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2500 Mod
Old 20th August 2016
  #1
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sonicrevolution's Avatar
 
🎧 10 years
2500 Mod

Very brief. I just pulled the 100mf caps out that are next to the THAT chips, and I highly recommend you do as well. The image got a little bigger, field a bit deeper, the low end had a touch more bloom, and it just felt better during playback. I am able to more effortlessly dig into unorthodoxed extreme compression settings now without hearing the compression. Go into your unit, and twist the caps out.

-Matt
Attached Thumbnails
2500 Mod-2500-mod.jpg  
Old 20th August 2016
  #2
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1 Review written
🎧 10 years
EDIT-
Talked to Paul a while back, he says just do it... he would know. Have no fear...but inspect your work! What I said about advice in geekslutz below stands.

Don't twist the caps out, carefully de-solder and save. You could easier short something by 'twisting' them and you may want to return to stock for a sale.

If you post this in geekslutz, ask nicely, then some of the experts [David Kulka, John Roberts, Charlie Bolas, Jim W., Richard C, Todd, Doug, Ms Evanna, and more I overlooked, etc., etc.] and possibly even the always helpful API folks could tell you where they are in the circuit, why they are there, and what you could/should do to properly bypass them, if there might be a better value/grade/brand, etc,...

There are many helpful really knowledgeable folks there if you ask nicely, they are often forthcoming with excellent advice, for well --free!

Best-
Jonathan

Last edited by [email protected]; 31st December 2016 at 05:25 PM.. Reason: Talked to da Wollff
Old 20th August 2016
  #3
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🎧 10 years
Hi Jonathan, yes my post seems a bit abrupt regarding the terminology i use for removing the caps. I had a discussion with Paul Wolff, who said they thought the control voltage stage was unstable, so inserting the two caps across the control lines slowed them down to where they would never be unstable, resulting in loss of transients. Pulling them, he said, gets it back to where he intended. First hand experience, my ears told me pulling them was a great idea. I do recommend a tech or someone experienced under the hood if you have not done something like this. They do very easily twist out, I knew what to look out for when doing this, to desolder would require, it seems, pulling a lot more things apart in the unit just to get to it, it is tight. Just make sure nothing is touching when the caps are removed. Again, a lot of this is directly from Mr. Wolff. regards


-Matt
Old 21st August 2016
  #4
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antichef's Avatar
 
🎧 10 years
I see an empty hole on the board, but I don't really see where you removed them from -- is it in the picture?
Old 21st August 2016
  #5
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lynngraber's Avatar
 
1 Review written
🎧 10 years
Would not opening the compressor and twisting components off the board void the warranty?
Old 21st August 2016
  #6
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antichef's Avatar
 
🎧 10 years
I bet it would - mine's out of warranty anyway, though. I will absolutely desolder, btw, and if it looks too difficult to do that, I'll skip the whole thing
Old 21st August 2016
  #7
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sonicrevolution's Avatar
 
🎧 10 years
Caps

They are right behind the THAT chips. The black rectangular chips. They wiggle out fairly easily.
Attached Thumbnails
2500 Mod-image.jpeg  
Old 21st August 2016
  #8
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🎧 10 years
Perfect - thanks
Old 22nd August 2016
  #9
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Channel time's Avatar
 
🎧 5 years
Anyone got any before/after comparisons to check?
Just to dispense with confirmation bias potential etc etc before I jump in all gung-ho on it
Old 22nd August 2016 | Show parent
  #10
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sonicrevolution's Avatar
 
🎧 10 years
Quote:
Originally Posted by lynngraber ➑️
Would not opening the compressor and twisting components off the board void the warranty?
Mine has been out of warranty. But I presume it would.
Old 23rd August 2016
  #11
Gear Addict
 
🎧 10 years
someone who's done this must have recorded an A/B test... anyone?
Old 23rd August 2016
  #12
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🎧 10 years
If I muster up the cojones to try it, I'll post before/after clips.
Old 24th August 2016
  #13
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Philip Marinelis's Avatar
 
🎧 5 years
Paul Wolff (the 2500 designer) has posted this mod on FB. So I guess this is quite a legitimate tip. He says that these caps were not in his original design.
In the FB comments, some have stated that API stopped putting these caps in later units, though an exact date has not been given
Old 24th August 2016
  #14
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🎧 10 years
If you're not into snipping/twisting, I can confirm that you need to pull the main board, which is over my pay grade (at least with something like this). Don't try to desolder those capacitors from the top like I did - or you're gonna have a bad time, so to speak.

