Best DIY amp for Magnepan

[Panelhead]

Your best option may be keep the A21 and upgrade to a source with balanced output.
Personally when looking at amplifiers lack of balanced inputs is a real drawback.

 

[JR4321]

A few thoughts as someone that has owned five pairs of Maggies over the last 25 years, from SMGas to 3.5s:

1) You don't say which Maggies. Smaller Maggies don't need as much power as larger ones.
2) Is is a common misconception that Maggies are hard to drive. Maggies are almost a purely resistive load, mostly close to 4 ohms with some models dipping to about 3 ohms. As long as the amplifier you have is comfortable driving a 4 ohm load, you are fine. The idea that they require a lot of current is pure bunk. The requirement for current is very simple: the amount needed is that which keeps the voltage from sagging into a given impedence. For example, putting 500 watts into 3 ohms requires 13 amps of current. Hardly the huge 50-100 amp current capabilities that so many amplifier companies seem fond of touting as needing to drive speakers.

So all that said, I would say the best value for your money would be recapping your A21 amp.

1. 3.7i
2. My A21 is about 5yrs old so I doubt any new caps are needed. It works fine and always has.

Just wondering if something with better measurements would be noticeable to my ears; seems unlikely.

 

[CDMC]

1. 3.7i
2. My A21 is about 5yrs old so I doubt any new caps are needed. It works fine and always has.

Just wondering if something with better measurements would be noticeable to my ears; seems unlikely.

The only thing I see that a new amplifier would help with with the 3.7i is more power if you are clipping. Even then, you would need to get something that puts out about a 1kw per side to have any real difference (3 db increase from your current 400 channel a side). Generally, the A21 has been regarded as a good match to Maggies.

If it were me, and I were itching to change/upgrade something I would take a different route. Purchase a UMIK-1 and download REW and measure your room. Take a look at your decay times. If they are over 400-500ms, some room treatment can make a huge difference in sound. For a few hundred dollars in treatments (I like GIK Acoustics), you can make a marked improvement in your sound. In my case, my living room is very lively (hardwood floors, windows, ceilings, and a 700+ ms decay in the midrange). Absorption treatments really helped mid range glare. If you are using a subwoofer, REW also makes integrating it much easier.

 

[MRC01]

1. 3.7i
2. My A21 is about 5yrs old so I doubt any new caps are needed. It works fine and always has.
Just wondering if something with better measurements would be noticeable to my ears; seems unlikely.

I've had the 3.6R for the past 20+ years, driving them with an Adcom 5800 that is even older (and similar to the A21). These speakers can just barely use all of the 400 watts this amp can deliver. Not that I've done that often, else I'd lose my hearing. At very low frequencies (30 Hz), it's just barely enough power to make the panels rattle against the stops. These speakers are almost, but not quite, as efficient as their specs say they should be. As long as the amp has enough power (400 w continuous is enough), they should actually be *easier* to drive than conventional dynamic speakers due to their relatively flat impedance vs. frequency.

Note: by 400W continuous I don't mean these speakers can take 400 W of continuous power. I mean they can take 400 W of power on transient musical peaks, and it's good to have this peak speaker power demand within the amp's continuous capability.

That said, the 3.6 and 3.7 are highly revealing speakers with their 5' long ribbon tweeters. Distortion on mine measures -60 dB or less in the treble where our ears are most sensitive to it. So you need a clean amp. If it has elevated noise or distortion, you may hear it.

 

[JR4321]

Your best option may be keep the A21 and upgrade to a source with balanced output.
Personally when looking at amplifiers lack of balanced inputs is a real drawback.

I've used a Schiit Gungir (it broke) with balanced outs. A Cambridge DacMagic with balanced outs. I recently got the Topping E30 which is RCA outs. Doubt I'd pass a blind test between any of them, honestly. I got the first 2 used and the Topping was only $120, and after selling used, not much money spent.

 

[JR4321]

Yes, that's what I was wondering. I've never used a different amp with these speakers, so I was wondering if one of these Class D's with great measurements would be a noticeable change.

 

[JR4321]

That said, the 3.6 and 3.7 are highly revealing speakers with their 5' long ribbon tweeters. Distortion on mine measures -60 dB or less in the treble where our ears are most sensitive to it. So you need a clean amp. If it has elevated noise or distortion, you may hear it.

Yes, that's what I was wondering. I've never used a different amp with these speakers, so I was wondering if one of these Class D's with great measurements would be a noticeable change.

