an engineer should understand why different tubes (actually even of the same type and brand) have different perceived sound in a given circuit
These differences in tube parameters might be in some cases brand-dependent, but in principal they only affect bass in a specific circuit.
Thinking of some tubes having more bass than others is nonsense.
These differences in tube parameters might be in some cases brand-dependent, but in principal they only affect bass in a specific circuit.
Thinking of some tubes having more bass than others is nonsense.
A valve does not have a sound (unless you drop it on the floor). A valve plus a circuit may have a sound, especially if it is a poor circuit or a poor valve.aldovan said:
The bass response of a triode output stage depends mainly on the ratio of the anode impedance and the OPT primary inductance. The anode impedance should not vary much between valves of the same type, and in any case a good design will take account of this.
The perceived bass response may depend on other things like bias point, as distortion can give the impression of bass even when true bass is missing.
So it is impossible to say what valve brand 'X' sounds like in bass terms without seeing the circuit. Valves work down to DC; it is the circuit which imposes an LF rolloff.
My friends
I make tube projects in the last 15 years.
The sound of a specific tube can vary greatly from one manufacturer to another.
Per exemple, a Kenrad 6SN7 have a more pronounced bass that RCA 6SN7, per exemple.
In the same conditions, same polarization and plate resistance.
The difference occurs in the plate construction and materials.
Talking about 300B, the Chinese and the modern factories do not always use the same materials for coated the cathode and the internal components of the valves as plates.
The internal construction and the spaces do not is exact the same all cases.
Them a 300B may respond differently than another, even with the same polarization.. Only those who are ignorant as many of this group can be idiots not realize it.
Aldovan
I make tube projects in the last 15 years.
The sound of a specific tube can vary greatly from one manufacturer to another.
Per exemple, a Kenrad 6SN7 have a more pronounced bass that RCA 6SN7, per exemple.
In the same conditions, same polarization and plate resistance.
The difference occurs in the plate construction and materials.
Talking about 300B, the Chinese and the modern factories do not always use the same materials for coated the cathode and the internal components of the valves as plates.
The internal construction and the spaces do not is exact the same all cases.
Them a 300B may respond differently than another, even with the same polarization.. Only those who are ignorant as many of this group can be idiots not realize it.
Aldovan
If all 300B are the same, them a Shuguang 300B have exactly the same frequency response of a Western Electric 300B, them are exactly the same tube,the details in the sound are the same and the value of both is exactly the same...
Easy, no ?
Shall I send you my certificate at the University?
You understood that I speak of strong bass for sure.
Any under 60 y.o. Engineer would not have had tubes even mentioned at the University, so an engineer certificate wouldn't help much in that area.
Just sayin' .
I started studying Engineering in Buenos Aires in 1969
and all the rage was SS, then new Digital Electronics (discrete Flip Flops by the way) ; tubes were despised.Now if you got your Degree in , say, 1956, yes, I must agree you would have a solid Tube formation.
And in that case you'd know that tube frequency response is flat from DC to several MHz .
No (referring to post 27), because people pay money based on what is printed on the outside of the glass. They may also pay money based on valve reliability - which depends on materials and vacuum quality. You may note that I did not say "all 300B are the same". However, I would expect all competently-made 300B to have about the same frequency response.
One of the things which sometimes happens on worldwide public forums is that someone asks a question and doesn't like some of the answers he gets. One of the things which then sometimes happens on worldwide public forums is that the questioner insults those who see things differently from him. Words such as "ignorant" or "idiot" may be used.
One of the things which sometimes happens on worldwide public forums is that someone asks a question and doesn't like some of the answers he gets. One of the things which then sometimes happens on worldwide public forums is that the questioner insults those who see things differently from him. Words such as "ignorant" or "idiot" may be used.
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Unless you have built an improbably poor circuit design, any perceived difference in bass is in your imagination. The frequency and distortion response of valves does not change with frequency. Valves are much more consistent than your ears and brain. An engineer would know this.
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Any under 60 y.o. Engineer would not have had tubes even mentioned at the University, so an engineer certificate wouldn't help much in that area.
Just sayin' .
I started studying Engineering in Buenos Aires in 1969
Now if you got your Degree in , say, 1956, yes, I must agree you would have a solid Tube formation.
