Gyraf 1176

[MJGreene Audio]

In my humble opinion compared to the 1176's and SSL bus comps that I use in studios its a case of close enough for rock and roll.

That is very well put.... After using well over a hundred different 1176's and about 50 LA2A's and noticing that virtually none of them sound the same you just have to go with the general flavor of the units. Use the ones that sound good or great and leave the ones that sound like crap or just don't seem to be working un-patched and un-used. They are all in the same family, even the reissues and purples, and all give similar results.

At the end of the day if you have the time to split hairs about the re-issues or the kit then maybe you should be either getting on with your work or just working harder.

My exception to that would be the $1500.00 fuzz boxes mentioned above that should either be sent off for repair or just used for target practice.

I always use the phrase: "Quit your bitching and just start fixing." We can bitch all day about whats not right but what we should be doing is just getting the best out of what we have.

Rant over, Your milage may vary.
Michael Greene

[Hulk]

I have build the G1176 and it sound great I have put in the SLAM funktion too and if you take the time (and money) you can make your DIY look great!!

[GGreen]

Heres a somewhat blurry picture of my first pair....

http://colourofsound.8088.org/comps.jpg

GFX

[3rd world order]

Originally Posted by gfx

Heres a somewhat blurry picture of my first pair....

http://colourofsound.8088.org/comps.jpg

I dig the bright blue meters... sweet

how does this work? you order a kit with all the parts from gyraf and assemble at home or...?

i'm in the philippines so tracking down parts is kinda tricky... if it's not EXTREMELY common i have to get it flown in.

[valverec]

I've built one of these too. It sounds very much like an 1176, but it's not EXACTLY like any specific model, as far as sound goes. It's close, but mine is modded a bit, so that had an affect on it. Gryaf models his after the version (can't remember which one) that didn't have an input tranformer and a high quality (5532 I think) opamp on the input instead. I put an input tranformer on mine, so it kind of made it more of a hybrid. Like I said though, the compression, and the way it compresses (with a fet) makes it sound and operate just like an 1176. Honestly, I'd take either or in a session and not think twice about it.

[The Spark]

Hulk, that looks awesome.

[Mozart]

This is kind of old thread, But can someone point me on what power transformer to get for my dual (gyraff) 1176? Preferably Toroidal...

[norman_nomad]

Originally Posted by Mozart

This is kind of old thread, But can someone point me on what power transformer to get for my dual (gyraff) 1176? Preferably Toroidal...

Digikey has toroidals that'll work. You need to know the voltage and amperage requirements to pick the appropriate transformer.

Do you happen to know these?

[Mozart]

AC 2 x 24 V , 2A, 50VA (W)

I was looking there, I don't know which one...
Not that experienced with electronics..
Thanks,
Kostadin

[norman_nomad]

Originally Posted by Mozart

AC 2 x 24 V , 2A, 50VA (W)

Here's what you're looking for: Digi-Key - AA50502-024-ND (Amveco Magnetics - AA50502-024)

Although I think that amperage is pretty high.

[gyraf]

I agree. Our DIY-version is based on the rev#F model that we happen to have plenty of in our studio - and it tends to be cleaner/clearer/more-boring than the classic class-A-type output stages used in earlier versions. We based the DIY-project on this design both because it makes much broader availability of parts (the old ones are based on a properitary output transformer) and because I knew the sound so well from our own originals, thus enabling us to substitute with widely-available parts with sonics close to our original.

I'd take a real "old version" 1176 any day - but also the recent Purple reissues are very good indeed..

Jakob E.

[dbbubba]

Originally Posted by Will Shanks

The UA re-issue is based on Rev. D/E. All the different revisions (9 total) shared the same output transformer.

You guys argue and roll on endlessly without knowing what you are talking about!

I just pulled schemos for two revs of 1176s (G and K to be specific) and neither have the same output tranny.
The K has a single secondary and the G has three secondary windings where the third allows for an option to have a 60 ohm output.

The Purple Audio MC76 (the only Purple schemo I have) has a tranny that resembles the G revision. It is a dual primary.

