Woohoo, first step down the DIY path

[memphisindie]

Originally Posted by Eemo1

... and that's why you should buy the real thing from a store.
we'll, some of the units that people build are not supposed to be easy or have instructions for newbs. learn how to crawl before walking etc.

Not an improvement on silence, yet, posted anyway.

[Tinfly]

Originally Posted by Eemo1

... and that's why you should buy the real thing from a store.



we'll, some of the units that people build are not supposed to be easy or have instructions for newbs. learn how to crawl before walking etc.

I would have to respectfully disagree. If the forum is public, then tacitly everyone is
welcome. Each member has their own reason for being there. I can understand the "crawl before walk" mentality as a personal mantra but to force others - seems a bit extreme.
Why can't those experts just ignore threads that bother them? One doesn't have to share info.
Or perhaps that forum should be private with a vetting process? Seems to me that sharing
info and teaching/helping someone else who respectful is one of the coolest things you can do.
Sorry to push this thread further of course, Dean.

[Dean Roddey]

Originally Posted by Eemo1

we'll, some of the units that people build are not supposed to be easy or have instructions for newbs. learn how to crawl before walking etc.

I did. This is my fifth project, all the previous of which went very well.

[memphisindie]

Dean, ignore that troll.

[Dean Roddey]

I've made some progress. The squealing and distortion is gone. But there are some anomolies that I can't figure out. I've been doing a lot of measuring, but it's difficult because the voltages that everyone says to look at are on the original 1176 schematic which is vaguely like the Mnats one, but only vaguely so. It has the same basic sections, but is pretty different in the details.

When I try to do the Q-bias adjustment, the voltage at the outputs are supposed to stop going up at a fairly reasonable voltage as the Q-bias trim pot is cranked up, like in the upper 1 to 2VAC range I think. Mine doesn't stop anywhere near there. It will go up to like 16V or more. That's clearly not right.

I found one other person who said they had this problem. But then they subsequently said it went away for some unknown reason, so that didn't help. It would seem kind of reasonable to think that it would be some resistor being too low resistance at some point, but I'm not sure. And all the resistors were measured going in and have been checked by eye where there's any question during measurement and all seem right.

The Mnats calibration videos say to crank the Q-bias trim all the way up, then bring up the output to +1. But with the Q-bias trim all the way up, it's putting out enough juice to weld with, so clearly it's not just that the meter based calibration scheme isn't valid, since the same issue exists the other way.

I was at least trying to measure through up to where it started running up really high when the Q-bias is raised up. I kind of ran out of steam a bit ago but I think it was good up to the gate of the second to last transistor, then the drain of that one (which feeds into the last transistor's gate) seemed to exhibit the wild output level. But, does that seem reasonable, that that transitor could raise the level that much?

But whatever was going into the gate of that last transitor seems to be what shows up at the XLR outputs. It seems to drive the brown winding of the output transformer, and that seems to be what directly drives the other side of the transformer, with the others being involved in some sort of feedback'ish type of loop back into the power output driver section. So it doesn't seem like that last transformer is adjusting the level downwards. But all the resistors around those last two transitors seem to be correct, so I don't think that's an issue.

The schematic is at the bottom of this PDF file if anyone cares to look at it:

http://www.geocities.com/m_natsume/f...6LNREVD_V2.pdf

[Eemo1]

Originally Posted by memphisindie

Dean, ignore that troll.

not a troll sir.

just trying to point out, that by getting to know some basic stuff get's you on the way. no need for exact instructions after that. something like wiring a transformer...


i mean, take recording as an example. how to I sync to protools, what's the best mic for x, how do I get levels right... all the usual questions everywhere. what do you tell them? - learn, read this, try that...

you study and practise for years to do stuff like recording or mixing.


btw, I build one 1176, didn't work. tried to troubleshoot it for a week. after a week, I built it again from scratch. bingo.

[Dean Roddey]

Originally Posted by Eemo1

not a troll sir.

just trying to point out, that by getting to know some basic stuff get's you on the way. no need for exact instructions after that. something like wiring a transformer...


i mean, take recording as an example. how to I sync to protools, what's the best mic for x, how do I get levels right... all the usual questions everywhere. what do you tell them? - learn, read this, try that...

you study and practise for years to do stuff like recording or mixing.


btw, I build one 1176, didn't work. tried to troubleshoot it for a week. after a week, I built it again from scratch. bingo.

I don't mind spending years to learn to record in mix, since that's what I'm interested in doing. An 1176 is just a tool to do that. Spending years to learn enough to build my own 1176 from scratch without help isn't very practical though. That would take all the time I have available to do the thing I actually want to do.

It's impossible to build it again from scratch without ordering all of the parts again, unless you are going to try to desolder every part out of the boards, which would be pretty much a disaster.

[Eemo1]

Originally Posted by Dean Roddey

I don't mind spending years to learn to record in mix, since that's what I'm interested in doing. An 1176 is just a tool to do that. Spending years to learn enough to build my own 1176 from scratch without help isn't very practical though. That would take all the time I have available to do the thing I actually want to do.

