. Hence I was exceedingly curious in finding out the end result, sound quality, of his design and implementation. Here I’m running his 6005 power amp in my setup (details below) for the 3rd week, despite some components in the 6005 amp may not be totally run-in, I would like to share my subjective views, based on my audio approach above, on Jeff’s 6005 creation.

Soundstage reproduction - gigantic soundstage extended well beyond the four walls of my very small (120 sq feet) size listening room is just breath-taking, never happening to my system in my 40+ years of audio life.

Low level information reproduction - tracks after tracks, be that musical instrument or vocals, low level details reproduction, which in my opinion, is critical for reproducing emotional contents, is stunning to say the least, again this level of reproduction set a substantially higher record in my system.

Lightening speed & huge dynamic music contents reproduction - Every day in the past 2 weeks I was stunned, without exception, by the speed of not only the top end, but the full frequency spectrum of music contents, this is what I consider crucial for life-like music reproduction.

Dead quietness - there were many technical discussions on Jeff’s unconventional designs on power supply, biasing etc., which is beyond my ability to fully understand, but the fact is, to my ears and to the Beauhorn 104 db brutal revealing efficiency, the 6005 amp is DEAD QUIET

Emotional music contents reproduction - There will be little disputes that emotional contents is one of the most critical elements of music reproduction, in my experience all of the above elements, soundstage, low level information, speed & dynamic and low noise floor are all critical for reproducing the most important element of “EMOTION” for music, needless to say this is another champ coming out from the 6005 amp !

Unconventional rare piece
There is a saying: different horses for different course, you may have different kinds of opinions on the 6005 amp if you have a chance to audition, nevertheless, I see Jeff’s 6005 amp is an excellent example, at least to me, of a piece of stunning, perhaps, unconventional rare piece of hardware, which provides a super structure for music signal to travel through with the least hinderance overall. The fascinating aspect of our hobby of music reproduction is, we all can then utilitse this piece of valuable hardware to reproduce music we want by tuning it to your likings!

I would like to thank Hifivision for providing this platform and all the people who contributed to this thread and particularly, millions of thanks to Mr. Jeff Medwin. Please keep on sharing your joys, experiences and findings, good or bad, in the world of music reproduction and DIY.


My System
My current power amp setup : PassLab SIT 3, 15W transistor amp, DIY 437A interstage 300B, 7 Watts monoblock power amp, primary source, digital source from my AMD music server running 16+16 cores CPU with FULL linear power supply rails to the mobo, running Windows 11 PE (pre-installation edition) OS of total size of only less than 10% of normal Windows 11, all running in RAM and only playing internal files stored in SLC SSDs; Other sources : Strain gauge phono system; 15 IPS tape system, Studer C37; Passive preamp, LDR DIY module; Beauhorn speakers with no cross-over, 104 db efficiency
 
As I was a very late comer to this forum and the 6005 diy amp thread created by Jeff Medwin was closed for comments, I hope you guys don’t mind me sharing my findings on the 6005 amp here !


Audition of 6005 Power Amplifier - Subjective Opinions


Background

Being an audiophile for over 40 years in Hong Kong, I consider myself very fortunate in the sense that I have full access to almost ALL successful high-end audio products, all within an 88 square kilometres area ! Years ago I stumbled into one of Jeff Medwin's Audio Forum articles, my understanding of Jeff’s overall design direction “ less is more, shortest signal path, small output amplification and high efficient speaker system ” matches mine tightly. Hence I was exceedingly curious in finding out the end result, sound quality, of his design and implementation. Here I’m running his 6005 power amp in my setup (details below) for the 3rd week, despite some components in the 6005 amp may not be totally run-in, I would like to share my subjective views, based on my audio approach above, on Jeff’s 6005 creation.

Soundstage reproduction - gigantic soundstage extended well beyond the four walls of my very small (120 sq feet) size listening room is just breath-taking, never happening to my system in my 40+ years of audio life.

Low level information reproduction - tracks after tracks, be that musical instrument or vocals, low level details reproduction, which in my opinion, is critical for reproducing emotional contents, is stunning to say the least, again this level of reproduction set a substantially higher record in my system.

Lightening speed & huge dynamic music contents reproduction - Every day in the past 2 weeks I was stunned, without exception, by the speed of not only the top end, but the full frequency spectrum of music contents, this is what I consider crucial for life-like music reproduction.

Dead quietness - there were many technical discussions on Jeff’s unconventional designs on power supply, biasing etc., which is beyond my ability to fully understand, but the fact is, to my ears and to the Beauhorn 104 db brutal revealing efficiency, the 6005 amp is DEAD QUIET

Emotional music contents reproduction - There will be little disputes that emotional contents is one of the most critical elements of music reproduction, in my experience all of the above elements, soundstage, low level information, speed & dynamic and low noise floor are all critical for reproducing the most important element of “EMOTION” for music, needless to say this is another champ coming out from the 6005 amp !

