Ultimate Aragon 18K Rebuild

OK, more pics....You can see how massive this preamp is compared to the 28K.
 

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OK, more pics....You can see how massive this preamp is compared to the 28K.

Looks great from all angles. :) Very very nice!

That 28K has a pretty interesting history as well. it's the 28K that Aragon probably should have built . But where there's a will, there's a Mondialfan! so that's a great photo of two legendary Mondial/Aragon units that now set the bar for the rest of us Aragon fan boys to "oooh and ahhhh" over.
 
:idea:

Also, a quick tech question. Just wondering, since you're using the remote controlled dual mono autoformer's; do they slave together accurately when adjusting volume remotely? I'd assume they would (have to), to maintain proper stereo balance. I just wasn't 100% sure. But I guess, you haven't even had to chance to play with it's features yourself? :confused:

Finally, a quick Kevin question; is Kevin retiring? I seem to remember reading recently that he was ramping down his mod business, and I wasn't sure if that were true or not? For me, I hope not. But, if that's what Kevin wants, I'm happy for him! :D

The attenuators don't really slave together. It operates with the intent that both IR receivers, one for each attenuator, will get the IR command simultaneously. This is the reason for the large oval opening in the center of the faceplate, which is to give a large enough opening to keep from blocking the IR signal for one detector or the other when at odd angles. So far it appears to work and they track pretty well. I have seen issues where one or the other doesn't make a full step up or down. This is easily remedied by hitting the L or R balance button to even them back up. This is a quirk albeit a minor one which is much better than getting up every time you want to change the volume level IMO.

Retiring? :) I wish... I've got about 10 years before I can start thinking about that.
I'm not retiring, but I will be winding down my audio modding hobby. It was never a business for me, it was just a way to stay involved in audio and make a little side cash or trade for gear to support my audio hobby. My daughter will be going to college in another 18 months and I need to start using my spare time to make some additional money. One of the other engineers I work with has been after me for some time to take on a business opportunity with him and it looks like we are going to move in that direction. I expect that will take up any additional time I may have beyond my 8 to 5 job.
 
Here's some feedback from Kevin regarding the sound of the preamp. I hope Kevin won't mind me quoting him.

"I spent about an hour and a half tonight comparing your new super 18k to my upgraded 28k and it definitely sounds superior to my ears. The top end is extended and much more detailed than my 28k. The 28k sounds exceedingly rolled off and laid back after listening to your 18k. The funny thing is that's listening through a set of Acoustat Spectra 22's being driven with a Hafler XL- 600 neither of which is known for being laid back."
 
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Well I finally wrapped this project up. I'm really happy with how the whole thing turned out, of course Dr K was willing to go the extra yard to make sure everything in this project came out professional. The face plate and knobs Dr K had polished and then chrome and gold plated make this component look like a multi-kilobuck preamp. I've had some time to relax and listen to Dr K's new pre now and its a definite improvement over the 18k/28k pre's I have upgraded. What immediately jumps out at me is the amount of low level detail and the extended top end that appears with this pre in the signal chain as opposed to my own modded 28k. I do not hear a huge amount of added bass response, however the Acoustat Spectra 22's aren't a deep bass speaker so it might be there, but just undetectable with my configuration. I do notice an improvement in the soundstage depth which I'm sure is attributable to the better low level detail as well. When comparing his pre to mine I find myself eager to switch back to it from the 28k every time I go to compare the two. For me that is a big factor, if I am eager to switch back to one component from another one there's an improved level of musicality for me.

