ADR F769X-R

[ej_whyte]

I have a ADR F769X-R "Vocal Stresser" which could do with a bit of work, but I'm not sure whether I want to keep it or sell it. I've heard they are a but tricky to set up, so i'm not completely sure how much work it needs really, as without the manual I don't know if its just user error.

The meter glass is smashed so that definitely needs replacing, although the meter does work. Still trying to work out the I/O. One pair goes through the whole EQ & Comp chain whereas the other is only the dynamics section or something like that? All the dynamics functions seem to work as the meter moves as expected, likewise with the EQ, however as I mentioned, I haven't verified the audio quality as I can't get any output. Also power lamp goes off after a couple of seconds although unit continues to work.

I know the manual is available from ADR, but just thought it was worth checking if anyone has a PDF to share?

What is the rough value of this unit, both in its unrepaired state and if I went through it all recapping etc.?? It has the optional sowter(?) transformer IO

Thanks

 

[abechap024]

Beauty.

 

[desol]

I'd say it's probably worth $800 to 1.2k in good working condition. I've never used the unit but the compressor is well known...i've read at a few different places that the eq's weren't as special...YMMV. Unit has the nice transformers.

Meter glass should be available from Sifam. Director 14 series.

 

[Brian Roth]

The schematics for the Compex are here:

http://www.brianroth.com/library/audio+design/

I have the additional Vocal Stresser schemos, but I'm away from home for a few days.

Bri

 

[abechap024]

I would say recap it and try it out. I've heard these are great units. And looks likes everything is on cards that can pull out. That makes it even easier.

 

[Sammas]

I have an almost identical unit. It will certainly need a recap!

Mine also had cracked glass on the meter. I found it very similar to repair using the clear plastic disks that come with a stack of 50 CDR's. You know, the clear protective disk on the top and bottom of the stack?

Removing the meter is tricky, but get it out and remove the bezel. Break out the remaining glass, cut your plastic to size, stick it in, reassemble and you are away!

Next to my C1 meters, it looks identical!

 

[ej_whyte]

Good idea on the meter plastic, I'll have a go at that. Anyone care to give a guess at its current value? Im too busy to fix it at the moment but I need some money :/ trying to weigh up whether to sell it as is or wait and fix it to obviously sell it for more.

If I could have the full schematics when you are back Brian that would be great thanks

Cheers

 

[topcat]

The schematics are available from the rather spiffing AnalogRules wesite
http://analogrules.com/manuals/scamp1.html
The 760 file include the 769 data
Great piece of kit...was the default standard creative tool (along with an AKG spring reverb) in many UK commercial radio stations in the early 80's...Many creatives found it quite difficult to come to terms with (too many knobs?)...

Enjoy the possibilites
tc

 

[chriss]

I have two compexes in my studio and I'd say once you understood how they want you to set them up, it's not that tricky at all. You just have to a) switch in the limiter only (set the compressor's ratio to 1:1) and set the input to make it limit whenever there are real peaks. And then you can b) Switch the Limiter off or leave it in - just as you like and go on with the rest of the setup.

I like these units a lot. I'd say they are way better FET-compressors than the1176s and not as hyped as these.

Chris

 

[topcat]

I'd say they are way better FET-compressors than the1176s and not as hyped as these.

Totally agree Chris....very sweet devices...
the guy's at A+D came up with some great bits of kit... The Compex 2 was very underrated too and the panscan was also lot of fun


tc

 

[abechap024]

You could try to put it on the black market. Hard to say how much someone would pay for it...considering the condition, I would say low end 600$ high end 1,000$ but who knows. Thats coming from someone who thinks fixing it wouldn't be that hard....

But for all we know, maybe the transformers are fried? (the transformers alone are probably worth around 400$)

If you at least got it passing signal you could probably get at least $800...

 

[pucho812]

If you want character those units have character.  The vocal stressor and the compex are awesome.  However they do take some time getting used to. I have a client who has both and loves them. Although at first he would swear that the compex never worked.  I tested everything from wiring to the unit and never found a problem but he would swear it doesn't work.  So one day i say with him and watched him use it, well of course it didn't work for him because everything has a volume control including a stereo volume controls(input and output) that are independent from the 2 channels and is always working even in dual mono mode. So not only did the individual compressors have I & O volume control there is also a main stereo volume I & O control. Quirky unit in terms of how it operates but boy what a sound. It's responsible for the drums on when the levee breaks. As for the vocal stressor it's cool too. Worth fixing and using for sure.

 

[fazer]

The Stressor was my go to compressor/EQ for vocals back when I worked on a Neve all the time.  Once you dial them in, its a great vocal sound.  I think the EQ has a great sound.  It was back in the 80's I used it.  I have a Scamp rack I bought from someone closing their studio and still use SO1s and the S24 analog delay/flanger.  Also have a panner and the parametric EQ's .  I like the simple Eq in the stressor way better.  Sounds more natural in the top end.  My S01s have needed repaired and mostly calibrated numerous times over the years.  Once you get them calibrated, things start working really well. Nice on drums/toms.

