Power needed for Maggies
Some years ago I ran my Magnepan MMG's with my first DIY amplifier, I believe it was called the Mighty Mouse, an EL34 PP tube amp, outlined in Audioxpress magazine. I preferred it in ultralinear mode where it was putting out about 19W. Never listened really loud or anything but it sounded great. Ran the MMG's for several years in our home theater driven by an old Quad 303 (rated at 40W into 8 ohms) and only at very high volumes did the sound start to get glassy. It sounded much better than my Yamaha integrated which was rated for 85 watts into 8 ohms. I think Maggies really need current. The EL34PP tube amp had an over sized power supply and the Quad 303 has a huge transformer, considering rated output.
Dan
Some years ago I ran my Magnepan MMG's with my first DIY amplifier, I believe it was called the Mighty Mouse, an EL34 PP tube amp, outlined in Audioxpress magazine. I preferred it in ultralinear mode where it was putting out about 19W. Never listened really loud or anything but it sounded great. Ran the MMG's for several years in our home theater driven by an old Quad 303 (rated at 40W into 8 ohms) and only at very high volumes did the sound start to get glassy. It sounded much better than my Yamaha integrated which was rated for 85 watts into 8 ohms. I think Maggies really need current. The EL34PP tube amp had an over sized power supply and the Quad 303 has a huge transformer, considering rated output.
Dan
Thanks 6l6 my question was driven by a better pairing of the 20 pairs I got from b&d . Thinking I will end up driving a pair of f4 in balanced mode and voice the system by the pre-amp of a tube nature. It more fitting the parts I have to use than going after that 2rd harmonic reduction . Your thoughts are always welcome Regards.
Just another data point:
I have the little MG-12/QR and also the MG-3.6/R. In both cases, they need an amp that is rated at more than 100 wpc into 8 Ohms, in order to reach their maximum usable output level without the amp starting to clip. I am not saying you must use a higher-rated amp with those speakers. But there would probably be times when you would wish that you had a higher rated amp, with them.
I have the little MG-12/QR and also the MG-3.6/R. In both cases, they need an amp that is rated at more than 100 wpc into 8 Ohms, in order to reach their maximum usable output level without the amp starting to clip. I am not saying you must use a higher-rated amp with those speakers. But there would probably be times when you would wish that you had a higher rated amp, with them.
The Firstwatt amps, especially the F4, can pass an awful lot of current -- and that's what the Magnepans need. Remember that an F4 has a 300-400W PSU...
If you are looking for more power with lots of current ability, a BA-3 complementary with many outputs will be able to pass enough current to stun a herd of oxen.
The BA-complementary output stage is identical to the F4. And you can easily add more output devices.
If you take that amp and increase the rail voltage a little, say 30V, it will have more voltage swing and therefore even more power.
Yes, it will need a big case and lots of heatsink.
If you are looking for more power with lots of current ability, a BA-3 complementary with many outputs will be able to pass enough current to stun a herd of oxen.
The BA-complementary output stage is identical to the F4. And you can easily add more output devices.
If you take that amp and increase the rail voltage a little, say 30V, it will have more voltage swing and therefore even more power.
Yes, it will need a big case and lots of heatsink.
You cannot have more current without more voltage. The maximum output current and the maximum output voltage and the rated maximum output power are redundant. i.e. If you know one, you know the other two, for a given power supply, amp, and load.
The rated maximum output power is rated at the onset of clipping for a sine signal. It depends on the available rail voltage, the Vclip voltage of the amp (the minimum voltage between the amp's power rail and its output), and the reservoir capacitance (assuming the transformer is sufficient), which then also determines the maximum ripple amplitude.
Maggies can't use any more current than any other 4-Ohm speaker of the same efficiency, when producing a given output sound level (if you also account for the fact that they are dipole-type speakers). But they are not hugely efficient. So they need some significant power, to get loud-enough. But that's it.
Their drivers (not considering the crossovers) are actually an almost purely-resistive 4-Ohm load, up to well-above 10 kHz at least. So, in that sense, they are easier to drive than some "normal" speakers.
If you never want to push them to their maximum usable output level, then an amp rated at 100 W/ch into 8 Ohms should "work". But having used them with such amps, I would not recommend using an amp rated at 100 W/ch into 8 Ohms, and 150 W/ch into 4 Ohms.