After performing this work I have to wonder what's the big factor affecting the sound? Most of the circuit and parts changes in this pre I've implemented in past upgrades. Dr K did go with some high end Vishay Naked foil resistors and silver wire as well as eliminating a large amount of the signal traces on the board which is definitely something I haven't done in the past. Surely all of those quality parts add up, but I have to think that the attenuators is where the biggest change was made. This experience definitely has me thinking about aftermarket attenuator options for my next personal preamp project. ;)
 
Well I finally wrapped this project up. I'm really happy with how the whole thing turned out, of course Dr K was willing to go the extra yard to make sure everything in this project came out professional. The face plate and knobs Dr K had polished and then chrome and gold plated make this component look like a multi-kilobuck preamp. I've had some time to relax and listen to Dr K's new pre now and its a definite improvement over the 18k/28k pre's I have upgraded. What immediately jumps out at me is the amount of low level detail and the extended top end that appears with this pre in the signal chain as opposed to my own modded 28k. I do not hear a huge amount of added bass response, however the Acoustat Spectra 22's aren't a deep bass speaker so it might be there, but just undetectable with my configuration. I do notice an improvement in the soundstage depth which I'm sure is attributable to the better low level detail as well. When comparing his pre to mine I find myself eager to switch back to it from the 28k every time I go to compare the two. For me that is a big factor, if I am eager to switch back to one component from another one there's an improved level of musicality for me.

First, extremely awesome work on your part. You should feel proud of what you've accomplished. Well worth a pat on the back. Plus, you should have pulled a Bob Carver (since it'll me matched with Carver amps), and signed the chassis with a silver Sharpie! Make it all fancy! :bowdown:

After performing this work I have to wonder what's the big factor affecting the sound? Most of the circuit and parts changes in this pre I've implemented in past upgrades. Dr K did go with some high end Vishay Naked foil resistors and silver wire as well as eliminating a large amount of the signal traces on the board which is definitely something I haven't done in the past. Surely all of those quality parts add up, but I have to think that the attenuators is where the biggest change was made. This experience definitely has me thinking about aftermarket attenuator options for my next personal preamp project. ;)

And this was going to be my next question; what component change made the biggest impact on sound? But, as you've stated, I guess it's the sum of the whole. Every little bit helps. Any desire on your part, to now upgrade your personal preamps to another level? Step it up, now that you've heard it's possible? :naughty:


Thanks.
 
Well I finally wrapped this project up. I'm really happy with how the whole thing turned out, of course Dr K was willing to go the extra yard to make sure everything in this project came out professional. The face plate and knobs Dr K had polished and then chrome and gold plated make this component look like a multi-kilobuck preamp. I've had some time to relax and listen to Dr K's new pre now and its a definite improvement over the 18k/28k pre's I have upgraded. What immediately jumps out at me is the amount of low level detail and the extended top end that appears with this pre in the signal chain as opposed to my own modded 28k. I do not hear a huge amount of added bass response, however the Acoustat Spectra 22's aren't a deep bass speaker so it might be there, but just undetectable with my configuration. I do notice an improvement in the soundstage depth which I'm sure is attributable to the better low level detail as well. When comparing his pre to mine I find myself eager to switch back to it from the 28k every time I go to compare the two. For me that is a big factor, if I am eager to switch back to one component from another one there's an improved level of musicality for me.

After performing this work I have to wonder what's the big factor affecting the sound? Most of the circuit and parts changes in this pre I've implemented in past upgrades. Dr K did go with some high end Vishay Naked foil resistors and silver wire as well as eliminating a large amount of the signal traces on the board which is definitely something I haven't done in the past. Surely all of those quality parts add up, but I have to think that the attenuators is where the biggest change was made. This experience definitely has me thinking about aftermarket attenuator options for my next personal preamp project. ;)

Many thanks to Kevin for his incredible work on this preamp!! This was a very rewarding project to undertake. Kevin could become a very successful modder given his knowledge and workmanship.

Based on my experience, the changes that contributed to the majority of sound improvement are bypassing the input capacitors (fully direct coupled) and installation of the inductive volume control. Then the Zfoil resistors and bypassing the PS electrolytics with appropriately sized film caps. Then perhaps bypassing the stock selector switch with relays/direct RCA connections and bypassing the stock balance switch altogether (dual mono inductive volume control used as balance). The silver/gold hookup wires and highend Furutech and DH Labs RCAs are icings on the cake.

