Permit me to make a clarification to the final paragraph of my post above. Don's KT88-based amp is just that, not a preamp as I incorrectly stated Don informed me that he makes no assertion that his amp is a significant improvement over an fully-upgraded HK C-II, but does rival it. If you are one of the lucky people to have an HK C-II, Don is the guy to see to get it upgraded to modern standards. I have one and it is sonically vastly better than the stock unit... dead quiet in operation. However, if you are not fortunate enough to have a stock C-II, Don can build you an amp with modern components that will have the same sonic performance of one of the most legendary tube preamps that has ever existed. And this at a fraction of the cost of such an amp produced by the major audio companies. Whitestix
Don Sachs 3 octal tube preamp... latest version
Don Sachs modified all my old HK Citation I, II, and IV and, as a protege of Jim McShane, did a marvelous job on all of them. He currently produces his own preamps, amps, and phono amps. I got one of his first prototype DS1 preamps, and just got it back with this Third Generation upgrades, with included upgrade coupling caps ad Jupiter copper output caps. His prototype preamp was simply stunning, using four 6SN7 octal tubes and a rectifier. It was easily the best preamp I have ever heard, stunning in detail, soundstage and frequency extension. Now with the latest upgrades, it is subjectively 15%-20% better overall. The Treasure CV181 tubes were a significant improvement as well. In 45 years of having good to great gear, this leaves me with no desire to look beyond it. Don is tirelessly looking for improvements in his gear and as you can see in his note below, there is room for improvement, albeit at a price. Overall, I think with his latest upgrades, I have maybe $2200 invested in the amp. Below you can see other upgrades here can perform in an already excellent preamp:
"Just finished this one in a mirror finish dark cherry case. Best one yet. It has dual mono remote Khozmo 64 step attenuators. You can make them go up and down together, but there is a button on the remote that lets you unlink them and turn one up or down, then relink. So it is also a balance control. Sounds even better than the stereo Khozmo remote version. Also, this guy sent my two pairs of Duelund .47 uF caps he wanted paralleled. So 1 uF Duelunds per channel and also one of those fancy Duelund silver foil bypass caps per channel. Finally, he wanted me to use this Neotech silver/gold stranded 26 gauge hookup wire on one set of inputs and also the whole signal chain for the rest of the preamp… the run from the selector switch to the attenuators, then to the board, then to the output jacks. So I can listen to one input that is all Neotech $8 /ft wire and then I can switch to another input that has my usual Canare copper stranded for the input to the selector switch. I CAN hear the difference, with the expensive wire being more detailed. This is the best one so far and is a notch or two above the one I just sent you provided the rest of your system will let you hear it. "
If you are interested in learning more about Don's equipment, you can Google "Don Sachs Consulting" to link to his audio website. He is now making a 70wpc KT88-based tube preamp that he feels is much better than the fully-modified HK Citation I amp a very modest price of around $2600. He ought to know has he has upgraded dozens of them. Highly recommended. Cheers, Whitestix
"Just finished this one in a mirror finish dark cherry case. Best one yet. It has dual mono remote Khozmo 64 step attenuators. You can make them go up and down together, but there is a button on the remote that lets you unlink them and turn one up or down, then relink. So it is also a balance control. Sounds even better than the stereo Khozmo remote version. Also, this guy sent my two pairs of Duelund .47 uF caps he wanted paralleled. So 1 uF Duelunds per channel and also one of those fancy Duelund silver foil bypass caps per channel. Finally, he wanted me to use this Neotech silver/gold stranded 26 gauge hookup wire on one set of inputs and also the whole signal chain for the rest of the preamp… the run from the selector switch to the attenuators, then to the board, then to the output jacks. So I can listen to one input that is all Neotech $8 /ft wire and then I can switch to another input that has my usual Canare copper stranded for the input to the selector switch. I CAN hear the difference, with the expensive wire being more detailed. This is the best one so far and is a notch or two above the one I just sent you provided the rest of your system will let you hear it. "
If you are interested in learning more about Don's equipment, you can Google "Don Sachs Consulting" to link to his audio website. He is now making a 70wpc KT88-based tube preamp that he feels is much better than the fully-modified HK Citation I amp a very modest price of around $2600. He ought to know has he has upgraded dozens of them. Highly recommended. Cheers, Whitestix
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