Any mods to do to C414 ULS?

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Khron

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The XLR connector is a bit loose. Not terribly so but there's a noticeable wiggle. What do I need to do to fix it? Tightening the Phillips head screw doesn't help.

If anything, isn't it good that it IS compliant, as opposed to having the pins fixed and stiff, and have them under tension / stress every time a connector is plugged in? As long as the ground-screw makes good contact with the housing... 🤷‍♂️
 

Icantthinkofaname

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*
If anything, isn't it good that it IS compliant, as opposed to having the pins fixed and stiff, and have them under tension / stress every time a connector is plugged in? As long as the ground-screw makes good contact with the housing... 🤷‍♂️
As long as the connector doesn't break I guess. It's the only mic I have that has a connector like that, so it's not something I'm familiar with.

On the plus side, the mic's self noise is very low. It seems to have less noise than my CAD M179s and Sennheiser MKH 8050 just going by ear with preamp at the same gain. I'm just judging by ear and how much hiss I hear. I'm also a bit surprised at how small the C414 is, which is actually a benefit for me cause I like being able to be a bit more efficient with space.
 

kags

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Nov 2, 2019
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Has you guys actually used the Jim Williams modded B/ULS? I my experience and opinion, it actually is quite an improvement here. Wish I owned one before he self-retired from mic mods. He emailed me exactly what he did for them though.
I had an Audio Upgrades 414 B/ULS at a studio I used to share and it was a very good mic- more useful than other 414s. If I remember correctly it had a low output level, but that wasn’t a prob. This was the 90s when the 414 B/ULS wasn’t yet a collectible investment. I wouldn’t mod one today…
 

Icantthinkofaname

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Has you guys actually used the Jim Williams modded B/ULS? I my experience and opinion, it actually is quite an improvement here. Wish I owned one before he self-retired from mic mods. He emailed me exactly what he did for them though.
Can you share that? I don't think I'll do anything to mine cause I'm liking it as is, but I don't think the forum he posted the process to is around anymore.
 

Recording Engineer

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Even better, his original post!
Jim Williams C414 B/ULS & TLII Mod:

“Oh jeez, folks! Can't we all just get along? To restore peace in the audio world, here it is:
First, you're gonna need a high end desolder tool (about $500). Remove the transformer. Remove the 470 pf and 100 pf yellow polycarb Wima caps. Remove the 220 uf output cap. Remove the 47 ohm resistor on the output. Remove the resistor up againt the outside 470 pf yellw Wima. Install it on the back of the pcb. Looking at the TL2 preamp pcb print, install 2 47 ohm 1/8 watt Roederstein MK-1 1% metal film resistors, matched to .1 % or better. Use a precision 4 1/2 digit meter or better. Install 2 1 k 1/8 watt matched resistors by the trim pot. Use Roderstein MK-1 or better. Install the 2 output caps, one on each pcb as shown. Use Panasonic 270 uf/50V FA series. On the filter pcb, install a 1N4148 diode next to the filter caps. On the back of the pcb, put a Wima .01 250 V MKP-2 cap across the .22 uf white mylar cap. Put a MIT Multicap .1 uf 200 V PPMX across the .33 uf mylar cap. It will fit if centered at the middle of the pcb. Place another .1 uf 200 V PPMX MIT cap across the 270 uf Panasonic. It will slide in where the old output cap went. Back on the preamp pcb, put a Wima 100 pf 2.5 % 800 V FKP-2 where the old yellow 100 pf pad cap was. Put a 470 pf 2.5% FKP-2 where the old yellow 470 pf was, the one on the outside edge of the pcb. Now re-assemble the cards together. Re-install the removed pattern select switch with the 2 screws. You now have room to put in the other 470 pf Wima cap in. Set up a DVM on DC volts and probe the center pin of the 3 pin board connector. Trim voltage trim to 62 volts, DC, + - 10 mv. Coat the preamp inputs, new caps and FET with a thin layer of polystyrene comformal coating. I can provide the parts, most of which are custom made, but no guarantees if you have problems. You will also need magnifiers as this is tiny stuff. You must use SN 62 silver solder or better. Clean off all flux but don't spray anything near the capsule! One last tip for all 414 B owners: the supplied wind screen is covered with a fabric that sheds fibers, all new mics are packed in them and all have fibers all over the capsule. You can remove them safely by fraying the tip of a Q-tip to a fine tuft, then carefully and very lightly brushing/dragging the fibers off. Really helps the air on top.

Jim Williams Audio Upgrades
http://www.audioupgrades.com
 

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