Speaker run-in/burn-in/play-in/....

Last week I had a moment of pure joy and happiness right before I entered a state of shock and a few hours later some kind of relief.
Pure joy and happiness: finishing my DIY speakers.
State of shock: hearing them for the first time.

I got some nice ingredients like ScanSpeak 18WU-4741T00 and D3004/664000, Mundorf copper foil coils, Jensen copper foil capacitors for the tweeter and Clarity Cap ESA for the midwoofer side of the crossovers and Kimber 8TC for internal wiring and birch multiplex. Crossovers are piggypacked in seperate, decoupled wooden boxes on the back of the cabinet, speaker cables directly soldered to the crossover avoiding cost and possible soundloss from whatever terminal.
I put on a record, turned up the volume and my happiness was gone.
No bass, awfully harsh highs and dominant mids that made everything sound hollow. After spending a lot of money on parts and a lot of time on refinement of a given design it's horrible to get the feeling you could have gotten other worldly better speakers for half the money in one afternoon without construction time, dirt, effort and all that. But hope was not all lost, so I connected my computer to the preamp and fed my system with pink noise and left for a few hours.
I turned on some music and had the feeling there's potential for a happy end. Emphasis on mids gone, highs sweeter, still little bass. What made me uncomfortable was that the midwoofer on the one speaker was moving a lot less than on the other. I checked my crossovers, found no wiring mistakes and kept wondering.
Then I put my hand over the tweeter. On the one speaker the sound changed a whole lot, on the other I wasn't sure if it did at all or if I tried to imagine it.
A day forward I put on my reference record (Old Man Gloom - Seminar II DoLP). Not the expected weight the vinyl carries. But the chassis on the left and right speakers finally behaved the same. Which I double checked with some mono recordings like the days before.
A few days on with more pink noise and various records at various volumes I'm getting happy again and growing extremely curious about where the changes for the better will stop. Jensen claim 600 hours maturing time for their paper in oil capacitors so it won't get boring.

I have been playing around with the "paddle" the tonearm is mounted to. Originally I had planned to mount a double paddle, one on top, one on bottom and connected to each other. I went for the single paddle, damped with bitumen on the underside. Now I tried various feet, spikes, blocks of wood, POM and cork between the paddle and the rack. Changes in sound: none. Quite interesting. Maybe it's a sign that my system is at it's upper edge., maybe I'm deaf or maybe by accident my tonearm is VERY well constructed as is.
Apart from that I spent the last six or so weeks calculating and building a new pair of speakers. Details and picture are to follow.
Record currently playing: Phillis Dillon - One Life To Live 12"

Special post for Michael Lim

Ok, I ripped off Funk Firm's mighty Vector Drive. But as stuff like this is common knowledge for engineers I still can sleep at night. I wrote some place else that my turntable wasn't built for looks and this pictures are proof. Whereever precision was needed I did my best to achieve it. my measuring devices are in the 1/100 mm range and I used them a lot.


For best results mount the motor pulleys so that their outer contact points to the belt are in the exact same distace to each other.


The extra pulleys are bearings with ceramic balls. The seals on the inside are removed, two bearings stacked on a screw, a slim washer is added so the nut doesn't rub against the bearing and the whole thing mounted on the plinth.
I can't comment on any improvements in sound quality because this turntable was built like this from the start. But I can tell you it doesn't sound bad at all.

Where can you go from there??

I exchanged the old felt mat with a Funk Achromat. Slight but noticable improvement in sound and no more static discharge. Very nice.
And as I'm still in the process of listening to ALL of my records again there are still no photos. Which isn't so bad as the finished turntable isn't exactly beautiful. It was built for SOUND and it does just that.

Busy busy busy

Soooooo kids, no new photos or postings as the first record is spinning!!!! Hawkwinds mighty Space Ritual is spinning on my new turntable, going through my tube preamp Jürgen van Look built and my Manley Mahis.

Ingredient Bonanza

So far we added aluminum (7075 T6 if anyone cares...), slate, brass, lead and epoxy to the mix. Stay tuned for POM, bitumen, stainless steel, bronze and ruby. And ceramic. And rubber. We're getting close to putting the mechanics together. Oh, and there will also be some carbon fiber to fix a problem that occured because I changed the original design about a gazillion times sice I first started.

More resonance control

Brass, slate and underneath some hidden lead. A few days back I posted a picture where you could see the slots I machined into the basic aluminium piece of the turntable. These will be filled with this mixture and epoxy. 70% slate 10% brass 10% lead in 10% epoxy. It then looks like this:


Metal has a "ring" to it. Which is bad. Filled with this goo the ring is gone. I took the idea from swiss machine tool manufacturer Studer who invented their trademark GRANITAN in the seventies to substitute cast iron as the material of choice for machine bases. For detail why and all that check wikipedia and the Studer site. As the name implies the mighty GRANITAN is composed of granite and epoxy. As slate is highly regarded in hifi for base plates I used it instead of granite. No deeper thoughts or calculations are behind this, just the feeling it won't be totally wrong.