Me ofcourse!
Two things...Everyone hears differently...so you don't like a 300b design...I have only heard 3 or 4 300b (All sounded quite different) but not coloured..or not more coloured than the many SS designs I have heard... But then again I don't go for neutral or coloured sound...but for sound that I seem to think sounds good..whatever it sounds like..
Secondly..I respect your and ofcourse Thorsten's views...both of you have a hell of a lot of experience and also theoretical knowledge. Basically I am just an observer throwing in a few personal views or hopefully
however...not to insult Thorsten...or you ...but it is absolutely pointless to argue with Thorsten he is always right!
Cheers,
Bas
Vive la differance! or something
Hi,
Lol... Vive la difference, Bas.
We ususally say that when talking about the ladies....
A good friend of mine happens to own an AN Baransu. I heard it a few times on his Lowthers (very coloured but efficient) and I must say these amps sound really great.
At 41.500 $ a pair they don't come cheap and I can assure you that my humble OTLs, pricewise at least, sound at least as good and don't even exhibit the slightest trace of hum which the Baransu still do.
On the downside, my OTLs tend to push up the electricity bill a little more....
On the plus side, I don't have to pay half as much for a set of replacement tubes; the 6080 being the cheapest dual powertriode for the time being.
Cheers,
Lol... Vive la difference, Bas.
We ususally say that when talking about the ladies....
A good friend of mine happens to own an AN Baransu. I heard it a few times on his Lowthers (very coloured but efficient) and I must say these amps sound really great.
At 41.500 $ a pair they don't come cheap and I can assure you that my humble OTLs, pricewise at least, sound at least as good and don't even exhibit the slightest trace of hum which the Baransu still do.
On the downside, my OTLs tend to push up the electricity bill a little more....
On the plus side, I don't have to pay half as much for a set of replacement tubes; the 6080 being the cheapest dual powertriode for the time being.
Cheers,
We aren't in the same company
There are big, big differences in our experience and engineering skills.
He has Two plus years in Tubes, the rest in pro audio connecting jacks etc.
I have 25 in tube audio design. Before that I worked in RF designing etc. with tubes. 44 years with tubes total.
He couldn't design a simple coupling circuit with cap and resistor that could mimicked a straightwire even closely. I also saw his schematic and well........ the sonics could be much better with a better design.
There are big, big differences in our experience and engineering skills.
He has Two plus years in Tubes, the rest in pro audio connecting jacks etc.
I have 25 in tube audio design. Before that I worked in RF designing etc. with tubes. 44 years with tubes total.
He couldn't design a simple coupling circuit with cap and resistor that could mimicked a straightwire even closely. I also saw his schematic and well........ the sonics could be much better with a better design.
Hi,
Steve,
While I can agree with you from what I see, I am surprised by the way you need to attack TL.
Most of my knowledge comes from reading hundreds of books, assimillating them, hands on experience and gut feeling.
My linguistic knowledge helped alot and while alot of people see me as a guru, I certainly don't see myself that way.
We're here to help people, not to critise the ones needing help.
These are though times for all of us and the forum reflects this. I respect you as a designer, I really do.
IOW, I respect diversity in all its forms.
Cheers,
Steve,
While I can agree with you from what I see, I am surprised by the way you need to attack TL.
Most of my knowledge comes from reading hundreds of books, assimillating them, hands on experience and gut feeling.
My linguistic knowledge helped alot and while alot of people see me as a guru, I certainly don't see myself that way.
We're here to help people, not to critise the ones needing help.
These are though times for all of us and the forum reflects this. I respect you as a designer, I really do.
IOW, I respect diversity in all its forms.
Cheers,
The reason
Hi Frank,
Frank, I definitely want to set the record straight. No way do we have similar experience.
For the record, I have 25 years in tube audio, 44 years total with tubes, Designed RF tube equipment, was a radio amateur at 16-17 years of age, and designed and built much of my own equipment as an amateur.
He has two+ years in tubes, the rest in proaudio.
In post 72 of this string, another sly tatic, telling me how to design a simple 300b amp, as if he is some expert.
Of course the inference is that he can design the best, putting himself on a pedestal,
when he couldn't even suggest/design a CR coupling section that mimicks a straight wire.
The above comment was to emphasize the difference between us.
While he was trying to show how intelligent he was, "faking it" so to speak, that he was so educated. I was showing that he couldn't do a simple coupling circuit. Thus a big difference in experience and design ability between us.
I want to make sure the record is straight, that he and I have totally different amounts of experience. A post or two above seems to indicate we have similar experience. Nothing could be further from the truth.
I hope this sets the record straight.
Hi Frank,
Frank, I definitely want to set the record straight. No way do we have similar experience.
For the record, I have 25 years in tube audio, 44 years total with tubes, Designed RF tube equipment, was a radio amateur at 16-17 years of age, and designed and built much of my own equipment as an amateur.
