Why is the SD Powerstage...
- Thread starter Aceman
- Start date
Watts are watts, doesn't matter if it's tube or SS. Watts are a math calculation, not a perception. The perception that we have of each topology is subjective and based on bias, expectations, and the result of trying to break them. If you operate both topologies in a linear range, they should in theory sound and operate pretty much identical to each other.
I was not aware they made a 200-watt version. My bet is that they both have the same amp module and the only difference is the power supply. And what is the difference of the 30-watts between them? About 1db in potential output!!! Let's assume that 100 watts of their output is 1:1, so anything beyond that is the only real difference. This means that of teh next available 100 watts, there is only a 30-watt difference. This difference at the wattage they operate at is only mathematically different in acoustic output by .7db ( that is .7db as in .3db less than 1db ) all things being equal. The easy rounded-up math means that the 200-watt version will only produce roughly 1db more actual output.
It is a sales tactic. What is the easiest way to have two products that appear to have different performance points? Have two that are the same thing and de-tune one of them. The 170-watt version is probably the one that actually costs them the most to produce, so pricing the 200-watts cleverly will drive more purchases to it, creating more $$$. That is me just postulating though.
I was not aware they made a 200-watt version. My bet is that they both have the same amp module and the only difference is the power supply. And what is the difference of the 30-watts between them? About 1db in potential output!!! Let's assume that 100 watts of their output is 1:1, so anything beyond that is the only real difference. This means that of teh next available 100 watts, there is only a 30-watt difference. This difference at the wattage they operate at is only mathematically different in acoustic output by .7db ( that is .7db as in .3db less than 1db ) all things being equal. The easy rounded-up math means that the 200-watt version will only produce roughly 1db more actual output.
It is a sales tactic. What is the easiest way to have two products that appear to have different performance points? Have two that are the same thing and de-tune one of them. The 170-watt version is probably the one that actually costs them the most to produce, so pricing the 200-watts cleverly will drive more purchases to it, creating more $$$. That is me just postulating though.
Aceman
I am your doctor of love!
Ahhh - now that seems very plausible.
170 through 8ohm = ~100 watts, so loud, but no speaker blowing loud. Loud and safe....
stevie_bees
Cat In The Hatministrator
Also, bear in mind that the actual output will depend on the impedance of the speaker cab, so it's probably 170 watts into 2 ohms, and less into 4/8/16 etc, which would put it into more recognisable power outputs for us simple guitar players.
beaubrummels
Well-known member
Ah ha. So for more practical usage (8 / 16), it sits 5-15w under the common cab ratings. (100 / 50). So clean power, will work with any speaker combo. AmIright?
Oooh, another fun one! Solid-state amps produce wattage by converting current into voltage. The voltage source is loaded down by the speakers ( load ). This is why the wattage changes with differing loads. 100 volts into 16ohms is different than 100 volts into 8ohms or 4ohms. You can think of a class-D amp as being a fixed voltage amplifier, it produces a peak voltage regardless of the load and that voltage is what determines the wattage it produces at X load impedance.
A tube amp works differently in that it converts a voltage into a current source. This means that it will produce the same relative wattage regardless of the load upon it. This is because of the output transformer. The output transformer simply takes the load impedance from the speaker and converts it into more or less a fixed impedance at the plate of the power tubes. Said another way, a 4, 8, or 16ohm speaker presents the same relative load on the tubes because the transformer converts the total impedance to be very similar regardless of the speaker attached to it ( assuming you have a 4,8, or 16ohm speaker plugged into the corresponding tap ). Since the tubes swing the same voltage regardless of the load, the transformer converts that voltage into a lower one in exchange for current. This is why a tube amp produces pretty much the same wattage regardless of the speaker load you use provided you use the matching tap ( output impedance selection ).
Solid State amps have some pro's and con's over tube amps. Generally, they have MUCH better distortion characteristics. They are also generally much more linear ( what goes in is what comes out ) to that of tube amps. They are also MUCH MUCH more efficient and will produce significantly more output wattage with significantly less demand from the walls outlet. A tube amp that produces 120 watts of output may draw 200 or more watts from the wall, whereas a Solid State amp may produce that same 120 watts only drawing 100 watts from the wall. Many Class-D amps have a 90% + efficiency and will convert wall power into output with significant efficiency. Where Solid State does seem to fall short is when they are driving low impedance loads. A class-D amp driving a 4-ohm load will have much more wattage, but will also have much more distortion to go with it. A tube amp will have more or less the same distortion ( that it naturally has ) regardless of the speaker impedance. Solid State amps do not sound good when clipped. Tube amps tend to sound ok when clipped because of the way they distort when they are. Solid State amps are also less colorful in sound when pushed to their limits. They produce harmonics, overtones, and distortions differently than tube amps and often not in a desirable way.
A tube amp works differently in that it converts a voltage into a current source. This means that it will produce the same relative wattage regardless of the load upon it. This is because of the output transformer. The output transformer simply takes the load impedance from the speaker and converts it into more or less a fixed impedance at the plate of the power tubes. Said another way, a 4, 8, or 16ohm speaker presents the same relative load on the tubes because the transformer converts the total impedance to be very similar regardless of the speaker attached to it ( assuming you have a 4,8, or 16ohm speaker plugged into the corresponding tap ). Since the tubes swing the same voltage regardless of the load, the transformer converts that voltage into a lower one in exchange for current. This is why a tube amp produces pretty much the same wattage regardless of the speaker load you use provided you use the matching tap ( output impedance selection ).
Solid State amps have some pro's and con's over tube amps. Generally, they have MUCH better distortion characteristics. They are also generally much more linear ( what goes in is what comes out ) to that of tube amps. They are also MUCH MUCH more efficient and will produce significantly more output wattage with significantly less demand from the walls outlet. A tube amp that produces 120 watts of output may draw 200 or more watts from the wall, whereas a Solid State amp may produce that same 120 watts only drawing 100 watts from the wall. Many Class-D amps have a 90% + efficiency and will convert wall power into output with significant efficiency. Where Solid State does seem to fall short is when they are driving low impedance loads. A class-D amp driving a 4-ohm load will have much more wattage, but will also have much more distortion to go with it. A tube amp will have more or less the same distortion ( that it naturally has ) regardless of the speaker impedance. Solid State amps do not sound good when clipped. Tube amps tend to sound ok when clipped because of the way they distort when they are. Solid State amps are also less colorful in sound when pushed to their limits. They produce harmonics, overtones, and distortions differently than tube amps and often not in a desirable way.
LLL
New member
I dig your posts; you're obviously well educated (and of course accurate) with these topics. We need more like you.
Animal
Well-known member
For fun.
IMENATOR
Well-known member
I was just checking out the PowerStage 170 as a potential backup for my ISP Stealth. If you are into Stereo rigs the Stealth costs less than the PowerStage 170 and can be used either mono or stereo and provide the same amount of power, the only drawback is it is not as small but the benefit is you get rid of potential ground loops caused by two different power amps. I think I will stick to the ISP Stealth
IMENATOR
Well-known member
The stereo one does not have any eq, it just a flat clean power amp. There is a smaller one, just half the size and power, that one does have eq but not sure about any preamp in it.
