[BUILD] 1176 Rev A - Back to the beginning...

[orangerec]

R44 is fine, checking all the resistor values again in the GR meter driver.

 

[orangerec]

Ok, I figured it out. I was using 5088 instead of 3707s and for some reason this was my issue. I was correctly installing them into the extra base pad configured for them on the board but for some reason It wasn't working. I replaced them with the 3707s and all is well.

 

[phatmateo]

I'm using 2n5088's so I'll let you know how mine goes when I test it.  I was also wondering what tp10 and 11 are for as well.  You aren't alone orangerec

 

[mnats]

Ok, I figured it out. I was using 5088 instead of 3707s and for some reason this was my issue. I was correctly installing them into the extra base pad configured for them on the board but for some reason It wasn't working. I replaced them with the 3707s and all is well.

Either transistor will work just fine if the devices are functional and they are correctly installed.

 

[mnats]

I'm using 2n5088's so I'll let you know how mine goes when I test it.  I was also wondering what tp10 and 11 are for as well.  You aren't alone orangerec

Have either of you taken a look at the schematic or the calibration procedures?

 

[orangerec]

Hey mnats, yes I have followed the cal. videos. I have built a few DIY projects including a G1176 with great success, but I'm not as savvy as some around here. I am a novice and have been involved for about a year.  I'm definitely not stating there is something wrong with the board. I troubleshot to the best (limited) of my ability but, I couldn't get it to work with the 2N5088s. Thank goodness for this forum. I'm a full time audio engineer and love using my own gear.

 

[0dbfs]

Hey orangerec,

Did you end up swapping all of the 5088's or just the ones in the gr section?

Cheers,
Jonathan

 

[orangerec]

I just changed all of them.

 

[ethervalve]

For those who haven't already ordered parts, I'd just like to add that my experience mirrored what mnats said on his revA page:

The 2N5088 typically has a higher beta than the 2N3707 in the samples I've tested.

I bought forty 3707s and not a single one had an hFE reading high enough for Q7-Q10; All the 2n5088s I tried were well over 250 hFE.

So I used the 3707s everywhere else. I hope it works out ok...

 

[orangerec]

ethervalve,
Have you tried it out yet? I just swapped them all out but I'm going to try the 2N5088s on Q7-Q10 later. I put all of them on sockets, so it will be easy to swap.

 

[ethervalve]

great idea using the sockets...
sadly i haven't fired it up yet... I'm just waiting with bated breath)for a friend to finish drilling/labeling the case for me.
So what do you think of yours so far, orangerec? All the bugs ironed out? was it worth it for you?

 

[dukasound]

Hi Mnats
If I decide to buy your pcb's, because in my country doesnt work
Paypall how is possible to pay you. Too how much can be shipping
to Montenegro, Europe, for one or two set.
Thanks in advance
Duka

 

[orangerec]

Sorry for the late response, been working for a couple days straight. YES! Definitely worth the build. Like I said, we have a couple blue stripes at work and upon firing up mine, I noticed the power transfer curve (character) is very much like the original. I haven't used it in a mix yet, waiting to install it in a box and I also need the faceplate. It seems like mine also has a bit more headroom than the original at the input. I do have a little issue with the "all buttons in" mode.  Mine distorts but I haven't investigated it yet. So far I'm happy, more later. Back to recording.  8)

 

[Stagefright13]

As far as transistors I used 3708's on all 3 of my Mnats compressors. They almost always pass the 250 test. This was noted in the rev D thread about the 3707's poor performance... But Noteworthy here I am sure!

If you don't have an hfe tester the 3708 will work just fine. I had only 1 slightly low one out of maybe 75 of them.

My Rev A is only waiting on a case wich should have any day. Can't wait!

PS. I got some more carbon resistors for my board so I will change out the ones in the audio path after I get it running to see the difference. I am measuring them for actual value first. I got alot. Details pending...

John

 

[Stagefright13]

WOW that's a pretty extensive BOM 0dbfs. Thanks for sharing. As far as I can tell all looks good to me. But I am just an amateur experimenter. But that looks like it took quite alot of work! Great job!

John

 

[orangerec]

Stagefright13, have you run signal or calibrated it yet? I have 3707 on sockets and have replaced them with 2N5088s with no luck (yes, I used the extra base pad). My unit only works with 3707s. I am having a problem calibrating the unit with the null and zero adjust. The DC voltage across R74 is always .851 and as I change R75 there is not change on the DC meter but my VU meter reacts to the adjustment. So your saying the 3708s pass the test, I'll probably try some of those.

 

[Stagefright13]

Nope, drilling holes in the case right now... Be a while before I fire it up. Will let ya know.

 

[ethervalve]

bump. Any updates with your builds folks?
I'm currently troubleshooting a couple problems on mine (ground loop and problem getting the vu to zero... more than likely just careless mistakes on my part)

 

[orangerec]

Ok, I'm closer. I used the 3708s in place of the 3707s and the unit is responding well, thanks stagefright13. I ran all the calibration procedures and the unit is working. The slight issue I'm having is on pads tp10 ad tp11, where I measured the DC voltage for R75 (null adjust), I could only get a reading of 0.21, while the revD threads mention this should read 0. Is my reading of 0.21 ok (close enough)? My trim pot (multi-turn) is turned up almost all the way. Hoping an experienced builder could chime in here.

The other weirdness I'm experiencing is with my release pot. When I turn it all the way CW (fastest release) it bypasses the gain reduction. Sounds like the same thing the attack does when turned CCW (off position, using the attack w/ switch). I haven't changed he release pot yet, that'll be my first try, but if anyone has experienced anything similar, let me know. 

 

[Stagefright13]

Mines done except the wiring. Everything is bolted in. Hopefully my session gets done at a reasonable time today and I can finish it later. I'll put an extra pot of coffee on...

Which trimmer did you use for R44? Mnats stated earlier in the thread he used a 5k pot to get some extra adjustment range on his. This is what I did also but I have the other one just in case.

John