[BUILD] 1176LN Rev D DIY

[tazman]

Hello everyone. I built my 1176 Rev D back in 2011. The unit had been performing great until a few months ago. I cannot figure out what the heck is wrong with it. The input pot seems very sensitive, as in, as soon as you turn it up the compressor starts to engage heavily. It also seems to distort at times and the behavior seems erratic. If it's left on for a while it seems to behave differently than when used after a few minutes of being turned on. It doesn't seem to be over heating.

I went through the calibration process and it seems to go through ok. I'm lost! (BTW, anyone in the Tampa, FL area?)

 

[f.aiseur]

Hello people!
Im sorry to add to this quite long thread, but i have some transformer infos to seek :
Audiophonics dont do custom toroids anymore, Hairball is not selling their Avel Lindbergs, so im looking for some new source for a 1176 project.
Ideally in Europe, and even better if they do custom toroids (because i also need one for a StaLevel build).
Contacted toroid.hu and toroid.cz but didnt have any answer yet...

There is this one with 2x24V out, so maybe it can still work properly on a 1176?
https://www.audiophonics.fr/fr/tran...transformateur-torique-30va-2x24v-p-5649.htmlHas anyone tried a sec:24V?

Any help appreciated guys!!

 

[MonoCutter]

Hi,

This is the correct version.

This is what i used for my 1176. They do a good job and will be delivered from Germany.

Dennis

Edit: I'm really sorry for the confusion. Of course you need two secondary windings. I copied the wrong link by mistake.

 

[Logain]

hello all! so on the build of my second 1176 Im building a stereo pair and the second one has noise/ distortion whenever I engage the compressor even without having any compression happen. makes me think its a problem in the GR METER DRIVER AMP, I have a fully working one and they meter out the same for resistance values everywhere. Connections cool good and all that, any ideas what to look at next? Please and thank you!

 

[gswan]

Check all the bias voltages in the various stages to see that they are correct (you might have a transistor in backwards). Also use a sig-gen and a scope to see where the distortion is happening when you put a pure sine wave in. Be aware that the first stage amplifier after the GR FET generates a lot of third-harmonic distortion, which is partly where the flavour of the 1176 comes from.

 

[Logain]

how much change In volts is a problem like 10% or more? "sig-gen and a scope"? not familiar with those terms. thanks for the response too this is frustrating I bought them both like a year ago then moved and life stuff got in the way lol

 

[gswan]

A 10% difference probably indicates a problem, depending on where it is and the tolerance of your components.
A signal generator and oscilloscope are standard test equipment for electronics work. They allow you to see what is happening at various points in the circuit and confirm that it is doing what it is supposed to be doing. Without measurements to confirm you really have no idea if it is performing correctly.

 

[Logain]

dang maybe need to invest in them if I'm gonna keep building... thank you

 

[gswan]

They are only useful if you know how and where to use them.

 

[Logain]

Yeah and they like 200 bucks at least I might just fold and pay Hairball to get to up and running proper at this point I could of been using it for the last year lol

 

[gswan]

Sounds like you probably are better off finding someone who can help you diagnose and fix the faults and also calibrate it for you. Then they can check that it is operating OK by measuring the ratios, response and gain etc.

 

[Logain]

yeah I just have a meter and a tone/ signal generator from waves, if there was more DIY kits out there I might invest in all that.

 

[f.aiseur]

Hello all!

i mistakenly ordered a « normal » 25k pot (without switch) for attack, do you know how critical it’d be to use it in a rev d build? And how should i « bypass » the switch?
And/or could someone give me a proper reference for the spdt pot?

Thank you, lovely day to all of you

 

[Bobby Baird]

https://www.mouser.com/ProductDetail/315-2415F-25KHeres the pot with the spdt switch I used.

 

[f.aiseur]

Thanks Bobby!

 

[f.aiseur]

Hi, it’s me again!
(for mods : its not brand/product related post but more type/configuration....but i still had to upload the picture as i dont even know how to call those, sorry about that)

I’m trying to hook up the input transformer today. I got an UTM2546, see picture.
I’d like to know if anyone here used them? Or any other same-looking/made transformer? (How are they even called?!)
Im specially interested to know how you mounted it and fixed it to chassis? what configuration did you choose (i think i’ll do the second, 10k : 2,4k) and also how did you do for the grounding?
Would it be a good practice to direcltly link pin 6 of the transfo (gnd) to the chassis?