 

[desol]

I just purchased a pair of S01's that i'm racking. I'm looking forward to getting them going. The trimmers look a bit grungy and they look like they need a recap..., and probably need to be recalibrated.

Pucho: Pretty sure the comp's used on Levee were the older F700's...which were vertical units in a helios desk.
Both the Scamp and i believe the Compex are based on the F700 circuit.

 

[chriss]

It's responsible for the drums on when the levee breaks.

Of course the LZ-drums have nothing at all to do with John Bonham... I knew this myth HAD to appear in a compex-thread. :-\

 

[ej_whyte]

Looks like I will keep it for now and fix it up when I get a chance then. Can anyone shed any light on the two different sets of XLRs?

Thanks

 

[David Kulka]

Below is the text from an addendum that I wrote for the F769X-R manual, which attempted to untangle some common confusions with this unit. (I guess I was feeling a little sarcastic or impatient when I drafted it. )

[size=10pt][size=10pt]"The ADR F769X-R Vocal Stresser is a unique box with powerful capabilities, but new users are often puzzled by some of the unusual (and confusingly labeled) connections and controls. Here are some tips to help you get started, and better understand the main functions (and design quirks!) of the Vocal Stresser.

1. The first thing you need to know is that this is a mono unit with one EQ and one Compex compressor/expander, that can be combined in various ways. Don’t be fooled by the mono/stereo coupling switch, which is not even connected on most units! The Channel 2 XLR’s on the rear panel are the main input and output connections. On some units this is indicated on the silkscreening, but on others it is not.  (Why was Channel 2 the main I/O? Just to confuse people, we suppose.) If you have a patchbay, connect both pairs of XLR’s. Channel 1 is the Vocal Stresser In/Out, and Channel 2 is the EQ Only In/Out.

2. These units were wired Pin 3 hot, and most are unbalanced. (Transformers were available as an option, but few units have them.) If you are patching into balanced gear everything will probably be fine, but if you are patching to or from unbalanced, your XLR cables must be wired Pin 3 hot, or you’ll have problems. Some units have been converted to Pin 2 hot. To avoid problems, we suggest that you pop the cover to check whether it has transformers, and to see whether it’s Pin 3 or Pin 2 hot.

3. Now it’s time to power up and learn the operating modes, which are controlled by 3 switches. When the 3-position EQUALIZER switch in PRE, audio goes through the EQ, then the Compex. In POST, audio goes through the Compex, then the EQ. In SC (sidechain) mode, EQ and Compex I/O are split, but the EQ out drives the sidechain or the Compex. In other words, the Compex output is not EQ’d, but gain reduction or expansion is. Boosting the 5-10 K range on the EQ section can make the Stresser act like a de-esser. (The unlabeled lamp above the EQUALIZER switch is just a power light. It does not indicate modes.)

4. There’s another very important switch - SYSTEM IN/OUT, on the left side of the EQ section. This switch isolates the EQ and Compex sections. The manual explains that when IN is selected, the EQ and Compex and chained and with OUT selected, they are separate. However, on many of the Vocal Stressers we have seen, this switch is installed backwards! (Why? Just because it’s English, we suppose.) Experiment with this switch to see whether or not your labeling is correct. If your switch is not correct, we suggest that you rotate it, or make your own labels, to avoid confusion.

At this stage we’ve cleared most of the initial hurdles, and you should be ready to start Stressing. Most of the EQ and Compex controls are straightforward, but here are a few more pointers...

• The Compex SYSTEM IN/OUT switch is just a bypass switch for that section. It doesn’t change signal flow in the unit.

• The limiter and compressor sections are separate and can be used at the same time.

• In many units, the MONO/STEREO COUPLING switch is not connected. However, by adding a connector to the rear panel, two Stressers can indeed be linked for stereo use."[/size][/size]

 

[ej_whyte]

Hi David,

Sorry I've only just seen this reply, thanks for all the info, i'll give it another try later. There is just one point i find confusing still, you say Ch2 is the main I/O, but then in the same paragraph say that Ch1 is the vocal stressor and Ch2 is EQ only?

Cheers
Elliott

 

[ej_whyte]

Right, I had a good fiddle with it today and I think i've got it cracked. Thanks for the advice David, after reading it back it does make sense but its just hard to follow when you haven't got the unit there with you.

Basically Ch2 goes through the whole channel strip and functions just as you would expect. Ch1 is like an alternative input + output for the EQ section, which is selected by putting the EQ system switch to out, and when set like this the signal going to Ch2 still goes through the compex.

Well now that i've got the hang of it it all seems to work Pots could do with a bit of clean and possibly a recap, but thats all, pretty good for ~30 years.

Cheers

 

[ej_whyte]

The unit is now in the black market BTW: http://www.groupdiy.com/index.php?topic=51886.0

Cheers