Unconventional rare piece
There is a saying: different horses for different course, you may have different kinds of opinions on the 6005 amp if you have a chance to audition, nevertheless, I see Jeff’s 6005 amp is an excellent example, at least to me, of a piece of stunning, perhaps, unconventional rare piece of hardware, which provides a super structure for music signal to travel through with the least hinderance overall. The fascinating aspect of our hobby of music reproduction is, we all can then utilitse this piece of valuable hardware to reproduce music we want by tuning it to your likings!

I would like to thank Hifivision for providing this platform and all the people who contributed to this thread and particularly, millions of thanks to Mr. Jeff Medwin. Please keep on sharing your joys, experiences and findings, good or bad, in the world of music reproduction and DIY.


My System
My current power amp setup : PassLab SIT 3, 15W transistor amp, DIY 437A interstage 300B, 7 Watts monoblock power amp, primary source, digital source from my AMD music server running 16+16 cores CPU with FULL linear power supply rails to the mobo, running Windows 11 PE (pre-installation edition) OS of total size of only less than 10% of normal Windows 11, all running in RAM and only playing internal files stored in SLC SSDs; Other sources : Strain gauge phono system; 15 IPS tape system, Studer C37; Passive preamp, LDR DIY module; Beauhorn speakers with no cross-over, 104 db efficiency
Thanks LlLiu for the brief write-up about the 6005 amps sonic performance. I can imagine how they would be sounding as I too own a 2019 KT88 DC amplifier designed by Jeff. Enjoy your music 🎶.
 
As I was a very late comer to this forum and the 6005 diy amp thread created by Jeff Medwin was closed for comments, I hope you guys don’t mind me sharing my findings on the 6005 amp here !


Audition of 6005 Power Amplifier - Subjective Opinions


Background

Being an audiophile for over 40 years in Hong Kong, I consider myself very fortunate in the sense that I have full access to almost ALL successful high-end audio products, all within an 88 square kilometres area ! Years ago I stumbled into one of Jeff Medwin's Audio Forum articles, my understanding of Jeff’s overall design direction “ less is more, shortest signal path, small output amplification and high efficient speaker system ” matches mine tightly. Hence I was exceedingly curious in finding out the end result, sound quality, of his design and implementation. Here I’m running his 6005 power amp in my setup (details below) for the 3rd week, despite some components in the 6005 amp may not be totally run-in, I would like to share my subjective views, based on my audio approach above, on Jeff’s 6005 creation.

Soundstage reproduction - gigantic soundstage extended well beyond the four walls of my very small (120 sq feet) size listening room is just breath-taking, never happening to my system in my 40+ years of audio life.

Low level information reproduction - tracks after tracks, be that musical instrument or vocals, low level details reproduction, which in my opinion, is critical for reproducing emotional contents, is stunning to say the least, again this level of reproduction set a substantially higher record in my system.

Lightening speed & huge dynamic music contents reproduction - Every day in the past 2 weeks I was stunned, without exception, by the speed of not only the top end, but the full frequency spectrum of music contents, this is what I consider crucial for life-like music reproduction.

Dead quietness - there were many technical discussions on Jeff’s unconventional designs on power supply, biasing etc., which is beyond my ability to fully understand, but the fact is, to my ears and to the Beauhorn 104 db brutal revealing efficiency, the 6005 amp is DEAD QUIET

Emotional music contents reproduction - There will be little disputes that emotional contents is one of the most critical elements of music reproduction, in my experience all of the above elements, soundstage, low level information, speed & dynamic and low noise floor are all critical for reproducing the most important element of “EMOTION” for music, needless to say this is another champ coming out from the 6005 amp !

Unconventional rare piece
There is a saying: different horses for different course, you may have different kinds of opinions on the 6005 amp if you have a chance to audition, nevertheless, I see Jeff’s 6005 amp is an excellent example, at least to me, of a piece of stunning, perhaps, unconventional rare piece of hardware, which provides a super structure for music signal to travel through with the least hinderance overall. The fascinating aspect of our hobby of music reproduction is, we all can then utilitse this piece of valuable hardware to reproduce music we want by tuning it to your likings!

I would like to thank Hifivision for providing this platform and all the people who contributed to this thread and particularly, millions of thanks to Mr. Jeff Medwin. Please keep on sharing your joys, experiences and findings, good or bad, in the world of music reproduction and DIY.


