Home Planar Speaker Asylum

Welcome! Need support, you got it. Or share your ideas and experiences.

Hello, and question about inductance value for Magnepan SMGa

Dear colleagues,
After lurking, reading and learning for some good months, I decided to register and share my experiences with my Magnepans. Hello everyone.
Well, I was happy with my Audio Notes but for that inescrutable reason decided to go for a pair of SMG-as. I've always loved planars since I heard them first many years back. I once owned a pair of Apogees, but both my wife and amplifier -at the time- (and in no particular order) stopped my experiencing futher.

So I got a nice used pair some weeks ago on the bidding site for almost no money, suspected ready for the bricolage.
When the SMGas arrived home I was pleasantly surprised that, even though the cloth was quite worn and the wood trims needed caring, upon doing the upskirt the coils were absolutely perfect: no greening, no lifting…., nothing wrong; only maybe the mylar was a bit sticky had accumulated some dust. I'm keping the original fabric and not doing any restoration of the guts at this stage.
First connection to the amp was disappointing till I discovered that both fuses were cut and no treble was coming from the panels. Also one of them was wired out of phase. ---* follows a NOTE(1) on this
But otherwise the speakers had been admirably taken care of.
I have to thank Paco (group user) for his advice and friendly contact, and following the many advices and wise posts by many of the users here, I took up the crossover modification. I also spoke to Tony Gee of Humblehomemadehifi (thank you!!), and finally went down the following path. I will be brief further on:
- Dismantle the wiring, including the fuse.
- Keep the original scheme for cap and inductance connection.
- Replace original capacitor with 1 x Obbligato Aluminium Foil (47uF) + 1 x Jantzen Superior-Z (3,3uF) + 1 x Vishay MKP1837 (0,01uF) per box more or less totalling the original specs.
- Replace original inductance with 1 x Jantzen Audio WaxCoil (AWG14, 0,68mH, 0,202Ohm) ---* follows a NOTE(2) on this.
- Re-wire without the fuse and resistor with Duelund "foil in silk" cable and DH Labs silver 12AWG wire.
All of the above mounted into a wood box which I have treated for vibration and resonance and that I will fill up with sand (following Paco's advice).
I have added a pair of WBT plugs to connect to the amplifier.

Note(1): ok, my amplifier is a classic valve integrated Audion Sterling ETSE (standing for Extended Triode Single Ended).
Ok, before you think I know beans, let me tell you the SMGs don't need tenths of watts to deliver that wonderful sound they're famous for.
My re-capped amp just puts out 14w of clean, wonderfully refinate watts into the Maggies and because I don't need outrageous volumes, the sound is lush, delicate but full. I don't need more bass.

Note(2): The original inductor should be a 0,78mH (even though it doesn't read so anywhere but in your posts here). I've settled for a 0,68mH one because I did not have any available source at hand at the time.
Does this make a great difference ? I don't have the tech knowledge, and don't feel like rewiring the old stock ones back ! Your advice here will be highly appreciated.
Nice to be here. Greetings from sunny Spain!


This post is made possible by the generous support of people like you and our sponsors:
  Kimber Kable  


Topic - Hello, and question about inductance value for Magnepan SMGa - AntonioJ 02:52:30 09/05/14 (3)

FAQ

Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.