He has two+ years in tubes, the rest in proaudio.
In post 72 of this string, another sly tatic, telling me how to design a simple 300b amp, as if he is some expert.
Of course the inference is that he can design the best, putting himself on a pedestal,
when he couldn't even suggest/design a CR coupling section that mimicks a straight wire.
The above comment was to emphasize the difference between us.
While he was trying to show how intelligent he was, "faking it" so to speak, that he was so educated. I was showing that he couldn't do a simple coupling circuit. Thus a big difference in experience and design ability between us.
I want to make sure the record is straight, that he and I have totally different amounts of experience. A post or two above seems to indicate we have similar experience. Nothing could be further from the truth.
I hope this sets the record straight.
Hi Steve,
You make reference to designing a simple neutral sounding coupling circuit. When I designed the coupling circuits for my amp, I used the standard calculations for the -3db points. And I took into consideration the recommendations for component values in the data sheets. For instance, for my 2A3/300B output stage, I came up with .22uF/50K rg. ( I use fixed bias and the data sheets for both 2A3 and 300B calls for a max value of 50k for the grid resistor. Which limits any variation in the coupling circuit to the value of the coupling capacitor.)
Are there any other calculations I should have considered?
I also read your white papers. You make mention of raising components off the chassis. In my amp I have my caps and other components on stand-offs or stand-off platforms (though, not for the reasons you state in your white paper, but more so for convenience sake). How do you elevate your components above the chassis? Your writing has got me questioning how effective my solutions are in reducing stray capacitance.
Here is a shot of my amp internals:
An externally hosted image should be here but it was not working when we last tested it.
And a shot of my power supply internals:
An externally hosted image should be here but it was not working when we last tested it.
Hallo Steve,
Sorry if I offended you. I was trying to make a joke of the fact that I have heard that it is not possible to argue with Thorsten.
With all due respect I don't think it is all that important that Mr. T only has 5-10years or whatever amount of experience.
One should judge someone's opinions on the back of what they have built and what that sounds like. Thorsten contributes a lot of his time and effort in sharing his ideas (however wrong they may be in your eyes)...I have no idea what his stuff sounds like..but once again on the back of other opinions I also doubt that the high GM tubes are the solution per se..Like they say in America..the jury is still out on that. And it is an individual choice in the end anyway.
In the end I am very glad to have you and mr T. about so that we (I) can learn from you both and absorb whatever we like.
Cheers,
Bas
Sorry if I offended you. I was trying to make a joke of the fact that I have heard that it is not possible to argue with Thorsten.
With all due respect I don't think it is all that important that Mr. T only has 5-10years or whatever amount of experience.
One should judge someone's opinions on the back of what they have built and what that sounds like. Thorsten contributes a lot of his time and effort in sharing his ideas (however wrong they may be in your eyes)...I have no idea what his stuff sounds like..but once again on the back of other opinions I also doubt that the high GM tubes are the solution per se..Like they say in America..the jury is still out on that. And it is an individual choice in the end anyway.
In the end I am very glad to have you and mr T. about so that we (I) can learn from you both and absorb whatever we like.
Cheers,
Bas
Re: More mistakes Thorsten?
Konnichiwa,
Absolutely.
So, you heard at a HiFi Show some 300B Amplifiers, probably NON of those I mentioned (because most of those companies are not at these kind of shows). It seems so far that you have not actually worked on Amplifiers with 300B Output Valves yourself.
So, based on your postings, you make ex cathedra pronouncements about the abilities of all 300B equipped amplifiers with NO first hand experience of even hearing 300B Amplifiers in your own system context (where you could make a direct compariuson with your other amplifiers) AND you advise people about 300B Amplifiers without EVER having build one.
I do feel that advise should come from experience, not unfounded opinion, but that's just me.
How do you know? And no, I do not have 2 maybe three years in tube design. I have zip interest in a ****ing contest with you along the lines "my whatchamacallit is bigger than yours". Neither my experience with valves in general nor yours is the topic of dicussion, it is actually the EXPERIENCE with 300B Output Valve equipped amplifiers. Oh, I messed with Valve electronics since I was about 8 or so years old and that is a LONG time back now, but yes, I have done industrial electronics and pro-audio plus service on audio and TV Gear (including much valve based stuff valves) as well, not that any of that particulary matters.
Let us first separate two different strands. I recommend for a simple 300B Amplifier a RC circuit with a -3db Frequency of 3Hz. I do this because such an RC circuit leads to a low phaseshift (< 10 degrees) and minimal group delay (< 1.2mS) in the audio band. Compared to the low frequency behaviour of even the very best output transformers manufacturered (never mind speakers) such amounts of phaseshift and group delay are minimal and hence the Amplifiers behaviour at low frequencies remains determined by the output transformer. There is simply no material benefit from using larger values as long as conventiona output transformers are used.