Last edited by antichef; 24th August 2016 at 05:59 PM..
Old 24th August 2016
  #15
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🎧 10 years
so for those of you that have done this mod... what do you think about the way it sounds?
Old 24th August 2016
  #16
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Brett 123's Avatar
 
🎧 10 years
Do you need to put a jumper in their place is is it ok to leave that part of the circuit broken ?
Old 25th August 2016
  #17
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🎧 15 years
just pull those fuggers outta there
it sounds better
get a needle nose plyers and carefully work them out

it should take about 3 to 5 mins per cap

dont just yank them

work them out carefully and have patients

they will eventually break off

then if the legs are still in place after you get the main part of the cap out, you can get those to break free as well with needle nose

good luck and be safe
Old 31st August 2016
  #18
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🎧 10 years
Did this. Definitely a change. My question is, why were they put in there in the first place?
Old 31st August 2016 | Show parent
  #19
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Brett 123's Avatar
 
🎧 10 years
Quote:
Originally Posted by lynngraber ➑️
Did this. Definitely a change. My question is, why were they put in there in the first place?
A change for the better ?
Old 31st August 2016 | Show parent
  #20
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🎧 10 years
Quote:
Originally Posted by Brett 123 ➑️
A change for the better ?
Yes, for the better.
Old 31st August 2016 | Show parent
  #21
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antichef's Avatar
 
🎧 10 years
Quote:
Originally Posted by lynngraber ➑️
Yes, for the better.
do you have a good stable source of power for your 2500? I wonder if the capacitors were put there to help deal with dirty power sources.
Old 31st August 2016
  #22
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🎧 5 years
I'd like to hear API engineers' current take on this one.

It would be good to know.

Old 31st August 2016 | Show parent
  #23
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🎧 10 years
Quote:
Originally Posted by antichef ➑️
do you have a good stable source of power for your 2500? I wonder if the capacitors were put there to help deal with dirty power sources.
Just a monster power 3500.
Old 31st August 2016 | Show parent
  #24
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kafka's Avatar
 
🎧 10 years
Quote:
Originally Posted by Philip Marinelis ➑️
In the FB comments, some have stated that API stopped putting these caps in later units, though an exact date has not been given
Interesting. If some folks posted serial numbers, either way, it might narrow things down. If they conclusively stopped using them, I'd have no problem taking the diagonal cutters to them and be done with it.
Old 1st September 2016
  #25
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antichef's Avatar
 
🎧 10 years
well, mine's just a couple of years old - serial 2655-14 -- it came with the capacitors
Old 1st September 2016 | Show parent
  #26
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1 Review written
🎧 10 years
Quote:
Originally Posted by kafka ➑️
Interesting. If some folks posted serial numbers, either way, it might narrow things down. If they conclusively stopped using them, I'd have no problem taking the diagonal cutters to them and be done with it.
Cutters really aren't necessary. Gently wiggling them broke them off easily at the board with no leftover stubs.
Old 8th September 2016 | Show parent
  #27
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sonicrevolution's Avatar
 
🎧 10 years
Quote:
Originally Posted by Brett 123 ➑️
Do you need to put a jumper in their place is is it ok to leave that part of the circuit broken ?
No jumpers. Leave as is after they are pulled.

Matt
Old 8th September 2016 | Show parent
  #28
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sonicrevolution's Avatar
 
🎧 10 years
Quote:
Originally Posted by stringbean01 ➑️
so for those of you that have done this mod... what do you think about the way it sounds?
Better transient response, more open, and the compression sounds a bit more natural if you will. The box in nature is punchy and forward, however, I feel those attributes become a bit more organic feeling with the caps gone. Paul said they thought the control voltage stage was unstable, so inserting the caps across the control lines slowed them down to where they would never be unstable, and killing the transients. something implemented in theory that looked right on paper but did not translate to the musical realm.
Best

Matt
Old 8th September 2016
  #29
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ghostwriter's Avatar
 
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🎧 10 years
Audio examples would be greatly appreciated.
Old 8th September 2016
  #30
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callmelaub's Avatar
 
🎧 5 years
Anyone from API could answer why the caps where put in?..thanks
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