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...So any suggestions on a stereo parametric rackmount? The Ward Becks sounded fantastic and I hated to sell, but that's how I got the Neves.

Comments

RemyRAD Sun, 02/22/2009 - 20:13

I don't see why you tried to install this particular IC chip in your LA 4? The LA 4 does not use any 8 pin dual OP-Amps. It uses quad 14 pin, 4136's or, TLO75's (no longer available even though it is the same internal circuit as a TLO74 which has different pinout's so you can't use those either without a complicated adapter mechanism) and a couple of single 8 pin LM301, TI 741's, LF 351 or, Signetics 5534's, which require minor component changes.

You blew it up because you didn't do your research. Quite frankly, I doubt whether you destroyed the output transformer? You just have a chip that can't work because of the pinout's and it's not supposed to be a dual. Just because they all LOOK alike doesn't mean their pinout's are all the same. Geez wiz. What were you thinking? This is what happens when you try to "make something better" that's already good. Don't try this with the tires on your car as they are already round.

You purchase a certain product because you want that product the way it is. If it's not what you want you don't buy it. That's simple commonsense. Making something "better" means you have created something else. That's not smart. You wouldn't spend $400 for an LA 4 just to turn it into a $100 Alesis 3630. Or maybe you would?

There is no reason to modify equipment for the sake of modifying equipment. If you want a newer limiter? Buy a newer limiter. If the audio isn't good enough, because of old designed chips, sell it to somebody that can appreciate it and buy yourself a new cheap unit. The old LA 4's have their own characteristics sound & were not made by the same company as the new ones and there were two different versions of those older ones. Many of the new Universal Audio units are not compatible with the older UREI units when it comes to parts either. For instance, it's almost impossible for me to replace a meter in one of my early 1980s silver 1176's. Not the same as my black 1976 1176. Which is not the same as the new Universal Audio 1176. The meters in appearance, from the front, look almost identical but they're mounting system is completely different. So don't destroy the value of your units by trying to improve them. Restore it back to what is indicated in your schematics. I purchased a pair of used LA-3's that some moron modified to be "transformer less". Then, the idiot changed the T4B optical device from an electroluminescent panel to LEDs. What he did was convert a perfectly good LA-3A to a bastardized LA-4. WTF? I restored it back to it's original glorious factory indicated schematic.

I know a good thing when I have it. You need to learn that too.
Ms. Remy Ann David

anonymous Sun, 02/22/2009 - 20:26

Many well-known techs are modding the LA4A units and one standard mod is a pair of oa2604's swapping out the rc4136. You in a orevious post suggest modding and following yours and other professionals advice, I ordered these opamps. Speaking with some techs I was assured it was not the opamps but possibly a capacitor or some other occurrence. I can appreciate original machines but technology found a deficiency in the slew rate and suggests upgrading to another opamp.

RemyRAD Mon, 02/23/2009 - 09:47

I never told anybody to modify their LA 4, just to modify it. I did say you can directly swap between 4136 & tlo75 that were in the later units, if you can find any NOS or even used ones. If there are no 75's available, a 74 can be fitted to an awkward, homebrew adapter if you are hellbent.

There are plenty of folks that love their old blackface LA 4's with 4136 operational amplifiers and have no intentions of changing them just to upgrade. Slow slew rate doesn't mean much in a properly designed unit. Few people realize that API 2520's have as slow a slew rate as 4136 chips of 1.5 volts per microsecond. But because of the design the units never slew because it was designed for its sound, complete with ancillary output transistors. You may have spoken to other technicians that will tell you how to modify your units to be something other than what they were. 2 duals cannot directly swap for a quad without major modifications to the circuit board or without building a complicated custom adapter, while changing other parts on the circuit board to accommodate it.

So you really hated the sound of your LA 4? Now how does it sound?

Really, just because you may have had the financial wherefore all to upgrade still doesn't make sense. I should rip out the discrete circuitry & all of the transformers from my Neve console. Replacing the discrete circuitry with somebody else's chip. Replacing the transformers with somebody else's transformer. Then I would have an imitation Neve console that doesn't sound like a Neve but looks like a Neve that might sound better than a Neve but wouldn't sound like a discrete transistor Neve. Paul Wolff, a friend & former owner of API, even swapped out his 2520 on me with a Signetics 5534 integrated circuit chip, in my 3124 preamps, just for laughs. Allen Side's of Ocean Way even says he has the best sounding integrated circuit chip Neve ever made. That means it doesn't sound like a discrete transistor Neve. At NBC TV I had my choice of a 32 input integrated circuit chip Neve or a 24 input all discrete transistor Neve. Management couldn't figure out why I would want 24 input's instead of 32 (3115's versus 33 115's)? It's because it was the sound I wanted and I had used both for nearly 20 years. The 32 input unit was actually newer & in better condition. This is what experience teaches you. Now you know my reasoning. The older Neve requires much more effort on my part in restoration. It is as it was in 1974.

Sorry if you misinterpreted me as being contradictory. That was not my intention to confuse you. I hope you can get your LA 4 operational again. I'm sure you'll be able to.
Ms. Remy Ann David

anonymous Mon, 02/23/2009 - 09:54

Ha ha ha......it doesnt! You suggested a mod and you admit that so......I still appreciate the advice..... I ordered the browndog adapters that have the 2604's on them so they have 14 legs. Interesting about the API's as am researching those. Oh well, I'll appreciate her as soon as she wakes back up. Dark was not an attribute I wanted from my compressor.

anonymous Tue, 02/24/2009 - 07:53

It's alive...it's alive.....I had no idea that opamps went in a certain way so after reinstalling the 2604's she is alive and well to my knowledge and working her little self.....whew......pin 1 needs to correspond to pin 1 on the board folks...note to self: make sure all questions are answered. I remember asking that question but didn't hear an answer so thought I was safe....Thank you all for your help and guidance!

anonymous Tue, 02/24/2009 - 15:54

Ok it's obvious that I screwed up but only with the best intentions of improving but not re-engineering. The pin 1 was important in installing new opamps and with that keeping me from sleep, I re-installed the chips correctly and she is back to normal, hopefully longterm. I will stop with the mods for now...but my quest for eq modules ,because of my love for what the Ward Beck sounded like, has me contacting my peeps for a pair of raw eq modules like the telefunken and siemens etc....This is fun and I hope that we reuse what some of the great minds created and faded into obscurity but now will skip around their retirement saying "they finally got it" when we proclaim their design oh so perfect for that great track......I am having fun so lighten up...and don't spend a fortune on that piece of nostalgia.....

Link555 Tue, 02/24/2009 - 16:56

Holy crap.....dude...
I mean dude..... thats first week SH$#

thats one hell of a way to learn,
Next time ask, lots of us here could have passed some basic info on....

ok so those opamps are probably trashed now.
What is there part number?

Get the data sheet and check where the power inputs are (VCC VEE and GND) if by flip the chip you connected them to the wrong power rail.....time to replace the opamps.

anonymous Tue, 02/24/2009 - 18:21

It was fun and hey....the compressor is still working and if I go basck to the 4136's so be it....but they threw in a 2134 to try so maybe I can switch one out....Yeah I wish they had answeed my question. Its not like I dont research the hell out of stuff.....They were burr brown 2604's on browndog adapters for replacing 4136's.....I think/hope/pray they are fine....