 

[JR4321]

The only thing I see that a new amplifier would help with with the 3.7i is more power if you are clipping. Even then, you would need to get something that puts out about a 1kw per side to have any real difference (3 db increase from your current 400 channel a side). Generally, the A21 has been regarded as a good match to Maggies.

If it were me, and I were itching to change/upgrade something I would take a different route. Purchase a UMIK-1 and download REW and measure your room. Take a look at your decay times. If they are over 400-500ms, some room treatment can make a huge difference in sound. For a few hundred dollars in treatments (I like GIK Acoustics), you can make a marked improvement in your sound. In my case, my living room is very lively (hardwood floors, windows, ceilings, and a 700+ ms decay in the midrange). Absorption treatments really helped mid range glare. If you are using a subwoofer, REW also makes integrating it much easier.

Yikes! It would be mighty loud to clip this thing. I've measured over 100dB.

I have a lot of treatment, though it's all absorptive. Dispersion has been recommended for me, and of course I've read the Toole recommendation for reflection rather than absorption and the first points. That hasn't been my experience for best sound, however. At some point I will try some dispersion products to try for myself.

I do use Dirac, and love it. My next step is to update to DiracLive, as I use the 1.X virtual soundcard version on a Mac Mini. Attempting to debug a playback problem with Dirac and Amazon Music HD...

 

[March Audio]

I've used a Schiit Gungir (it broke) with balanced outs. A Cambridge DacMagic with balanced outs. I recently got the Topping E30 which is RCA outs. Doubt I'd pass a blind test between any of them, honestly. I got the first 2 used and the Topping was only $120, and after selling used, not much money spent.

Balanced connections don't, in themselves, sound better than rca single ended connections. Or vice versa for that matter. The benefit of balanced is that rejects noise through common mode rejection and eliminates the fundamental flaw of RCA. That being the problem of the shield signal conductor being used to connect component chassis, often being connected to safety earth and the inevitible ground currents flowing in it. (audible ground loop hum in extreme circumstances)

I would always choose balanced if available to avoid these issues, however don't expect it to necessarily sound better.

 

[March Audio]

Yes, that's what I was wondering. I've never used a different amp with these speakers, so I was wondering if one of these Class D's with great measurements would be a noticeable change.

Well, FwIW we were exhibiting in the room opposite the Oz Maggie dealer at the Melbourne Hifi show last year and he swears by his class d amps for them.

Is it going to improve over your Para? Don't know.

Good luck resisting scratching the itch

 

[ezra_s]

that amp looks like a beast.

Found this in the manual, not sure if it helps

"Total Protection - Current Overload
Specialized current-sensing transistors are connected
to the output stages of the A 21 to constantly monitor
the current flow through the output transistors. If the
current drawn by this stage exceeds a predetermined
safe level due to a load impedance below 1 ohm or a
short circuit at the speaker terminals, the output relay
will open immediately to prevent any of the output
transistors or other parts from failing. "

 

[JR4321]

Well, FwIW we were exhibiting in the room opposite the Oz Maggie dealer at the Melbourne Hifi show last year and he swears by his class d amps for them.

Is it going to improve over your Para? Don't know.

Good luck resisting scratching the itch

Apologies for any offense, but...I have difficulty taking advice from anyone who is selling these products.

 

[Wes]

Keep the A21. Continue the story with bigger Maggies (20.7 ?), whatever they come out with next, room tmts., tinkering with angles and distance from rear wall, better source material - masterings, and room tmts.

or add DWMs

 

[MRC01]

that amp looks like a beast. ...

No surprise. High bias class AB amps are not efficient. 400 continuous wpc into 4 ohms is close to the maximum output power possible on 120 V power. Any more than that, and they can start to trip 20 amp breakers.

The Adcom 5800 weighs nearly 60 lbs., has a max continuous power draw of 1,800 VA (15 amps @ 120 V), with a huge amount of regulation capacitance. When you first turn it on, the lights in the room dim briefly and it will occasionally trip a 20 amp breaker. When you turn it off, the music keeps playing for at least 3-5 seconds without any audible change as it drains the energy in the power supply.

One can see why class D amps are becoming more popular. In the past they had noise & distortion issues. But some of the newer class D amps Amir has measured suggest they've overcome that problem.

 

[JR4321]

or add DWMs

I have a pair of Rel Stratas. Very pleased with those.