vintage 1176 restoration PICS!

[soundguy]

I finsihed it up right before my session tonight and was able to put it to work, sounds really good, totally different from my old 1176 and the purple, which was my goal. I restuffed the board with all holco resistors, used black gate electrolytics and panasonic metalized film caps. Kept the original in/out transformers and have a torroid in the power supply. After I calibrated it, I noticed the power supply was sitting at 31V, no smoke or anything, is this ok?

Im gonna order some to find out, but do you guys think the 2n3707's have a significant sonic impact on the unit? I had 2n3391a's in the sidechain and they didnt work, but 2n5088's are working fine right now.

I put the ratio switch bank on independant DPDT's and then added a spdt on the panel from the attack switch to switch the limiter circuit in and out. I think, however, this was redundant, it seems like if I switch the all the ratio switches to the off positon, the limiter circuit gets bypassed. If anyone else tries this, might be something to look into.

Is there a way to use a marinar 31267 for the input transformer in this circuit without modification?

I need to post some pictures and eventually some sound samples.

thanks everyone for their help, this box turned out really cool.

dave

 

[Svart]

I'm working on using 31267's for my N*ve pre inputs but they are giving me trouble at the moment.. if only i knew more about trafos..

:thumb:

PS. finishing up the frontpanel for my dual mono 1176 box. It's been "working" for a while though it seems to act a bit funny.. the input and output gain are very sensitive and when turned up slightly lead to a large jump in hiss and hum.. I've also noticed, or rather barely noticed it compressing.. watching the console VUs tell me that the unit is working but it's hard to tell by ear.. is this normal for this unit? I don't have a real one to compare it to.. I'll be working on it more as I finish my neves, my 9k pres, my optocompressors and other various works in progress

:guinness:

 

[soundguy]

svart-

I havent built one of the 1176 versions up here as projects yet, this current thing Im doing I built on an old 1176 board. Based on this old circuit and the purple audio update to it, when it kicks in, its very noticable. The meter tracking can be set up to be very good as well, Ive found with mine, there isnt much gain reduction that I can notice before the meter moves. I dont know if this is applicable to the projects up here, but assuming the meter control part of the circuit is the same, I dont see why it would behave differently.

dave

 

[Svart]

well I meant the Vu on the console from the feeding track and the VU on the return track from the 1176 since i haven't installed the VUs in the compressor yet.. :green: the channels are set to unity and you can watch the VU on the return channel go down as you compress more.

ah but i'm not worried about it right now it *works* and I'll be digging into it soon enough..

good luck!

 

[soundguy]

I tried out some marinar 31267's on the input tonight-

the spec utc input is 500/200 so 2.5:1 right?

I tried the 31267 at both 10K/2k4 and 10K/600. The smaller ratio sounds much fuller and present to me and I think I prefer it in this circuit based on the following:

I have an old 1176 which I recapped with BC caps and its basically a cool fuzz box, very dirty. I also have a purple MC76 which is much cleaner and probably my desert island box. I wanted to turn this 1176 into something that would sit between them both and with the components I selected, it sounds really cool but it is a bit sterile and dry sounding yet dirtier than the mc76. This was with the ouncer. With the neve iron, it got chunkier and a little more distorted in a good way.

Can anyone help me to understand how the circuit is reacting in regards to the impedance the circuit is seeing from both the ouncer with the 200 ohm secondary and the 31267 with the 2k4 secondary? My practical understanding of transformer implementation is basic at best, so bear with me... Should I not be focused here on the impedance present on the secondary but just look at the ratio of the transformer instead? I imagine some circuits are more specific about input impedances and perhaps this one is more forgiving, I dont know. Just trying to get a basic techincal understanding of how the circuit is reacting to the differences between the two transformers. I of course understand that the transformers sound totally different and are presenting a different texture to the circuit but a little "book smarts" on this one might do me good right now. The circuit seems more distorted with the 31267 in comparison to the ouncer, wondering if this is because of the different turns ratio or if it is because of the diffferent impedance on the secondary? also, with the secondary in parallel the quality of the distortion changed quite a bit, the bass seemed a little rolled of in comparison, and of course you get that "in front of the circuit" thing that happens with higher turns ratios.

anyhow, thats my reaction now, any thoughts from you guys?

dave

 

[gyraf]

[quote author="soundguy"]the spec utc input is 500/200 so 2.5:1 right?[/quote]

No, sqr(2.5):1= 1.6:1 - turns ratio is square root of impedance ratio

And 31V is fine for the 30V line

 

[soundguy]

check it kids:

http://www.glideonfade.com/images/tech/1176.jpg

http://www.glideonfade.com/images/tech/1176inside.jpg

sounds REALLY good.

dave

 

[Family Hoof]

Dave,

That looks really cool! What are you planning to do about front panel markings? I'd leave it mostly empty if it were mine :grin:. Also, what prompted you to change the input trafo to marinair? That's totally awsome that it worked out. Congrats.

 

[soundguy]

I dont bother with front panel markings ususally, just a piece of tape, kinda prefer the mad scientist look. If Im not engineer a session here, Im at least in the building if someone needs to know what is what but Im the primary user at the studio, so its not a real big deal, I know whats what. If I had a more commercial structure I would likely label the panels though.

I have an old 1176 and a purple, I initially put a ouncer on the input of this one as well, and since I built the thing from the start to sound different from the other two, I started plugging in other input transformers and liked what the marinair did in conjunction with what I had soldered to the board. It was a pretty clean sounding circuit, so the marinair helped to dirty it up a bit, I think it might be a little over the top on an old 1176 though.

Im so psyched that this thing came together, got to use it on a session recently and it was awesome. In retrospect I kinda wish I had used a gold panel. I have a rev F 1176 that Im thinking of doing the same thing to, I might do a gold panel on that one.

dave

 

[radiance]

Congrats! Looks very Good. Also glad to hear it sound's good. Did you compare it with a Gyraf clone?