1200 WATTS - WHY ?

[ThisBass]

This is a common misconception about guitar amps. The amount of "punch" and "low-end" that an amp puts out has nothing to do with the rated wattage. You can have an 8,000 watt amp that has no punch. It's all about your power supply and the size of the smoothing capacitors. People often call them filter caps, but that is not really their primary function, it's a byproduct of them doing their main job. They act like batteries: they smooth out the very rippled DC B+ line coming off your rectifier by filling in the gaps in power. In the case of the Sunn 1200s, it has massive smoothing capacitors rated at 10,000uf!! That's about 2x-4x larger than what is typically in guitar amps. That is where you're getting your low end punch. It's the same concept as car stereo competition guys that throw those huge 1-2 farad caps on their amplifier power supplies. It completely eliminates sag and gives a massive punch on the low end notes, which require more juice from the supply voltage, not more wattage on the output.

I=C*dV/dt

Charging caps are not meant to "smooth" snake oil considerations.
Once properly designed there is no need to oversize cap "C" dimensions.

 

[ThisBass]

@agedhorse I was hoping youd chime in!
So in layman's speak it's a combination of wattage and the bigger caps needed for that power?

The caps do have to charge and discharge energy which in number is proportional to the pushed output power.

 

[Nevada Pete]

is it peak to peak, average or rms watts? there is a difference.

Good question. However, Peak to peak, average or RMS watts mean next to nothing unless you also know what frequency is being tested. Is the amplifier being tested for power output at 1kHz, 20 to 20,000 Hz.? Or what? Several other factors come into play. Among them, of course, is what load impedance is the amp being tested at, and what is the total harmonic distortion (THD)?

The Jule M2500, for example, is rated at 2500 Watts RMS @ 4 ohms.

[Invalid or Expired Link Removed]

This power amplifier employs the Hypex UCD 2K which is a class D OEM amplifier module manufactured in the Netherlands. At 4 ohms / 1kHz, the 2500 Watts RMS is rated at 1% THD. At 4 ohms / 1kHZ and 1,000 Watts RMS, THD is a little less than .1%. At 4 ohms / 1kHz from 200 to 600 watts, THD is more or less .06%. The amplifier module is also rated to run at 2,000 Watts RMS at 2 ohms.

Invalid Link Removed

However, the above only begins to give you a picture of what this amplifier is, and what it can do compared to other amplifier modules which may be rated differently. Certain class D amplifier modules often used in MI are rated for power output at 20 Hz to 20 kHz, not just at 1 kHz. Obviously, the amplifier rated at 20 Hz to 20 kHz gives you a much better picture of what the amplifier is really capable of, such as down low in the bass frequencies where power really counts. This is because ordinarily, it's easier for amplifiers to make power at 1 kHz than it is for them to make power down low at say, 30 or 40 Hz.

 

[ThisBass]

Good question. However, Peak to peak, average or RMS watts mean next to nothing unless you also know what frequency is being tested. Is the amplifier being tested for power output at 1kHz, 20 to 20,000 Hz.? Or what? Several other factors come into play. Among them, of course, is what load impedance is the amp being tested at, and what is the total harmonic distortion (THD)?

The Jule M2500, for example, is rated at 2500 Watts RMS @ 4 ohms.

[Invalid or Expired Link Removed]

This power amplifier employs the Hypex UCD 2K which is a class D OEM amplifier module manufactured in the Netherlands. At 4 ohms / 1kHz, the 2500 Watts RMS is rated at 1% THD. At 4 ohms / 1kHZ and 1,000 Watts RMS, THD is a little less than .1%. At 4 ohms / 1kHz from 200 to 600 watts, THD is more or less .06%. The amplifier module is also rated to run at 2,000 Watts RMS at 2 ohms.

