All things G1176 - the new "repost" thread.

[Mbira]

I moved this to the "calibration thread so it will be easier for people to find this info next time...

 

[gyraf]

I really don't think it matters... But as rule-of-thumb, ALL ac voltages you see mentioned are RMS unless otherwise specified..

Jakob E.

 

[Mbira]

saw your reply after I moved things...Thanks Jakob...

 

[Ted]

I've some problems with my 1176 clone.
I start with building the power supply only; everything was right +30v and -10 where fine.
When I stuffed my board and checked powered up the second time. I felt the 7824 where too warm.
Isolated only the output pin from the 7824 I measure 24v. But in the circuit it came out 3volts? -10v is okay
I checked the board several times on bloops but I can't find anything.
Somebody any idea where to start?

Thanks for reading!

Ted

 

[gyraf]

Ted,

Try with a small heatsink for the 7824. It'll shut down if it gets too hot..

Jakob E.

 

[Ted]

I've used a small heatsink. And one 7824 is already "burned" out.

ted

 

[Ted]

I fixed it. Changed the 135 and the 136.





Ted

 

[gyraf]

:thumb:

 

[thedug]

I found an oscillation in the 2 1176s that I built..

I put the cap in parallel with the 1.2K resistor that hangs off of pin 6 of the NE5532.
39pF and 12pF are the values I used. Both eliminated the osc. completely.

Approx 700 kHz, 0.5Vp-p measured at pin 6 of the 5532.

Thoughts?

 

[gyraf]

I never had that...?

 

[imo]

i had a question on the 135 and 136. WIth my challenged schematic skills, it seems that you still need to twist the pins to get them to fit correctly on the rev 7 gyraf design. the schematic seems to back this up. I ask as i thought in trolling through the forums that this wasn't necesary in the latest revision. I think i hit an information overload, and could use a clearer and wiser mind backing this up.
i give thanks
Ian.

 

[gyraf]

Yes, you need to twist the legs when using BD135/136 output transistors - the latest PCB is still made for BD518/519 (as printed on the component side).

Jakob E.

 

[thedug]

Any ideas what that could be?

 

[dukasound]

Hi
I am finishing my Dual G1176. After assembling I put signal without fet's and everything is OK. If Input and output pots are on about 12.00 it is like signal with true bypass.
Problem is:
When I put BF245A I lost signal. Zero on G.R position on meter I can adjust!
What to do?
I check all voltages and its OK.
Thanks
Duka

 

[thedug]

Should I be worried about this extra cap for the oscillation effecting the sonics?

Did I do the right thing? Should I look into other things? I.E. Could this indictate another problem?

 

[Lowfreq]

Hey everyone,

As one might guess I'm havin a few problems with my G1176.
I'm using mnats version with an OEP a262a2e transformer.

Anyway, the prob i'm having is that altough the compressor works and is compressing well it seems strangley slow sometimes. For example if i consatntly sang/talked/rapped etc the compressor is happy and works well. However if I stop for anything more than a second, to take a breath etc, it takes a short time for the comp to respond to the first burst of my voice again. I tried this with an extreme setting 20:1 etc, fast attack blah blah, and the note the comp dosen't catch always distorts and peaks the meter.

I've been through the whole bias procedure and the Gain zero/trck parts went sweet, but nothing happened at all witht the Q-bias part, which i thought would be very important.
Checked for shorts etc, no luck....................I'm a bit confused

I've read and searched a bit through this thread, but 53 pages is a lot to wade through while getting ready for a tracking session tonight.
Any ideas or expeirence with this one anyone?

regards

Steve

 

[dukasound]

[quote author="dukasound"]Hi
I am finishing my Dual G1176. After assembling I put signal without fet's and everything is OK. If Input and output pots are on about 12.00 it is like signal with true bypass.
Problem is:
When I put BF245A I lost signal. Zero on G.R position on meter I can adjust!
What to do?
I check all voltages and its OK.
Thanks
Duka[/quote]
I solved!!!
Wire from point 7 from main board to pin 7 on ratio switch board didnt soldered (on both channel)
Because I add stereo interconection and switch for compresor I made mistake.
Now to match fet :?
Duka

 

[Brizco]

Hello!

have a similar problem with my gyraf 1176 like some others before:

signal passes thru, without hum. input and output potentiometer are working.
but: i cant hear any compression. (vu meter is not working too, but doesnt matter now).

i havent calibrated yet.
i only have 0.7 volt on the 10v rail. (by the zener)
i checked for shorts, values and soldering...
all diodes are soldered the right way.
i got 10v on R85.

i dont know what more to do... or where to search...
so i be thankful for some solution inputs! thank you!!

 

[gyraf]

i only have 0.7 volt on the 10v rail. (by the zener)

That is your problem. Find out why...

Jakob E.

 

[Gachet]

Hi every body,

I just realized that i used carbon 5% for the near total resistors instead of metal 1%...
What kind of problems could I meet when using my unit?

I've ordered fairchild semi conductors...are they really crappy (i've read this somewhere)

And when using an input transfo on mnats rev H pcb, the caps marked * are optional?
I'm not obliged to put those on the PCB...Am I right?

thanks

PS:I've read the FAQ on mnats website and lots of threads but I'm still confused.Maybe because it's hard for me to discover at the same time DIY and technical english ... :roll: