All things G1176 - the new "repost" thread.

[intercorni]

Hello,
where can I buy a resistor 1K1 / 1W?

Thanks,

Cornel

 

[Harpo]

use 2x 2K2 / 0.5W resistors in parallel

 

[casrec]

Mouser has tons of them

 

[skal1]

hey lads need some help with my 1176 mnats j board. rotary switch for ratio and meter .



Ok just a minor problem No Compression /attack and release control.


i have tested  all transistor, every things fine  ,voltage are near to those in  the first post  of the thread.

the only thing i am not sure of is ic 1 voltages in the gr stage , has any one got that info to hand

thanks

skal1

 

[gswan]

There are no IC's in the GR stage, so you don't need to worry about that (yet). The IC you are probably referring to is in the metering stage and does not affect the GR amp.

You'll need to probe to see that you have signal going into the GR stage when out of disable mode. Then check to see that it is being rectified and appearing at the attack/release controls.

 

[skal1]

gswan ,


what do i measure these points with a dmm or a scope.

skal1

 

[gswan]

To see the signal I'd suggest a scope. It will give you a better indication of what's going on.

 

[skal1]

ok have not got a scope but i can do some science with sound card and music program, at what point dose the signal enter the gr amp gswan ?..

do not  know if  this  help,  you can see  the output signal on the 1176 meter, that part is working fine .


skal1

 

[dustbro]

i'm having the same problem with my rev F board. what did you end up doing to fix this? which transistors did you need to replace? if anyone has any ideas, they would be much appreciated! thanks,

Replace your BD135/BD136 transistors

 

[skal1]

i'm having the same problem with my rev F board. what did you end up doing to fix this? which transistors did you need to replace? if anyone has any ideas, they would be much appreciated! thanks,

Replace your BD135/BD136 transistors

@dustbro

the vu section is working fine output  transistors are  working fine , the thing dose not want to compress , needle just havor's just below 0db no movement , all voltage are fine , i just can not put my finger on it , it is like the gr control amp is not getting any signal.

now this is what i call a brick wall limmmiter

please some one help been at foer about 10 hour have'nt slept yet, can let it bet me...


skal1

 

[danjpiscina]

Replace your BD135/BD136 transistors

Thanks! That was what it needed. Got her up and running!

 

[gswan]

ok have not got a scope but i can do some science with sound card and music program, at what point dose the signal enter the gr amp gswan ?..

I assume you have a circuit for the module. The signal goes through the 'bypass' switch into the GR amp at point (22), through Q12/13/14/15 and the two rectifiers and out of point (19) into the attack/release pot assembly.

 

[skal1]

I assume you have a circuit for the module. The signal goes through the 'bypass' switch into the GR amp at point (22), through Q12/13/14/15 and the two rectifiers and out of point (19) into the attack/release pot assembly.
[/quote]


ok i understand that ,so assume that ponit 22  gets the signal from pin  y  is that correct ?



ok 1 more ? , is the meter switch 4 pole 3way or 3pole 4way.

thanks

skal1

 

[skal1]

hi ,still no change with this thing , what are the voltages for q1 and q2  theses  should be bf245 ,right

skal1

 

[gswan]

ok i understand that ,so assume that ponit 22  gets the signal from pin  y  is that correct ?
ok 1 more ? , is the meter switch 4 pole 3way or 3pole 4way.

Have you looked at the circuit?
Point 22 gets the signal via the GR bypass switch, which comes from the divider on the ratio switch which is fed from the top of the output pot.

The meter switch is whatever you chose to use for your unit. Usually a 3 way is sufficient.

 

[gswan]

hi ,still no change with this thing , what are the voltages for q1 and q2  theses  should be bf245 ,right

The voltages on Q1 and Q2 depend on the ratio setting and on how you have calibrated the unit. They will be different for each unit so there's no point publishing voltages for them.

The FETs are either BF245A or 2N5457 devices. Did you plot the FET characteristics first to see if the devices you chose were fairly matched?

Have you performed the calibration and gain tests?

 

[skal1]

thanks for suggestions.

it is kind of work now the gr meter is now show downwards movement away from 0 db , i had to turn the fet around but works now, their is still no signs of compression on the output .

skal1

 

[skal1]

hey fix it , the bf245A  was incorrectly soldered. here is a frequency response for my 1176  , do not how to read the finding thou.Measurments taken in bypass mode 0db pink noise .

as far as a can make this has  bandwidth  16hz  to 20khz but it has -7db role off. is their any thing ican do to rectfi they  -7db role off , plus i am only getting -21db.

Heyi might be reading the data wrong so if i am please tell me  , thanks

URL=http://img249.imageshack.us/i/1176frresponce.tif/]

[/URL]


thanks

skal1

 

[Whoops]

Hi,

I'm just finishing building my G1176, although I still need to buy a meter.

I'm building it into a 1Unit rack case,
do you know what meters could I use in a 1U rack build?

thanks

 

[kazper]

Depends on the case used...

AL-19 will work on most if done in a M or B configuration on a par metal 1.44" high case. The meter will not fit inside a par metal case.

You could fit a Sifam AL15 retro on the inside with carful planning or on the outside.

Other meters are available that fit a smaller size. Look up VU meters on Newarks site and you can see a few from Farnell. I have some options in the mix but I'm a ways away... parts are on order...



Kaz