Langevin AM-16 DIY?

[Whoops]

yes, I also have some problems with the search function.
is there any way of searching inside a thread?

it's crazy when you have a thread with 30 pages, and the info you need is somewhere in the middle.

thanks for the info,
going to do some searches on "morning". By the way, why all this secret code names ... ? is there any legal issues involved?
I thought that the patent was so old that had expired already.


Was checking some prices , the sowter trannies are 55 pounds each, so 110 pounds + plus shipping, if you sum PCB and components plus shipping it will probably be the same amount you paid.Off course you still need to spend some money racking them.

Gonna check if I can get some for the same price. Last times I checked they were around $500, and $750 already racked.

thanks.

 

[emrr]

Potential legal issue would be Manley owning the name and the rights, and Mercury Audio making and selling a repro.  No idea on the connection between them.  Though I don't see it as any more of an issue than 1176 or LA-2A boards. 

 

[Whoops]

so basically the code name was just to keep it safe at the time?

 

[emrr]

i assume so.  it was slightly before my time here. 

 

[thomasdf]

I am late after the battle, but interested in any AM16 compatible iron, any pointer ?

@CJ do you still have any of the precious images you uploaded here back in the days ?

 

[thomasdf]

I will answer myself, and share my findings so far : input can be Carnhill VTB2381 or UTM 2581 : 1/2.5 + 2.5
Output is trickier, there is a Carnhill transformer, seems it is wound to specs for AML kits, trickier in that it is a 4 taps primary for 2 push pull style Maybe it can be replaced by two transformers work side by side ?

edit : Sowter has them, too, here are their specs :

Input :
9775
1Ct+1CT : 4+4
50,150,600 / 2K5 + 2K5

Output :
9765
1+1+1+1:1+1
600/150,600

 

[Whoops]

I am late after the battle, but interested in any AM16 compatible iron, any pointer ?

There's only 2 options,
but both are really good. Cinemag and Sowter

Cinemag should be a good source because it's said that the original Langevin AM16 transformers where designed by Reichenbach Engineering. Later on Ed Reichenbach was the founder and owner of Cinemag.

CM-28121

Langevin AM-16 input transformer (See CM-28122)

CM-28122

Langevin A M-16 output transformer (See CM-28121)

Sowter also had AM16 compatible transformers:

 

[thomasdf]

Thanks a lot. I have written to Igor / UTM to ask him about that.
Cinemag would be awesome for sure, but lately post Brexit and all, buying from the US and UK has been disappointment over disappointment... Crazy crazy taxes + carrier taking fees over the taxes, arg.
I was thinking of going 500 format, so I think I should try to see if I can source the Cinemag PCB mount style in Europe.

It could be done 51x and run on 24VDC, or 500 format and run on +/-16VDC, like the AML does.

 

[zzzzz]

Thanks a lot. I have written to Igor / UTM to ask him about that.
Cinemag would be awesome for sure, but lately post Brexit and all, buying from the US and UK has been disappointment over disappointment... Crazy crazy taxes + carrier taking fees over the taxes, arg.
I was thinking of going 500 format, so I think I should try to see if I can source the Cinemag PCB mount style in Europe.

It could be done 51x and run on 24VDC, or 500 format and run on +/-16VDC, like the AML does.

Cinemag has the whole schematic and everything as a pdf on their site. Was thinking about DIY-ing this a while ago but didn’t make any moves on it. Too many projects…

https://cinemag.biz/application_notes/PDF/AN-107.pdf

Kinda awesome you can run it on a single +24v rail. Grab a Power One linear module and you’re rockin or even a SMPS with appropriate filtering tbh…?

Edit: haven’t really looked into it at all but another idea to get a more “authentic” version in terms of power could be to get the AML kit but instead of running it in in a 500 rack, build it out in a regular chassis enclosure with an edge connector and hack a +24vdc rail into it. Idk what the schematic looks like though.

 

[thomasdf]

AML kit is 500 format so +/- 16VDC. The original design is +24VDC, but I suppose that with +/-16 you get more headroom ?

I am on holiday next week and I'll take the laptop with me, to work on the PCB design... to be continued. I haven't found a 500 / 51x blank card that I could open in Eagle yet.

 

[zzzzz]

AML kit is 500 format so +/- 16VDC. The original design is +24VDC, but I suppose that with +/-16 you get more headroom ?

I am on holiday next week and I'll take the laptop with me, to work on the PCB design... to be continued. I haven't found a 500 / 51x blank card that I could open in Eagle yet.

I have a 500 series Eagle lbr that I use and I think a 51X too that I got from somewhere (untested because I don’t have any 51X racks). Will PM you later.

 

[thomasdf]

All right, thanks

 

[Brian Roth]

AML kit is 500 format so +/- 16VDC. The original design is +24VDC, but I suppose that with +/-16 you get more headroom ?

I am on holiday next week and I'll take the laptop with me, to work on the PCB design... to be continued. I haven't found a 500 / 51x blank card that I could open in Eagle yet.

Colin (AML designer) used a rather large of "array" of resistors on the negative 16V rail to drop the voltage. Four 130 Ohm 5 Watt R's in a series/parallel configuration. Net resistance is 130 Ohms.

It's been awhile since I was poking around in one, but I believe the R's resulted in an 8 Volt drop on the negative rail, resulting in an overall 24 V supply. He did a similar design with the Neve modules he sells....but used a 3 terminal regulator for the voltage dropper instead.

Bri

 

[Whoops]

I have a Chae (old Prodigy Pro owner) PCB from the Langevin project that was on this forum many years ago.

The circuit is true to the orignal, each PCB has 4 Mic Preamps section plus a PSU.
The Mic Preamps sections can easily be cut in the PCB to make individual channels.

I will only build 2 preamps, so I can cut my PCB and have 2 Preamp section available if anyone is interested.
It's an high quality PCB and I have all the documentation for this project.

So if anyone is interested in a PCB for 2 channels pleasa PM me.

 

[thomasdf]

Ok, I am officially done with Eagle, haha... Moving to Kicad ! Which means I need to find the 51x / 500 blank in Kicad format, and no luck so far. I have tried converting Eagle lib to Kicad, but no super convincing, yet.
To be continued

Edit : found 500, not 51x. Working on it