Hi all,I've been looking at the urei 1176 compressor schematic and often wonder why this unit must have a output transformer on it. Is there another method in which i could use the output of this circuit without the use of a an output transformer. When you look at the schematic for this essentially it is the most expensive part of it. If you could eliminate the output transformer it would make it more viable to build. So could anyone suggest to me how it could be removed from this circuit. I would appreciate any help i can get as far as i can see before it hits the output transformer it hits 13.7 volts so i assume that it would have to be brought down to about 4 volts peak to peak. cheers
http://www.gyraf.dk/gy_pd/1176/1176sch.gifYou do not need the output transformer at all. These are useded in professional gear to provide a balanced, floating output of nom. 600 ohms.
If the transformer does not have a 1:1 turns-ratio (I did not look-up the specs) you may need to adjust the gain of the output amp.
But...why would you use a 30+ year old design as a DIY project when modern and better designs are available?
E
If the transformer does not have a 1:1 turns-ratio (I did not look-up the specs) you may need to adjust the gain of the output amp.
But...why would you use a 30+ year old design as a DIY project when modern and better designs are available?
E
better designs
Hi thanks for the responses what new designs would you suggest are better than the urei 1176 for some reason all audio engineers seem to put this particular design of compressor on a pedastool. Iam more than happy to try new designs and i have a particular interest in compressors i have been trying a few different ones to see. I have seen the optical designs that are out there such as the what compressor and mnat joe weak optical design haven't seen any other fet designs for diy always nice to find a pcb layout if possible or a vero but not always possible but not a huge problem to make your own if you find a really good schematic that will do a great job. Iam trying my best to work out how to one day design some different components but not at that competency level just yet but love building the different designs that i find around the place. Lots of good stuff out there i take my hat of to some of the guys they do a really good job at what they do in regards to some of the projects very talented. i really enjoy reading about them. If anyone can suggest any good compressors to do for diy yourself i'd love to hear about it and converse on how they go. cheers
Hi thanks for the responses what new designs would you suggest are better than the urei 1176 for some reason all audio engineers seem to put this particular design of compressor on a pedastool. Iam more than happy to try new designs and i have a particular interest in compressors i have been trying a few different ones to see. I have seen the optical designs that are out there such as the what compressor and mnat joe weak optical design haven't seen any other fet designs for diy always nice to find a pcb layout if possible or a vero but not always possible but not a huge problem to make your own if you find a really good schematic that will do a great job. Iam trying my best to work out how to one day design some different components but not at that competency level just yet but love building the different designs that i find around the place. Lots of good stuff out there i take my hat of to some of the guys they do a really good job at what they do in regards to some of the projects very talented. i really enjoy reading about them. If anyone can suggest any good compressors to do for diy yourself i'd love to hear about it and converse on how they go. cheers
can't get that chips
Hi any full projects for compressor like the urei 1176 rather than over priced unavailable chips in australia that is. that are on the the diy plane for compressor there aren't any i know of of i guess it make an old 30 year old design more viable when you take a look at the prices of that chips and that there not easily available still open to other options.
Hi any full projects for compressor like the urei 1176 rather than over priced unavailable chips in australia that is. that are on the the diy plane for compressor there aren't any i know of of i guess it make an old 30 year old design more viable when you take a look at the prices of that chips and that there not easily available still open to other options.
The old stuff does have particular sonic signatures that some engineers prefer over the modern stuff, but some of it comes from the output trafos. If you're up to building it you could replace the entire line amp section with a modern output buffer circuit, but it wouldn't be an 1176 any more.
It sounds like you want to build a high quality unit on the cheap, but if you add it all together including high quality switches and such, the trafos don't add that much to the price.
It sounds like you want to build a high quality unit on the cheap, but if you add it all together including high quality switches and such, the trafos don't add that much to the price.
Hi to all.
This particular circuit of 1176 is LN version with 1:1 output transformer. If you look carefully there is an electrolityc cap between output stage and transformer. There was an earlier version of 1176 with class A output stage where was used special transformer......If you want to build this compressor there is a lot of information on Gyraf's page......Because I build some of these for my use here you got some advice. First of all. This is very good and nice sounding compressor, It can't be compared with chip compressors. It has unique sound and character. If you decide to diy it use newer boards....I think it is rev e or f....if you want to avoid trace cutting to get rid of hummmmm. The most expensive part is enclosure. Than you need some pots and switches...and of course nice analog VU meter. The transformer is ,,standard 600:600e so dont worry. But you need some experience to build it and to calibrate it. At the end there is just minor cost to buy such transformer. But it is also possible to wound it yourself. And there is also a lot of information on ,,prodigy professional,, forum........
