AD797 RAT oapms talk

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AD797 RAT oapms talk

Goga
Dear people hello!

Recently I have read about the RAT history there is a great article in Tone report.

I wanted to know and have a little discussion about the oamps mensoned in the article
and also I'm providing you an ebay link to check out prices ant tell me if this
opamps are ok or not, what brand to buy etc.

Thanks and I hope we make a nice discussion on this subject.

http://www.ebay.com/itm/1x-Dual-to-Mono-Op-amp-module-AD797BR-replace-OPA2604-/262450099170?hash=item3d1b3eb3e2:g:0ZEAAOSwEK9T7IJU
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Re: AD797 RAT oapms talk

notnews
For those who either don't read TR or don't have it handy:





Personally, I love the Burr Brown opamps.. the OPA- and OP- series ICs sound great to me. The one above is too expensive, and there are cheaper and more expensive ones, and both in PDIP and SOIC format.

The graphic really does highlight the utility and advantages of the TL071... it's actually a great opamp for the price.
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Re: AD797 RAT oapms talk

Goga
Thanks for your reply dear friend.

My taste goes with your opinion too. I stick with BB opa134 too.

Hope someone else will share experience not just in RAT pedal but
in some types of drive/distortion that might be the best for them.

Cheers
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Re: AD797 RAT oapms talk

rocket88
Administrator
For some reason I can't listen to the clips you posted, but I personally prefer and use NOS LM308 plastic IC in the ones I build and sell. But, really at the top of my list is NOS LM308h metal can IC. They're higher gain, and it's hard for me to describe the tonal difference, but it just has something extra the I find other ICs I've used lack.
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Re: AD797 RAT oapms talk

notnews
Rocket - my bad, I should have clarified... I just took a screenshot of the TR spread and posted it here. There are no links embedded in the photo, but the TR magazine has them.

I haven't had the pleasure of using one of those metal-can LM308's, but I've heard that same sentiment from others also. Slew Rate is an interesting thing to play around with and be conscious of.. higher rates don't always translate into a "better' sound, as Rocket's anecdote suggests.
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Re: AD797 RAT oapms talk

rocket88
Administrator
Haha. It's ok man. I wa so confused and figured it was my iPad not letting me do it.

What makes the rat sound like it does is connected to th slow slew rate. But, that doesn't mean you like that sound, maybe the higher sounds better to your ears.

Not news, I kinda bought out all the ones I've found that are NOS, he'll I bought out our Bulgarian friend 2x, I think I've got 80 sitting in my stash. Been debating if I'm going to do a small run with them, or keep them for my personal builds. The newer metal fans don't sound the same to me, and don't get me started on the chinese ones, such a waste.
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Re: AD797 RAT oapms talk

Travis
Administrator
A little light just went off in my head and now I need to pick up a couple of those metal can LM308s so I can do a tagboard Rat like I did with that Dist + a while back. How badass would that be?

 photo 6E01C0EA-EE64-4B92-9177-85CC176D0897_zpsnigxlpyh.jpg
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Re: AD797 RAT oapms talk

IvIark
Administrator
Looks great mate
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Re: AD797 RAT oapms talk

Goga
In reply to this post by Travis
Travis,

I'll seriously reconsider building pedals after your post :D

Awesome man!!!!

So here is My Fuzzulator with TL071 and BBOpa 134.

I wont post pics from the inside because I'm not very proud of it :D
the pedal sounds awesome to my ears. I tried all the options suggested
this was my perfect one.



"And I know that some will ask how did I print this so: This is done by very expensive printer that can print on wood, metal, glass etc. Fortunately my friends have that company and they did it for free.
The subject in dis discussion is Oamps and pedals that can sound different better worst all regarding Oamps."  
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Re: AD797 RAT oapms talk

Travis
Administrator
Thanks Mark and Goga! I drew a tagboard layout for the Rat last night so the wheels are in motion!

Love the graphics Goga! Very pro quality stuff. I need to get some pro printing done, wish I had access to a machine like that!
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Re: AD797 RAT oapms talk

jcdenton825
In reply to this post by Goga
Hey Goga, hope you are doing well

I am the author of this article, and I'd like to thank you for reading it and sharing it!

This article was a long time in production, it took me a while to choose which op amps to buy and test, but Pro Co was very gracious and actually helped me in the process.

