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Old 2nd August 2012, 01:29 PM   #1
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Default My faithful Forte Model 3

I have a Forte Model 3 that I bought in the mid 90s that I use with a pair of ProAc Response 2s. I'm using them as my main monitoring systems in my recording studio and they've really endured over the years but lately I've noticed a drop in the top end, they sound a little "tired" for lack of a better word.

I guess this is to be expected considering the age of both amp and speakers. I recently compared the duo set-up to some self-powered speakers, one pair being Genelecs and the lack of top end was really prevalent. The Pro-Ac/Forte combo still sounded better, warmer and much more spacious.

I've got new tweeters and woofers coming for the Response 2s hoping to put them back in shape.

Here's my question: does my Forte need upgrades and maintenance? What can I do to make it sound like it once did when new?

Thanks for your help!
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Old 2nd August 2012, 02:16 PM   #2
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Old 2nd August 2012, 02:41 PM   #3
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Quote:
Originally Posted by miserlou View Post
make it sound like it once did when new?
Exchange the electrolytic cans.
20 year old lytics are like tired shoes with holes in the bottom, with stacked capacitors as in the Model 3 that becomes more aggravated.

(better would be to swap in higher voltage single cans, but 100Vdc ones are a bit expensive. You'd need 90Vdc minimum, but usual is 80V or 100)
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Old 2nd August 2012, 04:14 PM   #4
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Okay, I've made a big mistake...for some reason I thought it was a Model 3, it's actually a Model 1a! So sorry for the mistake, is this a game changer?

-Rod
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Old 2nd August 2012, 04:16 PM   #5
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What exactly will new eletrolytic cans do? Better top end? Or just overall better performance?

Thanks!
Rod
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Old 2nd August 2012, 04:35 PM   #6
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Quote:
Originally Posted by miserlou View Post
Model 1a
Not a lot, the 1A is a class A model, but apart from the stacked cans totally identical.
Not that heavily biased, but the power supply electrolytics will be out of breath too after 20.
Overall.
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Old 2nd August 2012, 04:46 PM   #7
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I will have my tech get right on some new caps. Any brand suggestions?

The 1a is ice cold, is that because bias needs some re-adjustment?

-Rod
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Old 2nd August 2012, 05:02 PM   #8
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Quote:
Originally Posted by miserlou View Post
The 1a is ice cold, is that because bias needs some re-adjustment?
Definitely.
The heatsinks of the 1A are not large enough to go full throttle on the bias, but they should be hot to the touch.

Any decent brand will do, Panasonic T-HA are affordable and would be my first choice.
Trouble is that you need cans with screw terminals, to make the exchange easy, United Chemicon are affordable ones with screw terminals, CDE would be my choice, but a couple of times more expensive.
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Last edited by jacco vermeulen; 2nd August 2012 at 05:12 PM.
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Old 3rd August 2012, 09:52 PM   #9
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Is there anything I should do besides change the power supply electrolytic caps and adjust the bias?
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