All things G1176 - the new "repost" thread.

[Consul]

Okay, here are the links:

http://studioconsul.net/techtalk/stereo1176/jh_comp_psu.pdf
http://studioconsul.net/techtalk/stereo1176/jh_fc2_sch1.pdf
http://studioconsul.net/techtalk/stereo1176/jh_fc2_sch2.pdf
http://studioconsul.net/techtalk/stereo1176/jh_fc2_sch3.pdf

Very interesting stuff, but it wasn't exactly what I'm after. I remember a posting on the old board about some device that can link 1176s in stereo.

Thank you much for the info anyway, though, Apache5. And if anyone wishes me to take these schematics down, I will do so post haste.

 

[boodthee]

Hi Consul and everybody else!

First of all (as this is my first post), I want to say thank you to everybody here for this great forum and especially to gyraf for the great projects!

I am currently in the process of building a dual 1176 which I also want to make stereo linkable. I was about to ask the same question as Consul here...
What I found on the net is this schem of the 1176 Stereo Adapter
http://www.jblproservice.com/pdf/Vintage JBL-UREI Electronics/UREI-1176SA.pdf
But on the other hand I think somebody said (somewhere?!) that it would be possible to just connect the units as is...?!?
It would be great if someone could explain what the stereo adapter circuit is actually doing as I don't fully understand it...what is the battery for? And is it possible/advisable to link two 1176s directly?

Thanks in advance
Stephan

 

[mnats]

There was a good thread that covered stereo linking but it must have been at the old forum. From memory the thread went like this: someone tried various published circuits found on the internet. The JBL document contained what was thought to be an error in the resistor value. It looked like someone penned in a new value on the BOM in the UREI-1176SA.pdf document. The Purple Audio circuit was similar and also didn't work properly. I believe one or the other caused excessive battery drain. I think deanp920 had two linked fairly closely by simply matching the two gain control FETs.

Apparently without trying it out himself, Jakob casually tossed out a suggestion for modifying the stereo link circuit and suddenly everyone had a working stereo link when all previous published circuits failed. I must have archived it somewhere and will post back when I find it unless this jogs someone else's memory.

 

[The Landlord is Dead]

I can't find the BD518/517 driver transistors nor the replacements suggested at the NRG web site.

I read somewhere that they can be swapped with NTE189 & NTE128P, in stock and available at mouser. Anyone try this? Are they pin compatable?

 

[orson whitfield]

THE FOLLOWING ARE QUOTES I GATHERED FROM THE OLD REPOST THREAD REGARDING THE BD517 and BD518:

"BD518 = NTE189 - check with swedish chef, has some 518's that are replacements from Jakob
BD517 = NTE128P"


"BD517:
..And also make sure that you've mounted BD517/518 correct: one is oriented opposite of the other..-- check with swedish chef, has some 518's that are replacements from Jakob

NTE 128P's for the BD517's
I got the BD518 and BD517 from www.telepart.co.uk.

BD518:
..And also make sure that you've mounted BD517/518 correct: one is oriented opposite of the other..- check with swedish chef, has some 518's that are replacements from Jakob

NTE 189's for the BD518's
I got the BD518 and BD517 from www.telepart.co.uk. "

 

[mnats]

[quote author="The Landlord is Dead"]...nor the replacements suggested at the NRG web site.[/quote]
BD135 @ Mouser
BD136 @ Mouser
Lots of their stuff doesn't appear in the print/.pdf catalog. Just do a search on their site.

 

[Jonathan Hayward]

Orson, you sorted?

the attack is dramatic comparing fully ccw to cw, try speech or recorded speech.

The unit needs a shot while 1/2 hour on the safe side to warm up to a stable temp. My regs were too hot to touch so maybe don't worry about that if the supply voltages are good (-10/+30), but does your intermittent noise happen after this warm-up?

I'd really recommend even a cheap old scope for this project (evilbay £10 job), espesh as you already have the signal gen., you really get to understand its operation more clearly.

