I think/know this amp is what you ideally need if it really has a DF = 1, so if you can't afford it, find the closest to it within your budget: Diavolo SET 300B Copper Reference 10w Integrated Amplifier – Art Audio US
GM
GM
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First of all, I'm very grateful for all the efforts of everybody that is dedicating some time to help me to understand the subject: amps output impedance and full range drivers, thank you very much for the patience too.
Okay, I organized my thinkings about all this subject, and concluded that is a technical consensus, that for the majority of full range drivers be powered optimally, the low damping factor aka output impedance is vital.
Instead of still asking the thoughts about every amp that I found the damping factor specs, and their respective synergy with the full range driver that I want to use, I think is a much better way I learn how to read the specs properly, and this is my main difficult till now.
So, here are my questions, there's a quote that i did not understood, and the doubt numbered bellow the quote.
1. What is the specs nomenclature that I must look on the full range drivers specifications, in order to know if will provide synergy with the amp, when considering the output impedance of the amp? and how they are the commonly variants nomenclatures and unit of measurements presented by the manufactures?
For example, the damping factor of a Luxman tube integrated amp is described as 4 Ω (and a number 1 after this, without a unit of measurement about this 1), where I have to look on the specs of the full range driver, In order to know if will be a good match? this amp will be a good or bad match with the Fostex FE0208EZ? and why?
https://www.fostexinternational.com/docs/speaker_components/pdf/fe208ez.pdf
2. What is low Q units drivers? Never heard this terminology.
3. This sentence is like if i was trying to read a sentence in Chinese, don’t understood nothing after “so output impedance is typically...” and then goes this crazy numbers and equation..
4. I presume this is when the amp manufacturer provide the output impedance spec, correct? when they describe as damping factor it's different? how different?
I’m reading this as 0.1 greater than 1ohm, my reading is correct?
This 0.1 is what? Volt? Watt? Other measure that i have no idea?
5. What exactly means to know: what do the 4ohms or 8 or 16?
6. So I presume that is common that manufacturers present the damping factor in just Ohms measurement right? still not understand why this is a good measure to be used with the Fostex FE208EZ, neither where on the driver’s specs I have to look to understand this...
7. First means: for SETs with output impedance equal or greater than 2.5Ω, correct? What means the ~ on the second statement? What differs from the First statement?
8. This whole statement is totally trying to read chinese, everything, understood absolutely nothing, mostly because all the math involved, my fault of course, due my lack of repertoire on the subject.
9. While checking the specs of this amp, I noticed that they specified like this: Output Impedance as 4Ω and 8Ω. But on the statement of the friend here on the Forum, he tells me that the Damping Factor is 1, so I presume that he made a calculation to convert the Output Impedance value, that was presented in between this two values of Ohms, to Damping Factor value of measurement, correct? If yes, how I can do this calculation using a tool that is provided on the web, where I just put the number and the conversion is made? Such auto calculator tool is available?
Oh and, the Damping Factor is 1 what? what unit of measurement?
Many thanks to all! I hope that I was clear, I done my best trying to be concise and please forgive my bad english.
Okay, I organized my thinkings about all this subject, and concluded that is a technical consensus, that for the majority of full range drivers be powered optimally, the low damping factor aka output impedance is vital.
Instead of still asking the thoughts about every amp that I found the damping factor specs, and their respective synergy with the full range driver that I want to use, I think is a much better way I learn how to read the specs properly, and this is my main difficult till now.
So, here are my questions, there's a quote that i did not understood, and the doubt numbered bellow the quote.
1. What is the specs nomenclature that I must look on the full range drivers specifications, in order to know if will provide synergy with the amp, when considering the output impedance of the amp? and how they are the commonly variants nomenclatures and unit of measurements presented by the manufactures?
For example, the damping factor of a Luxman tube integrated amp is described as 4 Ω (and a number 1 after this, without a unit of measurement about this 1), where I have to look on the specs of the full range driver, In order to know if will be a good match? this amp will be a good or bad match with the Fostex FE0208EZ? and why?
https://www.fostexinternational.com/docs/speaker_components/pdf/fe208ez.pdf
2. What is low Q units drivers? Never heard this terminology.
3. This sentence is like if i was trying to read a sentence in Chinese, don’t understood nothing after “so output impedance is typically...” and then goes this crazy numbers and equation..