I can't wait to get my hands on the preamp!
 
I can't wait to get my hands on the preamp!

Your ear's are probably even more eager :) looks phenomenal and based on Kevin's account of the performance, it sounds like you have a very special unit heading back your way.
 
Any desire on your part, to now upgrade your personal preamps to another level? Step it up, now that you've heard it's possible? :naughty:

No doubt! I'm always thinking about improvements that can be made and how to implement them. You can't come away from a big project like this one and not have some things you want to do to your own gear.
 
Your ear's are probably even more eager :) looks phenomenal and based on Kevin's account of the performance, it sounds like you have a very special unit heading back your way.

Most definitely! I will post a review after I get my hands on it for about a week.
 
It's been a couple of months since any updates. So, just curious, has the system came together yet? I wonder if the Carver amps and ALS speakers are in place yet, and if so, how is everything sounding as a whole? It should make for an epic system.

Also, there's some curiosity about the ALS speakers, elsewhere on AK. It would be nice to hear an update specifically about the speakers, if possible?

http://audiokarma.org/forums/index.php?threads/newest-carver-amazing-line-source.711587/

Thanks! :thumbsup:
 
It's been a couple of months since any updates. So, just curious, has the system came together yet? I wonder if the Carver amps and ALS speakers are in place yet, and if so, how is everything sounding as a whole? It should make for an epic system.

Also, there's some curiosity about the ALS speakers, elsewhere on AK. It would be nice to hear an update specifically about the speakers, if possible?

http://audiokarma.org/forums/index.php?threads/newest-carver-amazing-line-source.711587/

Thanks! :thumbsup:

Hi sorry for my tardiness. My work keeps me busy. I have the ALS but have not set them up. Bob is fine tuning the prototype Silver 7s and has said it is the best sounding amp he has produced. My Aragon 18K project is complete and its sound has exceeded my expectations. I will be posting on my threads soon with some overdue pics.
 
Your ear's are probably even more eager :) looks phenomenal and based on Kevin's account of the performance, it sounds like you have a very special unit heading back your way.

So I have listened to the 18K for about 24 hours. First thing I noticed was the see through transparency of the preamp. Compared to my passive Tortuga Audio LDR preamp (with top of the line Furutech RCAs and neotech silver/gold hookup wire and battery power supply) and upgraded dual mono version of the Don Sachs tube preamp (Duelund CAST copper and silver coupling caps, Furutech RCAs, and silver/gold hookup wire, and four Black Treasure 6SN7 tubes), the 18K is the most transparent preamp. In fact, it is one of the most transparent preamp I've heard. The high frequency reproduction production is something special. It is so delicate, nuanced, and extended and is best of the lot. Don Sachs preamp is a champ in imaging and staging, and the 18K is almost as good. It just falls short of the 3D floating images the tube preamp is capable of. However, the size of the soundstage of the 18K is just as good if not slightly more expansive. The 18K midrange is almost as smooth and grain free as the Tortuga, a champ in this area. Dynamics is equal to, if not better, than the Don Sachs tube preamp. On dynamic bass passages, my walls start to buzz. It's not one note bass or room mode that's the cause. The bass hits you like a hammer. I don't think the 18K is fully broken in yet because of its huge film bypass caps in the power supply, new electrolytic power supply caps, silver/gold hookup wire, new Furutech RCAs, and new Zfoil and wirewound resistors in the signal path. I won't get a handle on its full potential until about another 100 hours of use.

The down side of the 18K is the finicky dual mono remote control. Sometimes, the channels don't track together. Some steps are not precise and don't "lock" on properly, and the sound seems slightly muted when this occurs. These problems can be overcome by using the balance control, but it is annoying. The problems are by no means fault of Kevin who built this preamp. The problem lies with the Elma switch attached to the autoformer.

I will post an image of the 18K in my rack soon. It's a monster compared to other components on the rack. It literally takes over an entire level of my rack which is designed to hold two normal sized components.
 
