All things G1176 - the new "repost" thread.

[Spencerleehorton]

Hi Hairball Audio,

bit confused on exactly which one you are referring too as there seems to be many threads out there, same with this G1176 as well.
could you let me know which one please?
Also with what you have suggested will this solve all my problems? not having attack and release really is a big stumbling block, also would like to have the slam function if you have any pointers.

regards

Spence.

 

[Spencerleehorton]

Hi Hairball,

if your meaning do i have a star grounding scheme, yes i do.
do you have any ideas or info on the other problems?

attack and release dont seem to have any effect?

volume jumps when switching between ratios?

all help welcomed as i could really do with this unit working as i got some sessions coming up i could really use it on.

regards


Spence.

 

[Spencerleehorton]

Hi Hairball,

Are you meaning follow this page from Mnats?

http://mnats.net/1176-wiring-rotary.html

looks similar, will read through and hope i find something that i havent done.

regards

Spence.

 

[Echo North]

I was thinking this:
http://mnats.net/1176_reva-d_hairball_wiring_power.html

Just pay attention to the parts about XLR and power cap grounding (at the end).  Sometimes if you don't ground the - of one of the big power caps you can get general wackiness.

 

[Spencerleehorton]

Hi Hairball,

I have looked at that page you suggested and cant see anything about XLR or power cap on there? could you be a little more specific please.

regards

Spence.

 

[carival]

[quote author="joe-electro"]
The "original 1176" used a Teledyne FET marked "U2244".  I'm lucky enough to have five original FETs. I've done exhaustive research trying to find any data on this part and the closest I can come is an FET made by Teledyne with the part number "U224-4".  I'm guessing it's the same part.  Point is, to my knowledge, original 1176s never used the 2N5457 (or 5458 or 5459) at all.

http://jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-1176LNmanual.pdf

if you look at the various 1176 schematics, you can see that they changed from what they called the "DF60214Q" (which was usually a U2244) to the "urei 13-0027" which was either a U2244 or a house selected 2n5457/8/9 type part.  i have a repair bulletin from urei that called for a 2n5457/8/9 as a replacement part for 13-0027, so it could be that most of the 1176s with 2n5457s were ones that had been repaired.



ed

[/quote]



Great to find this!  I know it's an old post from an old thread, but, I've been searching for DF 60214Q fets for a long time with no luck.  Never came across the u2244 reference.  For about twenty years I have owned an original blue stripe that had these 60214 fets.  It died, and a "well respected" shop that is known for their work on UA/ Urei gear fixed it.  It worked fine, but the gain staging and the sound were very different.  Not to my liking.  The shop is kind of defunked.  I would love to get it back to where it was originally.  Maybe not as versatile as other revs, but very special.  It had previously been serviced/ recapped with the original fets and was working perfectly.  Anyone want to offer some guidance/opinions/ recommendations?  I have largely repaired and maintained most of my gear for a long time.
thanks,
chris

 

[twhanny]

hi I think I have the same Problem like spence...

I did the calibration step by step like its written in this calibration manual:

http://www.masonaudio.org/ma_files/G...alibration.pdf

Q bias : OK
Dist. Trim : OK
GR Meter Zero: OK

GR Meter Tracking: Problem!!!

I put a 1 kHz, 50mV signal, Set the input level 12oclock and set output level to the same 50mV signal like the input.
Than I switched to GR mode. and turned up the level of my input signal at the signal source...
both input and ouput signals are increasing 1:1... so if I turned up the INput signal at the source, the Input and the Output signal was always at the same value... no 6dB gain reduction!!! I tried to trim the tracking ADJ R54 on PCB, only 2db result on the VU - Meter...

I tried to put in a audio signal, no Reduction, no compression,...

maybe I did something wrong but I can`t find the problem on the PCB or on the wiring...


Can someone help me? Anyone heart about this problem allready???

thankfully!
twhanny

 

[Spencerleehorton]

Hi Twhanny,

yes sounds very similar to my problem, im gonna be doing the following tomorrow?:

The X and the Y connection is connected to the balancing board, it does specify to connect them before the transformer or balancing board to the switch first.
16, 15, 17 connections need 2 conductor screened wire to ratio pcb
Output needs 2 conductor screened wire
28/29 wires need to be twisted together
22 and 7 need 2 core shielded wire twist shields together and find a ground point, there is one available very near where they need to be connected
Track down any ground loop
Input from XLR needs a chassis point and to points 1, 2, 3 needs 2 core shielded wire to pot.

if i still get the same results after im gonna be really confused!!
Im now following the Mnats G1176 page:

http://mnats.net/1176.html

lets hope we both figure out whats going  on!!


regards

Spence.

