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Tympani ferrous parts

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Posted on May 28, 2017 at 13:50:59
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Having acquired a pair of Magneplanar Tympani-IVa speakers missing their back plates onto which are installed the speaker wire connectors and fuse holders, I contacted Magnepan to inquire about the availability of replacements. To my surprise and delight, Magnepan found a complete set! They were offered to me at a VERY reasonable price, not just the plates themselves (which is only what I was looking for, intending to install Cardas binding posts, and leaving out the fuse holder), but fully assembled with all parts.

I decided to go ahead and have all the parts installed on the plates, just to be able to fully restore the speakers to stock form, knowing I can replace or bypass the stock parts if I choose to. The cheesy little wire connectors are definitely going to be being replaced with Cardas binding posts, but I hesitate to bypass the fuses, even though I have a nice stable tube amp I will be driving the m/t panels with. I'm not terribly worried about damaging those drivers, but would still prefer to leave the fuses in place if their presence isn't too detrimental to the sq of the speaker.

So, my question is: Disregarding the matter of the extra solder joints resulting from the holders being in the signal path, is the fuse holder itself a cause of sonic degradation? Is that holder made of steel, or other ferrous metal? If so, they are definitely out, risk be damned!

 

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RE: Tympani ferrous parts, posted on May 28, 2017 at 23:32:13
Satie
Audiophile

Posts: 5426
Joined: July 6, 2002
 Yes on all counts.

It is detrimental to sound

It is ferrous

Play without then install and play with it in line and decide for yourself on the sound vs. safety equation.

You need quite a hefty tube amp for the mid/tweet section. 4 X KT88 per side and can squeeze by on 2X KT150 or 2X 845 class AB. That unless you play sotto voce

 

RE: Tympani ferrous parts, posted on May 29, 2017 at 05:32:40
neolith
Audiophile

Posts: 4842
Location: Virginia
Joined: February 21, 2002
Contributor
  Since: December 2, 2004
 Since soldering is not a problem for you and you want to keep the fuses without the holders, get fuses with pigtails.




"Our head is round in order to allow our thoughts to change direction." Francis Picabia

 

RE: Tympani ferrous parts, posted on May 29, 2017 at 11:34:48
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Thanks guys. It surprises me that no one has come out with a copper (or at least brass) fuse holder. There is a guy offering a Maggie "upgrade" kit on Audiogon, which includes a little solid copper (I believe) rod to replace the fuse---when the problem is not the fuse itself, but rather it's holder!

Yup Satie, I have a Music Reference RM-200 MK.2 to try with the m/t drivers. It puts out over 100w/ch (and 8 ohm, 4 ohm, 2 ohm, and even 1 ohm speaker taps!), which should work in my small room. If not, I have a couple of pretty good ss amps (PS Audio, Electron Kinetics---old, but so are the speakers ;-) that will.

 

Soundwise..., posted on May 29, 2017 at 12:19:04
YRY
Audiophile

Posts: 491
Location: So. California
Joined: April 4, 2002
 ...best to eliminate both fuse and holder.

 

RE: Tympani ferrous parts, posted on May 29, 2017 at 13:53:49
kentaja
Manufacturer

Posts: 4614
Joined: March 26, 2001
 You can find copper base metal fuse holders at Mouser. This is what I use with the Stax speakers and retrofitted my ARC REF300 with this type of fuse holder for each output tube. Minimal sonic impact.

 

RE: Tympani ferrous parts, posted on May 30, 2017 at 00:33:07
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Thanks Kent, I'll look into Mouser.

 

RE: is the fuse holder itself a cause of sonic degradation? ..., posted on May 31, 2017 at 04:14:49
andyr
Manufacturer

Posts: 12551
Location: Melbourne
Joined: September 2, 2000
 As I think neo commented - they most certainly are (a source of SQ degradation). So I would recommend getting rid of them.

20 years ago, when I 'renovated' my MG-IIIas, I replaced the stock tweeter fuse-holders with some 'audiophile' panel fuse-holders ... because I was worried about blowing a ribbon! I had to make up L-shaped brackets, to fit the new fuse-holders onto the back plates.

There never were any mid-panel fuse-holders on these IIIas as the dealer I bought them from had already removed them, when I bought them from him! :-))

15 years later, when I made up my 'Frankenpans' by combining T-IVa mid/ribbon panels with MG-2.5 bass panels (so they are, basically, T-IVas with only 1 bass panel each side), I removed the tweeter fuses. So for 10 years, I've been running without ribbon fuses - so I would say, providing your amp doesn't clip ... there is no 'danger' in running without tweeter fuses.

Andy

 

RE: is the fuse holder itself a cause of sonic degradation? ..., posted on May 31, 2017 at 06:59:09
kentaja
Manufacturer

Posts: 4614
Joined: March 26, 2001
 It is not really a question of sonic degradation but of degree.

Does a fuse, fuse holder degrade the sound? Yes. If done properly is it that big of a deal? A question each individual will have to answer. IME a properly implemented fuse/fuse holder has minimal sonic impact.

I restore the Stax F-81/83 speaker. They use a fuse/fuse holder on the input to protect the delicate audio transformer. Does the speaker sound better without the fuse versus fused? Yes but I would say the speaker has 98% percent of its available performance with the fuse in place. This difference is indeed small.

In the case of the Stax I would never use them without the fuse. Pop an audio transformer and you are looking at a $1500 repair. With the Magnepan ribbon I might be tempted to go without the fuse because if a ribbon fails it is a $100 repair.

All of this comes down to ones tolerance in the performance versus cost ratio.

 

RE: Yes - and no! ..., posted on May 31, 2017 at 13:36:45
andyr
Manufacturer

Posts: 12551
Location: Melbourne
Joined: September 2, 2000
 I would agree with you when you say "All of this comes down to ones tolerance in the performance versus cost ratio." Amplifiers have fuses too and - as with your Staxes - I would never remove them, to get just that bit more SQ.

But there are too many stories of people blowing ribbons before the fuse blows, so I am not persuaded that I'm doing anything particularly risky, in running without Maggie fuses. BTW, in Australia, blowing a ribbon will cost you in excess of $500, what with shipping costs back to the importer, in Sydney! :-((

Andy

 

RE: Yes - and no! ..., posted on May 31, 2017 at 17:32:06
kentaja
Manufacturer

Posts: 4614
Joined: March 26, 2001
 Agreed. The fuse is no guarantee that the ribbon will not blow. Many factors involved in the failure mode of a ribbon.

Fortunately here in the US replacing the ribbon is not that bad cost wise. I would be inclined to remove the fuse and take the risk. $500 for a replacement is getting pricey.

 

RE: And yet ..., posted on May 31, 2017 at 17:54:42
andyr
Manufacturer

Posts: 12551
Location: Melbourne
Joined: September 2, 2000
 In 6 years of running entirely fuse free, I have never had the ribbon amp clip (I run 3-way active), and blow the ribbon. So there is no risk, IMO. :-))

One advantage in 3-way active, I guess - the ribbon amp is not starved of power when a big bass transient occurs!


Andy

 

RE: Yes - and no! ..., posted on June 1, 2017 at 08:15:32
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Thanks one and all. I am fairly confident in the stability and clipping behavior of my m/t amplifier, the Music Reference RM-200 Mk.2. It puts out almost 150w at 4 ohms (from only a single pair of KT-88's!), and my small room (14' 3" x 13' x 8') minimizes the Tympani's power needs (employing bi-amping, a ss amp for the bass panels). No fuses it is!

I already have the Cardas binding posts, I'm just waiting for the terminal plates to arrive from Magnepan. As Kent described, the T-IVa's former owner soldered his speaker cables directly to the speakers internal wires, which I am NOT going to do.

 

RE: Yes - and no! ..., posted on June 1, 2017 at 22:42:43
gregdunn@indy.net
Audiophile

Posts: 3
Location: Midwest USA
Joined: April 13, 2017
 The difference in any electrical quantity between having the fuses in circuit and bypassed will almost certainly make no difference in perceivable sound quality. Expectation bias is a powerful psychological effect and it has resulted in many audio myths such as this.

If you feel differently, by all means perform a test. Have a reliable third party at hand to bypass the fuse with a heavy-duty jumper. Listen for an extended period with the third party connecting and disconnecting the jumper, but not telling you which state is which. In addition, they should randomly NOT change the state when they tell you they are actually doing so, in order that you do not key your expectations to a known state change. Have them log at least 20 instances to be sure it's not just lucky guessing, and track your judgement for each one.