Now to my own schematic.
Anyone who would have bothered to analyse the schematic would have nticed that there is a choke in the grid circuit (and another in the anode circuit). Anyone who sucesfully would have completed EE101 whould know that the presence of such reactances considerably changes the behaviour of the coupling circuit. As it stands, the LC coupling sections are tuned to partially equalise the output transformers LF rolloff and do so with minimal shifts in phase and group delay, overall making as a whole an amplifier with a more extended LF response than commonly possible with a given output transformer and still phase/group delay errors as low as permitted by the output transformer. Now what specifically was your criticism with this arrnagement again?
Funny. I remember clearly stating that I actually check my parts for sonic neutrality (using usually wire bypass tests). So now you take refuge to deliberatly misquoting me?
Funny, you make an a priory assertation without, it seems, having ever understood how the circuit actually works.
Well, I will leave it to the reader in this thread to decide who they should listen to.
You know the saying: "If you have to ask...."? I leave it to the kind to complete it for your case....
Oh, before I forget, I have known people who where professional musicians for > 40 Years, which did not stop them from being also dreadful, unable to play well (like getting the notes right or playing with emotion). Simply having done something for a long time does not inherently infer any particular claim to be actually GOOD at it.
Sayonara
Konnichiwa,
Positron said:
Absolutely.
Positron said:
So, you heard at a HiFi Show some 300B Amplifiers, probably NON of those I mentioned (because most of those companies are not at these kind of shows). It seems so far that you have not actually worked on Amplifiers with 300B Output Valves yourself.
So, based on your postings, you make ex cathedra pronouncements about the abilities of all 300B equipped amplifiers with NO first hand experience of even hearing 300B Amplifiers in your own system context (where you could make a direct compariuson with your other amplifiers) AND you advise people about 300B Amplifiers without EVER having build one.
I do feel that advise should come from experience, not unfounded opinion, but that's just me.
Positron said:
How do you know? And no, I do not have 2 maybe three years in tube design. I have zip interest in a ****ing contest with you along the lines "my whatchamacallit is bigger than yours". Neither my experience with valves in general nor yours is the topic of dicussion, it is actually the EXPERIENCE with 300B Output Valve equipped amplifiers. Oh, I messed with Valve electronics since I was about 8 or so years old and that is a LONG time back now, but yes, I have done industrial electronics and pro-audio plus service on audio and TV Gear (including much valve based stuff valves) as well, not that any of that particulary matters.
Positron said:
Let us first separate two different strands. I recommend for a simple 300B Amplifier a RC circuit with a -3db Frequency of 3Hz. I do this because such an RC circuit leads to a low phaseshift (< 10 degrees) and minimal group delay (< 1.2mS) in the audio band. Compared to the low frequency behaviour of even the very best output transformers manufacturered (never mind speakers) such amounts of phaseshift and group delay are minimal and hence the Amplifiers behaviour at low frequencies remains determined by the output transformer. There is simply no material benefit from using larger values as long as conventiona output transformers are used.
Now to my own schematic.
Anyone who would have bothered to analyse the schematic would have nticed that there is a choke in the grid circuit (and another in the anode circuit). Anyone who sucesfully would have completed EE101 whould know that the presence of such reactances considerably changes the behaviour of the coupling circuit. As it stands, the LC coupling sections are tuned to partially equalise the output transformers LF rolloff and do so with minimal shifts in phase and group delay, overall making as a whole an amplifier with a more extended LF response than commonly possible with a given output transformer and still phase/group delay errors as low as permitted by the output transformer. Now what specifically was your criticism with this arrnagement again?
Positron said:
Funny. I remember clearly stating that I actually check my parts for sonic neutrality (using usually wire bypass tests). So now you take refuge to deliberatly misquoting me?
Positron said:
Funny, you make an a priory assertation without, it seems, having ever understood how the circuit actually works.
Positron said:
Well, I will leave it to the reader in this thread to decide who they should listen to.
Positron said:
You know the saying: "If you have to ask...."? I leave it to the kind to complete it for your case....
Oh, before I forget, I have known people who where professional musicians for > 40 Years, which did not stop them from being also dreadful, unable to play well (like getting the notes right or playing with emotion). Simply having done something for a long time does not inherently infer any particular claim to be actually GOOD at it.
Sayonara
Cool down guys !
Lets talk/post about amps and topologies guys, not about each other!
Thanks to all of you for your contribution on Tube amps.
I think I'll start with a 6C33C-B tube amp and later on build my self a nice 300B or an OTL ala Frank
But that is planed for the next year if I'm still around
Best regards,
Audiofanatic
analog_sa said:
Lets talk/post about amps and topologies guys, not about each other!
Thanks to all of you for your contribution on Tube amps.
