All things G1176 - the new "repost" thread.

[API]

Hi Pedro.

Thanks for the info!
Great to paralell two 2k2 resistors, why didnt i think of that!

I am going to read through all the pages, was just looking for some quick answers since i am going to order all the stuff tomorrow and need to go to bed!

Thanks,
Dennis

 

[rbaker]

I'm having the same threshold performance as described in this thread by some. I've seen both possible solutions (extra trimmer to adjust the threshold or the replacement 2n5457 fets)

I just placed an order for the addition trimmer and the fets so I'm planning on messing around with both of them...in the interim, who else has done what? Anyone found either solution to be more effective than the other?

Also are some people just building it stock and not noticing that it's compressing A LOT :grin: or is it just dependant on the consistency of the fets as jakob has suggested?

 

[imo]

I had the best success with the 5457. It increases the threshold a decent amount. Just out of curiousity are you using the input transformer? I have built three of the units, and the only one that had this issue used the Lundahl on the input. The trimmer seemed to work well for a couple of people
Ian

 

[rbaker]

yes I am using the lundahl input transformer. On your others did you use the electronically balanced or the oep?

I really like do like the sound of the unit overall. Maybe I'll mess around with the oep. They are cheap, thats for sure.

I tracked vocals and bass for a little while but it just needed more output level. In bypass there's level FOR DAYS so I know it's just compressing too much.

Will the 5457 change the sound at all?

 

[imo]

For more output you can mod the output transformer for 1:2. You can find info on this in this thread.
I used the Lundahl on input as well, also made an electronically balanced version. I have more headroom before compression kicks in on that unit.
Ian

 

[rbaker]

I have mnats board. I believe it's already wired 2:1

 

[enthalpystudios]

[quote author="dukasound"]OK
Bad english :sad:
I ask this:
If we used Lundahl on out and wired 1:2 or 2:1. Both primary and secondary are wired in series.
On both Jakobs and Mnats boards C15 ? 470uF is connected to minus of Lundahl transformer (pin 1 for 2:1 and pin 10 for 1:2) and plus of windings (pin 4 and can 3 for 2:1 and pin 7 for 1:2) goes to ground.
On Jakobs pcb Bal. Out plus goes to pin 9 who is positive.
On Mnats board (1:2 ratio) Bal out plus goes to pin 5 who is negative.
It is it.[/quote]

i just checked over the lundahl 5402 datasheets and mnats and jakobs pcb layouts.

my jakob/gustav board doesn't have any labels for -/0/+ on the molex output header, but as they are marked in the pdf file on gyraf.dk, it does appear that the output of the darlington pair drives the (-) output, after the lundahl is all said and done. a quick flip of the molex would fix that, as long as it doesn't matter whether or not you actually use the (+) markings for windings as indicated on the lundahl datasheet. i don't see a phase reversal happening there, just at the molex header.

seems to be correct on the mnats board, but i have a feeling that this is just a matter of the silkscreening/labelling, of which there actually isn't any on my jakob/gustav board.

just some thoughts... so if you use the jakob/gustav layout, it may be a good idea to scope the output pins just to double check which is actually in phase and which is out.


i just realized these things while looking at how to hook up an output transformer off board, as i'm building a pair with b11148 copies, and a pair with ll1517's

 

[Magnus Lindberg]

Nevermind, I solved it.... :grin:

 

[rbaker]

[quote author="imo"]I had the best success with the 5457. It increases the threshold a decent amount [/quote]

I put the 5457's in and finally got around to testing it out. It definitely helped with the threshold level---I can get a better level out of it, but it's still compressing pretty hard.

Has anyone listened to the difference? This might be totally psychological, but I just remember the 245's being a little more....buttery...if that makes any sense. I'm not going to say that the 5457 sounds bad, AT ALL, I just remember thinking that I'd use the 1176 more than my distressor when I had the 245s in and now I'm not so sure.

I ordered the trim pots, so now I just have to figure out where and how to put them in. I'm definitely curious if people who are using the oep input are having this problem and just not realizing it?[/i]

 

[W DeMarco]

So If your searchin for the answer to my problem with the VU pegged meter in GR Mode here it is.

This post started on page 72 and went on for a few pages.

After I checked voltages on transistors and other places, finding no problems I finally started retracking my interconnects. If your using the MNATS Boardset, this could be a problem for you. I found an unused hole labeld 18 next to another 18. Mnats board version takes many different trimpot sizes. Hole 18 is set next to a trimpot and connects to it through a trace. I was using the hole for a larger trimpot, unfortunatley I was using a smaller trimpot. Ergo, no connection to the trimpot.