With an amp rated at 100 W/ch into 8 Ohms and 150 W/ch into 4 Ohms, trying to crank up the output level "too high" blows the ribbon tweeter fuses in my MG-3.6/R speakers, when the amp clips and releases a spray of high-frequency energy. But with an amp rated at 250 W/ch into 8 Ohms and 400 W/ch into 4 Ohms, I can play them much louder, with no problem. And I am talking about "not-unreasonably-loud" (although "very loud") sound levels.
I have only been able to use my little MG-12/QR and big MG-3.6/R with the two amps, i.e. one amp that's rated at 100 w/ch into 8 Ohms and 150 W/ch into 4 Ohms (Adcom GFA-545 II) and one amp that's rated at 250 W/ch into 8 Ohms and 400 W/ch into 4 Ohms (Adcom 585).
Neither Magnepan model can reach its maximum usable output level with the smaller of those amplifiers. Both Magnepan models can very-easily reach their maximum usable output level with the larger of those two amps.
The point is, I don't know where, in between those two, the threshold is, at which an amp would have just-enough rated max power to drive them sufficiently, including up to their maximum usable output levels, without clipping. All I know is that they need more than the smaller of those two amps is able to give, if you want to be able to fully-utilize their output-level range. And I do suggest that you will probably want to have a setup that is capable of driving them to their maximum usable output level, without clipping.
The rated maximum output power is rated at the onset of clipping for a sine signal. It depends on the available rail voltage, the Vclip voltage of the amp (the minimum voltage between the amp's power rail and its output), and the reservoir capacitance (assuming the transformer is sufficient), which then also determines the maximum ripple amplitude.
Maggies can't use any more current than any other 4-Ohm speaker of the same efficiency, when producing a given output sound level (if you also account for the fact that they are dipole-type speakers). But they are not hugely efficient. So they need some significant power, to get loud-enough. But that's it.
Their drivers (not considering the crossovers) are actually an almost purely-resistive 4-Ohm load, up to well-above 10 kHz at least. So, in that sense, they are easier to drive than some "normal" speakers.
If you never want to push them to their maximum usable output level, then an amp rated at 100 W/ch into 8 Ohms should "work". But having used them with such amps, I would not recommend using an amp rated at 100 W/ch into 8 Ohms, and 150 W/ch into 4 Ohms.
With an amp rated at 100 W/ch into 8 Ohms and 150 W/ch into 4 Ohms, trying to crank up the output level "too high" blows the ribbon tweeter fuses in my MG-3.6/R speakers, when the amp clips and releases a spray of high-frequency energy. But with an amp rated at 250 W/ch into 8 Ohms and 400 W/ch into 4 Ohms, I can play them much louder, with no problem. And I am talking about "not-unreasonably-loud" (although "very loud") sound levels.
I have only been able to use my little MG-12/QR and big MG-3.6/R with the two amps, i.e. one amp that's rated at 100 w/ch into 8 Ohms and 150 W/ch into 4 Ohms (Adcom GFA-545 II) and one amp that's rated at 250 W/ch into 8 Ohms and 400 W/ch into 4 Ohms (Adcom 585).
Neither Magnepan model can reach its maximum usable output level with the smaller of those amplifiers. Both Magnepan models can very-easily reach their maximum usable output level with the larger of those two amps.
The point is, I don't know where, in between those two, the threshold is, at which an amp would have just-enough rated max power to drive them sufficiently, including up to their maximum usable output levels, without clipping. All I know is that they need more than the smaller of those two amps is able to give, if you want to be able to fully-utilize their output-level range. And I do suggest that you will probably want to have a setup that is capable of driving them to their maximum usable output level, without clipping.
I have the older version of the 3.x's, the IIIA's. I used to run them with an (original Pass Labs) Aleph 3 (2 x 30W 8 Ohm) and a Rowland Consummate Pre (18dB gain). Never blew the fuses, just did not have the power (or bass) I needed.
I now bi-amp through an active crossover, using the Aleph 3 for mid/hi and a 180W class A/B for bass. Beautiful sound. Plenty of power and bass. Still never blown a fuse.
Maybe my assumption about the cause is wrong. But it happened twice. And, with the same material, but with the bigger amp, and playing much louder, I have never blown the tweeter fuses (except for the time the remote-controlled volume knob on the preamp got stuck in clockwise mode! And I literally dived (dove?) across the room and caught it before it got ALL the way up. I am no longer tempted to bypass the fuses. <grin>).
