stereokillah

Opinion about api 554 EQ
« on: May 26, 2010, 02:16:44 PM »
Hi,
 A french guy's who bought 2 api 554 and would sold me it, i think to put it in my 51x Box,but after somme search on the web , i don't find a lot of information.
If some one got one  or worked with it and can give me some advice about it and one idea of price.



Thanks
if your neighbour is hunger .. don't give him fish, teach him how fishing ...


strangeandbouncy

Re: Opinion about api 554 EQ
« Reply #1 on: May 26, 2010, 03:10:37 PM »
Hi,



  I had a pair a long time ago. They got stolen.. I think they are fantastic, especially with the continuous sweep on the frequencies. They do not command the same respect generally as the 550. - I think that that is a shame! The main signal path is discrete, apart from the input buffer, which was a 748 on mine! I am sure you can easily upgrade to something faster. All the other chips are in the filters. I found them to be be much more flexible and usable, especially on drums, since the LF sweeps down to 30Hz(only down to 50Hz on a 550a), and the mid (with a sharp q option) down to 200Hz( only down to 400Hz on 550a, and with no sharp q option.) Check the frequency pots very carefully. Mine were fine, but i have seen others where they were horribly scratchy, and I think you will have trouble replacing them(?).

 As to value, well I can't help you there. I am sure that they are worth less than 550a's, cos they're not so popular.


   Good luck!



    ANdyP
. . . . RUH ROH . . . . .

QUEEF BAG

Re: Opinion about api 554 EQ
« Reply #2 on: May 26, 2010, 04:44:45 PM »
they do sound like api

input amp is a chip
the very early ones were a 741, icky
later versions switched to an LF356
a better choice.

I think this is the only sweepable freq. eq they made.

stereokillah

Re: Opinion about api 554 EQ
« Reply #3 on: May 26, 2010, 06:06:54 PM »
thank you for your reply,

 in fact it's a trading he want  twoo of my three gssl clonewith dbx 202 and turbo for his Eq's.
With your comment can think it's a good way for me, in one  Eq there is two 2520 with sticker 2520 api and in thze second there one like last and one black without stickers and nothing indicate on it.
i'll ask for the input buffer.
if your neighbour is hunger .. don't give him fish, teach him how fishing ...

envelope

Re: Opinion about api 554 EQ
« Reply #4 on: May 27, 2010, 03:17:03 PM »
They are a little finicky to service, with a very densely populated two sided circuit board, but if working well, they have great versatility. The pots are indeed hard to replace, prone to scratchiness, but there are few spots where cleaner can be injected.....
This photo is prior to a restoration. If you would like schematics, I can eMail them to you.
« Last Edit: May 27, 2010, 03:43:18 PM by envelope »

stereokillah

Re: Opinion about api 554 EQ
« Reply #5 on: May 27, 2010, 09:07:47 PM »
thank fine
Pmed yoiu my email, i'll take the paire tomorow but can't feet in the my 51x at time cause there are full boxed i need to change some card edge before.
if your neighbour is hunger .. don't give him fish, teach him how fishing ...

Re: Opinion about api 554 EQ
« Reply #6 on: May 27, 2010, 09:14:09 PM »
Mmmmmmmmmm.....

[silent:arts]

Re: Opinion about api 554 EQ
« Reply #7 on: May 28, 2010, 04:42:16 AM »
thank fine
Pmed yoiu my email, i'll take the paire tomorow but can't feet in the my 51x at time cause there are full boxed i need to change some card edge before.
for testing you can just remove the box

stereokillah

Re: Opinion about api 554 EQ
« Reply #8 on: May 28, 2010, 05:55:02 AM »
yes i ve got it  today and i've tryed but there is two  pcb suport with screw that can't be remove .

is the box realy necessary?
« Last Edit: May 28, 2010, 06:13:47 AM by stereokillah »
if your neighbour is hunger .. don't give him fish, teach him how fishing ...

