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PostPosted: 11 Aug 2017, 00:28 
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Joined: 06 May 2017, 18:49
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Location: Seixal. Portugal
Hi!
I have a Philips amplifier type EL6415 since 1995, on a dedicated mono system. 35 watts output, working in good condition.
It is used once or twice a week and it never gave me the slightest problem,
It's strange ... 22 years in my hand without any maintenance, except cleaning.
I use it to amplify two different sound sources: one Rhode & Schwarz EU 6201 in mono and
a Creative sound card attached to a computer that is responsible for storing and distributing vintage audio files, also in mono.
This amplifier is attached to a fairly large speaker, equipped with a B&W two-way speaker system.
I love the sound of this setup, especially with the Rhode & Schwarz EU 6201 tuner signal.
This amplifier was kicking around in a church and no one knew what to do with it.
Fortunately had never been opened, so I bought it with, even not testing it or opening it in the original location.
Already gave me many hours of musical pleasure and I want to continue with it for many more years, if possible
Recently it started to produce some background noise, albeit very slight. I presume the problem are the electrolytic capacitors. Or tubes.
I do not want to deliver this amplifier to anyone because I can not find anyone with the necessary experience. Anyway it is time to recap this amplifier, I want to know exactly what are the capacitors that need to be changed and what are the options in the market.
It's a job that has to be done methodically, so before start I would like to know your opinion on this subject.
I have the Service Manual in pdf but the file is way too big to send it, around here.

Can you help?
Thanks.

Macedo Pinto
Portugal


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PostPosted: 11 Aug 2017, 21:48 
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Joined: 04 Jun 2008, 20:59
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Location: Arizona, USA
Hi, I am not familiar with that particualr amp, but if you will PM me I'll provide an email (to me) that can handle large files and I'll give it a look see.

Good listening
Bruce

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PostPosted: 12 Aug 2017, 03:32 
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Joined: 01 Jun 2013, 09:05
Posts: 551
Is this it?
As you say if you like the sound don't just recap it and change everything or you will have a different/modern sound.
I know quite a few people that have just ripped everything out and changed it then the amp loses its magic.
But each to their own..

Regards
M. Gregg


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PostPosted: 14 Aug 2017, 01:22 
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Joined: 06 May 2017, 18:49
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Location: Seixal. Portugal
Gregg:

Thanks for the images you published. They're better than mine!

You are right! In fact, the last thing i want is to change the sound character in this setup.

But the question is: How should I proceed to prevent background noise (despite being very low) from increasing?

I have no concrete idea about the procedure in this case.

Being a tube amplifier, I predict that over time the situation may become worse, so my interest is to restore the good condition of it

Thanks for your your comment/interest!

Macedo Pinto
Portugal


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PostPosted: 14 Aug 2017, 04:18 
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Additional info,

Parts list.
If you can post pictures of the components side of the amp in particular the rectifiers for the HT (B+).
Just wondering if the rectifier is a selenium plate?(hopefully its a diode bridge rec)
https://en.wikipedia.org/wiki/Selenium_rectifier

R65 on the PSU acts as a discharge resistor so as long as its not open circuit the PSU caps should discharge over a time period.
Next tip take photos of the component side before you disconnect anything. (I don't suggest replacing anything at the moment)

Just a few suggestions,
If you replace electrolytic capacitors don't be tempted to upgrade the values to higher capacitance.
You need to describe the noise, is it hiss, hum, or crackle, drop out/volume change?

It is always good for others to have an input so you can get a cross section of opinion.

Regards
M. Gregg


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PostPosted: 14 Aug 2017, 21:11 
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Joined: 06 May 2017, 18:49
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Location: Seixal. Portugal
Gregg
Once again thanks.
Next weekend I will open the Philips EL 6415 and examine the circuit according to the information you sent me. However, I must clarify that the slight problem that began to appear is only HUM with no variation of intensity.
This began to appear about 4 months ago and until now has not gone beyond that. I keep turning on this amp about twice a week.
The amplifier does not present any more problems. No drop out, no hiss, no crackle, no volume change. Just that slight hum.
The amplifier's temperature remains constant, as it has always been.
Physically, nothing happened to the amplifier, which is solidly installed on a metal table, which also supports the Rhode & Schwarz type EU-6201 tuner.

Audio transmission still very clear, with no changes at all.


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