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Well, thanks for the full writeup. I'm already convinced I need to have my 18K overhauled.

Yes, it will be well worth it. IMHO, the major sonic degradation comes the huge input coupling caps of the 18K. If you bypass it, you will significantly improve the sound. Second major improvement will come from better attenuator, like stepped resistor or inductive volume control. I went overboard on my 18k, but I'm very very happy with the end result.
 
Mine has the Penny and Giles pots....I think that's what they're called.

I contacted Mondialfan a few years back, and intended to get his work, but life stepped in.

Probably I'll just turn him loose to do what he sees fit, with your thread as another fine source of ideas. Thanks, and enjoy that fine preamp.
 
Mine has the Penny and Giles pots....I think that's what they're called.

I contacted Mondialfan a few years back, and intended to get his work, but life stepped in.

Probably I'll just turn him loose to do what he sees fit, with your thread as another fine source of ideas. Thanks, and enjoy that fine preamp.

I apreciate the performance of the Mondial units, I still use a Lightly modded Aurum from time to time , But my Viva Audio -and Krell KRC get the lions share of use. The KRC is more kin to the Aragon unit and performs at a level that is quite different than my Aragon 18k II or Aurum . Upgrading and hot rodding can certainly make a good unit great and then there are those components that are completely stock and get high marks as they are. Certainly something I consider when deciding on upgraded PARTS in an existing component or simply UPGRADING to a different class of component altogether.
 
Mine has the Penny and Giles pots....I think that's what they're called.

I contacted Mondialfan a few years back, and intended to get his work, but life stepped in.

Probably I'll just turn him loose to do what he sees fit, with your thread as another fine source of ideas. Thanks, and enjoy that fine preamp.

P&G pots are considered one of the best pots ever made, other than the godly expensive TOTL Alps pot RK501. Congratulations on those rare pots.
 
P&G pots are considered one of the best pots ever made, other than the godly expensive TOTL Alps pot RK501. Congratulations on those rare pots.


I think that Mondial used Penny and Giles in a few of the Aragon models. the 18K MKii, Aurum, and even some 24K and 18K unit have P&G pots. ( initially it was an option) others use noble pots. Im not sure what the 28K or any of the Klipsch era models used.
 
I apreciate the performance of the Mondial units, I still use a Lightly modded Aurum from time to time , But my Viva Audio -and Krell KRC get the lions share of use. The KRC is more kin to the Aragon unit and performs at a level that is quite different than my Aragon 18k II or Aurum . Upgrading and hot rodding can certainly make a good unit great and then there are those components that are completely stock and get high marks as they are. Certainly something I consider when deciding on upgraded PARTS in an existing component or simply UPGRADING to a different class of component altogether.

Hi, I love the sound of Viva gear! I almost bought one of their amps 8 years ago, but I needed more power. Beautiful gorgeous sound, though.

The modded 18K I have sounds nothing like a stock or lightly modded 18K. It's in another class. The underlying 18k is very well designed and elegant, other than the input coupling caps. I prefer simple elegant circuits (e.g., most Tube amps/preamps, Pass Aleph and First Watt) over the complex (Mark Levinson, Krell). I've auditioned very well known $10k+ preamps, and my 18K competes with them and in certain respects surpasses them (transparency and high frequency performance). I moved to passive preamps about 7 years ago because I found property set up passives (proper impedance matching and short cable lengths) to my ears are better than most active preamps out there regardless of cost. However, my recent foray into modding Mondial designed preamps have changed my views about affordable active preamps.

The great thing about this project was the relative pittance in cost in upgrading the 18K compared to moving up to a higher class $10K preamp with similar performance. Even $10k+ preamps do not use type of parts used in my 18K because they would to considered too expensive or exotic. However, my ultimate dream active preamp would be the Dartzeel NHB-18NS or Ayer KXR Twenty. These are truly cost no object preamps in my book, but come at a cost ($27k+). If I hit the lotto...
 
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