From being in the room with those clips and op amps, I can tell you with almost absolute certainty that the difference was very subtle, if not at all. Most of the changes came from the attack and feel of the pedal, which is why I decided to post slew rate with every op amp. The AD797 was more immediate and snappy, while the TL061 or the LM308 was a bit more sluggish. Not much change in the frequency response, they *maybe* had a little more high and low end tightness and articulation.

Actually, the biggest tonal change I got was from powering it at 18v as oppose to 9v. The mids were wider and the dynamics are not as hard compressed, it felt generally more hi-fi and you can tell more of the differences between the op amps. I think you should start with an LM308, a TL071, and an OPA134. Run your RAT at 18v either with a charge pump or with just straight 18vDC, and then switch out the op amps to see which you like the most.

Happy hunting, and if you have any other questions please let me know!

All the best,

Yoel

BTW, really nice job on the enclosure and the pedal. Looks great!
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Re: AD797 RAT oapms talk

Goga
Sooooo I'm not happy I'm overwhelmed with feelings!

First of all I want to thank you for the support and the compliments.

I'm member of this forum for 5-6 years, doctor by profession, guitarist as a semi hobby profession and I didn't know anything about electronics when I first came here.
Mark, Miro, Andre, John, Travis, Franco (Ares audio IT) and all of you guys here thought me everything that I know now and  that's not much but I'm advancing and learning constantly :)

I sincerely wish you, a lot of good articles as that one for the RAT, a lot of new collaborations with geniuses willing to share their inventions with the masses.

Thank you 100 000 000 times :)

Goga (a.k.a Ej Brej- sorry for that guys I have two accounts I don't know why. It happened when my laptop died few years ago :)))))) )    
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Re: AD797 RAT oapms talk

jcdenton825
Wow well that's the nicest thing anyone has ever said about me or my articles, I'm really touched!


Truth be told, one of the reasons I'm in the writing game is for moments like these. Honestly I still don't know much about electronics but my knowledge is growing every day, thanks to of course guys like you on the internet and beyond. This was one of my more interesting pieces, as I expected some pretty wildly different results then what I got. After reading all the talk on forums about people trying different op amps I was floored that almost all of them sounded more or less the same! I like doing tonal "mythbusting", and I like to figure out the facts and science behind what makes great tone. I have a distaste for insanely overpriced gear (I'm looking at you Cornish), because nothing they put in that pedal can be worth what they charge. People tend to overblow vintage equipment as well, and I want to find out what it is that makes it sound the way it does, and why.

I did another feature for Tone Report a while back in a similar vein that you may enjoy:
http://tonereport.com/blogs/tone-tips/the-battle-of-muff-mountain-the-tone-report-civil-war-re-enactment

Really thank you so much for your kind words. It means so much to me!

-Yoel
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Re: AD797 RAT oapms talk

Travis
Administrator
I like that Big Muff article and it kinda mirrors my experience with that circuit as well.

A little while ago I got the sacred tall font green Sovtek Muff and I thought "wow this thing sounds amazing". Then I plugged it in along with my black Sovtek Muff (first pedal I ever bought) and found that although the knob positions may look completely different, the sound coming out of the amp is 99% identical. Of course I've built several clones and it's the same deal, the knob positions will look totally different but the sounds are the same.

I think the main reason is that the circuit is just really forgiving and in that sense it is a brilliant design.

I've got several other vintage pedals and have been both underwhelmed and also blown away. So the ones that blow me away keep me in the game.

I like getting geeky about vintage components and whatnot, but if you can't build a great sounding pedal for a couple bucks then you probably won't do it with the most expensive parts either. That's the way I see it.
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Re: AD797 RAT oapms talk

jcdenton825
Thanks Travis!

I've had a similar experience with vintage pedals, which was sort of the catalyst for that article.

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Re: AD797 RAT oapms talk

Travis
Administrator
Obviously with the Big Muff it's worth noting that the originals were inconsistent, and may have variations in component values that lead to one sounding better than the other. The Sovtek ones in particular were really consistent though, and as your article suggests, you don't need to spend years in r&d or buy special parts to make a great clone :)
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Re: AD797 RAT oapms talk

Silver Blues
Oh for sure. That's one of the great things about the Muff circuit, like my last build was a "Green Russian" with D223As and 2N2222As, definitely not your standard Big Muff fare and it rips nonetheless.
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