All things G1176 - the new "repost" thread.

[SIXTYNINER]

Thanks for post "Weiss" ,
the "question" is about voltages/ampere compatibility with 1176 vu meter out "source".

S.

if it fits in your case, why not? what is your concern?

 

[Greg S.]

you might check 'em

0dBu are 0,717V rms and 1,096Vpeak.
take a 10k trimmer as pre resistor and adjust it at 0dBu by using a freq.-generator.

should work

 

[r2d2]

....Very bad weather this week end ... 
( hmmmmm ..... better stay at home    .....  )

between possible things to do ....  ,  why don't try to get a diy 1176 to put on the bass track / channel ?

Well : let's go to the online "grill" .....
(R2D2 Cpu "transistors" very very "hot" .....  )

After a day and half "grabbing" on servers (and tons of web pages....)
found very much info, docs,  helps , ....... tons of broken links too .... 
G1176 by Gyraf it's  the first candidate....

"unfortunately"  the only thing/info not found is a list of Transistors replacement
for the original old "obsoletes"  ....  ???
(.... obsolete only for manufacturers and distributors , not for "diy ers" and analog sound "lovers" )

Please somebody have some help to share about ?

....also a post about transistors replacement , to put in the 1176" Meta" page (as well ) will be great . 

Thanks in advance
peace
R.

ps
But : What transistors are placed on the UA 1176 reissue ?  ???

 

[gyraf]

BD135/136 seems to work well for the output stage.

You could probably use any audio-driver transistor with similar specs without altering sound the slightest.

Jakob E.

 

[r2d2]

Hello "J" ,
many thanlks for post !

Please bd135-136 , replace all transistors required by bom ?

2X BF245A FET TRANSISTOR
BD517 NPN DRIVER TRANSISTOR
BD518 PNP DRIVER TRANSISTOR
2X BC560 PNP TRANSISTOR
8X BC107 NPN TRANSISTOR

peace
R.

"ps" (a bit long ps...) :
...... After spent about 2 days online ,only looking for "preliminary" info ....
(and still more time will be needed)

i'm thinking about the true final "cost" of the 1176 diy and other project too ...
seems to be getting more expensive than a 1176 original used  ,

X-2 days online for informations and docs "take-over"(about 13/15 hours a day tot :26/30)
X-now : time for find out parts (check bom list , fill the online order , more 5 , 8,10..... hours ?)
    ...please note that many components price go low by the quantity ,
      then "normally" parts order (and cost) become for a device and half .
X-wait parts delivery : 2,3,4,5,6,7....... days ?
X-check parts delivered 1or2 hours ? (frequently parts order arrive not complete , then wait delivery for the rest of parts)
X-after all parts are delivered and checked , start to solder pcb , checking one by one resistors value  , matching parts , etc...
    with much attention for avoid mistakes and then other loss of time...
    can be a day and half sufficient ? ..... I think not for a well done work ....  :
X-after ending of soldering , time to work on the case , or buy one ready from some "driller" , "miller".......(more costs)
X-put pcb ,pots,vu meter etc... on the case , wire all together , about 5,8 hours ?
X-if all go well (very unlikely...) start to setting "bias" etc... for put the device in the correct working "condition" , 1,2,3..hours?

Then how much : Total ?

....  any other "unforeseen" excluded

BD135/136 seems to work well for the output stage.

You could probably use any audio-driver transistor with similar specs without altering sound the slightest.

Jakob E.

 

[mrkrawn]

Hi

Today i add a 500k trimmer to  R26  which is 56K for try the adjustable threshold.
The unit was calibrated before.
I find this mod very subtle.
but not really audible.
I use a trimmer as an adjustable resistor .
Should i try to connect it like a pot with ground?

Best

 

[hymentoptera]

You would definitely connect one side to ground to make it a trimmer. Other side would be input from near the output control, and wiper goes on to the ratio switch. But  even at it's fullest setting (0 ohms) the device will not perform as normal, since there would still be 500k to ground at the point making a 10/1 voltage divider. In others words there would be no way to take it out of circuit without adding a switch.

I believe the more common approach, however, is to place the new resistor between gain reduction switch (S1, pad 4 I think?) and ground. Some Hairball Rev D builders use ~ 100k to ground on an extra switch to raise the threshold. This would let you keep the existing threshold/ratio settings and engage the new divider at will by flipping the switch. I see no reason why a variable resistor couldn't be used instead, but i'd still recommend a switch so that you can turn the threshold adjustment "off" when you want to use the unit in normal mode.

 

[mrkrawn]

Thanks for this real clear answer.

 

[mrkrawn]

Hi

I have a real strange but funny problem on my 2nd 1176 channel and I would like to share it with you.
I finished 2 unit.Mnats rev H boards.
The two unit work perfectly.
all pots work (compression input output attack release ratio and meter)
all trimmers work (bias tracking zero meter and disto).

But on the second channel only, when i put the gain reduction mode (second step of switch)
the Vu-meter go the wrong way(to the right).
it works well, but in reverse
that's make me laught the first time but now it's really annoying.

