About a month ago, I posed a question on the circle and in doing so mentioned that I was using a Super Pas 4i. Frank responded that he had some ideas for improving the 4i but didn't have one handy. He offered to work on it for no charge in order to try out those ideas if I would just send it in to him. Of course, I said I'd be glad to.
The unit was returned to me Tuesday and I put it back into my set-up immediately. After four evenings of listening to music with it, I think I'm ready to make some comments.
The first thing I noticed was that the bass notes were stronger and better defined. This was particularly evident on rock music. It was much easier to follow what the bass player was doing than in the past with the old 4i. This was the case both with CDs and records. On classical (orchestral) music, the bass viols and cellos were also somewhat stronger but it didn't seem quite as prominent, perhaps because the music is more complex. Timpani, however, seemed to stand out more than before, and again, better defined. Overall, there just appeared to be more energy in the bass, which I liked.
The midrange was improved too. Again, I noticed this on both CDs and records. With vocals, the singers' voices were more lifelike and perhaps surprisingly, it was easier to make out the words vocalists were singing. I say "perhaps surprisingly" because I wasn't at all expecting that. I've always thought that was more a function of the front end or source rather than the electronics that follow. Another example is that with rock music, the various drums in a kit became much more distinguishable in terms of what they really sound like. With regard to orchestral music, the sound of the instruments whether it be strings, woodwinds or brass, again seemed to be more true to the real sound of those instruments. (I go to concerts.) This all adds up to greater transparency or clarity, and more detail. I want to add too that I listened to some big orchestral pieces by Mahler and Stravinsky, and even during the most complex and loudest passages the sound never became congested. There was always plenty of space between the different sections of the orchestral. Although I didn't listen to any chamber music, I did pay attention to those parts of the orchestral pieces which were not loud and complex. On those sections, the Super Pas 4i "improved" maintained all the delicacy I could ask for.
The highs were less tube-like and more detailed. This is my one caveat. I prefer records to CDs. I do own alot of CDs and listen to them some of the time for various reasons. New recordings with some exceptions are just not released on records, and sometimes it is impossible to find a good clean copy of a particular older recording on lp but the CD is available. I don't like the sound of many of the CDs I own as I find them harsh. For those CDs, I think there is a benefit to a slight "softening" of the sound that you get with tubes. The improved 4i gives me less of that "softening". For instance, one of the CDs I listened to last night was Dvorak's 7th Symphony conducted by Dorati on Mercury. It's a great performance and a fantastic recording, but it sounded "hard" as some CDs tend to do. I think it is more a function of the recording than the preamp as I think the preamp is accurately letting what's on the CD through. On other CDs, it wasn't a problem. The highs were just fine on the 1999 CD of Mahler's 10th Symphony conducted by Rattle on EMI. They were also not a problem on the Solti CD of Liszt's orchestral music recorded in the 70's by Decca/London. So my conclusion is that it is more a problem of the medium than anything.
Even with my one reservation, I found the improvement in the 4i to be really large and significant. I don't have any regrets about sending the preamp in for Frank to try out his ideas. Although I can't compare it to the current Ultra, Insight, and T-8 preamps, I did have a benchmark for comparison. In the past, I've changed my Super Pas 3 and 4i in and out of my set-up quite a few times. I know the difference between the two and know that the 4i always gave me a slight improvement in detail. While the 4i was away, I had the 3 plugged in and got re-accustomed to its sound. The improved 4i no longer gives me a slight improvement. The difference now is large.
I don't know any technical information as to what Frank changed. I also don't know what plans Frank has for this modification, or if he has any. If there are any questions concerning those things, they will have to be directed to him. I do suspect that he will follow my comments with some of his own.
I guess I have one last comment. I've been happy with the Omega III generation stuff for a long time. After hearing the improved 4i, I'm starting to feel the upgrade bug gnawing away.
Thanks Frank. It's good.