Invalid Link Removed

However, the above only begins to give you a picture of what this amplifier is, and what it can do compared to other amplifier modules which may be rated differently. Certain class D amplifier modules often used in MI are rated for power output at 20 Hz to 20 kHz, not just at 1 kHz. Obviously, the amplifier rated at 20 Hz to 20 kHz gives you a much better picture of what the amplifier is really capable of, such as down low in the bass frequencies where power really counts. This is because ordinarily, it's easier for amplifiers to make power at 1 kHz than it is for them to make power down low at say, 30 or 40 Hz.

1kHz is an approved standard measurement for telecommunication industry.
It makes sense cause the most sensitivety range of hearing ability is quite close to 1kHz .

edit,
I tink we all together as bass players don't have the force to introduce better common standards.

 

[Doner Designs]

I seem to recall hearing that it takes 10x the power to double the perceived loudness?

 

[agedhorse]

It's actually more efficient for class d amps to produce lower frequencies. 20Hz to 1kHz is almost identical in terms of power.

 

[CryingBass]

There was an Acoustic USA 360 reissue some years ago. It seems to have fizzled, which is a shame. I bought one, and it is all that it is cracked up to be. It isn't just loud, it sounds good while being loud. Or soft. It has a volume knob. I also like the sound of an original 360, but the new one is just a bit more versatile, since it has a switchable tweeter that the old one lacked. But, hit the bright switch on an old one, and you can get some pretty modern sounding results if you really want to.

For reference, the original 360 was rated at 200 watts. The reissues were rated at 400 watts. I have never, ever, cranked either one of them up very far.

My thoughts exactly. You got a legend2 and I wish those guys were still making the remakes. So few ( relative to today’s production nrms ) were made that many players will never get that thrill.

Maybe Mesa should consider a go at it

 

[cheechi]

It's actually more efficient for class d amps to produce lower frequencies. 20Hz to 1kHz is almost identical in terms of power.

considering this tendency, could it be possible to make an amp with a 'hybrid' or 'biamp' power section in which class D handles 20Hz to (arbitrarily) 500Hz, and either a second class D, or AB, or tube power section handles upper frequencies, possibly with some (adjustable?) overlap? The amp as a whole then outputs through the same cable to the same cab, and everything else is 'like normal' using the cab's crossover and/or physical limitations for outputting frequencies? So as far as the musician is concerned it's just like any other amp just with more/different knobs?

 

[CryingBass]

When this thread started I had my doubts.
Doubts removed. Excellent post gents!

TalkBass. I should probably be paying more for this.

 

[AE1]

This is not correct, I can't think of any bass speakers that have a 6-12dB higher response at 40Hz than mid band. Most are higher mid band, and hopefully not by 6-12dB.

Thank you for the correction

I apologise for the ambiguous language. Is hard to be precise and general at the same time

What I meant to say is this:

Then there is the frequency response. Efficient bass speakers usually offer a stronger LF response, equating to maybe 6-12 db more energy at 40 Hz than similar sized inefficient bass speakers. All conventional drivers exhibit LF rolloff when compared with the generally flat response area of the curve in the mid frequency range. Speakers delivering more mids and highs will sound louder because there is more harmonic power in the notes.

That difference in speaker system (driver and cabinet) performance has a huge impact on amp power requirements when playing in that LF region

It pays to use the best gear if we can work out what that is

 

[57pbass]

I’ve been using Bag End S12 and S15 cabs.

 

[agedhorse]

considering this tendency, could it be possible to make an amp with a 'hybrid' or 'biamp' power section in which class D handles 20Hz to (arbitrarily) 500Hz, and either a second class D, or AB, or tube power section handles upper frequencies, possibly with some (adjustable?) overlap? The amp as a whole then outputs through the same cable to the same cab, and everything else is 'like normal' using the cab's crossover and/or physical limitations for outputting frequencies? So as far as the musician is concerned it's just like any other amp just with more/different knobs?

Not from an electrical standpoint, not any way that I am aware (efficiently) but certainly you could biamp and combine the bands acoustically.

One way, but not terribly efficient, would be to drive a dual primary transformer and combine through the magnetic fields, but this way is fraught with all kinds of potential issues.

 

[BogeyBass]

Think he just means a proposed biamp system.