Diy transformer.
Core ei42
Primary 500 turns
Secondary 500 turns
If you wound for an example
p1=166 turns
s1=250 turns
p2=166 turns
s2=250 turns
p3=166 turns
you will get good results and frq response.
Of course you need to connect p1,p2,p3 in series and s1,s2 in series.....it is also possible to wound it on some other core but must be very similar in dimensions. I don't know exactly how thick was a package of laminations but I think some 15mm. I can check if you want......
Best regards
Taj
This particular circuit of 1176 is LN version with 1:1 output transformer. If you look carefully there is an electrolityc cap between output stage and transformer. There was an earlier version of 1176 with class A output stage where was used special transformer......If you want to build this compressor there is a lot of information on Gyraf's page......Because I build some of these for my use here you got some advice. First of all. This is very good and nice sounding compressor, It can't be compared with chip compressors. It has unique sound and character. If you decide to diy it use newer boards....I think it is rev e or f....if you want to avoid trace cutting to get rid of hummmmm. The most expensive part is enclosure. Than you need some pots and switches...and of course nice analog VU meter. The transformer is ,,standard 600:600e so dont worry. But you need some experience to build it and to calibrate it. At the end there is just minor cost to buy such transformer. But it is also possible to wound it yourself. And there is also a lot of information on ,,prodigy professional,, forum........
Diy transformer.
Core ei42
Primary 500 turns
Secondary 500 turns
If you wound for an example
p1=166 turns
s1=250 turns
p2=166 turns
s2=250 turns
p3=166 turns
you will get good results and frq response.
Of course you need to connect p1,p2,p3 in series and s1,s2 in series.....it is also possible to wound it on some other core but must be very similar in dimensions. I don't know exactly how thick was a package of laminations but I think some 15mm. I can check if you want......
Best regards
Taj
1176 ln remove output transformer
I just do not understand why the same circuit can not be achieved without this output transformer surely it can be done. What is so special about it and why does it definately need to be there for this so called unique sound i keep hearing about for the 1176 surely you could make this unit without and i really fail to see why it can't sound just as good
I just do not understand why the same circuit can not be achieved without this output transformer surely it can be done. What is so special about it and why does it definately need to be there for this so called unique sound i keep hearing about for the 1176 surely you could make this unit without and i really fail to see why it can't sound just as good
Hello
Well it can be done, actually it is allready. Just connect output after that 470uF cap and that is. And now here comes this ,,but,,. It depends why you need it. If you observe carefuly circuit you will noticed that it has ballanced input and output as well. This is ,,must,, if you will use it in professional aplications.....to avoid hum. Of course you can try with some chip line driver...such as ssm2141? or 2142 I can't remember.....or something from THAT corporation.......but no chip will balance signal so nice. And won't lift ground so good.....in case of hum. And good transformer has it's own sound. So 1176 is classic,legend.....something like american classic muscle car.....Will mustang souns nice with honda engine
This transformer will cost some 4-5 euros if I go to custom shop here in Slovenia and they custom wound it to me......
Best regards......and I hope that you will choose transformer.
Well it can be done, actually it is allready. Just connect output after that 470uF cap and that is. And now here comes this ,,but,,. It depends why you need it. If you observe carefuly circuit you will noticed that it has ballanced input and output as well. This is ,,must,, if you will use it in professional aplications.....to avoid hum. Of course you can try with some chip line driver...such as ssm2141? or 2142 I can't remember.....or something from THAT corporation.......but no chip will balance signal so nice. And won't lift ground so good.....in case of hum. And good transformer has it's own sound. So 1176 is classic,legend.....something like american classic muscle car.....Will mustang souns nice with honda engine
This transformer will cost some 4-5 euros if I go to custom shop here in Slovenia and they custom wound it to me......
Best regards......and I hope that you will choose transformer.