Or maybe your amp didn't have enough power, when clipping, to blow them.
Speaking of bass, even with the MG-12s, I was able to get too much bass. But I believe it was due to the room configuration. I had them on the long wall (well, 4 or 5 feet out from it), and there was a cabinet and TV against the wall, between them, and putting some unused 4-feet-tall box speakers along their inboard edges, between them and the corners of the cabinet that was between them, mostly blocking reflections from between the speakers, must have stopped some of the bass cancelation.
Or maybe your amp didn't have enough power, when clipping, to blow them.
Speaking of bass, even with the MG-12s, I was able to get too much bass. But I believe it was due to the room configuration. I had them on the long wall (well, 4 or 5 feet out from it), and there was a cabinet and TV against the wall, between them, and putting some unused 4-feet-tall box speakers along their inboard edges, between them and the corners of the cabinet that was between them, mostly blocking reflections from between the speakers, must have stopped some of the bass cancelation.
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IMHO, your success has a lot to do with bypassing the original Maggie crossover. Are your amps wired directly to the 1.6's drivers?
Gootee - while your statements are subjectively accurate, applying some math to the discussion makes things even clearer - a 400W amp will be capable of higher levels but just how much higher? Changing from a 150W RMS amp to a 400W RMS amp will increase your stereo SPL @3M from 98.3dB to 102.5dB. Do you really listen to music at these levels? - or are there other factors driving your preference for a higher power amplifier? Have you measured the SPL at your preferred listening levels?
My 50W tube amplifier is capable of delivering a wholly satisfying 94dB at 4m and I still prefer to keep my listening levels much lower than it's max output. At lower levels, I can listen to my system for hours on end without becoming fatigued while maintaining domestic (and neighborly) bliss at the same time.
A good amplifier allows one to listen to music a lower levels for longer periods of time and still remain engaged in the musical experience. A good amplifier will provide good detail, soundstage and dynamics even at lower listening levels.
As I stated in post 18 above, my 50W tube amplifier works much better than my 400W Bryston SS amp driving a pair of modified 1.6's in my listening room at my preferred listening levels. It is not necessarily true to suggest that a higher power amplifier will sound better and the OP's best bet will be to try several combinations of SS and tube amps to determine his best fit solution.
Jaimo,
I think I agree with everything you mentioned. I was not trying to comment on sound quality. My only point was that there are times when I could not reach a desired SPL because the amp that was rated at 150 w/ch max into 4 Ohms began clipping (according to its clipping-indicator LEDs). I would not want to make any assumptions about whether or not it is necessary to be able to reach any particular SPL. But in case the OP or another Maggie user wants to have the potential to use the entire range of SPL that their Maggies could provide, they should be aware of the rated max power that would be needed.
Dropping back to mere opinion, my opinion is that the SPL that can be acheived with MY 150W@4 Ohms amplifier is definitely not enough, in some situations. I normally listen at much lower levels. But when I can't quite get it loud-enough, it can be frustrating.
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Dropping back to mere opinion, my opinion is that the SPL that can be acheived with MY 150W@4 Ohms amplifier is definitely not enough, in some situations. I normally listen at much lower levels. But when I can't quite get it loud-enough, it can be frustrating.No worries Gotee - I completely understand your urge to wind up the volume for a more satisfying listening session - some music demands to be listened to at high volume.
I used to drive my 400WPC amp into clipping with my SMGa's but later found that I was using volume to compensate for the amps inability to drive the Maggies adequately. I don't have this urge with my tube amps.
A relevant point the maggies are a very flat 4ohm impedance curve where most so called 4 ohm speaker are a roller coaster of an impedance curve much closer to the text book than most. The need for power is far more level across the audio band than many speakers . This gives the tube amp a better shoot at performing well as the load is flatter on the output transformer and final tubes than most speakers. I will agree that about 250 adcom watts in to 4 ohm will get the job done 555 or one of its offspring .
I agree. I no longer use the external crossovers. The power amps are connected direectly to the MG3A's.
Basically , proving how bad 4B's are , those speakers love power and yes they benefit greatly from stands and setup , tilt is very important ....
Not quite , now do the calculation with real world music dB numbers and dynamics the difference is startling...
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