I think I'll start with a 6C33C-B tube amp and later on build my self a nice 300B or an OTL ala Frank
But that is planed for the next year if I'm still around
Best regards,
Audiofanatic
Hi,
Bas,
Having never seen a single GEC 6AS7G, I can't really tell you anything specific about them.
At Euro 15/EA the dealer should give you some warranty as to their quality.
Personally I prefer the 6080 which are around in abundance and I think you can buy them at ~Euro 10/EA if you buy in quantity.
I never had much luck with NOS 6AS7Gs but that could well be down to mere coincidence.
Cheers,
Bas,
Having never seen a single GEC 6AS7G, I can't really tell you anything specific about them.
At Euro 15/EA the dealer should give you some warranty as to their quality.
Personally I prefer the 6080 which are around in abundance and I think you can buy them at ~Euro 10/EA if you buy in quantity.
I never had much luck with NOS 6AS7Gs but that could well be down to mere coincidence.
Cheers,
Agenda?
First, Bas, I under stood what you meant, it was a sort of sarcastic statement. That is why I didn't mention it. No problems Bas.
--------------------------------------------------------------------
Now TL.
"So, you heard at a HiFi Show some 300B Amplifiers, probably NON of those I mentioned (because most of those companies are not at these kind of shows). It seems so far that you have not actually worked on Amplifiers with 300B Output Valves yourself.
So, based on your postings, you make ex cathedra pronouncements about the abilities of all 300B equipped amplifiers with NO first hand experience of even hearing 300B Amplifiers in your own system context (where you could make a direct compariuson with your other amplifiers) AND you advise people about 300B Amplifiers without EVER having build one.
I do feel that advise should come from experience, not unfounded opinion, but that's just me."
Me: "Well I didn't keep track but I know Audio Note, Wavac, Wavelength, Fi I believe, etc. was there. There were dozens of 300bs amps in the horn rooms, but didn't write them down.
You must remember, though, that if one looks at these two strings, you were the one who attacked the KT88s/6550s, even twice, before I responded. What is your excuse?? Let's get the facts straight.
Me: "You have 2 years, maybe3 in tube design, and before that proaudio?
You: "How do you know? And no, I do not have 2 maybe three years in tube design. I have zip interest in a ****ing contest with you along the lines "my whatchamacallit is bigger than yours". Neither my experience with valves in general nor yours is the topic of dicussion, it is actually the EXPERIENCE with 300B Output Valve equipped amplifiers. Oh, I messed with Valve electronics since I was about 8 or so years old and that is a LONG time back now, but yes, I have done industrial electronics and pro-audio plus service on audio and TV Gear (including much valve based stuff valves) as well, not that any of that particulary matters."
You: "Around two years ago I also started writing, first for the TNT-Audio on-line Magazine on Equipment modifications..."
Me: Seems to me this establishes the time you have been writing for ETM. So you joined ETM afterwards since you are writing for them now?
You: "For the last two years I have had my head deep in triodes and Valves of every kind. Most of my System is DIY."
Your own words my friend from your own biography at the site.
"Neither my experience with valves in general nor yours is the topic of dicussion, it is actually the EXPERIENCE with 300B Output Valve equipped amplifiers."
Actually it is also your use of the KT88/6550/EL34s too, right. And remember, it all started when you started attacking those tubes in two different strings out of the blue. Yet you have virtually no experience with these tubes do you.
Read Ian Whites article on the Fi amp for a similar experience.
http://www.enjoythemusic.com/magazine/equipment/0104/fix.htm
Notice that No comparisons are made with other amps at all, just the tube 6550 general Class of amps. Seems similar to TL's attack, a general attack on the tube.
Similar things have happened at other chat sites too. One clear example was when one started slyly condemning EL34/6550s and later 3 others joined in. They tried the same strategy as TL, arguing until one finally broke. He was selling the OPTs and another one, at his site, of the 4, from the same city, was selling DHT tubes.
You: "Let us first separate two different strands. I recommend for a simple 300B Amplifier a RC circuit with a -3db Frequency of 3Hz. I do this because such an RC circuit leads to a low phaseshift (< 10 degrees) and minimal group delay (< 1.2mS) in the audio band. Compared to the low frequency behaviour of even the very best output transformers manufacturered (never mind speakers) such amounts of phaseshift and group delay are minimal and hence the Amplifiers behaviour at low frequencies remains determined by the output transformer. There is simply no material benefit from using larger values as long as conventiona output transformers are used.
Now to my own schematic.
Anyone who would have bothered to analyse the schematic would have nticed that there is a choke in the grid circuit (and another in the anode circuit). Anyone who sucesfully would have completed EE101 whould know that the presence of such reactances considerably changes the behaviour of the coupling circuit. As it stands, the LC coupling sections are tuned to partially equalise the output transformers LF rolloff and do so with minimal shifts in phase and group delay, overall making as a whole an amplifier with a more extended LF response than commonly possible with a given output transformer and still phase/group delay errors as low as permitted by the output transformer. Now what specifically was your criticism with this arrnagement again?"