 

[The Landlord is Dead]

BD135 @ Mouser
BD136 @ Mouser

These have a minimum of 2000 per order. I'll just stick with NTE suggested replacements. It brings up a question though, what does it mean when they add an "S" or "STU" at the end of a product number. As in BD13510S or BD13510STU instead of just BD135. I assume you just can't automatically swap.

 

[Jonathan Hayward]

no suffix, S and STU are basically the same thing. If you look here
http://www.fairchildsemi.com/pf/BD/BD135.html

the page heading is bd135, but it shows the two suffixes being different packing methods, the packAGE - the TO-126 case - is the same.

If you get really stuffed, I'll post you a reasonably matched pair (136/137) which I used in my first 1176 - some of my haul from a skip after the Lewes flood.

 

[mnats]

[quote author="The Landlord is Dead"]
These have a minimum of 2000 per order.[/quote]

Sorry, yeah gotta watch out for those minimums from mouser. I also offer to send you a pair of 135/136s if you get stuck.

 

[orson whitfield]

Johnathan,

Thanks for asking. I checked the -10V/+30V and the numbers were darn close, closer than ever before but I didn't stop to see if there was a "-" next to the 10V places. Oh well, on my way to a gig so I don't have time to check again but i guess they were negative. THe point is the read outs were very close to what they are supposed to be. Ok next thing, the intermittent noise. Its all gone! I don't know what it was but its not back. :? :roll: Lets hope it stays that way. By the way I am on the look out for an ascilloscope, thanks for the rec.

Now, for the attack situation, I recorded myself reciting a tongue twister into Logic Audio (emagic) and looked at the wave file overview to inspect the differences between a full ccw setting and a full cw setting. The difference was that full cw limited the peaks and full ccw position allows the peaks to be a lot higher. For this test, I set the compression to 1:20. I guess the results are normal and expected; a fast attack doesn't let a lot of volume out the gate and vice versa for slow attack. I guess I expected a different result out of a 1176 style compressor where a slow attack really meant slow attack. Here it's really hard for ME to tell that it's slower. Overall it just sounds lower volumed and "compressed". (To all you people rolling your eyes right about now, remember I have never twisted the knobs of a real 1176 before, so I wouldn't know what they do).I also noticed a slight attenuation of the high frequencies aswell when the attack was set full cw. So, does this sound like its working to you?

Below are questions I posted but no one addressed.

Instructions on calibrating the G1176 from Gyraf web site:

"4: "GR meter Trck" (tracking). Set ratio to 1:20, set Meter to bypass. Input a 1kHz, 50mV signal. Set input level to ~12'oclock. Set output level so you get 50mV at the output also (now you have unity gain)." -

When I do this, I can't get anything higher than 20.9 mV at my output. Also, I am checking voltages using the AC voltage setting on my multimeter. Is that the correct setting or is DC?
When I turn the Output knob on the G1176 I get no difference in mV's.

Thanks for the patience and continued help. :thumb:

 

[deanp920]

Below are questions I posted but no one addressed.

Instructions on calibrating the G1176 from Gyraf web site:

"4: "GR meter Trck" (tracking). Set ratio to 1:20, set Meter to bypass. Input a 1kHz, 50mV signal. Set input level to ~12'oclock. Set output level so you get 50mV at the output also (now you have unity gain)." -

When I do this, I can't get anything higher than 20.9 mV at my output. Also, I am checking voltages using the AC voltage setting on my multimeter. Is that the correct setting or is DC?
When I turn the Output knob on the G1176 I get no difference in mV's.

Orson, If you use your DMM, you MUST stay within its' AC frequency response range, which is probably no more than 400Hz. Check your manual. There's no telling what reading you'll get at 1Khz. Stay around 250Hz so you can at least discount any errror in your meter.

Another crude yet effective meter is the software version of a VU meter that can be downloaded for free from PSP Audioware. You can calibrate it and everything! Works OK in a pinch.

Your DMM at a lower test freq.(250Hz) is much better, though.

