Langevin AM-16 DIY?

[dukasound]

Hi
Where I can find socket for AM16 plug.
Thanks
Duka

 

[CJ]

We had a thread at the old place on this.
Ask Twist Turner if he is still alive. (Drummers lead a hard life)
Only other option I know of is getting stroked for one on EvilBay.

 

[dukasound]

[quote author="CJ"]We had a thread at the old place on this.
Ask Twist Turner if he is still alive. (Drummers lead a hard life)
Only other option I know of is getting stroked for one on EvilBay.[/quote]
Thanks "Richie"
Is this your guitar :grin:

 

[fazeka]

Headstock needs to be the larger 70s Fender type :razz:

 

[CJ]

Yeah, and no middle pickup.

 

[Rob Flinn]

Socket info on this thread

http://www.groupdiy.com/index.php?topic=986&highlight=am16

 

[fazeka]

I forgot about that CJ!

Yeah, Richie would totally lower that middle pickup flush with the 'guard.

Or was that Richie's brother Yngwie?

 

[CJ]

Don't forget the scalloped fretboard.

 

[jensenmann]

What happened to this project? Has anybody built an AM16 or was it done with mirroring the PCBlayout? Which iron did you use? Was there any A/Bing to the original AM16? :?: :?: :?:
This thread was more interesting than a movie and now it ends before the climax. You guys are like the light techs in my company. Some of them think the work is done when the lightconsole is programmed.

Hmmm

Sorry for getting awful

:guinness:
Jens

 

[rafafredd]

I think the only option is the sowter clone irons.

 

[CJ]

Oh, I don't know, I am making a little progress.
Put these thru the wave machine the other day.
Ready to cut, drill, and stuff:

http://vacuumbrain.com/The_Lab/Langevin/am16_pc.jpg

Most of us start ten projects at once, surf the forum too much, pull in parts little at a time, then all of a sudden it's rackmania!

 

[rafafredd]

I got a AM15 comming. I´ll strip the board out and let the transormers seat there with my new DIY board. Those comes with the same transformers.

Nice looking boards, CJ. Let us know how it goes...

 

[CJ]

OK Jens got me feeling guilty, so I took a few hours off to get some work done on the AM.

Milled the boards apart:

http://vacuumbrain.com/The_Lab/Langevin/am_mill.jpg

drilled the holes and stuffed a few 1% metal films:

http://vacuumbrain.com/The_Lab/Langevin/am16_pc3.jpg

http://vacuumbrain.com/The_Lab/Langevin/am16_pc2.jpg

The surplus joint has the 2N5210's at five for a buck, so I think I will drop in.

 

[jensenmann]

:thumb: :thumb: :thumb:
This looks cool.
CJ, you got pretty good tools as I see!
I fear I have to wait with my projects til it´s getting warmer. Right now we have -10deg Celsius, much too cold to work in a garage.
Jens

 

[CJ]

OK, I scored some cool heatsinks for the 16 at the surplus:

and some cool motorolas:

Stuffed some more parts. Got a cool nos old school inductor.
180 uH instead of 220, but no biggy.
Orig vs diy:

the back. bought the wrong value 2 watter!
will fix later

I bought 6 of the motorola output transistors so I could try for a matched pair.

I used a 10k base to collector bias resistor and a 369 ohm resistor on top of the collector.
I used 16 volts dc.

here are the numbers i got.

The values are for volts measured at the collector, base volts, and collector current:



Q1- 6.05 Vc 0.656 Vb 30.75 ma
Q2- 5.25 0.667--32.9
Q3- 4.89--0.687--34
Q4- 5.32--0.694--33.2
Q5- 5.15--0.688--33.2
Q6- 5.33--0.686--33

I used Q5 and Q6 for the pair.

I also pulled out the original RCA's an measured them using the same test:

Q1--Vc 3.847 Vb 0.662 37.7 ma

Darn! not very close to the ones I bought!

So I measure the second RCA and look what I get:

Q2- Vc- 5.62 Vb 0.673 and Ic =32 ma!!! very close! I'm happy.

Weird how mis matched the two RCA's were. Maybe one got a little hot a while back,l or maybe matching isn't important in this circuit, like PRR mentioned.

Some inductor info: the original has a dcr of about 6.8 ohms if you are sourcing. 220 uH

the dcr is important if you don't want a bar b q.

Also, I discovered some neat things about the board.
This guy was pretty clever. The input x-former primary comes back to the output transformer secondary wires at the connector pin.

This minimizes the flux loop which keeps hum low. Also, triple shielded cans. And the input iron is inside the rails for even more reduction.

Also, the input transformer primary, where the mic wires hook to, are brought out to one end of the pc board, run all the way to the other side, and brought out to the connector. Thes are those long traces you can see in the pics. Two of the traces on the top, two on the bottom. Directly over each other. Can anybody guess why?
Why didn't he just wire a cable harness to the connector? This is what is done with the pri centertaps.

Well, I measured the capacitance between traces that were oriented on top of each other and got exactly 75 pf each! Pretty clever. The original board has 83 pf, so this artwork is good. A slightly thicker board is the difference.

Anyway, this capacitance shunts rf and tv noise at the input of the pre-amp. Prety cool. I am glad we decided to use the original board for the artwork.

BTW, the parts for the board come out to about 5 bucks, not counting the board itself.


I'll take the Eagles if you give me 7 points.
See ya!
cj :grin:

 

[MikoKensington]

Not to be a jerk but...

...I'm a jerk. :twisted:

 

[jensenmann]

:shock: :shock: :shock:
All DIY?
Jens

 

[Technetium]

...I'm a jerk.

put those in a proper rack & remind everyone how little u paid for them & then u'll be a total dick :wink:

 

[dukasound]

[quote author="MikoKensington"]Not to be a jerk but...

...I'm a jerk. :twisted:[/quote]
Miko thanks for pic :thumb: .
Now I know how is racked AM16 :grin:
Duka

 

[Gus]

CJ cool find about the traces!!!!!! Now people are going to argue about the dielectric change for different board materals affecting the sound! Ha Ha