Hello, new member here. I wanted to post the rebuild of my Aragon 18K preamp here. Until recently, I have not been what you call a solid state fan or an active preamp fan. However, several months ago I had Ken Ealey rebuild an Acurus RL11 that I got for paltry $150 on eBay. I've been using passive preamps all along (stepped resistor, autoformer, and LDR) as I have found them to be more transparent and free of artifacts than any active preamp I have auditioned including 5 figure preamps. I was surprised to find out how good the Ken Ealey rebuilt RL11 is. In some respects, it surpassed the best passive preamps I have used (ie, better dynamics, both micro and macro, and more realistic high frequency performance). I asked myself if I achieve even better results, so I looked into its more sophisticated brother, Aragon 18K, which I found on eBay for around $300. But Ken Ealey has no mod for the 18K and was too backed up to even try.
This is where Kevin (aka Mondial Fan) comes in. As you may know, he is a prominent member here and has worked on many Mondial designs including the Aragon preamps. I contacted him to see if he would be willing to build the ultimate 18K. I wanted the following.
1) Critical signal pathway resistors to be replaced with naked Z-foil resistors from Vishay for low power circuitry and NOS US manufactured Mills MRA resistors for the output.
2) Bypass the large value electrolytic caps with good film caps and bypass the input coupling cap altogether.
3) Bypass the preamp's selector switch and balance control.
4) Use dual mono remote controlled autoformer volume control (amorphous core, hand wound by a specialist in the Netherlands). The dual mono volume control can also function as balance control.
5) Use Neotech Silver/gold hookup wire in the signal path.
6) The preamp can be either a PASSSIVE preamp going through the autoformer volume control only or an ACTIVE preamp going through the 18K circuitry, selected by simple relay switch.
7) RCA sockets are true copper (ie, 99.5% copper). Most audiophile RCA sockets that are claimed to be copper are actually alloys containing significant amount of other metals (eg, brass or bronze).
8) Kevin has his own version of Aragon preamp power supply, which is over spec'd using toroidal transformers and increased capacitance over the largest power supply Aragon built for Aurum preamp. So I decided to use his power supply with more mods including film cap bypass, AC filter, and additional supply for remote volume control.
9) This rebuild required entirely new PS and preamp chassis, so we designed new custom chassis for this project.
Here are some photos of the power supply. More to follow.
This is where Kevin (aka Mondial Fan) comes in. As you may know, he is a prominent member here and has worked on many Mondial designs including the Aragon preamps. I contacted him to see if he would be willing to build the ultimate 18K. I wanted the following.
1) Critical signal pathway resistors to be replaced with naked Z-foil resistors from Vishay for low power circuitry and NOS US manufactured Mills MRA resistors for the output.
2) Bypass the large value electrolytic caps with good film caps and bypass the input coupling cap altogether.
3) Bypass the preamp's selector switch and balance control.
4) Use dual mono remote controlled autoformer volume control (amorphous core, hand wound by a specialist in the Netherlands). The dual mono volume control can also function as balance control.
5) Use Neotech Silver/gold hookup wire in the signal path.
6) The preamp can be either a PASSSIVE preamp going through the autoformer volume control only or an ACTIVE preamp going through the 18K circuitry, selected by simple relay switch.
7) RCA sockets are true copper (ie, 99.5% copper). Most audiophile RCA sockets that are claimed to be copper are actually alloys containing significant amount of other metals (eg, brass or bronze).
8) Kevin has his own version of Aragon preamp power supply, which is over spec'd using toroidal transformers and increased capacitance over the largest power supply Aragon built for Aurum preamp. So I decided to use his power supply with more mods including film cap bypass, AC filter, and additional supply for remote volume control.
9) This rebuild required entirely new PS and preamp chassis, so we designed new custom chassis for this project.
Here are some photos of the power supply. More to follow.