Revitalization suggestions for my 22 year old Ion mono amps

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Hi All,

I'd like to refresh my amps that I guess after 22 years need new caps and maybe also could benefit from changeing some other components for modern 'better' sounding ones. Any recommendation for good grade replecement caps? Is it any idea to change the rectification diods for fast recovery types or any better alternative? Other suggestions?
Any one familiar with my amplification, Ion Systems power supply TX750 and mono amps MA40?
Each mono stage has 2x22000 uF (63V, 85 degC, Elna), output caps 2x10000 uF (35V, 85degC, Rubycon), 1x10 uF (50V), 3x22 uF (63V), 1x470 uF (25V) plus some ceramic and plastic caps.
When looking around I can find the right spec however the replacement caps I find are always to big! The 22000 uF are 40x100 mm and the 10000 uF are 25x45 mm. If you look at the layout (one channel) there is not much space for bigger ones.

All suggestions are welcome.

Cheers,

Mikael
 

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Size is the problem from your piccys.

These would fit but are "only" 15000uf, which personally I don't think would be an issue in the slightest. You gain from having the performance of a modern component, which probably has a higher ripple rating than the originals. Screw terminals though ?
VISHAY BC COMPONENTS|222210118153|CAPACITOR, 63V 15000UF | CPC

For the 10000,
Your Search Results | CPC

I would leave the rectifiers alone.
If it were me I would replace the preset pots (first making sure I knew what they do and how to reset them... and making sure any idle current pot was set for minimum current first switching on)
 
Dear Mooly,

Thanks for the input and links, very much appreciated! I didn't realize that the pots could be a source of bad or good sound but I guess it would be as sensitive as any pot, quality wise!?

Cheers,

Mikael
 
Dear Mooly,

Thanks for the input and links, very much appreciated! I didn't realize that the pots could be a source of bad or good sound but I guess it would be as sensitive as any pot, quality wise!?

Cheers,

Mikael

I have a bit of a dislike of preset pots... they tend to fail with age. The "rivets" that clamp the resistive track to the pins/legs can loosen, the wiper connection can also become intermitent. At best this can add strange intermitent noise to the amp, often made worse by physical movement, at worst it can lead to unstable bias and DC offset problems.
 
Hi All!

I will pick up my own thread again. Since last time I've been looking for caps that would fit and I found some. However is there any differences in sound quality between let's say BHC, Kendeil, Mundorf, Rifa or Vishay BC? Is it beneficial to have the 'best' quality caps for both the main caps (22000) as the output caps (10000) or is it enough with the output ones?
The smaller caps of 10, 22 and 470 uF what would you recommend there, Elna Cerafines/Silmic, Nichcon etc? I guess these will 'tune' the voice of the amp too!?

Your experiences and suggestions.

Thanks/Mikael
 
The signal coupling Caps and the feedback capacitor can make a significant difference to the sound of an amplifier.
My favourites are the Elna Silmics but You may struggle to find ones that fit on your PCB.
Where size is an issue I find that Panasonic FC capacitors are available in a range of diameters.
In My opinion, The Panasonics give a fuller tonality to an amplifier compared to old original commercial grade capacitors, and the Silmics give a very detailed sound.
I also like to add bi-pass capacitors, typically a 0.1uF to 0.47uF polypropylenes to the underside of the electrolyics, Although some others prefer not to.....🙄
At least with monoblock amplifiers you can easily compare before and after!
 
Hi Xoc1 and thanks for the input!

So I'm now in the hunt for the Silmics or Panasonic FC when it comes to the 10, 22 and 470 uF caps. For the bigger 22000 uF I will settle with Rifa!
But then we have the output caps and what to pick? I found a few but have no clue which ones would be good? Rubycon USC 10000 uF/35 or 50V, Panasonic UQ 10000 uF/35 or 50V, F&T 10000 uF/40V, Mundorf MLSI 10000 uF/35 or 50V. Any suggestions or comments!?

Cheers/Mikael
 
Hi again!

FYI I just settled for RIFA PEH at the 22000 and Mundorf MLytic for the output 10000 and a mix of Silmics II and Nichicon MZ for the signalprocessing, new trimpots from Bourne and a fresh bypass caps from RIFA (0.1uF). To finish off I will also change the input RCA sockets and the speakerterminals with silverplated real copper ones. It will be exciting to hear the end result! Pictures will come!

/Mikael
 
Hi again!

FYI I just settled for RIFA PEH at the 22000 and Mundorf MLytic for the output 10000 and a mix of Silmics II and Nichicon MZ for the signalprocessing, new trimpots from Bourne and a fresh bypass caps from RIFA (0.1uF). To finish off I will also change the input RCA sockets and the speakerterminals with silverplated real copper ones. It will be exciting to hear the end result! Pictures will come!

/Mikael
 
So I finally managed to get the parts in place. It is an amazing lift in overall performance even from start but I guess it will be better after some hours of settling in. Same character as before but now dynamics, bass, ambience etc etc is so much better, can't stop listening. Have a look at the pictures/Mike
 

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