With a class D low frequency section

And then possible tube amp high frequency/mid section.

Then using a common 2 way speaker system. With separate inputs for LF and HF.

Basically a biamp system using a single cab.

And yes it's very possible

 

[DJ Bebop]

There was an Acoustic USA 360 reissue some years ago. It seems to have fizzled, which is a shame. I bought one, and it is all that it is cracked up to be. It isn't just loud, it sounds good while being loud. Or soft. It has a volume knob. I also like the sound of an original 360, but the new one is just a bit more versatile, since it has a switchable tweeter that the old one lacked. But, hit the bright switch on an old one, and you can get some pretty modern sounding results if you really want to.

For reference, the original 360 was rated at 200 watts. The reissues were rated at 400 watts. I have never, ever, cranked either one of them up very far.

Acoustic USA Launches With Revamped 360/361 Bass Rig

 

[Lowdown South]

Erm. I use a 150 w Fender for my jazz 6 piece band. Plenty loud enough. You guys need to think about your hearing.

 

[hellfleet]

I think I'm clearly in the minority here. I went from lots of SS watts to fewer valve watts.

I use a svp-cl preamp, many years ago I used to pair this with a PA type amp, I think I ran about 750w bridged into two cab. Sounded OK, I was happy enough with the tone, more volume than I could ever use. This was in a very loud rock band 2 (sometimes 3) guitarists all with half stacks. It was probably a very bad time of my life for my hearing. I'd always wanted an SVT but really didn't fancy dragging an 810. Also sound guys would always have a go at us for our stage volume (well justified) so I'm sure I'd have never really pushed it even in that band.

Since then I've been in more sensible bands and just play through a 4x10 (now two x 2x10s.).
I switched my PA amp for a mesa50:50 more associated with guitar than bass and its the best thing I ever did.

100W tube into 4 10 inch speakers gives me more than enough these days. I don't really even get to push this amp hard.

However:
- I rarely play a 5 string anymore. I don't know how well it would handle the low B if I was pushing it. I think it would be fine but not certain.
- When playing rock I'm quite happy for the power amp to snarl (sometimes I engage the low power 15 watt a side setting if I want more of that. With one guitar and a relatively quiet drummer even the 30W setup is fine!).

Still, I can't really see a situation where I'd need more than that as I don't play big rooms or outdoor gigs without PA support. Still,

 

[Spooky88]

You still need a good speaker to produce your low end freqs

Thank you for the correction

I apologise for the ambiguous language. Is hard to be precise and general at the same time

What I meant to say is this:

Then there is the frequency response. Efficient bass speakers usually offer a stronger LF response, equating to maybe 6-12 db more energy at 40 Hz than similar sized inefficient bass speakers. All conventional drivers exhibit LF rolloff when compared with the generally flat response area of the curve in the mid frequency range. Speakers delivering more mids and highs will sound louder because there is more harmonic power in the notes.

That difference in speaker system (driver and cabinet) performance has a huge impact on amp power requirements when playing in that LF region

It pays to use the best gear if we can work out what that is

That's why the fearful cabinets are so good. Look at the specs on the eminence 3015LF. The outdoor gigs I've performed at, that cabinet out performed the subs in the PA.

 

[AE1]

This is a common misconception about guitar amps. The amount of "punch" and "low-end" that an amp puts out has nothing to do with the rated wattage. You can have an 8,000 watt amp that has no punch. It's all about your power supply and the size of the smoothing capacitors. People often call them filter caps, but that is not really their primary function, it's a byproduct of them doing their main job. They act like batteries: they smooth out the very rippled DC B+ line coming off your rectifier by filling in the gaps in power. In the case of the Sunn 1200s, it has massive smoothing capacitors rated at 10,000uf!! That's about 2x-4x larger than what is typically in guitar amps. That is where you're getting your low end punch. It's the same concept as car stereo competition guys that throw those huge 1-2 farad caps on their amplifier power supplies. It completely eliminates sag and gives a massive punch on the low end notes, which require more juice from the supply voltage, not more wattage on the output.