And in that case you'd know that tube frequency response is flat from DC to several MHz .
I am technician in electronics as well.
I studied valves in the technical course in 1988.
In the federal technical school I studied, the valves are basis for learning JFETs.
Collect valves since 1998 and have more than five thousand units.
At the time NGG factory was manufactuting 300B tubes I read various positive comments on music sites informing the Guiguang 300B had a better sound quality than the Shuguang.
So I bought a pair, I cant say how is its sound as I dont own a 300B amp, but the built quality is very good.
First production was brown base, after changed to black base, before the factory was taken by Psvane.
The base isnt dry bakelite, its a nice plastic with some rubber sense.
The plate are black anodized metal, all inside metal connections are shine chrome and are encapsulated in glass as the big triodes.
There is two types of getter the usual barium dust at the glass wall and two metal donuts, both at the base of the glass.
The glass is thin and fradile just like any 300B made in North America, but it tinkling like a bell when hit, not tik, teck or bad sounds, its a good sign of phisical integrity.
Hope it help;
So I bought a pair, I cant say how is its sound as I dont own a 300B amp, but the built quality is very good.
First production was brown base, after changed to black base, before the factory was taken by Psvane.
The base isnt dry bakelite, its a nice plastic with some rubber sense.
The plate are black anodized metal, all inside metal connections are shine chrome and are encapsulated in glass as the big triodes.
There is two types of getter the usual barium dust at the glass wall and two metal donuts, both at the base of the glass.
The glass is thin and fradile just like any 300B made in North America, but it tinkling like a bell when hit, not tik, teck or bad sounds, its a good sign of phisical integrity.
Hope it help;
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The 300B is a power triode and typically is loaded into 2.5K to 5K in order to at one end maximize power transfer and at the other linearity.
The recommended loads and operating points for the 300B were published in tabular form 7 decades ago by Western Electric and provide data on harmonic spectra and maximum power output. These recommendations apply to pretty much all standard 300B made today with the caveat that some of the cheaper tubes may not operate well at the extremes of plate voltage or current
FWIW having designed a number of amps using 300B I will remark that they don't all sound the same under the same conditions of use, and that further careful measurements will usually reveal that rp is slightly higher or lower at the chosen operating point, if internal geometry* is slightly off it will result in higher than usual distortion, and in some cases spectral distribution of distortion will differ. Even the plate materials and secondary emission off of the plate differ from maker to make and can have measurable and audible consequences.
Some tubes are emission limited relative to others, others have stupid design mistakes like filament exposed directly to the plate (no grid coverage) which means at higher plate voltages they cannot ever be cut off and in fact will run away under some circumstances.
* Is grid pitch constant; are plate, grid and filament aligned properly (parallel/co-planar); are the electrodes properly centered, etc.
The 300B is a power triode and typically is loaded into 2.5K to 5K in order to at one end maximize power transfer and at the other linearity.
The recommended loads and operating points for the 300B were published in tabular form 7 decades ago by Western Electric and provide data on harmonic spectra and maximum power output. These recommendations apply to pretty much all standard 300B made today with the caveat that some of the cheaper tubes may not operate well at the extremes of plate voltage or current
FWIW having designed a number of amps using 300B I will remark that they don't all sound the same under the same conditions of use, and that further careful measurements will usually reveal that rp is slightly higher or lower at the chosen operating point, if internal geometry* is slightly off it will result in higher than usual distortion, and in some cases spectral distribution of distortion will differ. Even the plate materials and secondary emission off of the plate differ from maker to make and can have measurable and audible consequences.
Some tubes are emission limited relative to others, others have stupid design mistakes like filament exposed directly to the plate (no grid coverage) which means at higher plate voltages they cannot ever be cut off and in fact will run away under some circumstances.
* Is grid pitch constant; are plate, grid and filament aligned properly (parallel/co-planar); are the electrodes properly centered, etc.
That's all well and good, but modern designers have no real reason to be constrained by 70 year old technical restrictions.
They didn't have practical active plate loads. They were concerned with efficiency and cost. I'm concerned with lower distortion and better performance.
Increasing plate load WILL remove pretty much all tube manufacturing (and much of aging etc) differences. Problem solved. =)
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