Maggie fuses

Waker · « **on:** 20 Aug 2010, 07:04 pm »

Anyone have experience with replacing stock Maggie 3.6R fuses with audiophile grade? Should I use slow blow or fast blow? Stock is listed by factory as normal blow, but they may be on the slow side. I want to use the HiFi Tuning brand, available in either slow or fast. I am not worried about clipping or overloading at all--never had a problem. Thanks.

*Scotty* · « **Reply #1 on:** 20 Aug 2010, 07:45 pm »

You had better use fast. The ribbon tweeter will go up in smoke if it sees too much current for too long.
While the mid-panels have a larger overload margin they should also be protected by fast blow fuses. In the past I have blown blown all four fuses simultaneously on the Telarc recording of Groffs Grand Canyon suite.
Don't ask the Maggies to reproduce thunder as captured by Telarc at high loudness levels.
Scotty

Aom-Uom · « **Reply #2 on:** 21 Aug 2010, 08:14 am »

Hi,
fuses have a noticeable impact as they are very nonlinear. I would go for a low inductance (nonspiral) type.

trout2 · « **Reply #3 on:** 7 Oct 2010, 03:41 pm »

Replaced my stock fuses (3.6R's) with ceramic fast blow fuses (same values as stock fuses) at a cost of about $5/each. Noticed an extension of the high frequencies - Simple/cheap tweek that made a nice improvement.

Minn Mark · « **Reply #4 on:** 7 Oct 2010, 03:56 pm »

I recently bi-wired my 3.6R's and noticed an immediate, hotter high-end. Have been considering fuses, too, but I want more "air"---the Mags are plenty trebly enough for me. Happy to see others share. Has anyone tried other types of jumpers?

Mark

SteveFord · « **Reply #5 on:** 7 Oct 2010, 11:23 pm »

By jumpers do you mean those overgrown staples in the back? If so, try a short length speaker wire in it's place.
If you mean bypassing the fuses, no, I'm not that brave.

Letitroll98 · « **Reply #6 on:** 8 Oct 2010, 01:55 am »

Quote from: Minn Mark on 7 Oct 2010, 03:56 pm

I recently bi-wired my 3.6R's and noticed an immediate, hotter high-end. Have been considering fuses, too, but I want more "air"---the Mags are plenty trebly enough for me. Happy to see others share. Has anyone tried other types of jumpers?

Mark

Funny, I've tried several different speaker wire jumpers to replace the "staples" as Steve calls them and never had any luck, the staples always sounded better. And I was sure that almost any speaker wire, even lampcord, would be better. I'm still open to suggestion here as in my head I know a good set of speaker wire jumpers should sound better, just haven't found that to be the case.

Back on topic, I've just tried the teflon tape wrapped around the fuses that John (thechairguy) suggested some time ago. Early stages so nothing firm yet, but I think I hear an improvement. I want to also try trout's suggestion about the ceramic fast blows from the hardware store. They look indistinguishable from the high priced audio fuses and I bet they are the same, at least I believe it to be true, which is half the battle. Also add in the sand and polish the ends down to the copper tweak is on the boards. Fun with fuses, what's next.

Elizabeth · « **Reply #7 on:** 9 Oct 2010, 04:09 am »

I bought the $30 each fuses and put the four of them into my Magnepan 3.6 along with a 'coil' in the tweet resistor space. (the coil was recommended over at Audioasylum planar forum.
I would say I had an immediate minor impression of greater clarity, but really, I am not obsessive enough to take them out and swap back and forth until I 'know' exactly what they do. I spent the money they are in, and that's it.
Boring but true.

Letitroll98 · « **Reply #8 on:** 9 Oct 2010, 02:14 pm »

Quote from: Elizabeth on 9 Oct 2010, 04:09 am

along with a 'coil' in the tweet resistor space. (the coil was recommended over at Audioasylum planar forum.

I would say I had an immediate minor impression of greater clarity, but really, I am not obsessive enough to take them out and swap back and forth until I 'know' exactly what they do. I spent the money they are in, and that's it.
Boring but true.

