Anyone built an LA-2A's T4B opto unit from junk? i.e. a Nightlight
- Thread starter 777funk
- Start date
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solderspongebob
Well-known member
Hi there! You'll probably want this page: http://recording.org/users/kev/T4B.htm
Also if you do a search on here you'll eventually find an entire thread dedicated to making T4b's, but the conclusion of which was that you have to buy a quantity of silonex optos and test them all to get ones with the right characteristics to behave in a usuable way.
(However, if you find a new way of doing it please let us know - I have a D-LA2A getting slowly built and will eventually need T4b's also!)
Best of luck.
Also if you do a search on here you'll eventually find an entire thread dedicated to making T4b's, but the conclusion of which was that you have to buy a quantity of silonex optos and test them all to get ones with the right characteristics to behave in a usuable way.
(However, if you find a new way of doing it please let us know - I have a D-LA2A getting slowly built and will eventually need T4b's also!)
Best of luck.
SSLtech
Well-known member
Solderspongebob, -you'll probably like the next product which Rochey and I are working on...
Keef
Keef
solderspongebob
Well-known member
Mmmm...tantalising!
I have two T4B opto's built, tested and for sale right now. $100 ea. PM or email me if interested.
---Joe
---Joe
solderspongebob said:Hi there! You'll probably want this page: http://recording.org/users/kev/T4B.htm
Also if you do a search on here you'll eventually find an entire thread dedicated to making T4b's, but the conclusion of which was that you have to buy a quantity of silonex optos and test them all to get ones with the right characteristics to behave in a usuable way.
(However, if you find a new way of doing it please let us know - I have a D-LA2A getting slowly built and will eventually need T4b's also!)
Best of luck.
Thanks SolderSponge Bob! I appreciate it. That's the thing I saw. I'm assuming the connectivity is just the two prongs from the light on one side and the photo cells on the other. But I wonder how it sounds. It doesn't go into much detail there.
solderspongebob
Well-known member
IIRC, the EL panels used in the nightlights don't have a great lifespan, so end up needing replacing after a while.
Some of the members here have put considerable work into DIY-ing T4b's. See here: http://www.groupdiy.com/index.php?topic=19701 - much credit to them too! The knowledge and ability of some of the members here is staggering.
Some of the members here have put considerable work into DIY-ing T4b's. See here: http://www.groupdiy.com/index.php?topic=19701 - much credit to them too! The knowledge and ability of some of the members here is staggering.
punk
Well-known member
To 777Funk,
as for the sound of the t4b I built at http://recording.org/users/kev/T4B.htm with the vactrol and 115k resistors, the behavior compares favourably to a real t4b. The excel file with the attack and release graph is a dead link, but it was very, very close. The vactrol i used consistently has a fast attack but you'll need to get a few to find one with a slow release like the t4b.
The excel files of the comparison of the vactrol to the t4b were done by joe electro some time ago, thanks joe.
Honestly, in use, I have 2 which have a slightly faster release than the t4b which I quite prefer for the type of material i record. I use the la2 with the real t4b for bass guitar and not much else. vocals go through the vactrol.
you could build a handful for $20, so probably best to decide for yourself.
byron
as for the sound of the t4b I built at http://recording.org/users/kev/T4B.htm with the vactrol and 115k resistors, the behavior compares favourably to a real t4b. The excel file with the attack and release graph is a dead link, but it was very, very close. The vactrol i used consistently has a fast attack but you'll need to get a few to find one with a slow release like the t4b.
The excel files of the comparison of the vactrol to the t4b were done by joe electro some time ago, thanks joe.
Honestly, in use, I have 2 which have a slightly faster release than the t4b which I quite prefer for the type of material i record. I use the la2 with the real t4b for bass guitar and not much else. vocals go through the vactrol.
you could build a handful for $20, so probably best to decide for yourself.
byron
