[BUILD] 1176 Rev F/G - new board, new transformer!

[buildafriend]

Bump

1176 only works when the GR and +8 switches are engaged at the same time.

 

[Songguy]

Hi all,
I need help fixing my 2nd rev. F I did 2 stupid things.

First, I had the ground and red wires from the output pot wired backwards on the PCB. Those wires go to pad 16 at 15 on the pcb.

Second, I attached the shield ( I should have removed it from the cable) from the input transformer input (-)  to the to the input pad(-) on the PCB. The + to + was correct.

Result: fuse blown
            audio passes through but there is no compression.
            Meter works
I'm thinking about replacing the FET's and see what happens

Any thoughts?....anyone?

Please suggest how I can remedy this situation.
Many thanks in advance,
Chris

UPDATE: problems solved. had to replace GR METER DRIVER IC: TL071

 

[gzpz]

Hi-
I'm almost ready to start an 1176F build, I think I have everything except the 4.3 Ohm resistors.  Mouser sells these in only 5,000 quantities, but I need two.  Do you suggest an alternative or does anyone have a source for small quantities of these resistors?
Thanks,
Dan

 

[Majestic12]

Mouser has 4,3 ohm resistors with 1W rating in stock. You can use them, it won't make any difference.

 

[gzpz]

Thanks-
weird, I just went online to order the ones you mentioned, and now Mouser has 1/4 watt units 1% Panasonic, through hole axial, in qty's of 1!!! 
So now I'm ready as soon as the boards arrive!

 

[buildafriend]

What size fuses go in these bad boys?

 

[Hank Dussen]

I used 350mA. Slow blow.

 

[gzpz]

NEW build-  NO PROBLEMS!  I didn't have to change anything, just calibrate it and close it up!  Looks like I'm getting 80dB or more noise floor with input and output controls centered.  Yay! 

I just finished on Monday night.  I'm not anal about neatness (see pic below) but I am VERY careful about installing the right parts in the right orientation and neat soldering! 

I was concerned because I kept reading posts about problems.  I used the Mouser BOM from Hairball.  I actually never bothered to test my resistor values as I opened the Mouser envelopes, and was lucky because everything worked great. But next build, I am definitely going to check all parts with my VOM and suggest you do the same.  Got through the alignment vids with no problems, and I'm happily using my new build. 

A couple of minor dumb items that might help the next guy: 
1) put your VU meter in before you put in the pushbutton switches- you need the room!
2) I installed the components in the small boards supplied by Mnats.  I didn't realize that these are for the ROTARY not the PUSHBUTTON switches, and I should have used the boards supplied by Hairball.  It was obvious, but I hadn't fully unpacked the Hairball stuff and wasn't paying attention.  I had enough spare resistors on hand and loaded the proper boards without issue.

RE fuses...
I think they are supposed to be 250 milliamp slo blo 250vac 5x20mm.  Funny thing, as I was building my F series, my fuse blew as I tested it approx half way through the build.  I was bummed and ordered a bunch of both 250 and 315mA fuses thinking I was going to do a lot of troubleshooting once I finished.  I read that it was probably OK to use up to 500mA but that 250mA is correct.  As it turned out I must have just had a flaky fuse.  I'm able to use 250mA no problem, but I hear they may occasionally blow as they see a comparatively high turn-on surge... 

A couple of questions:
1) my VU meter, when left on GR does drift a little.  I believe this was true of the original 1176 too, but I wondered- why does it take a while to settle when turned on, and why does it drift?  Mine takes approx 10-15 minutes to get to exactly zero, and I see it is 1/4dB over zero now, having been on 3-4 hours.

2) my unit is a little "mellower" than I expected...  I wouldn't say it is "dark", but I was expecting something a little more aggressive than I got.  It is almost like a fast LA-2A the way it sounds.  I'm not complaining and I think it is actually getting more flat as I use it over the last couple days.  Is it settling in?  It actually seems to be a very accurate and can be a fairly subtle device!  Is this the "F" series?  Less sonic fingerprint?  Sure, you can squash the hell out of a signal, but if you are subtle you will be rewarded with a subtle result.  And it is really fast!  Tons of gain.  Now I'm thinking of trying a pair- never would have thought I'd want these on the mix buss, but it might be worth a try! 