4. I presume this is when the amp manufacturer provide the output impedance spec, correct? when they describe as damping factor it's different? how different?
I’m reading this as 0.1 greater than 1ohm, my reading is correct?
This 0.1 is what? Volt? Watt? Other measure that i have no idea?
5. What exactly means to know: what do the 4ohms or 8 or 16?
6. So I presume that is common that manufacturers present the damping factor in just Ohms measurement right? still not understand why this is a good measure to be used with the Fostex FE208EZ, neither where on the driver’s specs I have to look to understand this...
7. First means: for SETs with output impedance equal or greater than 2.5Ω, correct? What means the ~ on the second statement? What differs from the First statement?
8. This whole statement is totally trying to read chinese, everything, understood absolutely nothing, mostly because all the math involved, my fault of course, due my lack of repertoire on the subject.
9. While checking the specs of this amp, I noticed that they specified like this: Output Impedance as 4Ω and 8Ω. But on the statement of the friend here on the Forum, he tells me that the Damping Factor is 1, so I presume that he made a calculation to convert the Output Impedance value, that was presented in between this two values of Ohms, to Damping Factor value of measurement, correct? If yes, how I can do this calculation using a tool that is provided on the web, where I just put the number and the conversion is made? Such auto calculator tool is available?
Oh and, the Damping Factor is 1 what? what unit of measurement?
Many thanks to all! I hope that I was clear, I done my best trying to be concise and please forgive my bad english.
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I would suggest the the use of “the majority” is probably the wrong choice of words. It is true if you are talking about most Fostex FE series drivers and things like Lowthers, but their are many FRs that do not fall into this class.
dave
1/ This is determined using a box modeller ideally, the formula GM has given is theone you would use to find an effective Qt for any modeler that does not include a provision for high output impedance amplifier.
2/ Low Qt, typically less than 0.3 or so.
4/ the general term damping is most often used instead of the more salient output impedance. Damping is defined as the speaker impedance divided by the amplifiers output impedance. Usually specified at a nominal frequency. Since both the output impedance & the speaker impedance are generally not flat, the number at 1k often has little to do with the LF areas where is often most noticable,
5/ the OPT takes the output of the tubes (which can typically only drive high impedances) and transforms it to drive the much lower impedance of the typical loudspeaker. 4/8/16/32 are taps that have different ratios and the idea is to connect the speaker to the terminals that most closely match the speaker’s impedance. Given that many speakers — particularily ones w XOs have widly varying impedance picking the right tap is sometimes hook it up & listen.
6/ Damping factor is Ω/Ω so has no units.
8/ it is pretty clearly stated, you are going to have to lift your knowlegde level to comprehand it.
9/ that is not the output impedance it is the “size” of suggested taps for connecting the speakers to the OPT.
dave
2/ Low Qt, typically less than 0.3 or so.
4/ the general term damping is most often used instead of the more salient output impedance. Damping is defined as the speaker impedance divided by the amplifiers output impedance. Usually specified at a nominal frequency. Since both the output impedance & the speaker impedance are generally not flat, the number at 1k often has little to do with the LF areas where is often most noticable,
5/ the OPT takes the output of the tubes (which can typically only drive high impedances) and transforms it to drive the much lower impedance of the typical loudspeaker. 4/8/16/32 are taps that have different ratios and the idea is to connect the speaker to the terminals that most closely match the speaker’s impedance. Given that many speakers — particularily ones w XOs have widly varying impedance picking the right tap is sometimes hook it up & listen.
6/ Damping factor is Ω/Ω so has no units.
8/ it is pretty clearly stated, you are going to have to lift your knowlegde level to comprehand it.
9/ that is not the output impedance it is the “size” of suggested taps for connecting the speakers to the OPT.
dave
If my post was too long, the simple question is:
I just wanna know how to interpret the amplifier's output impedance (damping factor), in conjunction with the full range driver's specs.
What is the driver's spec that I must look, in order to know if the given amp will be a good match, or it will overdamp or underdamp the driver.
