Level Lock 500 series

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Eliani

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Joined
May 27, 2011
Messages
240
Location
Belgium
100DP1T1B4M7RE
100SP3T1B4M7QE

these are the switches I used, they are not often available, but most right-angled dpdt and spdt switches should do the job.
the footprint for an LL1528 transformer (or LL1935 in reverse) was put there in case people would like to use a low impedance input compared to the 50kOhm of the ina134. I'm sure you could wire in an original Shure microphone input transformer.
 

groselicain

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Joined
Feb 9, 2009
Messages
170
Location
Tennessee
Oh, great idea - I've got a shoebox full of those bad boys as well, so I'll give that a go!
Be sure and report back on your findings. For now I went ahead and populated the board with the standard BOM, but I'd love to get as close to the sound of the original as possible.
 

AllMixedUp

Member
Joined
Nov 15, 2020
Messages
22
I too have received my boards and can vouche for Eliani. Quality is high and shipping (even overseas) was fast - and he’s a helpful dude.
 

Eliani

Well-known member
Joined
May 27, 2011
Messages
240
Location
Belgium
Thanks guys for the nice replies!!
I try to help everyone with building their level locks! So a couple of pointers…

- Don’t forget to jumper (jumper or wire)
UB-send to UB-send1
UB-in to UB-in2
UB-ret to UB-ret2
UB-out to UB-out2
These are points for switching/testing purposes. If you look at the schematics you’ll see that you could take the blend option out of the schematics.

- THAT chips are far more superior to original INA134/DRV134 chips.

- If you are using anything else then the original transistors be sure to have a look at the orientation and pinouts, i know for a fact that if you use BC550C’s they need to go in reverse oposed to the silkscreen footprints!!

- Be sure to check my ‘errata’ pictures because I messed up on two tiny places on the silkscreen!!
The names R11 and R2 did not get neatly placed, so they appear to be in each orthers footprint.
The names R42 and R43 did get neatly placed but got be switched around.
 

MonoCutter

Member
Joined
May 16, 2016
Messages
7
Thank you very much! Mine arrived as well and i have nearly all parts at home.
The most time consuming step should be the wait on the THAT chips from china. :unsure:
 

z11111

Member
Joined
Jan 1, 2021
Messages
11
Location
USA
Found some toggle switches on eBay from the same seller in China that will likely fit the footprint: SPDT and DPDT - measurements aren't great but are prob close enough? I found DPDT on-off-on and SPDT on-off-on from Farnell in the UK which look like they fit, and JLM in Australia has the on-off-on dpdt,

Haven't dug into Mouser or Digikey yet to see if there are any sources in the USA but found a drop in DPDT on-off-on from Newark here with the same footprint as 100DP1T1B4M7RE. Personally, I have tons of solder lug mini toggles like this so I'll probably just run wire leads from the pads.
 
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