Hi
Don Sachs here. I am not trying to sell anyone anything and don't want to violate any of those sorts of rules so I will give my opinion. I have built and sold over 40 custom preamps built around the sp-14 board. My opinion is that if you take that board and use really good parts, wire, and attenuators you get a preamp that will compete with anything I have ever heard at any price. You cannot do it for $1500 though. More like $1800-$2200 depending on the case, cap and tube choices. It will run circles around a stock sp14, which is already a great bargain and wonderful preamp. That said, that extra $300-$700 is money well spent and will give you easily a 20-30% improvement. I have my own opinions on coupling caps and have heard many. The beauty of the sp14 is that there is really only one coupling cap and that is on the output. The rest is direct coupled except for the small cap on the Akido buffer and a decent cap is all you need there. The preamp should be tailored to match the rest of the system. Impedance matching is important. I have built passive preamps with very good attenuators and my opinion is they are nice, but a good tube preamp makes the music just leap out of the speakers in a way no passive preamp I have ever heard can. I have a number of customers who went from passives to an active tube preamp based on octal tubes and never went back.
Also, I have probably worked on 1000 pieces of audio gear in the past decade, both vintage restorations and lots of custom builds. I have my opinions on which resistor types sound best where, what caps to use where, etc... Everyone has their taste. What I can say is that I prefer the 6SN7 and other octal tubes in a preamp over ANY of small 12A*7 types I have ever heard.
Good luck to all and happy listening.
cheers,
Don
Don Sachs here. I am not trying to sell anyone anything and don't want to violate any of those sorts of rules so I will give my opinion. I have built and sold over 40 custom preamps built around the sp-14 board. My opinion is that if you take that board and use really good parts, wire, and attenuators you get a preamp that will compete with anything I have ever heard at any price. You cannot do it for $1500 though. More like $1800-$2200 depending on the case, cap and tube choices. It will run circles around a stock sp14, which is already a great bargain and wonderful preamp. That said, that extra $300-$700 is money well spent and will give you easily a 20-30% improvement. I have my own opinions on coupling caps and have heard many. The beauty of the sp14 is that there is really only one coupling cap and that is on the output. The rest is direct coupled except for the small cap on the Akido buffer and a decent cap is all you need there. The preamp should be tailored to match the rest of the system. Impedance matching is important. I have built passive preamps with very good attenuators and my opinion is they are nice, but a good tube preamp makes the music just leap out of the speakers in a way no passive preamp I have ever heard can. I have a number of customers who went from passives to an active tube preamp based on octal tubes and never went back.
Also, I have probably worked on 1000 pieces of audio gear in the past decade, both vintage restorations and lots of custom builds. I have my opinions on which resistor types sound best where, what caps to use where, etc... Everyone has their taste. What I can say is that I prefer the 6SN7 and other octal tubes in a preamp over ANY of small 12A*7 types I have ever heard.
Good luck to all and happy listening.
cheers,
Don