A simple hypothetical example:
Luxman LX-380 tube integrated amplifier's damping factor is described as 4Ω (and a number 1 after the ohm symbol, without a unit of measurement about this 1).
Where I have to look on the Fostex driver's specs, in order to know if this amp will be a good match, or it will overdamp or underdamp the full range driver?
https://www.fostexinternational.com/docs/speaker_components/pdf/fe208ez.pdf
Simple as that, I think I can't be more concise than this, I can't believe that I write massive texts, when I just could resume my doubt like this hehehe...
Best regards to all! and THANKS FOR THE MASSIVE PATIENCE with my noob questions!
I just wanna know how to interpret the amplifier's output impedance (damping factor), in conjunction with the full range driver's specs.
What is the driver's spec that I must look, in order to know if the given amp will be a good match, or it will overdamp or underdamp the driver.
A simple hypothetical example:
Luxman LX-380 tube integrated amplifier's damping factor is described as 4Ω (and a number 1 after the ohm symbol, without a unit of measurement about this 1).
Where I have to look on the Fostex driver's specs, in order to know if this amp will be a good match, or it will overdamp or underdamp the full range driver?
https://www.fostexinternational.com/docs/speaker_components/pdf/fe208ez.pdf
Simple as that, I think I can't be more concise than this, I can't believe that I write massive texts, when I just could resume my doubt like this hehehe...
Best regards to all! and THANKS FOR THE MASSIVE PATIENCE with my noob questions!
Sorry for all the confused questions about this topic, ask judgements about the amp's builder, and etc, I really appreciate all the efforts from all of you to help me understand some technical stuff about the topic anyway, I think this topic ca be closed or deleted, if everybody agrees, or keep it as the moderatos suggested, as maybe at least, it can provide helpful infos for someone that researches this subjects.
On my next threads I will try to organize better my questions and not to be so anxious about trying to lear everything at once...
All the best, for everybody, thanks!
On my next threads I will try to organize better my questions and not to be so anxious about trying to lear everything at once...
All the best, for everybody, thanks!
The higher the output impedance the flatter you want the impedance curve, or that the impedance curve is a mirror of the FR which when convolved (how much impedance modifies FR dependent on how high the output impedance is.
Scott has shown a forumla that calculates the mass corner, this can be used to determine more exact values, this needs to be !250-300 Hz for a proper back-loaded horn.
Nice looking amp.
That is 4.1Ω, it is common to use 4R1 to describe this.
I found description here: LX-380 | VACUUM TUBE AMPLIFIERS | PRODUCTS | LUXMAN | Seeking higher sound quality
They do not specify either output impedance or damping factor.
PP amps typically have lower output impedance. I suspect well under 1Ω.
I did find this review, they measured the damping factor at 1 into 4Ω, which is 0.5 into 8Ω.
Looking for data on the amp, i saw that you asked the same question here: Damping Factor: Tube Amps and Full Range Drivers, Need Advice... | Steve Hoffman Music Forums and at least in the 1st few posts you are not getting anything useful.
dave
Don't understood the ways that damping factor are presented, for example, on the PS Audio BHK Signature 250, damping factor is presented different:
Damping factor >150
Meanwhile the Luxman integrated, is presented 4ohms 1.
What means this signal ">" on the PS Audio's specs? Do not understood the presentation's variations...
So this Luxman amp have a super low damping factor right?
But I presume that are amps with damping factor even lower than this, as this Luxman is not a SET...
So this Luxman amp, have a proper damping factor for the Fostex FE208EZ? If yes, why? any spec that I must check on the FE208Z to conclude this? besides the fact that impedance curve graphic be very linear?
Damping factor >150
Meanwhile the Luxman integrated, is presented 4ohms 1.
What means this signal ">" on the PS Audio's specs? Do not understood the presentation's variations...
So this Luxman amp have a super low damping factor right?
But I presume that are amps with damping factor even lower than this, as this Luxman is not a SET...
So this Luxman amp, have a proper damping factor for the Fostex FE208EZ? If yes, why? any spec that I must check on the FE208Z to conclude this? besides the fact that impedance curve graphic be very linear?
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> means 'greater than'.