It's impossible to build it again from scratch without ordering all of the parts again, unless you are going to try to desolder every part out of the boards, which would be pretty much a disaster.

I understand your point. seems like you don't understand mine.

want to mix = spend years learning.
don't want to learn = let someone else do it.

want to build units = spend years learning.
don't want to learn = buy the unit.

[memphisindie]

Originally Posted by Eemo1

I understand your point. seems like you don't understand mine.

want to mix = spend years learning.
don't want to learn = let someone else do it.

want to build units = spend years learning.
don't want to learn = buy the unit.

Want to design mixes = spend years learning, intern, have ears, or, it's all for naught.
No ear or don't want to learn or intern = leave it to a pro

Want to build units on your own time = use the schematic and get help if you need it
Want to DESIGN units for others for money= spend years learning

I understand your point and it's kind of a strange one.
China and other countries have factories full of people that assemble electronics, precision measurement stuff, computers, and high end audio pieces and they don't know one thing about electronics. They just know how to operate their station for next to no money.

[iangomes]

Originally Posted by Eemo1

I understand your point. seems like you don't understand mine.

want to mix = spend years learning.
don't want to learn = let someone else do it.

want to build units = spend years learning.
don't want to learn = buy the unit.

That's exactly it! It wouldn't even take years, just some extra time dedicated to figuring out how the compressor works. Nice!!

Originally Posted by memphisindie

Want to design mixes = spend years learning, intern, have ears, or, it's all for naught.
No ear or don't want to learn or intern = leave it to a pro

Want to build units on your own time = use the schematic and get help if you need it
Want to DESIGN units for others for money= spend years learning

I understand your point and it's kind of a strange one.
China and other countries have factories full of people that assemble electronics, precision measurement stuff, computers, and high end audio pieces and they don't know one thing about electronics. They just know how to operate their station for next to no money.

Nice try memphisindie... but not quite. I'd have to disagree with your equations up there

[Eemo1]

im going to leave this at this.

Dean, I hope all the best to you and hope you get your unit working.

[memphisindie]

Originally Posted by iangomes

That's exactly it! It wouldn't even take years, just some extra time dedicated to figuring out how the compressor works. Nice!!


Nice try memphisindie... but not quite. I'd have to disagree with your equations up there

Well, I think people realize that I multiply when I should be adding....or subtracting...whichever it is...anyway, I'll exit, stage left....or right.....whatever it is.....

[Dean Roddey]

OK, so I've made some progress on the 1176. There was a resistor problem (a 470 instead of a 470K), but then I finally figured out that there's an issue on the ratio board. All this time the focus was on all these other things because it seemed like there was somthing really fundamental wrong, because turning up the q-bias to calibration would create pretty massive output voltages. But, it turns out that the last two positions on the ratio board have a problem. Once I moved down to the lower ratios, it works fine and I can calibrate it. Doh!

So that got me to looking into that, and I realized that A) I have six positions and B) the last one probably isn't the 20:1 mode but a Slam mode and I was using the last one instead of the 20:1 that I should have been using for the calibration and C) I can't even seem to find an explanation for what the six positions are. All the rotary examples I've seen have only 5 positions.

I'm guessing they are 2:1, 4:1, 8:1, 12:1, 20:1 and Slam, but I'm not sure. Anyway, it wouldn't have made much difference in the end that I was on the slam position since the 20:1 is problematic also. So even if I'd realized I was a notch too high, it wouldn't have mattered.

But in the 2:1 through 12:1 modes it seems to be working correctly, though I still need to do the meter calibration in one of the working modes and make sure that's correct. And then I need to figure out what's up on the ratio board that's hosing the last two settings.

At least in the working modes, boy is that a rock-n-roll sounding compressor. Really nice. I was running some bass through it, and it was doing it righteous.

So, it looks like finally I'll end up with my initially planned setup of LA-2A, 1176, and SSL comps, and Neve and API pre-amps. If I can rustle up some bucks later, I'd definitely like to do the stereo 175 vari-my project that Mr. Drip is supposedly working on. That would be the Bus Comp of the Gods, woudln't it?

[memphisindie]

Shouldn't the last position be a ducking mode? Like an infinity setting.

[Dean Roddey]

Originally Posted by memphisindie

Shouldn't the last position be a ducking mode? Like an infinity setting.

On the older rotary versions, which is all I've found any pictures of, it's a slam mode. But, I think you have to make some modifications elsewhere for the slam mode to work. But, that might be only relevant to older versions, not the most recent one. That's always the problem. It's hard to know what's relevant to what versions and variations.

I seem to vaguely remember seeing some mention at one point of a 2:1 or 1.5:1 mode being added at some point, so I'm assuming that that's the first one, which would leave the usual ones (4, 8, 12, and 20) plus the slam mode. So I figure that's the deal.