If you can't determine at least 16-17 out of 20 instances, then you've only shown that there is no audible difference to you. Enjoy your speakers and focus on the other thing which causes meaningful differences in sound quality - the source material.

If you are able to hit 20/20 in a properly double blind test, then please document it and let us know. World fame awaits you.

 

RE: Yes - and no! ..., posted on June 2, 2017 at 03:15:49
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Short-term A/B testing was proven to lead to inconclusive results years ago.

 

RE: Yes - and no! ..., posted on June 2, 2017 at 09:03:19
Norman M
 "My name is Edith Ann and ....."

https://www.youtube.com/watch?v=jJMKupYF14I

 

RE: Yes - and no! ..., posted on June 2, 2017 at 09:12:31
Norman M
 I find a big problem with long term is that it's not possible to accurately recall the details of what I previously heard, and also quite likely being in a different mood receptive to something else ....

 

RE: Yes - and no! ..., posted on June 2, 2017 at 10:09:58
Davey
 You really don't need to evaluate this subjectively.
Simply put an oscilloscope across the fuse when playing normally and you will certainly not see nothing. So, even objectively, the fuse is altering the signal somewhat. That's a good enough reason for me to remove it.

There is also the fuse-holder and related wiring which may be marginal in some aspect.

Dave.

 

RE: Tympani ferrous parts, posted on June 2, 2017 at 12:29:16
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Anyway, back to the topic. I measured the cavity behind the connector/fuse block terminal plate, and it is 5/8" deep. The short versions of the various Cardas binding posts are 3/4" long, so I'll make some 1" stand-offs to put between the plate and the MDF panel of the Tympanis, running the attachment screw for the plate through each. Either an aluminum or plastic tube, just big enough for the screw to fit into---an easy fix! The plate will then stand proud of the back of the Tympani a little, but so what?! If the speakers ever need to be shipped, the plate can just be remove, the internal wires snipped from the back of the binding posts. Magnepan is shipping the plates on Monday.

 

RE: Here you go, posted on June 2, 2017 at 18:41:21
josh358
Industry Professional

Posts: 12332
Joined: February 9, 2010
 Not to mention that fuses are known to be non-linear at high current.

Whether this has an audible effect, I don't know, but it's certainly measurable.

 

RE: Yes - and no! ..., posted on June 3, 2017 at 05:51:36
Satie
Audiophile

Posts: 5426
Joined: July 6, 2002
 ABX audiology tests are only useful to identify particular noises and distortion with very short simple signals like tones clicks tone bursts etc.. They are useless with music. Cognitively, as a test for the equipment rather than testing the listener's acuity, it is total nonsense. It is not structured to conform with how musical content is perceived and put to memory. Beyond telling if a piece of audio equipment is grossly incompetent vs. another, the ABX text is an engineer's bias and an incorrect supposition as to the way the hearing and audio processing work. All such evaluations must allow labeled listening - at no time is the listener to listen to a piece under evaluation without knowing (at least generically) what it is. Introduction of a "mystery" sample smears the differences between the particulars of the cognitive tree formed for each item by allocating the perceptual specifics of each unit into the other's cognitive tree.

Beyond grossly incompetent vs. useful, the ABX test is only capable of producing a null result. It is in itself a highly biased test design that disregards entirely how the test equipment (listener) works.

Functionally it is like having a monkey at the keyboard of the PC used to store measurements in the lab, assigning the measurements to files randomly to either item under test. It can not be a useful method to discern performance differences, it is entirely an engineer's conceit...

 

RE: Tympani ferrous parts, posted on June 13, 2017 at 19:53:53
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Having received the Tympani-IVa terminal plates from Magnepan, I removed the stock speaker wire connectors (those short little tubes with set screws, into which bare wire or banana jacks are inserted) and installed Cardas posts, which fit perfectly. While I had the stock connectors off, I took a little magnet (on one of those telescoping rods designed to pick up little parts you drop behind a work bench), and tested all the parts on the plates, and here's what I found:

The speaker connectors (those little tubes), the nuts that secure them to the plate, and the rivets securing the fuse blocks onto the plate are the ferrous parts. The non-ferrous parts are: the terminal plate, the circular clips (that are installed on the rear of the speaker cable connectors) onto which the internal wires are soldered, and the fuse blocks themselves. So, I can either solder the internal wires directly onto the Cardas binding posts, or onto the circular clips which can be installed on the rear of those posts.

