All things G1176 - the new "repost" thread.

[Greg S.]

I got a problem too..
4:1, 8:1, 12:1.. works all fine
Ratio 20:1 seems not working, the Compression isn't taking place.
Signal runs without compression through.

Seems there is a short, but I resoldered any Res and the Cap and cleaned the GR Board!
I measured any connection, resoldered using new Res and Cap and guess, the problem still exists.
Except of the Lorlin!
Now the funny part..

Got the exact same problem by another unit, same Layout too!

3 other 1176ers are working perfect, but 2 not..
it's just the 20:1 ratio that's not working!

Did anyone have/had the same problem?

Gyraf Audio 1176 LN Rev. 8, Gustavs V-K PCB, 11-2012

 

[Olegarich]

does bypass working correctly in 4:1 ratio?

 

[gyraf]

Lorlin end-stop setting problem?

 

[Greg S.]

it's gonna get worser!
My board makes absolutely no compression..
Just the Signal walks through.. 1 to 1

But let me tell..

In and Out works, Attack and Release - Not working
Ratio.. No Changes, so the Compressions is not working - the VU shows nothing.
but the VU shows the Out Level, this works.

I changed the Boards with another unit that works, same revision and same elements to check the Wiring..
This is not the Problem.
I Changed the FETs and both OP's too, still not working!
Thats also not the Problem.
I measured the Voltages, working all too!
Now I'm gonna resold any part again, perhaps there is something broken!

:-\

Which connection/wire is responsible for the GR?

Does someone have an Overlay for MNATS Revision J (Board 7) so I could compare the parts with the schematic!
I'm looking for this for while..
I just got the one with the discrete Values!

THX Guys for any Help or Inspiration

Cheers

 

[Greg S.]

UPDATE!

I got It!

a short between R 35 and R36
I changed both BF560!

et voila!

All the Ratios, all the Punch and Hell jeah! ITS a Monster!

By the way, I'm still looking for an Overlay with the Numeration of the Parts!

 

[s2udio]

Hows This

 

[gyraf]

Is there any reason the original layout can't be used?

www.gyraf.dk/gy_pd/1176/1176.htm

Jakob E.

 

[Greg S.]

THX MATES, you are making my Day 

Do you also got pics from the Ratio- and GR PCB?

@Gyraf
I really, really appreciate your work and all the support you offer.
It helped a lot in building my '76ers.

Got some pcb's from Gustav, the V-K's, based at the F-J Layout and there are the Parts-Values printed onto it.

But I often find expressions like:" R26, or R84." and I'm much faster in finding the correct one for modifying, you know?

 

[EvLoutonian]

Hello all,
    I noticed that on the Mnats board, he has the output transformer wired in series on both the primary and secondary for a 1:2 ratio and 600ohm on the primary and 2k4 coming out of the secondary. Is this more beneficial then wiring parallel on both ends so 600ohms is coming out of the secondary for a nominal impedance. Sorry for the stupid question, but I'm a newb and trying to figure out how to wire some transformers. I'm slowly learning. Thanks Guys!

Brandon

Sorry, i am speaking of the OEP transformers. Thanks again! 

Hey, Casrec.

I didn't see a reply to this old post of your's (above), so thought I'd ask again, as I'm looking for an answer on the same question,
re. the most suitable transformer (impedance / wiring) configuration for my 1176 Rev F/G builds..

Is it better to wire primaries + secondaries in parallel and keep the impedances in the range of around 600:150 (for input) and 150:600 (for output) ??

I'm a bit confused as, for example, with the original style B-11148 output transformer it seems to me to provide even lower impedances when wired in the standard parallel configuration, doesn't it?

(The 11148 output transformer has two primaries of 50 ohms each, and two secondaries of 150 ohms each, according to the Hairball spec's page)

Sorry, it's taking me forever to properly get my head around this!
Any clarifications on optimal figures for this circuit would be much appreciated!

Evan

 

[olla]

Hi!

I recently built two Rev G units. They both compress fine, but the sound is corrupted by high-pitched noise. Here is an audio sample: https://drive.google.com/file/d/0B7JgGQD8nFSLamZSVmZmRi1KNEpIbl9YWUQ1eXVnSFBiQzZF/edit?usp=sharing

In this sample, the input is set to max while the output is turned up from zero to max. The 1176 is connected directly to the sound card of which the sample is recorded from.

Any idea why this problem occurs and how I can fix it?

 

[Greg S.]

You got Peaks at 50Hz and 100Hz at ca. -60dB

and at

4kHz, 9kHz and 10kHz too, also -60dB

perhaps this helps ???

'76 is mono symmetric, right?

 

[Neko Neko]

Hello

Having a problem with my second g1176 build.

The unit is passing audio but low gain. I have 2v on on the collector of q3 & the base of q4. I know this should be around 12v. Reading through the thread this has happened before & the solution is wrong resistor value. I have checked all associated values, replaced r18 & q3 & 4. No change. I've got 25v before r18. It's got me stumped. Any suggestions?

Thanks in advance

 

[Neko Neko]

Well a bit of news. I have fixed other problem with the GR control amp so meter working as expected. Also when I lift the leg of r12 the correct voltage appears at q3 & 4 but of course the emitter of q2 jumps to 12v. I gave replaced nearly all of the components in this section now & still no ideas.

 

[Olegarich]

Hey guys, what could cause problem.

I have hum when I put out put pot full CCW, to zero in other words, then there comes hum but when raise it even with no signal hum goes away? Have you ever any thing like that?

 

[Olegarich]

anyone?

 

[gyraf]

Try a different ground for your output level potentiometer?

 

[Olegarich]

ok thank i will try it today.

 

[tata]

gents,

id love to understand some probably very basic thing : do we have to have the 2 sides of the GR board/switch to be linked? am i right that one side is setting the ratio, the other side is for the threshold "compensation"?
couldnt we just have 2x potentiometers for these?

if not, then someone please mercy me - id love to see a "paint by numbers" rotary style GR board w/ 2:1, 4:1, 8:1 and 20:1 ratios (no need for 12:1 or add 2:1 as extra). im too noob to 'translate' igor's schemo - i have Gustav's FETGrinder (built) and Hairball/mnats rev.A (poulating in process, id prefer the rotary version there too)

thank you

 

[timpanic]

Hello helpful people ,

I have a hairball 1176 unit from a friend to look at cause it has a strange problem and maybe someone had it before and can help:

The unit first works normal but after ca 40 minutes all ratios accept 20:1 suddenly aren´t working anymore.

The GR needle just goes far to the left and the output drops a little. in 20:1 it works normal.

When I turn off the unit for a while it works again on all ratios :/

I think it must be a thermical problem with a compoment. Is it a good idea to change the transistors in the VCA Section?

Thank you

 

[Olegarich]

after that happens, have you measured posstive and negative supply voltages?(+30 and -10) where they should be.