So How Do I Build A Compressor

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definity

New member
Joined
Jul 18, 2009
Messages
2
Hi, i new to this forum and have been lurking a while with a friend, and i just got a few questions to ask, where do u guys get your circuit diagram or do you build your stuff from scratch? I have been interested in building this sort of stuff with a while now, so i was wondering what a good compressor or eq to start on?
Many Thanks!
Def.
 
I would first suggest you start by reading...then read some more, then keep reading. Honestly, it's the best way to learn, there is a huge amount of knowledge on this forum, you need to go find it.

(the search function works pretty well also)
 
Depending on whether you are interested in "just building" or learning and understanding how equipment works, why it performs in a particular way, and then building, would provide a pointer for a direction to go in.


If it is the latter, then a very good starting point are manufacturer's data sheets - THAT Corporation are the VCA people and they have a good range of data sheets and application notes for their products. You will learn a lot about VCAs, sidechains, and dynamics in general. Couple the manufacturer's datasheets with this forum, and you have a vast amount to study!


Taking a timeline that pre-dates the VCA chips or gain-cell blocks from THAT Corp, DBX, Allison Research, etc, there is very little in the way of component datasheets. You have to rely on the publication of the ingenuity of circuit designers who know serious analog electronics.

This neatly leads us on to "just building" and the subject of cloning existing circuits. Below are a set of links gathered over a 10 minute period and cover some of the DIY projects that are on this website.

Pultec
http://www.groupdiy.com/index.php?topic=31285.0

Soundcraft, including the logo of the company.
http://www.groupdiy.com/index.php?topic=33241.0

SSL
http://www.nrgrecording.de/sll1_making_of.html

Calrec EQ
http://www.nrgrecording.de/html/calrec.html

These 4 have been specifically picked because in various ways they advertise the original equipment manufacturer:
*  The Soundcraft EQ is particularly noteworthy as it has both the Company name, and the Company's logo!
*  Calrec has the company name printed in the double-line manner that Calrec favoured in their engraved panel process. It also notes the model number PQ1549. The text font is very close to that which Calrec use.
*  The SSL compressor uses the Company name (Solid State Logic), its abbreviation, and the console range from which this stand-alone compressor is taken (4000 Series).
*  The pultec, well, just looks like a Pultec!

There are a number of issues that cloning of manufacturer's circuits, products, and equipment raise. They all have implications which I'm not going to go into in depth, merely note:
*  Breech of copyright.
*  Use of trademarks (Soundcraft) of an existing business.
*  Use of intellectual property - how many of the cloned products have been authorised by the original manufacturers?
*  Use of the name of a pre-existing business.
*  If a piece of cloned equipment fails and ends up the workshop of the real manufacturer, are they actually going to fix it?
*  If a piece of self-built equipment with the name and logo of XYZ Company on its front panel was the cause of a fire in a studio, the first port-of-call by investigators would be XYZ Company. Cue a field-day for the legal profession!

I do wonder what the reaction of Coca-Cola, Pepsi, or McDonalds would be if their products were cloned by a variety of people and made available through the internet.

I don't know if anyone has ever been taken to task over using the names, logos, and circuits of existing and still-active businesses.

Making a one-off to a very high standard for personal use is one thing (I'm not saying whether or not I condone it), but when there are numerous units manufactured, albeit for small-scale personal use by a number of people not associated, it's a manufacturing run and could be deemed a business, even if products were sold as not-for-profit, and this is where the legal ice could get uncomfortably thin.

The legal implications of actions taken by some people in their cloning activities are, in my opinion, poorly considered.

With all the smart folk and skills here, surely there is sufficient knowledge to be able to design from scratch some really good kit that is NOT related to manufacturers who could (and quite rightly so) get very hostile.




Well, Definity, I have gone off-topic by quite a bit and to get back to the "just building" route, it's a good way to sharpen your wiring, soldering and assembly skills, but does not do a great deal for knowledge of how or why a piece of kit works, except if something goes wrong and needs fault-finding. Even then, the creation from datasheets, research and tinkering provides a thorough education of in-depth knowledge that will make fault finding a far less daunting task - more of an intellectual challenge - I designed it, so I am more than capable of fixing it.


Gareth.
 
Hey mate  :)

I have only built 2, the Drips La2a Version 3 www.dripelectronics.com and the Mnats 1176 Rev D here. If you want more bang for the buck for all the hard work you put in, I would say go Drips La2a. They are both great sounding units, but the La2a gives you a better Commercial to DIY savings ratio. eg. both units are not cheap to build but if you compare how much each commercial item is on the market, you will see that the La2a gives you more bang for the buck even when buying the commercial unit second hand. You still save when building the 1176, but it all boils down to how much your time is worth and whether that time is better spent elsewhere.