Me: There is a big difference between specs and actually checking by listening. Again you admit you haven't actually checked to see if your coupling circuit actually sounded like a straight wire. Massive compensation my friend.
As you mentioned yorself, OPTs altar the sound, as well as do chokes; esp in the bass and treble regions. Had you checked by listening, you would have found the coupling circuit doesn't even approximate a straightwire. The inductor, vs a resistor, also lowers reactance as the freq lowers,
"the presence of such reactances considerably changes the behaviour of the coupling circuit" (by the way I do have an Electronics Engineering degree, graduated number 1 in my class. You?)
making the sound even worse vs a straightwire as reference. Lots of compensation is needed with this circuit. You haven't done any homework. However, it is good for pushing sales of inductors/OPTs, right?
Me: The last part, the way you are compensating is non-linear as you cannot perfectly do so with an inductor and cap. First, there is a resonance setup, which even if you could perfectly cancel isn't reproducable as the tolerances of the parts, esp the inductor, have a wide range of tolerances and will sound differently.
Secondly, you have introduced another distorting part, much more harmonic distortion than a neutral resistor, if you had bothered to check and measure. This adds harmonics which combine with the previous tubes and output tube to create high order harmonics, at least 4 times higher than without the inductor (remember it has high voltage amplitude). So much for your low order distortions of the 300b tube (which is really a falicy anyway if physics is to be believed). That is one of the reasons I heard the "toyish" sound from some of the amps. OF course other non-neutral sounding parts contribute.
Me: "So besides not checking for parts neutrality, in another string,"
You: "Funny. I remember clearly stating that I actually check my parts for sonic neutrality (using usually wire bypass tests). So now you take refuge to deliberatly misquoting me?"
No you didn't, by your own admission above. You simply calculated the response, plus from other posts you mentioned. And you haven't actually checked different caps to see if they which are sonic neutral have you.
Me: "we see you haven't checked a simple neutral sounding coupling circuit either."
You: "Funny, you make an a priory assertation without, it seems, having ever understood how the circuit actually works."
You nailed your own coffin from your above comments, got caught again. Need I say more?
Me: "I don't mean to be mean, but Thorsten these people have worked hard for their money and they don't need someone preaching at us when one can't even design a simple flat response sounding circuit, let alone a complete amp.
You: "Well, I will leave it to the reader in this thread to decide who they should listen to."
Me: Well, most if not the vast majority aren't blessed to have the education in this area to decide. They rely on those who tell the truth, who don't bluff, and who aren't taking anything under the table (I had to ask twice to get the answer). I volunteered the info without ever being asked.
"No one can serve two masters; for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and mammon."
In otherwards, the principle is in this situation, that it is impossible to be impartial as a reviewer if one is getting any kind of perks in the audio field.
Sorry, but that is the way human nature is.
You: "Oh, before I forget, I have known people who where professional musicians for > 40 Years, which did not stop them from being also dreadful, unable to play well (like getting the notes right or playing with emotion). Simply having done something for a long time does not inherently infer any particular claim to be actually GOOD at it."
Me: Very clumsy and very predictable answer TL.
First, Bas, I under stood what you meant, it was a sort of sarcastic statement. That is why I didn't mention it. No problems Bas.
--------------------------------------------------------------------
Now TL.
"So, you heard at a HiFi Show some 300B Amplifiers, probably NON of those I mentioned (because most of those companies are not at these kind of shows). It seems so far that you have not actually worked on Amplifiers with 300B Output Valves yourself.
So, based on your postings, you make ex cathedra pronouncements about the abilities of all 300B equipped amplifiers with NO first hand experience of even hearing 300B Amplifiers in your own system context (where you could make a direct compariuson with your other amplifiers) AND you advise people about 300B Amplifiers without EVER having build one.
I do feel that advise should come from experience, not unfounded opinion, but that's just me."
Me: "Well I didn't keep track but I know Audio Note, Wavac, Wavelength, Fi I believe, etc. was there. There were dozens of 300bs amps in the horn rooms, but didn't write them down.
You must remember, though, that if one looks at these two strings, you were the one who attacked the KT88s/6550s, even twice, before I responded. What is your excuse?? Let's get the facts straight.
Me: "You have 2 years, maybe3 in tube design, and before that proaudio?
You: "How do you know? And no, I do not have 2 maybe three years in tube design. I have zip interest in a ****ing contest with you along the lines "my whatchamacallit is bigger than yours". Neither my experience with valves in general nor yours is the topic of dicussion, it is actually the EXPERIENCE with 300B Output Valve equipped amplifiers. Oh, I messed with Valve electronics since I was about 8 or so years old and that is a LONG time back now, but yes, I have done industrial electronics and pro-audio plus service on audio and TV Gear (including much valve based stuff valves) as well, not that any of that particulary matters."
