All things G1176 - the new "repost" thread.

[Rob Flinn]

i have a voltage on m+/m-
value depends on unit bypassed (0)
or in gain reduction mode and adjustments of
gr pot and tracking pots on pcb...

The easy way to check whether you have a faulty meter is to check it out of this circuit like I said in the previous post. If it works when you you hook it up to maybe a CD player, then you know you have a fault with the 1176.

Does your 1176 pass a signal? If you have the meter switch set to output then the meter is just connected to the output of the 1176. If the 1176 is passing audio & you have proved the meter to work out of this circuit then it is likely that you have a problem with the meter selection/bypass board of wiring.

In gain reduction mode the mater action is affected by all the things you said, but also the FET byass adjustment.

 

[romeojesus]

my g1176 works good so far and seems to be ok!

i connected the vu to the headphone out of my
amp and cranked it up....

vu meter does not move

 

[Rob Flinn]

i connected the vu to the headphone out of my
amp and cranked it up....

vu meter does not move

Then I think you do need a new VU meter !

 

[romeojesus]

****...

thanks for your help!

 

[jrmintz]

Hi Everyone,

I fired up my 1176 and no joy. I only seem to have signal as far as the base of Q2, and odd voltages as follows:

Q2:
E .102
B .098
C .818

Q3:
E .189
B .818
C .255

Q4:
E .109
B .255
C 30.4

Also, the empty 5532 socket has +15.2 on pin 3, +15.2 on pin 5, and +30.4 on pin 8. All the others have 0. That's not right, is it? I've measured resistors around this area and they seem OK, and I changed Q2 but that's not it. The unit is not passing signal and starts to oscillate on the highest input voltage setting. Does all of this point to anything?

I have to go now, so I don't have time to get more voltage measurements, but I will later.

Thanks

 

[jrmintz]

*Bump*

 

[gyraf]

Seth,

- check supply voltage after R17 - should be some 25V
- double check for component values (spec. R17 - 6.8K / R18 - 22K)
- double check for pcb shorts
- check Q2-3-4

Jakob E.

 

[jrmintz]

Thanks Jakob

:thumb:

 

[keithcamilleri]

Hi JaKOB,

on the G1176 PCB there is a capacitor just before the Trafo outpu it is a 470uf ....on the PCB layout it printed as a 40V cap (the list said 35v), I used a 35v audigrade cap is that ok?

 

[gyraf]

35V is fine for the output cap. There'll never be more than 30V across it anyway.

 

[keithcamilleri]

thanks jakob :thumb:

 

[yan_b]

near the q bias there is 1000/35v cap, marked as optional (*), is it really optional, and if so souhld it be bypassed?

 

[gyraf]

The "optional" 1000u cap close to the output stage is a good thing to have as it serves as local reservoir for the output stage. If you leave it out, at least mount a 100uF/35V here.

Jakob E.

 

[keithcamilleri]

Hi guys

I am not surer that I bought the right toroid will this work on the 1176

25V-0-25V 160VA Toroidal Transformer

thanks ...

 

[Rob Flinn]

I am not surer that I bought the right toroid will this work on the 1176

25V-0-25V 160VA Toroidal Transformer

Yes it will work.

It is heavily overated for the job, but it will work.

 

[Gustav]

Not to rush it or anything, but I am making these boards 10 at a time right now, and I can see I will be out on the next shipment again. any updated on the revision ?

Gustav

 

[gyraf]

Sorry, not finished yet...

I'm getting too many orders for Gyraf stuff right now - but it's on top of my to-do list...!

Jakob E.

 

[Gustav]

[quote author="gyraf"]
I'm getting too many orders for Gyraf stuff right now
[/quote]

Excellent !
Dont worrie about it. Most people should be able to handle a scalpel. Im gonna make a decent size batch this time.

Gustav

 

[yan_b]

in the part list there is two 220p ceramic caps , and two 220p poliyesters caps, now in the layout (i saw a qustion in earlier post but without exact answer) there are one 220p beneath ic2 (5532) and two 200p above q3, and the two 2m2 resistors.
one 220p i could not find at all (maybe a mistake?).
now wich should be ceramic and wich should be poliy, if it's matter at all?

 

[gyraf]

The two 200p's paralleling the 2M2 resistors R7 and R9 should be 220p polyester types. The others ceramics.

Jakob E.