Could you please either elaborate what you mean by "coil" or link to the thread? Sounds very interesting.

And I agree with part two. I have so little time to listen anyway, not much time to obsess anymore.

andyr · « **Reply #9 on:** 9 Oct 2010, 11:11 pm »

Quote from: Letitroll98 on 9 Oct 2010, 02:14 pm

Could you please either elaborate what you mean by "coil" or link to the thread? Sounds very interesting.

Hi L98,

The "coil" is a microHenry (micro - not milli!

) inductor which goes in series with the ribbon ... you could use the connectors designed for the ribbon attenuation resistor. A guy called Al Sekela on the Planar Asylum thought up the idea - as Maggie true-ribbons make great RF antennae!

(The coil blocks off the RF.)

Regards,

Andy

Letitroll98 · « **Reply #10 on:** 10 Oct 2010, 03:03 pm »

Thanks Andy. Useless for us Quasi-ribbon owners.

*Scotty* · « **Reply #11 on:** 10 Oct 2010, 04:56 pm »

andyr,the true ribbon in the maggies is no better or worse an RF antenna than the unshielded speaker wire hooked up to it. A properly designed SS amplifier has a Zobel network across the speaker outputs which acts as a two pole filter to attenuate RF before it gets back into the feedback loop of the amp.
Introducing an unnecessary inductance between your amp and a near perfect tweeter is a bad idea. The only thing the introduction of a series coil between the ribbon and amplifier can do is dumb down the performance of the ribbon. The ribbon driver is an extraordinarily accurate transducer and it will tell you things about your source material and your system that you my not want to hear but that is no reason to shoot the messenger.
The fact that the maggie ribbon is directly driven is its greatest strength and it is the only true ribbon tweeter that is directly driven to my knowledge.
The ribbons performance was one of qualities I enjoyed most about the sound of my MG3a's.
Scotty
PS If the coil is not an air-core design you will be listening to the effects of the core material saturating as a function of the signal level passing through it.

*Scotty* · « **Reply #12 on:** 10 Oct 2010, 05:34 pm »

I may have mentioned this somewhere before but you can bypass the fuses with small value audiophile grade caps to good effect. The fuse is a non-linear resistor in series with the driver. You can give the high frequency signal a low impedance path around the problem with a .33ufd cap soldered to the fuse holder clip.
This may sound like a funny place to mention AC power filtering but it will directly impact how clean the highs sound. The ribbon will tell you when your system is full of grunge from noise on the AC.
Some of you may be able to realize a substantial increase in liquidity and sweetness by reducing the AC noise getting into the system.
Scotty

andyr · « **Reply #13 on:** 10 Oct 2010, 10:47 pm »

Quote from: *Scotty* on 10 Oct 2010, 05:34 pm

I may have mentioned this somewhere before but you can bypass the fuses with small value audiophile grade caps to good effect. The fuse is a non-linear resistor in series with the driver. You can give the high frequency signal a low impedance path around the problem with a .33ufd cap soldered to the fuse holder clip.
Scotty

Trouble is, the ribbon signal is still going through those steel Magnepan fuse holders.

It's better to replace them with some quality fuse holders. I used some Acme Audio cryoed silver fuse holders for the ribbons of my IIIas but I have now removed the ribbon fuses.

Regards,

Andy

andyr · « **Reply #14 on:** 10 Oct 2010, 10:56 pm »

Quote from: *Scotty* on 10 Oct 2010, 04:56 pm

andyr,the true ribbon in the maggies is no better or worse an RF antenna than the unshielded speaker wire hooked up to it.

Scotty

Possibly - but the IIIa ribbon is 1.5m long whereas my ribbon speaker cables are only 300mm long ... so the ribbon is picking up 5 times the RF. That said, I don't in fact use a series uH coil - I instead use a 1nF cap across the ribbon.

Quote from: *Scotty* on 10 Oct 2010, 04:56 pm

PS If the coil is not an air-core design you will be listening to the effects of the core material saturating as a function of the signal level passing through it.

And the ribbon sounds even better when driven actively (with no inductors/caps "in the way")!!