You: "Around two years ago I also started writing, first for the TNT-Audio on-line Magazine on Equipment modifications..."
Me: Seems to me this establishes the time you have been writing for ETM. So you joined ETM afterwards since you are writing for them now?
You: "For the last two years I have had my head deep in triodes and Valves of every kind. Most of my System is DIY."
Your own words my friend from your own biography at the site.
"Neither my experience with valves in general nor yours is the topic of dicussion, it is actually the EXPERIENCE with 300B Output Valve equipped amplifiers."
Actually it is also your use of the KT88/6550/EL34s too, right. And remember, it all started when you started attacking those tubes in two different strings out of the blue. Yet you have virtually no experience with these tubes do you.
Read Ian Whites article on the Fi amp for a similar experience.
http://www.enjoythemusic.com/magazine/equipment/0104/fix.htm
Notice that No comparisons are made with other amps at all, just the tube 6550 general Class of amps. Seems similar to TL's attack, a general attack on the tube.
Similar things have happened at other chat sites too. One clear example was when one started slyly condemning EL34/6550s and later 3 others joined in. They tried the same strategy as TL, arguing until one finally broke. He was selling the OPTs and another one, at his site, of the 4, from the same city, was selling DHT tubes.
You: "Let us first separate two different strands. I recommend for a simple 300B Amplifier a RC circuit with a -3db Frequency of 3Hz. I do this because such an RC circuit leads to a low phaseshift (< 10 degrees) and minimal group delay (< 1.2mS) in the audio band. Compared to the low frequency behaviour of even the very best output transformers manufacturered (never mind speakers) such amounts of phaseshift and group delay are minimal and hence the Amplifiers behaviour at low frequencies remains determined by the output transformer. There is simply no material benefit from using larger values as long as conventiona output transformers are used.
Now to my own schematic.
Anyone who would have bothered to analyse the schematic would have nticed that there is a choke in the grid circuit (and another in the anode circuit). Anyone who sucesfully would have completed EE101 whould know that the presence of such reactances considerably changes the behaviour of the coupling circuit. As it stands, the LC coupling sections are tuned to partially equalise the output transformers LF rolloff and do so with minimal shifts in phase and group delay, overall making as a whole an amplifier with a more extended LF response than commonly possible with a given output transformer and still phase/group delay errors as low as permitted by the output transformer. Now what specifically was your criticism with this arrnagement again?"
Me: There is a big difference between specs and actually checking by listening. Again you admit you haven't actually checked to see if your coupling circuit actually sounded like a straight wire. Massive compensation my friend.
As you mentioned yorself, OPTs altar the sound, as well as do chokes; esp in the bass and treble regions. Had you checked by listening, you would have found the coupling circuit doesn't even approximate a straightwire. The inductor, vs a resistor, also lowers reactance as the freq lowers,
"the presence of such reactances considerably changes the behaviour of the coupling circuit" (by the way I do have an Electronics Engineering degree, graduated number 1 in my class. You?)
making the sound even worse vs a straightwire as reference. Lots of compensation is needed with this circuit. You haven't done any homework. However, it is good for pushing sales of inductors/OPTs, right?
Me: The last part, the way you are compensating is non-linear as you cannot perfectly do so with an inductor and cap. First, there is a resonance setup, which even if you could perfectly cancel isn't reproducable as the tolerances of the parts, esp the inductor, have a wide range of tolerances and will sound differently.
Secondly, you have introduced another distorting part, much more harmonic distortion than a neutral resistor, if you had bothered to check and measure. This adds harmonics which combine with the previous tubes and output tube to create high order harmonics, at least 4 times higher than without the inductor (remember it has high voltage amplitude). So much for your low order distortions of the 300b tube (which is really a falicy anyway if physics is to be believed). That is one of the reasons I heard the "toyish" sound from some of the amps. OF course other non-neutral sounding parts contribute.
Me: "So besides not checking for parts neutrality, in another string,"
You: "Funny. I remember clearly stating that I actually check my parts for sonic neutrality (using usually wire bypass tests). So now you take refuge to deliberatly misquoting me?"
No you didn't, by your own admission above. You simply calculated the response, plus from other posts you mentioned. And you haven't actually checked different caps to see if they which are sonic neutral have you.
Me: "we see you haven't checked a simple neutral sounding coupling circuit either."
You: "Funny, you make an a priory assertation without, it seems, having ever understood how the circuit actually works."
You nailed your own coffin from your above comments, got caught again. Need I say more?
Me: "I don't mean to be mean, but Thorsten these people have worked hard for their money and they don't need someone preaching at us when one can't even design a simple flat response sounding circuit, let alone a complete amp.
You: "Well, I will leave it to the reader in this thread to decide who they should listen to."