After making this correction GR mode works like a charm. Thanks for all the help !!

All thats left is a bit more calibration and this baby ll be in service.

:guinness: :green: :guinness:

 

[gyraf]

:thumb: Thanks, DeMarco!

 

[API]

Hi again.

I think I solved most of my problems, but would love to get an confirmation on some of the stuff.

[quote author="API"]1. How large power transformer do need? Is 25va enough?[/quote]
I bought a 30va toroid, this should be enough, right?

[quote author="API"]2. The BC 107´s should these be NPN or PNP.
Also, should they be "just" BC107, or the A or B version??[/quote]
I got the NPN BC107 transistor.

[quote author="API"]3. The BC560, these should be PNP, right?[/quote]
Here i am still in the blue.
Someone suggested to get the BC560C version, is this crucial??
And they should be PNP, right??

[quote author="API"]4. Does the 1K1 carbon resistor need to be 1w and 1k1 exactly??
Could only find 1/2 watts in the Farnell catalog, does anyone know a source in Europe?[/quote]
I am still looking for this!

[quote author="API"]5. Does anyone know where i can find the 1N4740A Zener diode in Europe?[/quote]
Found this.


[quote author="API"]6. The switches, should these be shorting or non-shorting??[/quote]
I got non-shorting switches, but i am not sure if they are the right ones.

Thanks,
Dennis

 

[gyraf]

1. How large power transformer do need? Is 25va enough?

I bought a 30va toroid, this should be enough, right?

yes

2. The BC 107´s should these be NPN or PNP.
Also, should they be "just" BC107, or the A or B version??

I got the NPN BC107 transistor.

BC107 is only a NPN, that's why we do not specify further.

3. The BC560, these should be PNP, right?

Here i am still in the blue.
Someone suggested to get the BC560C version, is this crucial??
And they should be PNP, right??

BC560 is only a PNP, that's why we do not specify further.

4. Does the 1K1 carbon resistor need to be 1w and 1k1 exactly??
Could only find 1/2 watts in the Farnell catalog, does anyone know a source in Europe?

I am still looking for this!

Please read this thread (again?). Yes, it needs to me 1K1, and at least 1W. As suggested several times before, use two 2K2, 0.6W, connected in parallel.

6. The switches, should these be shorting or non-shorting??

I got non-shorting switches, but i am not sure if they are the right ones.

If it was important, we would have mentioned it. non-shorting are fine.

Jakob E.

 

[jlearman]

This is probably a dumb question, but I just built a dual 1176 with the mnats boards (including the separate psu board). As you know, when you're using the mnats psu, you have to jumper a section on the main board. My problem is that my VU lights aren't turning on...they're not getting any power from the main board, so I'm wondering if by jumpering the power section of the main board, I jumped the vu lamp output? If so, what do you guys reccommend for powering the VU and on/off light? I can I take something off the output of the PSU board (the +30 side, I imagine) If so, what kind of resistor would I need (wattage & resistance)?

Thanks for helping a newbie! I'll post some pics of the new comp later this week when my front panels arive.

 

[rbaker]

Are you sure the vu lamp isn't getting power? I'd test it with a dmm to see if there's voltage.

I'm not sure if you used a series resitor when you first hooked up the vu lamp, but depending on the voltage bulb you got, you probably need one. If you didn't use one, it might have turned on and blown really quickly. That is something that would have normally happened to me.

But yeah I'd check it to make sure there's voltage (ruling out that the lamp is not working)

 

[gevermil]

Can anyone email me a DETAILED photo of their stuffed PCB board
I know its a cheeseball request , but I made a bone head mistake and burnt a part or two and Im going nuts over this
Any help guys would be great .
G

 

[gyraf]

Gever,

Why is it not enough to look at the component overlay in the layout?

Jakob E.

 

[gevermil]

Thanks Gyraf .
I worked my way back and fixed the problem
:roll: Chimay ale sure is strong stuff

 

[Mr. Dave]

Would this power transformer work for the G1176, it's 35-0-35.
I'm using the Mnats pcb.
http://www.halted.com/commerce/ccp20783-toroidal-transformer-70-vct-20691.htm
Thanks,
Dave.

 

[gyraf]

2x35V is a on the high side - you'd probably be facing problems with too much heat - and probably also with electrolytic voltages. I'd recommend 2x30V maximum.

Jakob E.