The fuse block is connected to the + speaker wire connector, via a short wire with a circular clip, which is installed on the rear of the connector. That I am leaving disconnected.

 

RE: Tympani ferrous parts, posted on June 13, 2017 at 22:19:56
Satie
Audiophile

Posts: 5426
Joined: July 6, 2002
 If possible solder directly to the cardas terminals.

 

RE: Tympani ferrous parts, posted on June 13, 2017 at 22:35:08
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Yup Satie, that's my intention. I mentioned the other option just for the sake of argument and completeness.

By the way, my Ace hardware store has aluminum stand-offs (little hollow tubes, through which a mounting screw may pass) that are perfect for installing between the terminal plate and the Tympanis MDF frame, one at each corner of the plate. The terminal plate needs to be moved out a little to be able to use the Cardas binding posts---the posts are 3/4" behind the surface they are mounted on, the cavity in the Tympani frame behind the terminal plate 5/8" deep. I'm planning on using 1/2" stand-offs, for a little breathing room.

 

RE: Tympani ferrous parts, posted on June 13, 2017 at 23:35:24
Satie
Audiophile

Posts: 5426
Joined: July 6, 2002
 That would do it. But I like Ric Schultz' idea with simple poly binding posts - of externalizing the internal wire right by the binding posts and putting a bit of stripped wire through the hole in the binding post to mate with stripped wire from the speaker cable so you have no joints at all and easy access to clean up the contacts periodically.

 

RE: Tympani ferrous parts, posted on June 14, 2017 at 01:07:01
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Yeah, that's the purist/perfectionist way of doing it all right. A former owner of the T-IVa's may have done his hook-up that way, as the internal wires are sticking out the back, tinned on their ends. But I use my speaker cables with other speakers (ET LFT-8b's and LFT-4's, QUAD 57's), and I really don't want to modify them all. I'm willing to accept the small degree of loss caused by using Cardas binding posts and spades on my cables. I'm not a hi-fi fanatic, just an enthusiast!

 

RE: Tympani ferrous parts, posted on June 14, 2017 at 12:14:42
Satie
Audiophile

Posts: 5426
Joined: July 6, 2002
 would also work with bananas or pins on the speaker cable. Not sure about spades.

 

Consider a compromise?, posted on June 26, 2017 at 08:06:02
grantv
Manufacturer

Posts: 7728
Location: B.C.
Joined: January 15, 2002



Looks stock, performs better. I run my wires thru the connectors; wire to wire direct clamped using the factory connectors only (pass thru into connector only). If using larger wire, buy some screw type maurettes and again; wire to wire connection.

 

RE: Consider a compromise?, posted on June 26, 2017 at 12:21:27
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 The problem is the connectors themselves. They're steel! So are the nuts holding them onto the plate. Now, one could remove the connectors, run the internal wires out through the holes the connectors had been in, and solder the internal wires and speaker cable wire together outside the speaker---a/k/a the Ric Schultz (EVS) method. I don't want to do that, as I have multiple speakers I connect my speaker cables to, and I'm just not gonna mod them all. I mean, I like and want good sound, but I'm not a fanatic!

 

RE: Consider a compromise?, posted on June 26, 2017 at 17:54:48
Norman M
 It's not so easy to pin down exactly where fanaticism begins. Want "good sound", simply follow the instructions in the speaker's manual. OTOH, want to crap up your speakers, follow some of the suggestions here.

 

RE: Consider a compromise?, posted on June 26, 2017 at 23:01:21
BDP24
Audiophile

Posts: 1070
Location: Vancouver, Washington
Joined: September 12, 2013
 Ha, fair enough Norman! I consider replacing the stock Magnepan steel speaker terminals with Cardas binding posts no more radical than changing the stock wheels and tires on a car to bigger wheels and lower-profile tires, a very common customization. My Chevy Tahoe came with 16" wheels and 255/75 tires, front and rear. I replaced them with 20" wheels, 8-1/2" width in the front with 245/45 tires, and 10" in the rear with 275/40 tires. They afford better cornering and handling, just as the Cardas posts will (I presume ;-) provide better sound than the steel speaker terminal tubes Magnepan speakers come fitted with. Solid binding posts alone should be an improvement on those goofy Magnepan terminals, which are imo ridiculous.

 

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