I’ve spent a bit of time with the Tuba lately, and decided to post about two things that have been covered here a few times, preferred tubes and upgraded 15V power supply.
Have tried several of the common EL84s and ended up with two that I’m happiest with. The Siemens Sonotone are crystal clear and silky smooth. Nice leading edge and attack but never having a harsh or too forward presentation. I guess that’s not surprising since, for me, this amp never is harsh or mid forward. In fact, some have said it’s too relaxed.
That leads me to my #1 choice, the Polam or Telam EL84s from 1950s - 1960s. I first tried some in my Quicksilver a couple years ago, after reading reviews from guitar players on The Tubestore site. The guitar players’ description as “…very rich in harmonic content…” and “…could always tell the difference with these installed…” is exactly what I found in the QS. True timbre of all instruments and “alive” texture and touch. And yes, they behave similarly in the Tuba - all the above but never “thick”. Though I rarely suggest what other listeners should do, I can’t help saying that anyone with an EL84 amp should try a pair.
The benefit of a PS upgrade for the Tuba is less clear. I have used Acopian Gold Box power supplies for a few years. I use a 12V to power my Mac Mini server after the Uptone Audio Upgrade, and another 24V for my Atterotech Dante feed to Yggy. You buy in the specific voltage and amperage needed, and must wire them yourself since they’re made for industrial and not consumer use. They’re basic, way overbuilt, and once dialed in, never change or drift. They have been made for so many years I can always find the model # I need used or NOS. And I was now able to find a 15v 9A new for the Tuba. Pic also enclosed of the CUI power supply I got with the Tuba - don‘t know if it is what is supplied stock.
So after all that, can I tell the difference between the PS I got with my used Tuba and the Acopian PS? Well, perhaps…sometimes. In other words, I really like the Acopian and will keep running my Tuba this way, but doubt that my use of the word “perhaps” would prompt others to run out and do likewise.
As for this Tuba, as now set up, it is a unique amp in my system that will definitely be sticking around. It’s not about the most exciting rendering of primary sounds, (the QS and the WA6+ both do that) but its way with the ambience of acoustic instruments, the spaces around and between the primary sounds. The alive warmth of a guitar body presented by the Tuba, for example, is unmatched in my system.
So, food for thought folks, play on!
