LA-4 Help Thread!

[Betastalker]

Hello. New user and returning DIY builder.

I recently got 2 unfinished units.1 GSSL and 1 dual LA-4. A decent amount of work was put into them already when they arrived. But LA-4 needed A lot of work, but saturday LA-4 was finaly finished.

Up and running :

Now i have to make sure it sounds as close to the original as possible, any tips or ideas?

Regards. Caspar

 

[shot]

First of all... just a gentle bump on my last question http://groupdiy.com/index.php?topic=32615.msg716303#msg716303
If someone has a solution I'd be thankful!

Now for something completely different!

I've built my third LA-4 almost year ago, but I've never put it into an enclosure. It's still in the shoe box waiting to be finished.
It crossed my mind I could maybe combine it with Studer 169 EQ (project by Audiox - http://groupdiy.com/index.php?topic=33996.0)

I was thinking connecting this EQ just before the output transformer on LA-4, and using 169 EQ without balancing/debalancing circuit.
Now before I try it, is there any reason why it wouldn't work?

 

[peterc]

Hi all

I am using one of the small 'Behringer' type meters on my 500 series build, and have had to wire the meter the wrong way.

On the schematic, the opamp driver goes to the - side of the meter, and the + side is grounded. However, mine would work like this, I had to swap the connections. Anyone else had this issue?

I am only using it for gain reduction, as I have an LED meter for input and output.

Peter

 

[gyraf]

On these cheap chinese meters, "marked polarity may differ"

Jakob E.

 

[peterc]

Okaaay! Thx Jakob

 

[kml23956]

OK...I have read this thread an can't figure out if there is a consensus on which VTLs to use? Is there one?

 

[gyraf]

Putting VTL in above "smart search" box finds e.g.:

I am using the VTL4C4/2 and it sounds pretty good to me.  (..)

Finally I tried a Vactrol VTL5C4/2 as in my other unit and it works nicely now, the ratios gives me the expected compression. (..)

 

[peterc]

kml

If you have a look at the LA-IV doc in the first post, the VTL5c4/2 seems to be the most accurate replacement.

This is what I used and I am really happy with it.

Peter

 

[Gustav]

kml

If you have a look at the LA-IV doc in the first post, the VTL5c4/2 seems to be the most accurate replacement.

This is what I used and I am really happy with it.

Peter

I found it to be the only that was useable in the bunch of that type.

Gustav

 

[ilfungo]

Hi  kml23956
Also for me  (I have 2  real silver face LA4)  Vactrol VTL5c4/2 are the nearest...

 

[kml23956]

That was very fast. Thanks guys.

 

[Slabbefusk]

Hi Guys!

New user here. I got a question from a friend if I could make him a PCB or two for this project. Are there any files available for printing films for etching etc.? My Google-fu is not helping me much today.

Any help is much appreciated!

 

[Richmix]

Hello, just asking , anybody have the specs on the original photo element used in the LA4? I've never seen it mentioned anywhere….
Great data from all the posts here...

 

[gyraf]

Bo Hansén says (last post):

http://recording.org/index.php?threads/vactec-replacement-for-la4.40706/

 

[Whoops]

Hi,
I would really like to do this project.

Is there any chance that anyone has boards that might not use and could sell me?

Thank you so much

 

[Script]

Boards used to be available from forum member Gustav, who recently started a website/shop called PCBgrinder. Look at his "Hand of Light" compressor. Similar/same(?) thing -- maybe compare schematics.

 

[gyraf]

Yep, I think HandOfLight is the same, but on a pcb that's easier to work/understand.

Jakob E.

 

[Whoops]

Anyone knows a source for Vactrol VTL5C4/2?

Or if you have any spares to sell please let me know, would need 2 for my LA4A build

Thank you

 

[culteousness1]

Check Volker's WM thread for the vactrols.

Cheers,
Carsten

 

[gyraf]

Afaik, market has been vacuum-cleaned for every VTL5C4/2 out there - prices raised to insane heights just after it was clear that the production was discontinued (because of the EU ban on the optical cell).

If anyone knows of a good-priced stack of them out there, let me know: I know a guy who'd want them (for spare-parts)

I recently had to discontinue my G2 recording channel AND my G3 optical stereo comp - because of this issue...

Jakob E.