To say that the re-issue UAs don't sound true to what an original should sound like is pointless.
To begin with, they are recently manufactured.
The originals are almost thirty years old!

Any given original/vintage unit could sound different from the next because of many factors. Specifically the age of the unit, the conditions it was used in, length of service (time powered) and many more factors.
I have owned and used too many 1176s to count from blue stripes all the way to the final Rev K units.
THEY WERE ALL DIFFERENT!
If you had brand new units of all revisions that were built at once they'd all sound different. Different components.

I don't know what revision the UA re-issue is based on, but I bet that if you had an original that was based on the same revision as the re-issue and it was re-capped with the same caps as the re-issue... they'd sound damn close!

I read about the Gyraff unit about three years ago and at the time there were several differences in design. I was tempted to build one, but don't have the time.
While it would probably be a decent sounding compressor, I don't think it would be identical to any rev of an original 1176.
Then again, very few 1176s sound identical to one another!

Here's a real world example of how originals differ in sound:
I was in charge of building and maintaining six radio/TV production rooms in the '90s.
The rooms all had the same equipment and they all had a pair of 1176s.
The 1176s were used for V.O. record and stereo mix compression (yes they were properly linked.)
As each room was built I had to obtain a pair of 1176s.
Blevins, Harbor Sound, etc... I bought every 1176 I could find (they cost approx. $750.00 in '95 before the prices went through the roof)
Purples weren't around yet and UA had not started up yet.

Until the units were re-capped they didn't sound even remotely close enough to use as 2-mix compressors.
After re-capping I still had to swap the units around and find the best matches.
Because only a few were matching revisions some were only "close enough."
Because the 2-mix compression was light (2 db at most) the units matched close enough.

SO, ONLY TWO UNITS MANUFACTURED AT THE SAME TIME AND SUBJECTED TO THE SAME ENVIRONMENT DURING THEIR LIFETIME WILL REALLY SOUND ALIKE UNLESS METICULOUSLY RESTORED.

No two vintage units sound alike and no two models of clones or re-issues sound alike. Newly built units SHOULD sound alike though.

[norman_nomad]

Originally Posted by dbbubba

You guys argue and roll on endlessly without knowing what you are talking about!

I just pulled schemos for two revs of 1176s (G and K to be specific) and neither have the same output tranny.
The K has a single secondary and the G has three secondary windings where the third allows for an option to have a 60 ohm output.

The Purple Audio MC76 (the only Purple schemo I have) has a tranny that resembles the G revision. It is a dual primary.

To say that the re-issue UAs don't sound true to what an original should sound like is pointless.
To begin with, they are recently manufactured.
The originals are almost thirty years old!

Any given original/vintage unit could sound different from the next because of many factors. Specifically the age of the unit, the conditions it was used in, length of service (time powered) and many more factors.
I have owned and used too many 1176s to count from blue stripes all the way to the final Rev K units.
THEY WERE ALL DIFFERENT!
If you had brand new units of all revisions that were built at once they'd all sound different. Different components.

I don't know what revision the UA re-issue is based on, but I bet that if you had an original that was based on the same revision as the re-issue and it was re-capped with the same caps as the re-issue... they'd sound damn close!

I read about the Gyraff unit about three years ago and at the time there were several differences in design. I was tempted to build one, but don't have the time.
While it would probably be a decent sounding compressor, I don't think it would be identical to any rev of an original 1176.
Then again, very few 1176s sound identical to one another!

Here's a real world example of how originals differ in sound:
I was in charge of building and maintaining six radio/TV production rooms in the '90s.
The rooms all had the same equipment and they all had a pair of 1176s.
The 1176s were used for V.O. record and stereo mix compression (yes they were properly linked.)
As each room was built I had to obtain a pair of 1176s.
Blevins, Harbor Sound, etc... I bought every 1176 I could find (they cost approx. $750.00 in '95 before the prices went through the roof)
Purples weren't around yet and UA had not started up yet.

Until the units were re-capped they didn't sound even remotely close enough to use as 2-mix compressors.
After re-capping I still had to swap the units around and find the best matches.
Because only a few were matching revisions some were only "close enough."
Because the 2-mix compression was light (2 db at most) the units matched close enough.

