QUAD 63 (and later) Delay Line Inductors

Hi Jan,

I have been googling a little bit after reports from ETF 2022. However, I have failed to find anything with you and your DD Quads. Was it only a presentation you gave?

Here is a link to Holger Barske's flickr album. Seems to have been a nice event. ETF 2022

Mogens
 
No I also demo'd the set. Maybe Holger missed that.
There were others taking pictures. I will check.
The presentation should eventually be on line but it may be restricted to ETF participants.
It was a nice event, interesting speakers (mechanical and human), and a great venue, an old castle.
What I found less interesting was dragging the large ESLs up 24 steps of stairs ;-)

Jan
 
A few pics of my setup.

Jan
 

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One hour of work, and the coil board was taken out, checked, and reinserted - problem still persists. Another listening test with a signal generator indicates it is the panel on the top of the speaker,....

See attached picture, I checked the DC resistance of all coils in series (only one half shown) and tried to see if rattling them would cause a change, but nothing happened. All coils measured 3.1 ... 3.2H (measured with a PEAK LCR meter at 1kHz).

So, as ESL63 and others said, its the panels, not the coils. Thanks a lot anyway for the help!
 

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Jan-I see you have absorbing panels behind the quads. They help a lot. An important trick I have discovered- arrange the panels to reflect from Quad to the other panel. You get several benefits. First the reflections don't go back through the quad directly. Second you get two stages of absorption and its basically free.