Bottlehead Kits > Seduction

Seduction transformer mounting

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Doc B.:
I have mentioned before that the Seduction is the oldest of our current production kits. There have been quite a few minor changes over the years, most of which are documented in the current version of the assembly manual. Some capacitors and resistors you get with your kit will look different than those in the manual, but they are actually better quality. The biggest change that is not documented in the current manual is that the power transformer no longer mounts on the nylon standoffs. Instead of standoffs you now get some black fiber washers to fit over the mounting holes and a couple of extra screws. So you can mount that power tranny right to the underside of the chassis and be happy.

Modmad:
I received mine with the trans ready to fall off - and it did in my hands when I wiggled it - in a *factory*, not buyer, *built* non-kit w/C4S - that I traded a couple of my old demo cables for. The phono stage sounds very nice and nicer now with quickie upgrades I immediately made to it (more coming as the caps not in stock get here) but the trans mounting, stock, is mechanically bound for trouble leverage vs the tiny shoulder standoff isolators wise, and was deep in it as it arrived. The trans was klunking around, loose! I don't just repair stuff like this, I mod stuff - making things *better* is my way. I fixed the mechanical disadvantage problem - weight/leverage of the trans vs the tiny shoulder isolators by isolating the trans vibrationally at the same time. That top plate has a microphonicity problem anyway (understatement!). Did it with simple leftover Sorbo strips from my junk parts bins the width of the trans base, under, and the mounting ears size, over. And thread-locked the mounting screw/bolts w/removable lacquer (not in the pics - later step) - something that should have been done at the factory or by any kit builder in the first place! Those nuts will always work loose during any transit without this in stock form and with the certain-to-be mechanically troublesome arrangement I received it with. Have pictures of the mod, two of them attached to show the trans mounting upgrade.
 
Also vibe damped the underside of the top plate (not visible in attached pics). Not enough help, still too microphonic. Will be adding a constrained layer arrangement on top when I find a nice looking piece of black acrylic I want for that. Had to fix this up, quick. Traded for this because my phono stage just died, to add to the other two on my repair list and Harry Weisfeld (VPI) is coming here soon. Hate fixing, am into upgrading and trying new stuff. Didn't want to have to use my Krell phono section, modded or not, or others I have still working. Those are too sterile sounding.

Modmad
KWA

VoltSecond:
If you are using tube shields, remove the spring in side them.  You still get the shielding and it cuts the microphonics.

http://www.siteswithstyle.com/voltsecond/Foreplay_grommets/Foreplay_grommet.html  How I mechanically isolated the transformer in the Foreplay.

Doc B.:
Gosh I feel so inadequate now.

Paul Birkeland:

--- Quote from: Modmad on February 19, 2013, 05:56:12 PM ---\That top plate has a microphonicity problem anyway (understatement!).
--- End quote ---

I could have sworn that tubes are microphonic, not sheets of metal.

The twisted pair of black ground wires does not look factory built, by the way.

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