I recheck all my wires compare to my other channel.nothing wrong.
Change tl071.
i recheck xlr.
Test with my multimeter at X & Y point on main pcb to the meter switch.
it's ringing, so the signal go to the end of meter switch pcb.
Recheck 4 pos ratio and 3pos meter switch.(all good).
i decided to test another vu meter.but it the same.
I put news transistors to be shure, but that fuc*ing VU meter, always goes right when i move the input pot.

I continued to try to solved my problem, if by chance someone already had the same problem,
Please let me know

Best

 

[gyraf]

Could it be an internal meter error - try swapping the two meters?

 

[mrkrawn]

Thanks you gyraf
but i try to replace it with no succes.
i realise omit to put C6 at input pot.
I soldered  it, have a new try but it still go the wrong way.

 

[JW]

Hey folks,

I have a dual G1176 unit that I built up with OEP output transformers. I had been wanting to try a different output transformer for awhile, and as luck would have it, AML actually sent me the wrong Carnhill transformer for another project, which (I THINK) turns out to be a good candidate for the G1176. Judging from the coil resistances, the transformer is either a VTB 1148, VTB9070, VTB9057, or VTB9049, http://www.audiomaintenance.com/downloads/carnhill_design_guide.pdf on
These are all 1+1:1.7+1.7 transformers. I don't know how to tell if it's gapped or not

It can be wired 50ohm or 200ohm on the primary to 150ohm or 600 ohm on the secondary.

What would you all recommend for this circuit? (I typically have anything from 600 ohm inputs to higher modern impedances following the G1176)

One more question, does this need to be gapped or ungapped?

 

[mihailojocic]

Hello!

If I put input transformer in my G1176, is it still possible to use electronically balanced input?

Sorry if question is stupid, but I don't understand circuit enough. I'm just a musician! 

 

[hymentoptera]

Hello!

If I put input transformer in my G1176, is it still possible to use electronically balanced input?

Sorry if question is stupid, but I don't understand circuit enough. I'm just a musician! 

You will have to take into account that a different input pot is used. This is based on my experience with the Hairball Rev F and G, and may not apply to this project, as I've only ever stuffed the PCB or troubleshooted/repaired the G1176 units, never actually wired one up, and could be totally wrong in my assumption, but I'd think you need to be prepared to modify some things or change some resistor values... so it sounds like the answer would be no, not with the standard Lundahl transformer (I think)...

The real question would be "why" would you want to include both input options? Is there a particular result you're looking for? Did you already stuff the entire board and include both options' componants?

 

[mihailojocic]

The real question would be "why" would you want to include both input options? Is there a particular result you're looking for? Did you already stuff the entire board and include both options' componants?

It would be very cool to have "transformer-less/transformer" input switch on the front of the unit, like two options. In my head that sounds like grate idea! Components for  electronically balanced input isn't to expensive so I will keep them on the board if they don't interfere with transformer input.

 

[JW]

I actually have a G1176 with a switch that switches between an OEP input and a the IC input. I always leave it on the IC input though because the OEP input doesn't sound good for anything imo. It's way too pinchy and distorted. I wasn't aware I needed a different input pot though. That could be the problem. (Although, hymentoptera, are you sure you're not thinking of an earlier revision? I thought the revision G with the input transformer used the same input pot as revision J? Hmmmm.)

Anyway, I'm gonna remove the switch I think and just keep the IC input. Sounds fine.

I want to replace the OEP outputs as well though.

So this is a bump for my post a few back.

I have a carnhill that can be wired 50ohm or 200ohm on the primary to 150ohm or 600 ohm on the secondary. So, if I'm using the chip input, how should I wire the output? All the info I've been able to find so far just says 1:2, 1:1 etc. But what does the output of the compressor want? I'll be connecting to 600 ohm inputs of other gear as well as modern higher impedance.

Also, does it matter if the transformer is gapped or ungapped?

 

[hymentoptera]

...I wasn't aware I needed a different input pot though. That could be the problem. (Although, hymentoptera, are you sure you're not thinking of an earlier revision? I thought the revision G with the input transformer used the same input pot as revision J? Hmmmm.)

Anyway, I'm gonna remove the switch I think and just keep the IC input. Sounds fine. ...

You're probably right, I'm likely getting it confused with another version.

How did you wire up the input switch? Have any photos of the inside we could see?

 

[mihailojocic]

I actually have a G1176 with a switch that switches between an OEP input and a the IC input

Thanks!

How did you wire up the input switch? Have any photos of the inside we could see?

It should be very simple. I will do that with relay. 0A and 0B goes to + and - XLR,  NC to IC input and NO to transformer input.

 

[JW]

Yeah,

I'll take a picture soon as I open it up and try replacing the transformer with this Carnhill. I'd just like to know how to wire the Carnhill first.

 

[knight84]

Hi,

I just finished my G1176 with IC option. It works great in soundwise and noise floor. But the gain is very very low, at highest values of input and output pots, it is around 3-5 +db.
I know there are a lot of information in the forum to tolerate that issue. But I just want to be sure I might have done something wrong. Because that seemed to be extra low even that it was difficult to calibrate the item.