Is it the signal caps that vary the smoothness of the sound?  I've got an Angela 1uf polypropylene cap in the C-1 position (intended originally for a guitar amp), are Wimas more or less edgy?  Or is it the transformers that impart the biggest difference?

3) I've built a lot of gear over 40+ years, but this is my first compressor build.  Does anyone know of a circuit analysis description of the 1176?  I can recognize stages of gain, but I'd love to know how specifically this circuit works.  I'll keep puzzling over the schematic, but please post a circuit description if you know of one...


Thanks, and THANKS to Mnats and Hairball for such GREAT WORK!

I can't wait to track female vocals with this thing, I think it will be perfect for that.  I posted some '65 Jazz bass samples on gearslutz, played through a Bo Hansen DI and into an AML EZ1073, with and without the 1176.  Found if you search under the EZ1073 thread. 
-Dan

 

[tko]

Hi all,

I just received my A and F kits and all the parts and I wanted to check I had all the info before I started.

I have :
- Schematic from Mnats site for both boards
- Wiring for hairballs case from Mnats site
- BOM from Hairballs site with part placement #'s etc

Is there anything I am missing that I should look at before I start?

I have noticed a lot of the part #'s don't match the BOM but if look at the link from Hairball to the Mouser Cart  I can work out what has  changed.

Thanks in advance and looking forward it.

TKO

 

[Hank Dussen]

Just work slow and concentrated. Double check every part before you solder it and never 'guess' or 'assume' anything.
When in doubt, go through the documents and on the internet.
You should be fine.

 

[tkgore]

I'm confused on some of the wiring..

on http://mnats.net/1176_reva-d_hairball_wiring_meter_circuit.html

it states to follow the boards color coding.."Twist together the blue and red wires from the meter board connector and the transformer secondary from the output transformer"

PCB on Output Trx colors are brn, orange,red, yellow

EA-11148 Rev F/G Output Transformer- red,blue,yellow,orng,brwn, violet,grey, green wires

 

[mnats]

I'm confused on some of the wiring..

on http://mnats.net/1176_reva-d_hairball_wiring_meter_circuit.html

it states to follow the boards color coding.."Twist together the blue and red wires from the meter board connector and the transformer secondary from the output transformer"

PCB on Output Trx colors are brn, orange,red, yellow

EA-11148 Rev F/G Output Transformer- red,blue,yellow,orng,brwn, violet,grey, green wires

I think you're the first person to point out that the full instructions for the Rev F output transformer aren't included on the wiring pages. I'll try to include them at some point.

Meanwhile, the primary gets wired as shown on the board itself while the secondary is wired as shown on the schematic linked from the first post of this thread.

 

[tkgore]

I'm confused on some of the wiring..

on http://mnats.net/1176_reva-d_hairball_wiring_meter_circuit.html

it states to follow the boards color coding.."Twist together the blue and red wires from the meter board connector and the transformer secondary from the output transformer"

PCB on Output Trx colors are brn, orange,red, yellow

EA-11148 Rev F/G Output Transformer- red,blue,yellow,orng,brwn, violet,grey, green wires

I think you're the first person to point out that the full instructions for the Rev F output transformer aren't included on the wiring pages. I'll try to include them at some point.

Meanwhile, the primary gets wired as shown on the board itself while the secondary is wired as shown on the schematic linked from the first post of this thread.