1176 transformer sound
i really don't see why or how some output transformer could really make that much difference to the sound. providing you put some circuit on the end to make it balanced and do the standard balanced circuits at the beginning i really think if you put two units together one with balanced output circuits and one with a output transformer i really doubt one would hear much of a difference. Here in australia it will cost me nearly $110 dollars australian to get one output transformer. I think thats ludicrous for one. I wish i could get it for $6 dollars i would grab one in a heart beat so this is why i question it. I think you would still get a pretty good compressor without it. but I was hoping someone had experimented with this to maybe give me an idea if i was really trully barking up the wrong tree. Thanks for your reply's much appreciated
i really don't see why or how some output transformer could really make that much difference to the sound. providing you put some circuit on the end to make it balanced and do the standard balanced circuits at the beginning i really think if you put two units together one with balanced output circuits and one with a output transformer i really doubt one would hear much of a difference. Here in australia it will cost me nearly $110 dollars australian to get one output transformer. I think thats ludicrous for one. I wish i could get it for $6 dollars i would grab one in a heart beat so this is why i question it. I think you would still get a pretty good compressor without it. but I was hoping someone had experimented with this to maybe give me an idea if i was really trully barking up the wrong tree. Thanks for your reply's much appreciated
My advice is that you just simple believe that transformer has ,, special,, sound.......but of course you can try and learn it by yourself.......and try to solve hummmm caused by ground loop with unballanced output.
That simple transformer which I give you the specification works well with standard quality core.....for me it works well and for information....I own rental company and small recording studio......and of course lots of factory made compressors.....BSS,DBX,AVALON,DRAWMER.....and of course I have some diy 1176 units as well which I build with those homebrew cheap transformers....they work nice. Almost like lundahl ll5402. So once again I really recommend you this simple diy solution. Go and ask someshop which wound transformers. It is something like 5W mains transformer nothing special.......
I promise you won't be disappointed. When I come bach home (on tuesday) will measure how thick is stack of laminations.....and post a photo.
Go man and diy it...
Best regards
Taj
That simple transformer which I give you the specification works well with standard quality core.....for me it works well and for information....I own rental company and small recording studio......and of course lots of factory made compressors.....BSS,DBX,AVALON,DRAWMER.....and of course I have some diy 1176 units as well which I build with those homebrew cheap transformers....they work nice. Almost like lundahl ll5402. So once again I really recommend you this simple diy solution. Go and ask someshop which wound transformers. It is something like 5W mains transformer nothing special.......
I promise you won't be disappointed. When I come bach home (on tuesday) will measure how thick is stack of laminations.....and post a photo.
Go man and diy it...
Best regards
Taj
Rupert Neve himself said the sound of his classic mixing consoles from the 70's ( still very much in demand by recording engineers) was due to the transformers on every input/output of the console.
Since the transformer is a large part of the sound, different transformers will have a different sound. If you want the real 1176 sound you need the original transformers.
Since the transformer is a large part of the sound, different transformers will have a different sound. If you want the real 1176 sound you need the original transformers.
Hey....do anyone need plan for cloning neve 1073 output transformer...
Cbdb don't get me wrong .....I just offer cheap solution which works quite well.
But it is absolutely true that every transformer produces it's own sound. But all those sounds are much more similar than no transformer at all. Of course with proper wound transformer. I tried a lot of different transformers from jensen, cinemag,sowter,lundahl....diy and they all share transformer sound. For an example cinemag or lundahl is very transparent if compared with small transformer from oep which is a little darker. But it works well in di if you recording bas guitar......it depends. But almost all transformers souns well. Those diy too.
Best best
Taj
Cbdb don't get me wrong .....I just offer cheap solution which works quite well.
But it is absolutely true that every transformer produces it's own sound. But all those sounds are much more similar than no transformer at all. Of course with proper wound transformer. I tried a lot of different transformers from jensen, cinemag,sowter,lundahl....diy and they all share transformer sound. For an example cinemag or lundahl is very transparent if compared with small transformer from oep which is a little darker. But it works well in di if you recording bas guitar......it depends. But almost all transformers souns well. Those diy too.