Me: Well, most if not the vast majority aren't blessed to have the education in this area to decide. They rely on those who tell the truth, who don't bluff, and who aren't taking anything under the table (I had to ask twice to get the answer). I volunteered the info without ever being asked.
"No one can serve two masters; for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and mammon."
In otherwards, the principle is in this situation, that it is impossible to be impartial as a reviewer if one is getting any kind of perks in the audio field.
Sorry, but that is the way human nature is.
You: "Oh, before I forget, I have known people who where professional musicians for > 40 Years, which did not stop them from being also dreadful, unable to play well (like getting the notes right or playing with emotion). Simply having done something for a long time does not inherently infer any particular claim to be actually GOOD at it."
Me: Very clumsy and very predictable answer TL.
Re: Agenda?
Konnichiwa,
Whatever. I made my point sufficiently. As you are onbviously to keen on scoring "points" to chack facts (like datastamps on files and the like) there is little point in discussion.
But just for a simple point, I did not "attack" the KT88/6550 (gawd - we are paranoid, ain't we), I merely pointed out that compared to it, the much more linear (can be checked on any curve tracer) Directly Heated triodes sounded significantly better, enough so to condemn the KT88/6550 to average and unexciting commercial designs, but not worth to bother with for a DIY Enthusiast interested in best performance. For the record BTW, I worked with various russian near equivalents to KT88/6550 and EL34's in the 1980's and after that also the western versions, so I know them moderatly well.
Now what you read into my statements (and you do seem have a degree of phantasy and imagination bodering on certifiable) is your problem, not mine.
And I retain, you might wish to convert one of your KT88 SE Amp's to 300B's. You might find the experience enlightening and informing.
Sayonara
Konnichiwa,
Positron said:
Whatever. I made my point sufficiently. As you are onbviously to keen on scoring "points" to chack facts (like datastamps on files and the like) there is little point in discussion.
But just for a simple point, I did not "attack" the KT88/6550 (gawd - we are paranoid, ain't we), I merely pointed out that compared to it, the much more linear (can be checked on any curve tracer) Directly Heated triodes sounded significantly better, enough so to condemn the KT88/6550 to average and unexciting commercial designs, but not worth to bother with for a DIY Enthusiast interested in best performance. For the record BTW, I worked with various russian near equivalents to KT88/6550 and EL34's in the 1980's and after that also the western versions, so I know them moderatly well.
Now what you read into my statements (and you do seem have a degree of phantasy and imagination bodering on certifiable) is your problem, not mine.
And I retain, you might wish to convert one of your KT88 SE Amp's to 300B's. You might find the experience enlightening and informing.
Sayonara
point made.
"But just for a simple point, I did not "attack" the KT88/6550 (gawd - we are paranoid, ain't we), I merely pointed out that compared to it, the much more linear (can be checked on any curve tracer) Directly Heated triodes sounded significantly better, enough so to condemn the KT88/6550 to average and unexciting commercial designs, but not worth to bother with for a DIY Enthusiast interested in best performance."
Well I hope you didn't use the test a few years ago that I saw. It compared a WE 300b tube to a Chinese KT88. Hardly a fair comparison. I thought that was pretty sleezy tatic, and shows what some will do for a sale. Shows some organization too as I saw this at several chat sites, trying to pick up sales.
Alot of the sound quality is determined by the materials used in construction. Can't prove it, but may be much more important than the HD.
"I worked with various russian near equivalents to KT88/6550 and EL34's"
All tubes are different. Consider the Sovtek (EH), Svetlana. They all sound different. I don't like the Chinese, JJs (unless they changed the last 2 years) and other brands.
The design and parts neutrality makes a whole world of difference in the sound.
I don't care what tube others use. I could care less. That is there business. I try to be helpful when I can. When one posts a condecending comment which is not part of the string, though, I have to ask myself what the reason is. After all the string is already started in a particular direction for the very tube you support. I don't think that is paranoid, just seems very strange.
"But just for a simple point, I did not "attack" the KT88/6550 (gawd - we are paranoid, ain't we), I merely pointed out that compared to it, the much more linear (can be checked on any curve tracer) Directly Heated triodes sounded significantly better, enough so to condemn the KT88/6550 to average and unexciting commercial designs, but not worth to bother with for a DIY Enthusiast interested in best performance."
Well I hope you didn't use the test a few years ago that I saw. It compared a WE 300b tube to a Chinese KT88. Hardly a fair comparison. I thought that was pretty sleezy tatic, and shows what some will do for a sale. Shows some organization too as I saw this at several chat sites, trying to pick up sales.
Alot of the sound quality is determined by the materials used in construction. Can't prove it, but may be much more important than the HD.
"I worked with various russian near equivalents to KT88/6550 and EL34's"
All tubes are different. Consider the Sovtek (EH), Svetlana. They all sound different. I don't like the Chinese, JJs (unless they changed the last 2 years) and other brands.
The design and parts neutrality makes a whole world of difference in the sound.