I thought the 1176 was harder to build due to the spread of information and with the wiring and all, but Skylarks diagram makes it alot more easier and more sense.

If you build the Mnats 1176 Rev D, I can send you some stuff I gathered in my build process that you may find useful, BOM excell sheet, close up pics, etc. and hopefully you can skip some pitfalls that I went thru.

Don't be afraid to ask any questions, there's bound to be one person here that will help regardless, some will message you though than reply to your questions in the forum.  ;)

These two DIY's are pro sounding units!
 
nice post Gareth

Keep in mind when googling it [ why not ] , you may
stumble on other sites or pages which  " speak to you "
or make sense in a way you understand .

Cj took some time here to make a beginner series in the Meta
as always , search , research can't hurt to get more perspective
 
yeah i meant just plain googling / searching ............anywhere
why there just may be some fringe grps out there
never know where you may find an answer

Especialy for those who don't care for the way
infomation disapates around here , but ya gotta look

Trying to find an answer to fit your question is different
than just finding the answer
 
Gareth Connor said:
I do wonder what the reaction of Coca-Cola, Pepsi, or McDonalds would be if their products were cloned by a variety of people and made available through the internet.
Go right ahead and make your own Coca Cola: http://en.wikipedia.org/wiki/Coca-Cola_formula

If you know which ingredients to mix you are absolutely allowed to make your own stuff.

Just don't sell it. For profit or no profit. Don't sell it!

What you can sell is ingredients. Ain't no copyright on cinnamon...

It's no different with electronics.
 
The Drip LA2 like Canidoit suggested is an easy project and good for a beginner. That was my first project on here. Then I built a bunch of Mnats 1176's. I use both constantly and they never fail to please. They sound great on any kind of music. Kinda can't go wrong on them. And once ya build these thing I VERY MUCH doubt you will ever sell it lol...

John
 
Luny Tune said:
Gareth Connor said:
I do wonder what the reaction of Coca-Cola, Pepsi, or McDonalds would be if their products were cloned by a variety of people and made available through the internet.
Go right ahead and make your own Coca Cola: http://en.wikipedia.org/wiki/Coca-Cola_formula

If you know which ingredients to mix you are absolutely allowed to make your own stuff.

Just don't sell it. For profit or no profit. Don't sell it!

What you can sell is ingredients. Ain't no copyright on cinnamon...

It's no different with electronics.


There are indeed many suppliers of "electronic cinnamon" - components / ingredients. We have access to a good proportion of the suppliers.

Mixing of the components (ingredients) into a product is down to the ingenuity of the designer (circuit-chef).

The point is that by doing circuit clones and by placing company logos and trademarks on finished boxes that are not manufactured by the named companies, it seems pretty obvious to me that the knowledge of how to mix the components/ingredients is NOT known and therefore there is a very heavy reliance on copying the products of commercial businesses. The blind following of clone-build to form an exact copy of the original can be demonstrated by the questions posed by constructors such as "Will it still work if I do not use tantalum caps?".

It's one thing to say "Mmmm, that's a great compressor... I have loads of time on my hands, I will reverse engineer it and make one for myself" as compared with "That XYZ comp is really cool. I'm sure that if I reverse engineer it and make a dozen kits I'll be able to sell them. Putting XYZ's name, logo and model number on my professionally screen printed front panel will give it some credibility".
No it won't - it opens up a legal minefield.
How many circuit schematics are there that do not have some form of copyright note on them, either in text or the abbreviated circled "C"? What actually does "Copyright" mean in relation to self-build of one unit and creating a dozen kits for sale?

Luny Tune makes a good point about home-brewed Coca Cola with: "Just don't sell it. For profit or no profit. Don't sell it!"

Imitation is the greatest form of flattery.

I don't honestly think there are "N"-hundred audio businesses throughout the world with R&D labs re-inventing the wheel (or mic amp) every day; the wheel already exists, the challenges are to make it technically superior and commercially cheaper than the competitor's product. Part of this process is to gather information - including published material by competitors - to see if there is anything that could be done better, that is already being done better than the competitor, or indeed that the competitor has done poorly. Smart ideas move around the industry with service manuals as well as staff moving between companies. One example of circuit migration is the transformer-emulating cross-coupled balanced output stage that sprung up in half-a-dozen console manufacturers in the early-to-mid 1980s. It was good, cheap, worked, and was rapidly adopted but it was not a complete product merely a component/building block of a much larger product.