I am a confessed "CAPAHOLIC" - the bigger the better !!

In my long-term practical experience with a range of amps and models from different manufacturers I have discovered that over time as new models are released to the market they often include higher value capacitors in the power supply. These are basic full wave bridge (FWB) rectification systems with a single capacitor to each of the positive and negative rails.

In 1980 high powered PA amps featured large computer bus style capacitors, which cost the earth (and still do). But now domestic grade capacitors are finding their way into bass amps.

Over time capacitors have become progressively smaller and cheaper, allowing designers to use larger values - often in a smaller amp case. e.g in 1980 a computer bus cap of say 22,000 uF 63VDC would be 3 inches diameter x 6 inches high. Now a similar rated cap can be found with 1 3/8 inches diameter x 2 inches high - quite a difference. Not quite the same industrial quality but still does the job.

In larger amps multiple capacitors are now common because they are affordable and fit into the available space.

Advantages include:

• more energy storage for peak current draw
• reduced ripple current (hum)
• reduced power supply impedance for less voltage drop during peaks - i.e better power linearity
• better quality DC resulting in less (inaudible) ripple voltage modulation of the audio signal
• physically smaller and lighter weight power transformer for average current duty cycle
• better LF response when connected in series with the load - especially 2 Ohm loads
• better dynamic power response

However computer modeling shows that even with 100,000 uF the ripple voltage may still be higher with a large value single cap than with a simple PII filter - i.e smaller caps and a choke - as used in tube amps.

Ripple voltage is a natural product of rectification but can be eliminated by various design concepts requiring more complex circuitry - which increases cost. But it is cheaper as well as lighter weight when larger caps are used instead of a choke based filter or regulating circuitry, so that is what manufacturers choose for us

I disagree with some of BadCaps post above because filter caps are called filter caps because their primary function is to filter the rectified DC by smoothing the ripple voltage in a simple system. That concept goes back to at least the 1920's.

For the record, early tube amps used filter capacitors as low as 2 uF because that is all they had at the time. Consequently a filter choke was mandatory - otherwise the ripple hum was audibly unbearable. Tube rectifiers are also limited to filter cap size to prevent tube damage from inrush charging currents - so do not rush off and install huge caps in your tube rectified amp.

The beneficial byproduct of providing stored energy for peak currents is a bonus that came with the development of larger capacitors. An alternative is to use a higher current mains power transformer but that does not help when the peak audio signal coincides with zero or close to zero AC mains input voltage. A simple explanation is that the filter capacitors store energy for use between the AC mains input voltage cycles

Yes they act like batteries but also have a similar characteristic in that the internal resistance/impedance results in voltage loss. So again, the larger the caps the less likely voltage drop issues - i.e better power supply regulation.

In the case of the Sunn 1200S Bass Amplifier it is a Class H design, which means each leg of the output stage is connected in series such that the power supply capacitors are also in series. There are actually two sets of filter caps totalling 36,600 uF, but even though the nominal capacitance value is high the effective capacitance is reduced by subtraction - i.e 10,000 uF - 6800 uF in series. So what you get is the benefit of the high current storage but lose some of the benefits from the higher internal impedance

Nontheless the Sunn 1200 is a mighty top of the range bass amp designed to be 2 Ohms capable from its 16 power transistors. Designed by Fender it must be good.

As to "punch" that is a different issue. Punch is a function of dynamic power response. That requires instantaneous power from the power supply to all stages of the amplifier simultaneously - particularly the preamp.

It is common to see designers focus on the power stage and forget the preamp but the preamp also is dependent upon the main power supply. Even if the preamp power supply is separate it still usually derives its power from the same mains transformer as the power amp. So when a high current is drawn from the main power supply it causes the preamp supply voltage to drop also. A well designed amp will also feature adequately large capacitors in the driver and preamp stages so that each stage is relatively independent. The Sunn 1200S uses a regulated supply to the driver and preamp stages.