Best best
Taj
1176 alternative
Here is one alternative to throw at you guys. Iam not disregarding what you have said you have all made some very valid points and i appreciate your input i really do. Here is what i was thinking and of trying to do on this website superstars of the All electric kitchen if you take it look it the balanced line driver. very interesting way of tackling it without a output transformer. Allthough if you look at the electronics theory the main reason the output transformer is there is to match the output impedance not alter the sound. The main difference on using different transformer's may also be that your getting slightly different impedance matching therefore making your other equipment respond differently. With the ability to vary that i wonder also if there is a difference. I have approached different transformer manufacturers around and they have all said basically i will have to buy whats available. I was wondering can standard mains transformers be used. say one that has a 2:1 ratio. do output transformers for audio have special charachteristics and i was wondering on your homebrew 1176's what were the homemade type transformers and if i was going to a shop what would i exactly specify that i would want. of what i understand in the 1176 it is a 2:1 ratio transformer. made up of two 600 600 ohm primary and 2 150 150 secondary. is there such a generic garden type of transformer that can be used for this application. I have pondered many cheaper alternative that i can get my hands on but don't know enough on where to head next in regards to these output transformers. thanks again for everyones input
Here is one alternative to throw at you guys. Iam not disregarding what you have said you have all made some very valid points and i appreciate your input i really do. Here is what i was thinking and of trying to do on this website superstars of the All electric kitchen if you take it look it the balanced line driver. very interesting way of tackling it without a output transformer. Allthough if you look at the electronics theory the main reason the output transformer is there is to match the output impedance not alter the sound. The main difference on using different transformer's may also be that your getting slightly different impedance matching therefore making your other equipment respond differently. With the ability to vary that i wonder also if there is a difference. I have approached different transformer manufacturers around and they have all said basically i will have to buy whats available. I was wondering can standard mains transformers be used. say one that has a 2:1 ratio. do output transformers for audio have special charachteristics and i was wondering on your homebrew 1176's what were the homemade type transformers and if i was going to a shop what would i exactly specify that i would want. of what i understand in the 1176 it is a 2:1 ratio transformer. made up of two 600 600 ohm primary and 2 150 150 secondary. is there such a generic garden type of transformer that can be used for this application. I have pondered many cheaper alternative that i can get my hands on but don't know enough on where to head next in regards to these output transformers. thanks again for everyones input
Hi again
I make some output stages with SSM2142 from analog....and it wors ok but I discovered that those devices have a lot of hisss on output. I find on various forums thhat line drivers from THAT corporation sounds better and have lower noise....but somehow when I see transformer in circuit I just leave it there...
So the transformer at 1176 was standard 1:1 , 600:600 ohm unit. But people has discovered that you sometimes need to crank up really high the ,,output level ,,pot to get enough of signal. So this gives this idea to connect transformer in 1:2 configuration. It will give you some step up.....That is why i mentioned to you that you can wound something more on secondary.
About transformers...Of course they are intended to match impendances, or ballance the output but they have they own problems as well. Parasitic capacity and inductance will dramatically reduce upper freq. limit... that is the reason to wound it in ,,sandwich,, And enough inductance is needed to get good bass response. And here comes the difference with simple ,,mains,, transformers. And not to mention special alloys containing nickel and some even more exotic metals....it's science. If there you can find someone to wound diy ,,homebrew,, transformers those which I gave the spec. will go from some 25hz to over 40Khz so it is enough.....Of course some lundahl is probably better but will cost 10 times more....
Btw why do you need this compressor? 1176 is somehow tricky to build and adjust....and than it is little more complicated to use and has it's specific sound. Actually it is limiter.
If you need cheap compressor which work well in all situations there is ,,gsssl,, compressor on Gyraf's site. It uses only chips and it work nice....only thing which is there maybe little tricky is gr meter, but you can build a led meter for it. This compressor is realy cheap and effective. Proven. I build it once with no complications at all.
Tomorrow when I come back home will anyway send all exact information how I diy those output transformers......
Best regards and happy diy....
Taj
I make some output stages with SSM2142 from analog....and it wors ok but I discovered that those devices have a lot of hisss on output. I find on various forums thhat line drivers from THAT corporation sounds better and have lower noise....but somehow when I see transformer in circuit I just leave it there...
So the transformer at 1176 was standard 1:1 , 600:600 ohm unit. But people has discovered that you sometimes need to crank up really high the ,,output level ,,pot to get enough of signal. So this gives this idea to connect transformer in 1:2 configuration. It will give you some step up.....That is why i mentioned to you that you can wound something more on secondary.
About transformers...Of course they are intended to match impendances, or ballance the output but they have they own problems as well. Parasitic capacity and inductance will dramatically reduce upper freq. limit... that is the reason to wound it in ,,sandwich,, And enough inductance is needed to get good bass response. And here comes the difference with simple ,,mains,, transformers. And not to mention special alloys containing nickel and some even more exotic metals....it's science. If there you can find someone to wound diy ,,homebrew,, transformers those which I gave the spec. will go from some 25hz to over 40Khz so it is enough.....Of course some lundahl is probably better but will cost 10 times more....
Btw why do you need this compressor? 1176 is somehow tricky to build and adjust....and than it is little more complicated to use and has it's specific sound. Actually it is limiter.
If you need cheap compressor which work well in all situations there is ,,gsssl,, compressor on Gyraf's site. It uses only chips and it work nice....only thing which is there maybe little tricky is gr meter, but you can build a led meter for it. This compressor is realy cheap and effective. Proven. I build it once with no complications at all.
Tomorrow when I come back home will anyway send all exact information how I diy those output transformers......
Best regards and happy diy....
Taj
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