My System
My current power amp setup : PassLab SIT 3, 15W transistor amp, DIY 437A interstage 300B, 7 Watts monoblock power amp, primary source, digital source from my AMD music server running 16+16 cores CPU with FULL linear power supply rails to the mobo, running Windows 11 PE (pre-installation edition) OS of total size of only less than 10% of normal Windows 11, all running in RAM and only playing internal files stored in SLC SSDs; Other sources : Strain gauge phono system; 15 IPS tape system, Studer C37; Passive preamp, LDR DIY module; Beauhorn speakers with no cross-over, 104 db efficiency
Would you please provide more details about the sound stage that you describe? Specifically, how far in front of the plane of the loudspeakers are you able to identify virtual sound sources (voice and/or instruments). Also, do these frontal virtual sound sources exist only between the you (the listener) and the plane of the speakers, or do they extend behind you and and even behind the rear wall of your listening room? Lastly, does the sound stage that you describe depend on the source material (vinyl, digital, streaming) and type of recording (paired stereo microphones, multi-channel multi-mic mix?
 
Would you please provide more details about the sound stage that you describe? Specifically, how far in front of the plane of the loudspeakers are you able to identify virtual sound sources (voice and/or instruments). Also, do these frontal virtual sound sources exist only between the you (the listener) and the plane of the speakers, or do they extend behind you and and even behind the rear wall of your listening room? Lastly, does the sound stage that you describe depend on the source material (vinyl, digital, streaming) and type of recording (paired stereo microphones, multi-channel multi-mic mix?
In my previous descriptions regarding the soundstage exceeding the “4 walls”, I meant front wall, side walls and ceiling wall and for avoidance of doubt I only listen to 2 channels PCM files, re-sampled to 384k for further processing by my Lampizator Golden Gate (version 1) R2R DAC (modified to bypass various options and volume control to shorten the signal path). Depending on materials, I have heard some 80s music files which have been digitally processed for surround sound to project rear image, images between listener and speakers and images behind the listener, those digitally processed images are artificial and are not something I value much at all!

In my experience, the 6005 amp is a rare piece of gems that can project recording materials dimensionality with the LEAST percieved compression/hindrance, particularly with digital materials. It’s like the digital files have gone through a decompression chamber which rendered the music presentation with stunning dimensionality, not just images located at front and back, left and right and top and bottom, but more importantly, it's the recorded minute/air details filling most of the spaces in-between what I mentioned above, be that a vocal or musical instrument, they have their own dimensions created by moving air. Each and every time when I correctly up-graded my audio gears, the above dimensionality element improved without exception, but never before has the improvement been as great as what the 6005 brought to me.

I guess not surprisingly I found vinyl, not to mention 15 IPS tapes, can handle the dimensionality issue MUCH easier than digital source, I have been battling with digital source compression issue to create high fidelity sound for more than 10 years, never been so happy with it in the past couple of years, and now with the 6005 amp, I can finally sit down and really enjoy digital music rather than keep fiddling with the server hardware and software.
 
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Internal Amplifier Wiring Improvements on 1-12-2023


In 2021 I introduced on HFV a stereo 6005 SE DC amplifier build.

For 2022-23, I am doing a " triple " paralleled SE amplifier design, which I intend to be an all-out monoblock pair.

I recently took my personal 2021 Stereo single 6005 per channel amplifier, and paralleled both channels externally, to HEAR and get a taste of what that it does, with two 6005s as a double. ( Nice !! )

Two days ago, I got the idea to re-wire some long ( 13 inch ) 12 AWG leads I had in my 2021 stereo 6005 amp, and this post documents that.
It took me all day to do the change.

My reference TEST music is Gilbert and Sullivan Highlights, on CD, with the Rochester NY Orchestra. Human voice mostly. From the first two notes, I KNEW this was a nice improvement. On the first cut when the large background CHORUS entered, and sang their part ( hard to reproduce ) I instantly reacted by getting goosebumps on both my arms when listening.

On two other occasions on the CD , I yelled, literally at the top of my lungs " YES YES YES " and another time I loudly yelled " Go, Go , Go". So, I suppose I liked the re-wire of that one cap in each channel.

I took the time to photograph before and after, and denote it to any who have an interest. It is hilarious to me, the best sounding amps in THIS world are NOT ever made by EEs and pHDs particularly, but by JUST a few people world-wide, who LISTEN and build, and have a passion for it all. Never forget that !!


1-12-23  REV. ORIGINAL.jpg



1-12-2023 :

7h.jpg

TOP VIEW 1-12-23.jpg

Jeff
 
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Given the numerous components involved in your designs and limited space in stereo housing, moving on to mono-block configuration will certainly give you a natural advantage in achieving better positioning of components and to explore the alternative of paralleling the output tubes or even the push & pull configuration?
 
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