I might have solved my problem.. people can confirm or deny if this is true..

looking at a previous wiring diagram earlier in this thread
it states that output XLR goes to X/Y Meter board..
with the output transformer EA-B11148 schematic on Hairball (under the respected transformer...)
XLRpin1=ground
XLRpin2=positive
XLRpin3=negative

XLRpin2 goes to X on meter board
XLRpin3 goes to Y on meter board

if I read (still learning) this out-transformer right:
violet/green are the positive from the out-transformer and blue/grey are the negative
violet/green(EA-B11148)>>XLRpin2 >>>X(meter board)
blue/grey(EA-B11148)>>XLRpin3 >>>Y(meter board)

I hope I'm right...

 

[tkgore]

I got some trouble shooting to do.

dcV power rails tested within .5V of printed numbers (+30, -10) -- ok
Audio Passes through.. --ok

When output is turned past unity.. sound gets dirty and cuts off input sound(dont know if this means its working or not.)

VU Meter doesn't move no matter what I do.. I know its getting power, the light is on. --Problem
Fuse did blow when I first hit the OFF button, I replaced fuse with SAME fuse and it hasnt blown with OFF pushbutton pressed in

Ratio- when I change ratio from 20:1 to 4:1 it compresses the audio for a second and thats it. (short?)

INPUT works fine

 

[Echo North]

Did you measure the ratio?  It's not something you really see on the meter because the threshold changes with ratio.  Look here:
http://www.axtsystems.com/index.php?option=com_content&view=article&id=54:1176lnratios&catid=34:1176ln&Itemid=62

The attack control is super fast.  It's imposible to see it like you do the ratio.

Hi guys,

Happy new year to you all first of all!

I just wanted to post up my issue before I post photos tomorrow.

I have a RevF that is passing audio and sounding killer but my ratio buttons are not adjusting my ratio and I have no attack adjustments.

The Release is working brilliantly and it seem the ratio amount is fixed on one setting.

Is this something someone has seen before and what part of the build should I be looking at re testing?

In the setting its on it sounds soooooooo good.

I have run the calibrations fine too, so it very close!

Thanks in advance TKO

 

[svenandreen]

hi, guys!
When wiring the Hairball ratio push-button assembly today, pad #6 (where the shielded wire is supposed to go) managed to loosen and fall of the PCB  :-[. Noob as I am I probably run the solder iron a bit too hot or something. Is it any way I can fix this or should I just try to get a new PCB?

 

[grantlack]

hi, guys!
When wiring the Hairball ratio push-button assembly today, pad #6 (where the shielded wire is supposed to go) managed to loosen and fall of the PCB  :-[. Noob as I am I probably run the solder iron a bit too hot or something. Is it any way I can fix this or should I just try to get a new PCB?

find the trace(s) that connected to lifted pad.  find razorblade.  remove solder mask to expose trace(s).  solder.  succeed.

 

[svenandreen]

find the trace(s) that connected to lifted pad.  find razorblade.  remove solder mask to expose trace(s).  solder.  succeed.

thanx! now everything is stuffed, mounted and wired

 

[svenandreen]

Having some problems with calibrating my Hairball Rev F. When adjusting the Q BIAS I have followed the procedure in the mnats calibrationvideo:
feed the compressor with a 0dB  1 kHz sinus wave,
turn the Input knob full counter clockwise
turn the Output knob 3/4 full clockwise
set the attack to off,
the release to fully clockwise,
ratio to 20
and meter to +4.

The VU meter doesn't move until I turn the Output fully clockwise, and the Input about 1/4 clockwise.
If I turn both Input- and Output knobs fully clockwise and the Q BIAS trimmer fully counterclockwise, the VU meter reads only about - 8.
When I turn the Q BIAS trimmer fully clockwise the VU meter goes down to -20. I guess thats ok, but I'm wondering why I can't get the meter to read anything higher than -8...

Any clues?

 

[Autophase]

Hi Guys, This is a revision of a prevous post.
I'm going to build 2x  Stereo 1176's. I have settled on Revision G, I just have a couple of questions.

1: is this thread the main support thread for rev f/g builds?
2: I have access to a Transistor curve tracer so I have decided to pair all the FET's my self, what characteristics should I be looking for, are there specific settings common to most curve tracers that I should use?


Thanks