Progress Report Leo Bodnar clock inside R26 - full shield around PCB
I did add another piece of aluminium tape directly under the LB clock chip before trying the full wrap, seemed to tidy the sound further. (see first pic)
I made up the full sleeve shield using 0.5mm card with aluminium tape adhered to one side and wrapped around edges. This was Lidl beer six pack packaging, no expense spared, seriously though, it's good quality strong board with a printed side which enables the tape to be peeled off if you make a mistake).
Size of shield was 84.5x51mm x2 top and bottom, 15x84.5mm x2 sides.
LB machined end plates were used as templates before getting a scalpel out to cut the holes, and the card was trimmed to size after cutting all the apertures to 16x 51mm before wrapping with aluminium tape. I used the same principle of construction as the LB PCB Ali extrusion and relied on the clamping nuts on the BNCs and antenna to secure the ends. This way the PCB is completely wrapped in shielding and reasonably easily slid out once one end is released by unscrewing the nut/s.
Just so we are clear, the reason I have to make a new shield from scratch, the LB supplied sleeve in extruded aluminium is just too tall to get into the R26. (Available height in the area above the clocks' motherboard connection is just 19mm not 23mm - LB finished product)
On first listen there wasn't a huge difference, this may be because I'd already applied direct shielding cup on top of the LB clock chip and then below as well as the damping pad adhered onto the clock chip and that's given the lion share of any perceivable improvement. These mods was left in place under the full wrap.
If anything I'd say the sound was slightly more solid.
I have to give it a few days listen now to do the mod justice and listen to the usual suspects.....
On a footnote, I don't think mentioned, I did try a very good audio LPS on the LB, one from an Avondale Preamp which I had to use a buck convertor to ramp down the DC output to 7.5v from 18v, which isn't ideal, but sure enough with a more audio refined power supply, (Les W uses many tricks of his trade to gain better sound) there was more solidity to the sound, you were more drawn into what was being presented, it was subtle but you hear the difference when the ZeroZone is put back in. However, these Avondale LPS's aren't available off the shelf, if they were they would be pricey. I would still say that the LB is not that fussy over power unlike other components can be.
I just wanted to hear the difference that a really well designed audio LPS can make.
I might try a SMPS!
(LB for scale)(LB for scale)