 

[twhanny]

hi, Spence...

I found the error... check the Wiring on the back of  your Attack pots.
I was failing the wiring on the back of the 25k pots. Now I am redo the wiring and try the calibration again.

To find the problem check this out:

look at this pic! It has
http://www.hairballaudio.com/blog/wp-content/uploads/2013/09/IMG_0320-copy.jpg

http://www.hairballaudio.com/blog/wp-content/uploads/2013/09/rel-att1.jpg - in this schematic missing the numbers A B C of the 25k pots...attention!!! its easy to fail the wiring... have a look at the description of the pics.

here the whole wiring guide:
http://www.hairballaudio.com/blog/d_assembly/revd/wiring-your-compressor/

regards

twhanny

 

[twhanny]

i fixed it now...

now the calibration works perfectly... the compressor sounds very smooth... rev g like... hehe...

 

[Spencerleehorton]

Hi Twhanny,

well first off my attack pot is not like this one! its just a 22k lin pot, only has 3 tags? as per the original G1176 schematic?
now im really confused?
Have rewired and followed the mnats page and now i get a 120hz hum and loads of buzz on the input?
it still doesnt seem to play ball it is showing slight compression but not much, please could someone help me run through this all i would really love to get this thing going right and dont mind starting from the top again.

regards

Spence.

 

[Spencerleehorton]

Hi All,

ok well it seemed i had a ground loop on my psu for the balancing board, i've taken off the offending ground and its pretty quiet apart from some hiss!! so one step forward at least!!
Gonna replace the 100k/500k tracking adjust as the trimmer has broken and then will try calibrating.
Comparing it to bomb factory BF76 it doesn't sound as though it goes as far as the BF76 but maybe it will after calibration.
Will also put in DPDT switch for slam function.

regards

Spence.

 

[drask]

Hi Guys,

I've a problem with one of my 1176 rev J from mnats.
I've sound (1Khz) through my 1176 but it's kinda weird.
Here I can't find out the solution. Maybe someone could help me here.
Here it's the signal I get : https://mega.co.nz/#!7whiQTZQ!QszcE0A4ayi6-fNw5kLlYwU7dWFxWd_gq2W4W7a85bI
Really low level.

Thank's,
J.

 

[Spencerleehorton]

Hi Guys,

my prayers have been answered, C27 was the wrong value and now my 1176 works fine, calibrating and putting slam switch in tomorrow.
happy days!!

regards

Spence.

 

[Spencerleehorton]

HI Guys,

I found that i had put 220pf in rather than 220nf on C27, also the other one is 220pf so i need to change that, slightly low output at the moment and not sure GR setting works?
gonna put Slam switch in and change cap, also change meter for smaller one and meter has germanium diodes now which track better.
anyone know how to get more output?, i am using the balancing board rather than a transformer.

regards

Spence.

 

[Spencerleehorton]

Hi Guys,

hum and static hiss quite high level now?
have put in slam switch but not tested that yet.
now 220nf are in unit is cleaner but still has a hum and some HF noise.?
gonna try a few other things for calibration to see if this changes.
anyone have any ideas?

regards

Spence.

 

[Spencerleehorton]

Hi Guys,

seems i either had a dodgy lead or was driving the input to hard, as have now setup with left channel into 1176 then into line in and right channel into line compared the output levels and gain and all is good, compression has plenty of level and output once compression is in and slam function works like a charm!!
there is some slight hum and hiss but with output down and not on slam setting is about ok, once slam is engaged hum and hiss come right up and isn't great, is this normal?

Now to put together another unit and do the jack!.

regards

Spence.

 

[Spencerleehorton]

Hi Everyone,

have put in a new VU meter and made slight calibration for meter, unit works really nice now, acceptable noise from it now and slam mode is great!! cant wait to try it out in a session.
thanks to all that helped.

regards

Spence.

 

[JonnathanLopes]

Good evening, I'm Brazilian and am in need of a hint of you.
In this type of trimmer which I connect pin point 18? up or down? 

 

[Spencerleehorton]

it would be the middle leg of that type of trimmer.

regards

Spence.