Or more generally, how would anyone do withouth the pcb?


Thanks in advance!

 

[f.aiseur]

Hi All,

Built finished, but problem occurs straight at step one of the calibration.
Needle is reacting on input signal, but doesnt go up more than -20
(see video : https://drive.google.com/file/d/1GAaUZNlAoZiMs1Z_x3tef5FZGSdbZ9GZ/view?usp=sharing)

On voltages, i noticed issues in the GR meter driver section. here are the voltages :

Power supply
R87 : 29.9
CR6 : -10

GR control AMP
Q10 : 16.4
Q9 : 2.7 / 16.4
R42/3 : 3.3
Q8 : 14.1
Q7 : 3.8 / 14.6 / 4.1

GR Meter Driver
Q13 : -0.5 / 7.9 / 0 (-0.5 / -0.5 / -0.4)
Q12 : -1.5 / -2.4 / 7.9 ( -1.9 / 15.2 / -1.3)
Q11 : -0.5 / -2.4 / 8

Signal Preamp
Q2 : 0.5 / 1.7 / 0.8
Q3 : 1.1 / 11.2
Q14 : 29.9 / 11.4

Line Amp
Q4 : 0.3 / 0.9 / 5
Q5 : 2.6 / 2.9 / 25.4
Q6 : 28


So i tried to change Q12 and Q13. switched them 3 times so i dont think they're at fault. (different voltages in parenthesis are with different set of transistors)
I reflowed all connections in the area, couldnt notice anything weird. Went over the wiring guide twice and also couldnt find any oddities..


If anyone out here know what could be the problem, i'd appreciate the hint!
I am of course trying to find answer on this thread, but search couldnt bring me anything and im rereading the full thread since a few days (page 115 right now....)

Thanks for your time and support!

 

[dreamix]

Hi All,

Built finished, but problem occurs straight at step one of the calibration.
Needle is reacting on input signal, but doesnt go up more than -20
(see video : https://drive.google.com/file/d/1GAaUZNlAoZiMs1Z_x3tef5FZGSdbZ9GZ/view?usp=sharing)

On voltages, i noticed issues in the GR meter driver section. here are the voltages :

Power supply
R87 : 29.9
CR6 : -10

GR control AMP
Q10 : 16.4
Q9 : 2.7 / 16.4
R42/3 : 3.3
Q8 : 14.1
Q7 : 3.8 / 14.6 / 4.1

GR Meter Driver
Q13 : -0.5 / 7.9 / 0 (-0.5 / -0.5 / -0.4)
Q12 : -1.5 / -2.4 / 7.9 ( -1.9 / 15.2 / -1.3)
Q11 : -0.5 / -2.4 / 8

Signal Preamp
Q2 : 0.5 / 1.7 / 0.8
Q3 : 1.1 / 11.2
Q14 : 29.9 / 11.4

Line Amp
Q4 : 0.3 / 0.9 / 5
Q5 : 2.6 / 2.9 / 25.4
Q6 : 28


So i tried to change Q12 and Q13. switched them 3 times so i dont think they're at fault. (different voltages in parenthesis are with different set of transistors)
I reflowed all connections in the area, couldnt notice anything weird. Went over the wiring guide twice and also couldnt find any oddities..


If anyone out here know what could be the problem, i'd appreciate the hint!
I am of course trying to find answer on this thread, but search couldnt bring me anything and im rereading the full thread since a few days (page 115 right now....)

Thanks for your time and support!

If Im reading it correct, you have different voltages at the Q12 Q13 Emitters? anyway the voltages should be the same on both Q12 and Q13 EBC I think. Maybe you have mixed up the pinouts of these transistors? Here are some typical voltages around that area of a calibrated rev D

 

[f.aiseur]

Thanks for reply dreamix, as i used 3707, i followed the orientation marked on the pcb, so it should be good.
I remade some measurements now, and i have :
-1,6 / 18,1 / -2,4 on q12
-1,6 / 18,1 / -1,6 on q13
so this 18v is problematic obviously

if i switch from GR to +4, then the 18 turns into 5,02 at q13 - but stays at 18 on q12

 

[frenkonio]

Hi guys, I've tried to be in touch with Hairball through the website but didn't get any reply. Anyone with same issue? Thanks!