One important point overlooked is that at low frequencies the speaker impedance rises to maybe 8 to 10 times its nominal impedance. That has the effect of reducing real power output in that frequency range by a similar ratio.

So it becomes obvious why TBers are talking 1000 watts or more. To get 100 watts at 40 Hz the amp needs to be a 1000 watt capable amp so it will deliver 100 watts at 40 Hz into the speaker load of 64 to 80 Ohms. This is why 2 Ohm nominal loads are best for bass - but only if the amp will handle the low load value.

The Sunn and many of the Peavey amps will do this with ease.

WARNING: Extra capacitance results in a higher inrush/charging current at switch-on. This can blow the normal internal amp fuse and/or damage the rectifiers and/or power transformer. Proceed with care.

Comments are welcome.

 

[Lowdown South]

I am a confessed "CAPAHOLIC" - the bigger the better !!

In my long-term practical experience with a range of amps and models from different manufacturers I have discovered that over time as new models are released to the market they often include higher value capacitors in the power supply. These are basic full wave bridge (FWB) rectification systems with a single capacitor to each of the positive and negative rails.

In 1980 high powered PA amps featured large computer bus style capacitors, which cost the earth (and still do). But now domestic grade capacitors are finding their way into bass amps.

Over time capacitors have become progressively smaller and cheaper, allowing designers to use larger values - often in a smaller amp case. e.g in 1980 a computer bus cap of say 22,000 uF 63VDC would be 3 inches diameter x 6 inches high. Now a similar rated cap can be found with 1 3/8 inches diameter x 2 inches high - quite a difference. Not quite the same industrial quality but still does the job.

In larger amps multiple capacitors are now common because they are affordable and fit into the available space.

Advantages include:

• more energy storage for peak current draw
• reduced ripple current (hum)
• reduced power supply impedance for less voltage drop during peaks - i.e better power linearity
• better quality DC resulting in less (inaudible) ripple voltage modulation of the audio signal
• physically smaller and lighter weight power transformer for average current duty cycle
• better LF response when connected in series with the load - especially 2 Ohm loads
• better dynamic power response

However computer modeling shows that even with 100,000 uF the ripple voltage may still be higher with a large value single cap than with a simple PII filter - i.e smaller caps and a choke - as used in tube amps.

Ripple voltage is a natural product of rectification but can be eliminated by various design concepts requiring more complex circuitry - which increases cost. But it is cheaper as well as lighter weight when larger caps are used instead of a choke based filter or regulating circuitry, so that is what manufacturers choose for us

I disagree with some of BadCaps post above because filter caps are called filter caps because their primary function is to filter the rectified DC by smoothing the ripple voltage in a simple system. That concept goes back to at least the 1920's.

For the record, early tube amps used filter capacitors as low as 2 uF because that is all they had at the time. Consequently a filter choke was mandatory - otherwise the ripple hum was audibly unbearable. Tube rectifiers are also limited to filter cap size to prevent tube damage from inrush charging currents - so do not rush off and install huge caps in your tube rectified amp.

The beneficial byproduct of providing stored energy for peak currents is a bonus that came with the development of larger capacitors. An alternative is to use a higher current mains power transformer but that does not help when the peak audio signal coincides with zero or close to zero AC mains input voltage. A simple explanation is that the filter capacitors store energy for use between the AC mains input voltage cycles

Yes they act like batteries but also have a similar characteristic in that the internal resistance/impedance results in voltage loss. So again, the larger the caps the less likely voltage drop issues - i.e better power supply regulation.

In the case of the Sunn 1200S Bass Amplifier it is a Class H design, which means each leg of the output stage is connected in series such that the power supply capacitors are also in series. There are actually two sets of filter caps totalling 36,600 uF, but even though the nominal capacitance value is high the effective capacitance is reduced by subtraction - i.e 10,000 uF - 6800 uF in series. So what you get is the benefit of the high current storage but lose some of the benefits from the higher internal impedance

Nontheless the Sunn 1200 is a mighty top of the range bass amp designed to be 2 Ohms capable from its 16 power transistors. Designed by Fender it must be good.