I don't care what tube others use. I could care less. That is there business. I try to be helpful when I can. When one posts a condecending comment which is not part of the string, though, I have to ask myself what the reason is. After all the string is already started in a particular direction for the very tube you support. I don't think that is paranoid, just seems very strange.
Konnichiwa,
Actually, russia made quite a range of power tetrodes and pentodes that one might call "KT88 Class" and which I call near equivalents (just like I consider the 6S45 a near equivalent to EC8020 & WE 437A). Many where later re-labeled (and often re-pinned) and sold to the west as equivalents of western types. True equivalents are fairly recent of course.
On the other hand, we also had the whole East German RFT (excellent EL34's and EL84's, plus various commercial types of output Pentodes), Tesla and EI range of valves available. There was a lot of stuff going around and Valve Amplifiers where still in active commercial service in the 80's all over eastern europe even in studios.
Sayonara
fdegrove said:
Actually, russia made quite a range of power tetrodes and pentodes that one might call "KT88 Class" and which I call near equivalents (just like I consider the 6S45 a near equivalent to EC8020 & WE 437A). Many where later re-labeled (and often re-pinned) and sold to the west as equivalents of western types. True equivalents are fairly recent of course.
On the other hand, we also had the whole East German RFT (excellent EL34's and EL84's, plus various commercial types of output Pentodes), Tesla and EI range of valves available. There was a lot of stuff going around and Valve Amplifiers where still in active commercial service in the 80's all over eastern europe even in studios.
Sayonara
Give us a break.
"I worked with various russian near equivalents to KT88/6550 and EL34's in the 1980's and after that also the western versions, so I know them moderatly well.
Now what you read into my statements (and you do seem have a degree of phantasy and imagination bodering on certifiable) is your problem, not mine.
And I retain, you might wish to convert one of your KT88 SE Amp's to 300B's. You might find the experience enlightening and informing."
Well, just keep changing your story. You are just getting yourself in deeper and deeper. I don't need to read anything into your statements. Who has to interpret when you state things so clearly?
What about all the misrepresentations of my positions, demeaning my site, white papers, claiming to be an expert in tube design and then finding out you can't even design a simple coupling stage, let alone an amp. NO education that you have mentioned or in your bio.
Multiple denounciations of the 6550 class of tubes out of the blue (when the subject was building a 300b amp), when you just stated above "so I know them moderatly well". Not expertly, just moderately well. And even that statement seems to be an optimistic statement, from your own record. You seem to have changed your involvement with tubes twice from your bio.
But even two years of heavy involvement (quoted from your bio) is very short as one has to try different designs, order the parts each time, time to build the design, lots of hours to break it in, optimistically a couple of weeks, and then listen to it for some period of time to get a feel of the music.
And every time you need to try a new part, you have to order it, install it, and take alot of hours of breakin, and again listen. And you claim two years is enough time to get an accurate reading on a tube? Don't think so, especially when you don't seem to have the ability to design, maybe just copy and tweek?
And what experience you say you have, in the 80s, is totally irrevelant, the tubes are different today, been upgraded several times, as well as different brands than what you admit to messing with.
Give us all a break. You just seem to get deeper and deeper into the mire.
"I worked with various russian near equivalents to KT88/6550 and EL34's in the 1980's and after that also the western versions, so I know them moderatly well.
Now what you read into my statements (and you do seem have a degree of phantasy and imagination bodering on certifiable) is your problem, not mine.
And I retain, you might wish to convert one of your KT88 SE Amp's to 300B's. You might find the experience enlightening and informing."
Well, just keep changing your story. You are just getting yourself in deeper and deeper. I don't need to read anything into your statements. Who has to interpret when you state things so clearly?
What about all the misrepresentations of my positions, demeaning my site, white papers, claiming to be an expert in tube design and then finding out you can't even design a simple coupling stage, let alone an amp. NO education that you have mentioned or in your bio.
Multiple denounciations of the 6550 class of tubes out of the blue (when the subject was building a 300b amp), when you just stated above "so I know them moderatly well". Not expertly, just moderately well. And even that statement seems to be an optimistic statement, from your own record. You seem to have changed your involvement with tubes twice from your bio.
But even two years of heavy involvement (quoted from your bio) is very short as one has to try different designs, order the parts each time, time to build the design, lots of hours to break it in, optimistically a couple of weeks, and then listen to it for some period of time to get a feel of the music.
And every time you need to try a new part, you have to order it, install it, and take alot of hours of breakin, and again listen. And you claim two years is enough time to get an accurate reading on a tube? Don't think so, especially when you don't seem to have the ability to design, maybe just copy and tweek?
And what experience you say you have, in the 80s, is totally irrevelant, the tubes are different today, been upgraded several times, as well as different brands than what you admit to messing with.
Give us all a break. You just seem to get deeper and deeper into the mire.
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