Dean

 

[jhaible]

[quote author="Apache5"]I have 4pdf schematics about a stereo compressor based on urei 1176. I download them some months ago, but i dont remember where i found it. I can send to you by mail if you want... The title in schems is "JH .FC2 Stereo Compressor based on Urei 1176 J.Haible 2001"

Arnau[/quote]


You can find it here:
http://home.debitel.net/user/jhaible/hj.html

JH.

 

[al_p]

Hey Guys

i'm getting ready to put together a G1176. i just noticed the min order for the BD135/BD136 too. ouch. i guess i?ll go with the NTE subs.

one quick question. the push button switch banks on the REAL 1176, are these interlocking or latching? i know when you engage a new selection the previous selection disengages. but i got confused and forgot which is which. i THINK it?s interlocking...but i am seeking confirmation.

i'll hopefully be back in this thread next week, when constrution begins.

-AL

 

[orson whitfield]

Ok I think :roll: its callibrated. Is it normal for the Vu needle to be at - 20 when the compression is set to 1:4? The only time it's at " 0 " is when the compression ratio is set to 1:20. Once I reached the point where "the output level [was] half the input level", I set the "GR meter Trck" trimmer so the VU-meter read -6dBVU. But I was only able to do that after I played with the zero meter trimmer. I then "remove[d] [the] input signal and (re)set "GR meter Zero" for a reading of 0dBVU". This was the only way to get it set. Am I on track here? And by the way my DMM measured freq. from 10 Hz to 40mHz.

 

[The Landlord is Dead]

i'm getting ready to put together a G1176. i just noticed the min order for the BD135/BD136

Looks like http://www.digikey.ca/ has them without a minimum order.

 

[deanp920]

And by the way my DMM measured freq. from 10 Hz to 40mHz.

NO, that is referring only to the frequency values the meter will measure; ie., telling you what frequency a particular signal is alternating at. That specification has NOTHING to do with frequency response, Orson.

You are trying to measure the AMPLITUDE of a particular signal at a particular frequency.

Unless your meter is a very new one and cost better than $250, it probably won't make accurate AMPLITUDE measurements at frequencies over 400Hz.

Check your manual again.

Am I on track here?

I don't think so.

I think Mark Burnley posted a copy of my post from the the "More Gain" thread in the old forum where I wrote down all my calibration levels and voltage gains, including a synposis of the surrounding details of my test procedure. Find that info and try to duplicate those conditions. The numbers provided there reflect the G1176 working properly in its' unmodified condition. Just drop your test frequency to 250Hz to be safe side.

Is it normal for the Vu needle to be at - 20 when the compression is set to 1:4? The only time it's at " 0 " is when the compression ratio is set to 1:20.

It is impossible for us to know what that means without you providing details of the test conditions; ie., input signal level, where all the controls are set, etc.

Find a solid frame of reference(like the one I mentioned above), document it the next time you post for help, and let's go from there.

Take care,

Dean

 

[orson whitfield]

[quote author="deanp920"]
It is impossible for us to know what that means without you providing details of the test conditions; ie., input signal level, where all the controls are set, etc.
[/quote]

THank you Dean. What I meant was when NOTHING is plugged into my G76 and the power is on and I set the compression ratio to 1:20 the Vu needle is at 0. When I adjust the ratio to 1:12 and lower the needle gets closer to the left.

I am looking for that info.

 

[gyraf]

If the FD333 diodes are leaky, there will be a small difference in meter zero resting position depending on ratio. But it should not be more than +/- one dB or so on the meter scale.

Are you using "real" FD333 diodes, or a substitute?

Jakob E.

 

[orson whitfield]

I believe I have the correct specified part. I ordered part number 18C6399, Fairchild semiconductor FDH333. Here is the link from Newark:
http://www.newark.com/NewarkWebCommerce/newark/en_US/support/catalog/productDetail.jsp?id=18C6399

And here are it's specifications:
http://www.fairchildsemi.com/ds/FD/FDH333.pdf