Regards,

Andy

andyr · « **Reply #15 on:** 10 Oct 2010, 10:58 pm »

Quote from: Letitroll98 on 10 Oct 2010, 03:03 pm

Thanks Andy. Useless for us Quasi-ribbon owners.

Not quite, L98. QR owners on MUG have reported it works well with their Maggies, too.

Regards,

Andy

*Scotty* · « **Reply #16 on:** 10 Oct 2010, 11:09 pm »

Andy, what now protects the ribbon from catastrophic failure due a fault in an upstream component?
I would tempted to ask Hugh if he would see any problem in increasing the size of the capacitor in the zobel network on the speaker outputs to filter the incoming RF a little more aggressively. You could also put a zobel network right at the input terminals of the maggies to knock out any RF that the speaker might have picked up.
A network in this location has the added benefit of snubbing any ringing that might be taking place which will also make the highs sound harsh.
Scotty

Waker · « **Reply #17 on:** 1 Dec 2010, 08:15 am »

Update on fuse upgrades in stock Maggie 3.6Rs: I first tried the HiFi Tuning gold/ceramic series,slow blow, with silver filament and gold over silver/copper (?) end caps. The improvements were obvious--more clarity and air. Now, I have replaced the gold series with HiFi's new Supreme Series, fast blow. At $75 each, they feature silver filaments combined with 1% gold and pure silver end caps. I also exceeded the spec ratings by 100%, to 5 amp and 10 amp, for a larger conductor. Result: Another plateau of clarity and more midrange authority--more of the music is getting through that tiny fuse bottleneck. This is the easiest tweak by far, a very good cost/benefit ratio for the person who isn't into doing anything radical. Considering that the best mods eliminate the fuse paths, I should have gone even higher on the ratings. Am I worried about burning something out? Not at all--plenty of stable, pure power. Never have blown a stock fuse. So try these things.

andyr · « **Reply #18 on:** 1 Dec 2010, 08:24 am »

Quote from: *Scotty* on 10 Oct 2010, 11:09 pm

Andy, what now protects the ribbon from catastrophic failure due a fault in an upstream component?
I would tempted to ask Hugh if he would see any problem in increasing the size of the capacitor in the zobel network on the speaker outputs to filter the incoming RF a little more aggressively.

You could also put a zobel network right at the input terminals of the maggies to knock out any RF that the speaker might have picked up. A network in this location has the added benefit of snubbing any ringing that might be taking place which will also make the highs sound harsh.
Scotty

Sorry for the delay in responding, Scotty - I didn't see this one.

If you have removed the ribbon fuse, as I have done ... then nothing will prevent a spike from an upstream failure from coming through. If you still have the fuse in place, it might - just possibly - blow first!

A Zobel at the speaker terminal is a good idea to, as you say, remove RF which the Maggie drivers (not just the ribbon) have picked up.

Regards,

Andy

andyr · « **Reply #19 on:** 1 Dec 2010, 08:25 am »

Quote from: Waker on 1 Dec 2010, 08:15 am

Update on fuse upgrades in stock Maggie 3.6Rs: I first tried the HiFi Tuning gold/ceramic series,slow blow, with silver filament and gold over silver/copper (?) end caps. The improvements were obvious--more clarity and air. Now, I have replaced the gold series with HiFi's new Supreme Series, fast blow. At $75 each, they feature silver filaments combined with 1% gold and pure silver end caps. I also exceeded the spec ratings by 100%, to 5 amp and 10 amp, for a larger conductor. Result: Another plateau of clarity and more midrange authority--more of the music is getting through that tiny fuse bottleneck. This is the easiest tweak by far, a very good cost/benefit ratio for the person who isn't into doing anything radical. Considering that the best mods eliminate the fuse paths, I should have gone even higher on the ratings. Am I worried about burning something out? Not at all--plenty of stable, pure power. Never have blown a stock fuse. So try these things.

I'm sure it made an improvement by upgrading the quality - and thickness - of your fuses. But an even bigger improvement will be had be replacing the crappy Magnepan fuse holders with some decent ones.

Regards,

Andy