bkbirge

Re: Opinion about api 554 EQ
« Reply #9 on: May 28, 2010, 04:01:17 PM »
These might be mine, I just traded a pair to a guy in France for his D-La2a build. 554's are really nice eq's and probably the most musical parametrics out there. I've seen them go from $600 to $900 US each. If they are the ones I had you'll love 'em even with the wide era of 2520's that are installed.


stereokillah

Re: Opinion about api 554 EQ
« Reply #10 on: May 28, 2010, 08:57:19 PM »
oh it's yours, very small world!!! Dla2a, realy great machine , now he have two of my three gssl he said he must have it for a customer who want it on his mix ;he almost shed tears when he give me this eq, he said he have bad way during the shipping, he paid around 200 euros for custom fees, but he is happy too with the 2 gssl with turbo and DBX

could i use your Eq in stereo way ?
cause of the differents 2520

envelope  schematics received thank you

« Last Edit: May 28, 2010, 09:02:37 PM by stereokillah »
if your neighbour is hunger .. don't give him fish, teach him how fishing ...

strangeandbouncy

Re: Opinion about api 554 EQ
« Reply #11 on: May 29, 2010, 03:53:54 AM »
Hi,


   I doubt very much that you will hear any difference at all between the units! Mine had a real mishmash of 2520's in. If there is a difference, you could always convert x/y to m/s eq with you 554's, and convert back to x/y . . . . I have only really noticed a tiny difference with mic pre's at very high gain. I think that a lot of the "sound" is in the transformers, and it is especially the input transformer differences that count in API mic-pre's. There have been a few different input transformers over the years, I think . . .


   I have recently built a pair of Audiox's Studer 169-500's, with switchable top and bottom frequencies, no mid band. I have temporarily used two very different 2520's in them, and there is no iron to influence the sound. - 1 original (melville?) and one built using Fabio's board. I was going to swap them out for thew Neumann OA10's that I was going to build. I wont be bothering to do that, since they sound absolutely fantastic, and exactly the same. I guess that in a unity gain situation, that is not too surprising. Even at extremes of boost, they sound the same to me. Using a 5534 instead made it a tad more brittle at the top end.
 
   Also, you could replace the 2520's with 4 of the many types now available. I can personally recommend Peter Purpose for 2520's . . . . I think his are probably the most "authentic", since he reverse engineered an original.

   Bon chance!


      ANdyP
« Last Edit: May 29, 2010, 04:05:32 AM by strangeandbouncy »
. . . . RUH ROH . . . . .

envelope

Re: Opinion about api 554 EQ
« Reply #12 on: September 01, 2010, 12:03:21 PM »
reviving this old thread with a photo of the repaired 554 with an 'ML2520' OpAmp from white market, can't remember/find who the seller was anymore, but it was a great little kit to assemble.

The owner of the 2 API 554 units I serviced performed an 'ear listening' test, and decided that they sounded subjectively the same. The owner is a well seasoned engineer/producer with golden ears. I spent 20 plus years as a recording engineer before I picked up the soldering gun, and I agree that the '2520' modules in these particular EQ's do not overly contribute to the 'sound' so much as to audibly alter the 'sound' by swapping various version. In other units, they have a much more noticeable effect. (again....subjective)

All of the electrolytics could use an upgrade...the factory e.cap components were not excellent.

mikefatom

Re: Opinion about api 554 EQ
« Reply #13 on: December 13, 2010, 05:38:08 PM »
reviving this old thread with a photo of the repaired 554 with an 'ML2520' OpAmp from white market, can't remember/find who the seller was anymore, but it was a great little kit to assemble.

The owner of the 2 API 554 units I serviced performed an 'ear listening' test, and decided that they sounded subjectively the same. The owner is a well seasoned engineer/producer with golden ears. I spent 20 plus years as a recording engineer before I picked up the soldering gun, and I agree that the '2520' modules in these particular EQ's do not overly contribute to the 'sound' so much as to audibly alter the 'sound' by swapping various version. In other units, they have a much more noticeable effect. (again....subjective)

All of the electrolytics could use an upgrade...the factory e.cap components were not excellent.

Sweet!  8)



 

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