SO, ONLY TWO UNITS MANUFACTURED AT THE SAME TIME AND SUBJECTED TO THE SAME ENVIRONMENT DURING THEIR LIFETIME WILL REALLY SOUND ALIKE UNLESS METICULOUSLY RESTORED.

No two vintage units sound alike and no two models of clones or re-issues sound alike. Newly built units SHOULD sound alike though.

Yep... you've got it.

Even the FET element alone (responsible for the compression) is enough to render two different 1176's very different from on another in response.

I purchases 20 fets just to find 2 that had matching voltage curves when building my dual unit.

[dbbubba]

Good point!
I didn't touch on the actual FET used for the gain reduction on the originals.

On the UREI units the FET is labeled as Q1 and has an OEM or "UREI" part number.
Everything else in the 1176s had generic part numbers, but not the FET that did the actual gain reduction (Q1.)
I am sure that it was a relatively off-the-shelf FET, but they were secretive to a degree.
Q1 is doing the gain reduction and everything else is either controlling how Q1 does it's job or is a make-up gain or output level amp.

The alignment/calibration section of the original manuals states that the VVR Cal. Adjustment would need to be re-calibrated after components "aged" or the FET was replaced.

In short... there is no specific 1176 "sound."
You could say that there is a general sound, but the difference between any two vintage units can be anywhere.

[edanderson]

Originally Posted by dbbubba

You guys argue and roll on endlessly without knowing what you are talking about!

I just pulled schemos for two revs of 1176s (G and K to be specific) and neither have the same output tranny.
The K has a single secondary and the G has three secondary windings where the third allows for an option to have a 60 ohm output.

The Purple Audio MC76 (the only Purple schemo I have) has a tranny that resembles the G revision. It is a dual primary.

if you look at a rev A through rev E urei schematics, you will see that the output transformer in the MC76 (and now the MC77) schematic is EXACTLY the same. it is significantly different from the transformer in the rev F and rev G version, which in turn is different from the rev H and later transformer.

so, there were 3 different output transformer versions. the first was only used in the 1108 preamp and the rev A through rev E 1176. the second was used in the rev G and rev H 1176, the LA-3A, and the 1109 preamp. the third was used in the rev I and later 1176, the 1178, the LA-4 and some other things.

the urei 1176 manual, with schematics for ALL revisions, is available at the JBL pro service website:

Vintage JBL-UREI Electronics

the MC76 and MC77 manual and schematics are available from the purple audio site:

Product / Purple Audio, LLC

ed

[dbbubba]

My point was that one poster said that ALL 1176s had the same output transformer.
They don't.

IS the MC76 or MC77 output transformer EXACTLY the same?

I have spoken to Tom Reichenbach and Dave Geren at CineMag and they say that no one really knows who made any specific transformer in a UA/UREI product.
They said that UA/UREI sourced their transformers from several manufacturers.
This alone says that the sound will vary from lot to lot, unit to unit.

Plus, we are only talking about the output tranny.
At the input there were UTC transformers in some revs, Beyer in others, 5534 differential amps in the later revs, etc...

Coupled with the other component differences, that is a LOT of variance in design which would equal a wide range of "sound" differences.

[edanderson]

well cinemag do make the output transformer for the MC77. and tom's father's company reichenbach engineering wound them for purple back when they were still in business. personally i think it is possible that ed reichenbach designed the transformer for urei, since he did a lot of consulting and custom designs. but i don't have any proof of that, other than a some original transformers with the sort of datecode that reichenbach used. tom couldn't find it in his files when i asked about it years ago.

it is true that i have seen a few variations of the original urei 1176 output transformer. there were lots of changes to other parts of the circuit too. and certainly UA have gone through a few different manufacturers for their 1176 output transformer as well.

so, i don't disagree with your assertion that there are a lot of variables in the old urei units; apart from the different revisions there is also the maintenance history, as you mentioned. getting two vintage units to sound identical can be quite difficult, not coincidentally is a part of why andrew started making the MC76 in the late 90s. i just didn't want a new "internet fact" to be coined here that the purple MC77 output transformer is somehow more like a rev G than a rev D.

ed