Help with Modutec Meters for G1176

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pigsnoot

Member
Joined
Dec 26, 2009
Messages
19
Location
Belgium
So I'm working on a "cloned" gyraf 1176 board and case, and I have a modutec meter but I can't understand how to hook it up? It just has two terminals on the back, is it for the light AND the VU? Sorry if this is a stupid question, I couldn't find it in a forum search...

Also are there standard pot values for all revisions/boards? Or is this case sensitive?

I'm a bit confused about the output pot hookup, I saw different hookups for the 15-16-17 pads to the pot, I'm not sure how to hook it up on this "fake" PCB I got...

Man I'm starting to think this Is'nt so easy as I expected with these "unknown" boards.... :eek:



 

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If you have only two terminals on the meter, then it is the connection to the meter only and you don't have lamps/LEDs inside. You will probably need an extra illumination set if you would like to have them lit.

Did you compare your board with the 1176 schematics available on this site? As far as I can see on the picture, all connections for the pots are clearly marked on the PCB. You can find the values in the corresponding schematic. Doesn't the documentation you received with the PCBs mention the right values?
 
he bought these pre-stuffed, no documents provided. Just follow the values on this schemo. Should be okay.

http://gyraf.dk/gy_pd/1176/1176sch.gif

As for how the pot hooks up, top to 15, wiper to 17, GND (use the shield of a 2 conductor shielded cable) to bottom of the pot. With the schemo in hand, it's pretty much paint by numbers.

Normally this should go in the 1176 help thread, but this is a strange case with an unfamiliar PCB design and would be cluttered and lost there, so probably best kept separate.

Keep the questions comin, lets get this thing finished!

EDIT: PS, do you mean the meter has two separate 2-pin hookups? Then yes, one for meter, one for lamp. Should be fairly obvious which is which. I used a jewel modutec on mine, and it came with an external bridge recto to make it an audio meter, make sure you have a rectifier internally, or get/build a recto externally, or the thing won't work... which meter did you get?
 
Hey Guys thanx a million!

my meter looks like this on the back



I guess It's not illuminated then...Dang! Is it even possible to get inside these meters and put in a lamp? looks tricky

I also have the 25k Attack pot with spdt, I can't find it on the schematic and there are no real directions on Mnats gyraf site how to hook the spdt up, any ideas?

And then there's the pushbuttons that are mounted on their pcb's... It seems to me the "power" knob is not designed to handle 230v :
foto85n.jpg


Anyway thanx so much for helping out! I think I will be able to finish this with the help of you guys!

I'll keep you updated and will post some pics of the whole thing
 
It seems to me the "power" knob is not designed to handle 230v

It certainly isn't. But this does not mean it can't do the job. After all: how much current does it have to switch?
I have seen those switches in commercial equipment used as mains power switch without problems.
The only thing you should take care of is good insulation from the chassis and low voltage parts of the circuit.
 
The transformer I have is 230V 30VA 2X22V you think this pushbutton can handle both live and neutral switching?

About the Modutec meter, is it even possible to build a light inside that thing?
Thx!!
 
Isn't 30 VA a bit much for an 1176?
The problem is that the initial current when switching on a torrodial transformer is rather high, compared to a 'normal' transformer.
I would switch only one leg of the primary and use the two sections of the power switch in parallel.

About the light: no idea for that specific meter...
 
As for the light...does that meter have a flat panel on the front, or does the clear window have top, bottom and sides to it? You can usually fit a lamp UNDER the window if it's the latter. Or maybe a strip of leds.
 
Put it together yesterday, and to my surprise It's working!! BUT ...

The Attack SPDT Switch is weird, the compression kicks in in the "off" mode

And the release knob goes from slow (ccw position) to fast (cw position) ??

maybe I switched the 123 position on the lugs and put the resistor and cap on 2-3 instead of 1-2 ? or is it normal it goes from slow to fast?

SO maybe that's why the attack knob is only working in the off position too...

Then I'll have to calibrate, but I don't know sh¨t about that :) Is there any good tutorial online about calibrating a 1176?

Oh yeah and no lights in the meter, but I don't really care maybe....maybe I'll hook up a strip of leds somewhere
Thanx guys!!!
 
Fixed it!

Damn thing is working as it should!!

Happy!

Also found a calibrating video of Mnats on Youtube

Now I'm off to building the second one!

Cheers
 
SWEET... glad you got it running. My first 1176 had some real head-scratchers. One, because my jewell modutec meter already had a series resistor built into the recto, so I was adding the external 3.6k and that was screwing with my readings, making it impossible to calibrate. Another, because I had the 6.8k tant capacitors in backwards (the only type of cap I've ever seen with the ANODE marked with a stripe rather than cathode).

Good to see you soldier through!
 
yeah I'm really lucky the guy soldered everything in perfect! :)
The hookup was quite straight forward following the Rev J Mnats wiring, I just added Two bright white leds above the meter and calibrated using an external vu meter, but all went very good! I'm really happy with it!
Thanx for the tips and steering me in the right direction!
M
 

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