Like Dave, I do not see any damping factor (or output impedance) listed for the Luxman amplifier you refer to. Where are you getting the numbers you have cited?
Edit: I have just searched and found a Stereo Magazine article which lists some specs. for the LX-380 and states damping factor is 1 into 4ohms. Is that what you are referring to?
Like Dave, I do not see any damping factor (or output impedance) listed for the Luxman amplifier you refer to. Where are you getting the numbers you have cited?
Edit: I have just searched and found a Stereo Magazine article which lists some specs. for the LX-380 and states damping factor is 1 into 4ohms. Is that what you are referring to?
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The PS Audio spec is what you expect in a typical SS amp.
Damping = speaker impedance/ output impedance.
so Oz = Sz/D = 8/150 < 0.05Ω
Do note that this is taken at only 1 frequency and that the number here is well past the point of diminishing return.
Lux does not give a damping factor or output impedance. We only have a measurement which is in line with my suspicion above.
dave
Damping = speaker impedance/ output impedance.
so Oz = Sz/D = 8/150 < 0.05Ω
Do note that this is taken at only 1 frequency and that the number here is well past the point of diminishing return.
Lux does not give a damping factor or output impedance. We only have a measurement which is in line with my suspicion above.
dave
Luxman's LX-380 damping factor is via a test made by a magazine, here's the link:
https://beterbeeldengeluid.nl/wp-co...man-lx-380-d-380-stereo-magazine-issue-12.pdf
The PS Audio BHK Signature 250 is on their website:
BHK Signature 250 Amplifier | PS Audio
https://beterbeeldengeluid.nl/wp-co...man-lx-380-d-380-stereo-magazine-issue-12.pdf
The PS Audio BHK Signature 250 is on their website:
BHK Signature 250 Amplifier | PS Audio
The answer of this questions will clarify this subject a little more for me...
This Luxman amp have a super low damping factor right?
But I presume that are amps with damping factor even lower than this, as this Luxman is not a SET... right?
So this Luxman amp, have a proper damping factor for the Fostex FE208EZ? If yes, why? Besides the fact that impedance curve graphic be very linear, there's other specs that I must check on the FE208Z to conclude this?
Thanks.
This Luxman amp have a super low damping factor right?
But I presume that are amps with damping factor even lower than this, as this Luxman is not a SET... right?
So this Luxman amp, have a proper damping factor for the Fostex FE208EZ? If yes, why? Besides the fact that impedance curve graphic be very linear, there's other specs that I must check on the FE208Z to conclude this?
Thanks.
This one is are SET mono blocks:
Application Notes : SV811-3 SE Power Amplifier
Damping factor is 3.7, higher than the Luxman push pull integrated...
Interesting that the manufacturer tells:
"Despite of the existence of interstage transformer, this amplifier employs 5dB major negative feedback. This is because the damping factor without negative feedback is only about 1.7 due to the higher plate resistance of SV811-3 compared to 300B etc. By employing 5dB negative feedback, the damping factor can be set at an appropriate level: about 3.7."
Application Notes : SV811-3 SE Power Amplifier
Damping factor is 3.7, higher than the Luxman push pull integrated...
Interesting that the manufacturer tells:
"Despite of the existence of interstage transformer, this amplifier employs 5dB major negative feedback. This is because the damping factor without negative feedback is only about 1.7 due to the higher plate resistance of SV811-3 compared to 300B etc. By employing 5dB negative feedback, the damping factor can be set at an appropriate level: about 3.7."
No. It has a lowish damping factor (highish output impedance), highish output impedance, but optimum for the speakers you plan needs to be even lower… i think Scott actally made a suggestion earlier as to optimum ouptput impedance for the FE208e∑.
This is very much in the terrirory of having to consider the speaker impedance and mass corner, but not quite far enuff for the speakers in question.
You would probably be happy with this if you used 24g or higher speaker wire (if i recall Scott’s suggestion correctly).
dave
I think the Scott suggestion was this one:
Elekit TU-8600R 300B Power Amplifier / Headphone Amplifier Kit – diyAudio Store
Elekit TU-8600R 300B Power Amplifier / Headphone Amplifier Kit – diyAudio Store
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