As to "punch" that is a different issue. Punch is a function of dynamic power response. That requires instantaneous power from the power supply to all stages of the amplifier simultaneously - particularly the preamp.

It is common to see designers focus on the power stage and forget the preamp but the preamp also is dependent upon the main power supply. Even if the preamp power supply is separate it still usually derives its power from the same mains transformer as the power amp. So when a high current is drawn from the main power supply it causes the preamp supply voltage to drop also. A well designed amp will also feature adequately large capacitors in the driver and preamp stages so that each stage is relatively independent. The Sunn 1200S uses a regulated supply to the driver and preamp stages.

One important point overlooked is that at low frequencies the speaker impedance rises to maybe 8 to 10 times its nominal impedance. That has the effect of reducing real power output in that frequency range by a similar ratio.

So it becomes obvious why TBers are talking 1000 watts or more. To get 100 watts at 40 Hz the amp needs to be a 1000 watt capable amp so it will deliver 100 watts at 40 Hz into the speaker load of 64 to 80 Ohms. This is why 2 Ohm nominal loads are best for bass - but only if the amp will handle the low load value.

The Sunn and many of the Peavey amps will do this with ease.

WARNING: Extra capacitance results in a higher inrush/charging current at switch-on. This can blow the normal internal amp fuse and/or damage the rectifiers and/or power transformer. Proceed with care.

Comments are welcome.

I think you could get therapy for this......but I’m not sure.

 

[agedhorse]

I am a confessed "CAPAHOLIC" - the bigger the better !!

In my long-term practical experience with a range of amps and models from different manufacturers I have discovered that over time as new models are released to the market they often include higher value capacitors in the power supply. These are basic full wave bridge (FWB) rectification systems with a single capacitor to each of the positive and negative rails.

In 1980 high powered PA amps featured large computer bus style capacitors, which cost the earth (and still do). But now domestic grade capacitors are finding their way into bass amps.

Over time capacitors have become progressively smaller and cheaper, allowing designers to use larger values - often in a smaller amp case. e.g in 1980 a computer bus cap of say 22,000 uF 63VDC would be 3 inches diameter x 6 inches high. Now a similar rated cap can be found with 1 3/8 inches diameter x 2 inches high - quite a difference. Not quite the same industrial quality but still does the job.

In larger amps multiple capacitors are now common because they are affordable and fit into the available space.

Advantages include:

• more energy storage for peak current draw
• reduced ripple current (hum)
• reduced power supply impedance for less voltage drop during peaks - i.e better power linearity
• better quality DC resulting in less (inaudible) ripple voltage modulation of the audio signal
• physically smaller and lighter weight power transformer for average current duty cycle
• better LF response when connected in series with the load - especially 2 Ohm loads
• better dynamic power response

However computer modeling shows that even with 100,000 uF the ripple voltage may still be higher with a large value single cap than with a simple PII filter - i.e smaller caps and a choke - as used in tube amps.

Ripple voltage is a natural product of rectification but can be eliminated by various design concepts requiring more complex circuitry - which increases cost. But it is cheaper as well as lighter weight when larger caps are used instead of a choke based filter or regulating circuitry, so that is what manufacturers choose for us

I disagree with some of BadCaps post above because filter caps are called filter caps because their primary function is to filter the rectified DC by smoothing the ripple voltage in a simple system. That concept goes back to at least the 1920's.

For the record, early tube amps used filter capacitors as low as 2 uF because that is all they had at the time. Consequently a filter choke was mandatory - otherwise the ripple hum was audibly unbearable. Tube rectifiers are also limited to filter cap size to prevent tube damage from inrush charging currents - so do not rush off and install huge caps in your tube rectified amp.