[Dean Roddey]

Drip has now officially pre-announced their Fairchild 660 project. It's on the main page video now:

Drip Electronics . com

That will be pretty cool.

[mobius.media]

Originally Posted by Dean Roddey

Drip has now officially pre-announced their Fairchild 660 project. It's on the main page video now:

Drip Electronics . com

That will be pretty cool.

Pretty damn awesome. Wow, I hope Drip keeps putting out more great projects like this well into the future.

I bet that's gonna be an expensive one to do well. 12 tubes per channel plus the trafos.

I still think I'd do the 175b stereo first due to separate attack release controls (which the 660 likely won't have) and probably better bus comp performance for less money, but that's awesome he's offering this. Very tempting. Who doesn't want a Fairchild?

I hope he does some demo vids like for the 175b.

[Dean Roddey]

Yeh, it's not like a stereo 175 would be any sort of slouch by any means, and probably something you could bring in for maybe $1200'ish or something like that, or maybe less. I'd probably go that route myself before building a 660. But it would be pretty cool to have a monster like that for tracking. 12 tubes and a few trannies should certainly toast up that signal a bit.

[monkeyxx]

ooh nice! I am interested in further advice as to which would be the most useful to add to my collection.

[Dean Roddey]

Originally Posted by monkeyxx

ooh nice! I am interested in further advice as to which would be the most useful to add to my collection.

Obviously the 660 vibe is pretty nice and all that, and I'd love to do one. But if you saw the 175 demo video he had, that thing kicked some pretty serious butt. That vari-mu 'one big giant knee' type of compression definitely seems to have something very nice going on, and so different from other things. A stereo pair of those would be pretty massive for a lot of things I think.

[Dean Roddey]

So he posted some pics from the prototype board of the 660, and he says it's probably going to be $2K+ to build one, because of all of the trannies and tubes. And, I hadn't thought about it, but I guess it's stereo as well, so that makes it less of a hit at that price. Though, there again, you could do two 175s for somwhere in the $1500 realm, so that would still make the 660 a luxury item.

He did say though that it can be either a 660 or 670, according to which jumpers you install.

[Dean Roddey]

He has a first demo video up of the 660 prototype, and some pictures of the building of the first one. It's going to be a fairly challenging build I think. And of course doing two in the same enclosure will make it more so.

DripElectronics.com • View topic - the process

[Empty Planet]

This is a cool thread. Nice journal of your experiences, Dean.

Admirable resolve!



Cheers.

[Dean Roddey]

And I didn't even get into my tempestuous love affair during the Russian Revolution. I should get motivated and update it with the longer term 'where are they now' perspective and whatnot. I'll do that soon.

[Dean Roddey]

He posted some likely pricing today. The 660 $2300, and to add another channel for a 670 $3600. So fairly pricey, but trivial compared to what you would end up with compared to anything else out there that implements that design. Compared to an EAR at $11K I think it is, that's a steal.

[ddageek]

Dean Just wanted to let you know your projects convinced me and my 8 fingers to build the Classic Audio Products of Il pres!

[Dean Roddey]

Of course my lawyers are now insisting that I include in the fine print that anyone who kills themselves or destroys the known universe or becomes incapacitated in any way while building a DIY audio project inspired by this thread has done so purely of their own volition and neither Dean Roddey nor any of his world wide holdings, subsidiaries, mistresses, or minions (evil or otherwise) are responsible in any way for said mishaps, unless of course there's something in it for him in the way of insurance claims or sexual gratification.

[rkopald]

Dormant thread ressurection. Apologies. Nice read though, I think I might have to try to build something this year also. Nice work Mr. Roddey. I'm a little worried because I've only done basic soldering, but I think I'm going to do it anyway.

[tazman]

I built my SCA N72's, A12's and J99's about 2 years ago and they rock. I plan on building the MNAT 1176 Rev D, hopefully this winter. next will be the LA2A. I'd love to build two 1176's and have them lined for stereo.

I have a Distressor and am wondering if the 1176 will be THAT much different or would I be better off going for the LA2A to start with?!?

[Dean Roddey]

Originally Posted by tazman

I built my SCA N72's, A12's and J99's about 2 years ago and they rock. I plan on building the MNAT 1176 Rev D, hopefully this winter. next will be the LA2A. I'd love to build two 1176's and have them lined for stereo.

I have a Distressor and am wondering if the 1176 will be THAT much different or would I be better off going for the LA2A to start with?!?

I would do a Drip LA-2A. That will be fundamentally different from the Distressor (though the Distressor can sort of emulate that type of thing), and a vastly easier build than the Mnats 1176 because it's far better documented. I love mine. My 1176 is nice as well, but it was much more of a struggle to get done, and the same is happening to another person here on another thread right now. And you won't get anything like the help that you will doing the Drip stuff.

He also has an LA-2A that has both a fast and a standard type opto cell that you can switch between, which would be pretty nice. The LA-2A thing is really nice, but sometimes you can't use it because the 10ms attack time just isn't quite fast enough.