Yesterday I visited the home of a friend who recently completed the build of a VTA SP-14 line stage preamp and PH-16 phono preamp. I have one of the very few VTA SP-13 preamps. It was built by Troy for me. I chose the SP-13 because the board was small enough to fit a PH-12 phono board in the same case. I've long been interested in hearing the PH-12 next to a PH-16 and this was a golden opportunity.
We ran his PH-16 into one of the line level inputs on my preamp, which seemed like the logical way to compare. There was a lot of powering on/off and moving plugs for this, but it all turned out worthwhile.
The two recordings we listened to most were Scott Hamilton playing "That's All" and Wesla Whitfield "I'm So Lucky To Be Me". These links are to digital versions ripped from CD. Full Redbook resolution.
There was a considerable difference between the PH-12 and PH-16. Keep in mind that I've been listening to the PH-12 for about 6 years now, so I am very used to hearing that sound, and thus see that as how it is supposed to sound. The PH-16 was much darker, richer and almost "woolly" in the way it sounded. Particularly in the mid-range.
Then my buddy asked me what tubes I had in there and I had no idea. So we opened it up and found JJ EC88 tubes, which are a respected and low cost Chinese tube. He then pulled out his box-o-extra-tubes and we did some tube rolling. Wow. What a surprise! We listened to both Electro Harmonix and Phillips 6922 tubes. Both were less bright than the JJ EC88. The Phillips had the PH-12 sounding almost like the PH-16! Very interesting.
What kinds of EC88/6922 tube rolling have y'all done and what to you recommend?
And in case anyone is wondering what I'm running for tubes in the SP-13 line stage, I have Brimar Mazda 6CG7 tubes for the front end and the originally supplied RCA Clear Top 6CG7 in the back end.
We ran his PH-16 into one of the line level inputs on my preamp, which seemed like the logical way to compare. There was a lot of powering on/off and moving plugs for this, but it all turned out worthwhile.
The two recordings we listened to most were Scott Hamilton playing "That's All" and Wesla Whitfield "I'm So Lucky To Be Me". These links are to digital versions ripped from CD. Full Redbook resolution.
There was a considerable difference between the PH-12 and PH-16. Keep in mind that I've been listening to the PH-12 for about 6 years now, so I am very used to hearing that sound, and thus see that as how it is supposed to sound. The PH-16 was much darker, richer and almost "woolly" in the way it sounded. Particularly in the mid-range.
Then my buddy asked me what tubes I had in there and I had no idea. So we opened it up and found JJ EC88 tubes, which are a respected and low cost Chinese tube. He then pulled out his box-o-extra-tubes and we did some tube rolling. Wow. What a surprise! We listened to both Electro Harmonix and Phillips 6922 tubes. Both were less bright than the JJ EC88. The Phillips had the PH-12 sounding almost like the PH-16! Very interesting.
What kinds of EC88/6922 tube rolling have y'all done and what to you recommend?
And in case anyone is wondering what I'm running for tubes in the SP-13 line stage, I have Brimar Mazda 6CG7 tubes for the front end and the originally supplied RCA Clear Top 6CG7 in the back end.