The beneficial byproduct of providing stored energy for peak currents is a bonus that came with the development of larger capacitors. An alternative is to use a higher current mains power transformer but that does not help when the peak audio signal coincides with zero or close to zero AC mains input voltage. A simple explanation is that the filter capacitors store energy for use between the AC mains input voltage cycles

Yes they act like batteries but also have a similar characteristic in that the internal resistance/impedance results in voltage loss. So again, the larger the caps the less likely voltage drop issues - i.e better power supply regulation.

In the case of the Sunn 1200S Bass Amplifier it is a Class H design, which means each leg of the output stage is connected in series such that the power supply capacitors are also in series. There are actually two sets of filter caps totalling 36,600 uF, but even though the nominal capacitance value is high the effective capacitance is reduced by subtraction - i.e 10,000 uF - 6800 uF in series. So what you get is the benefit of the high current storage but lose some of the benefits from the higher internal impedance

Nontheless the Sunn 1200 is a mighty top of the range bass amp designed to be 2 Ohms capable from its 16 power transistors. Designed by Fender it must be good.

As to "punch" that is a different issue. Punch is a function of dynamic power response. That requires instantaneous power from the power supply to all stages of the amplifier simultaneously - particularly the preamp.

It is common to see designers focus on the power stage and forget the preamp but the preamp also is dependent upon the main power supply. Even if the preamp power supply is separate it still usually derives its power from the same mains transformer as the power amp. So when a high current is drawn from the main power supply it causes the preamp supply voltage to drop also. A well designed amp will also feature adequately large capacitors in the driver and preamp stages so that each stage is relatively independent. The Sunn 1200S uses a regulated supply to the driver and preamp stages.

One important point overlooked is that at low frequencies the speaker impedance rises to maybe 8 to 10 times its nominal impedance. That has the effect of reducing real power output in that frequency range by a similar ratio.

So it becomes obvious why TBers are talking 1000 watts or more. To get 100 watts at 40 Hz the amp needs to be a 1000 watt capable amp so it will deliver 100 watts at 40 Hz into the speaker load of 64 to 80 Ohms. This is why 2 Ohm nominal loads are best for bass - but only if the amp will handle the low load value.

The Sunn and many of the Peavey amps will do this with ease.

WARNING: Extra capacitance results in a higher inrush/charging current at switch-on. This can blow the normal internal amp fuse and/or damage the rectifiers and/or power transformer. Proceed with care.

Comments are welcome.

Some good information, some incorrect information, filled with some horribly misleading conclusions.

1. The old can style caps were big because the technology was obsolete. both the design and materials technology.

2. Modern high quality caps are far superior in every aspect due to monumental improvements in design and materials. Specifically ESR, energy density, temperature limits, ripple current and lifespan.

3. Newer amps use larger filter caps generally because the amps have higher rated power.

4. Peak audio current doesn't matter if it occurs at zero crossing of the AC power waveform because the audio is asynchronous.

5. The Sunn 1200S does not have its high tier rail's power supply caps in series with the low tier, its a separate cap referenced to ground.

6. Punch has many different definitions, most of which relate to preamp response and tone choices.

7. Virtually all modern preamps use supplies regulated down from a higher voltage, therefore raw higher voltage supply voltage sag is of zero consequence.

8. Power amp driver stages on bipolar power amps track the output stage as a byproduct of the topology itself, so sag tracks exactly proportionally. On MOSFET power amps, driver stages usually use a boosted driver supply not for sag but due to the need to offset much higher Vgs voltage thresholds.

9. Rising impedance at resonance is also accompanied by rising sensitivity, otherwise there would be a huge dip at resonance (which there is not). There is need to generate that kind of additional voltage swing at resonance and to do so would not be helpful in any way in practice.

10. 2 ohms is not necessarily the best impedance to run a bass amp at, nor are there any benefits other than to be able to run more speakers in a practical way. The reason 2 ohms became popular and common is that back in the day, it was much easier to design such amps due the the difficulty (as in impossible) of sourcing high voltage power transistors. High current devices were MUCH more practical than high voltage devices or totem pole designs.

I urge you to be careful in drawing the conclusions you do in the face of multiple practical real world examples that contradict your conclusions.