If you are going to copy XYZ's circuit and put it in your own box, don't use XYZ's trading name or logo - they did not make it.
For those who do use the logos and trademarks of businesses, as/when/if the XYZ Company discovers that their trading name has been used, there could be all sorts of trouble. I repeat two points from the earlier posting:

*  If a piece of cloned equipment fails and ends up the workshop of the real manufacturer, are they actually going to fix it?
*  If a piece of self-built equipment with the name and logo of XYZ Company on its front panel was the cause of a fire in a studio, the first port-of-call by investigators would be XYZ Company. Cue a field-day for the legal profession!


Perhaps the Moderators could consider splitting this post into "How do I Build a Compressor" and "Are Cloners Infringing Copyright and Trademarks?"
 
Jeez - is it just me or is this place getting a bit "weird" lately  ::) ::) ::)

Gareth, here's the original post below, a simple request for some info on what to build, being fairly new
to electronics and a bit of a novice.

There was no mention whatsoever of "clone" or "copyright" or "brand logo theft"

Thank God that I didn't receive a similar onslaught of responses when I first came here three years ago
I would have run for the trees whilst dodging the bullets !!

MM.




definity said:
Hi, i new to this forum and have been lurking a while with a friend, and i just got a few questions to ask, where do u guys get your circuit diagram or do you build your stuff from scratch? I have been interested in building this sort of stuff with a while now, so i was wondering what a good compressor or eq to start on?
Many Thanks!
Def.
 
OK, so how about this as a "Generic response" to a brand new PP forum member who asks his/her first question :

Dear DEF , Welcome to the Prodigy Pro Forum and a whole world of audio projects and electronics knowledge.
As there is so much data and product specific information here at your disposal, please do some reading in the
"New Members" sticky and also the "Meta" threads to get an idea of how things work here.
Our "search" function can be very handy if you need project information, for example if you are interested in
making and learning about the Neve 1073 - then type 1073 in the search and start reading.
Your efforts will be rewarded and you can avoid "constant repetition" of simple questions, most have been answered
at one time or another and it will avoid getting regular users "angry" with your repeated questions.

Have fun and remember to keep safety in mind when attempting any projects that require "mains voltage" to power them.

 
In an open forum like this, it is the task of the lurker-reader to separate useful from unimportant information. If someone becomes a burden to read they will be tuned out.

There are two kinds of people in the world, those who create original content and those who don't. Those who do are not surprisingly sensitive about being unfairly copied.

I agree that this doesn't need to be rehashed for every new thread, and we have explored this topic before so new thoughts on the subject can be posted to an old thread. 

That said I mostly agree with Gareth, while I also understand the mentality of folks who just want to get good results for little money (I used to sell audio kits).  We all have our pet peeves, mine is when people ask for answers on technical forums like this but cut you short when you try to explain how to figure it out themselves.. "Just give me the answer and don't make me work (too)".

Most designers started out copying the work product of other's to learn, but one important difference is that few stop there and constantly strive to improve upon what they see.

I also understand the futility of trying to alter other peoples behavior on internet forums, the mods have it hard enough and they have special powers.

JR

PS: FWIW I am currently contributing affidavits for a legal action between my ex-employer and another manufacturer over one of my patents. These IP lawsuits are expensive to prosecute and defend. I doubt that manufacturers would actually pursue individual infringements, but some companies are very aggressive. Perhaps inversely proportional to the merit of their IP ("Monster" comes to mind).
 
Pretty typical of news grps in general
someone responds to a post and quickly
it is diverted by others flaming the responder .

For as well as it does or does not work
the sticky welcoming people & advising to
check meta & searchs does help keep the posts
cleaner and promote better questions to utilize
the knowledge base here [ and there's always google ]
I know it's easier to just ask but one has to take some responsability

If you're shopping for knowledge ,any good consumer
would get three quotes and take the average and
while this is a pretty good place that we're proud of  it
[ thanks for all the help so far everyone ]
It's not the end all be all and won't save your life by itself
so don't limit yourself expecting to squeeze evrything out of here .




 
Flaming the OP was not the intention.

In a nutshell......

Original question: "How do I build a comp?"

Answer 1: Study circuits & data sheets & available material & experiment.

Answer 2: Build the thing, but be careful about using the names & logos of others..... you could be inviting unnecessary trouble from them if advertised to openly!

I for one do not want to see trouble visited on this good forum, but the penchant for copying, blah, blah, blah, may one day soon, result in problems which we can well do without.

Let us build, design, modify, take the good ideas from past experience - wherever that may come from - and use it to build good kit...... but without treading on the toes of big guys with big sticks.

There - no hint of lectures - just concern for the forum.
 
Woah thanks for all the reply guys much appreciated  ;D, and thanks for moving this to the Lab section wasn't sure where to post. i think i might have to save up so cash and start building these right away especially the LA2 drip
Thanks Def
 

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