Primaluna - Rolling pre tubes question...

I'm about to put up some info on the PrimaLuna website about this. First, in preamps all the small signal tubes have an equal effect on the sound and you can change out just one pair if you want.

On power amps and integrated amps the two 12AU7 (in older models 12AX7) that are in the center are the input tubes and they have gain, so they will make the most difference.

I've spent a lot of time on this. The stock tubes are surprisingly good sounding. Fabulous. The French-made 1962 vintage Cifte's will have a little more extension on top, and that's why the mids are not as up-front. But that will change in time. They have a lengthy break in period. I would say a couple hundred hours. But really it takes longer than that.

I've been running 60's vintage Mullard M8136 and they are really nice. I don't know if they are for me exactly. They have more body. The mids are fuller and pretty. But the reason it sounds this way is because it's more laid-back on top.

I've also tried some British-made Brimar CV4003. These are hard to find, but we recently scored a nice quantity of perfect ones. I've always liked them. They are between the two above.

I have customers with really good ears tell me that they love the stock tubes and I agree. I hope this helps. If you guys have questions on this it's really great to put them up here or audioasylum as others DO benefit even years later from your data.

Hi Davide256 I've never used tube dampers in a PrimaLuna. I'll try some for fun. Tube dampers are never "always good" or "always bad" as it depends on that single tube in your hand. A little bit of microphony can be good. It's something you have to try.

I am so glad we went with as many 12AU7's as we have. It's great for tube rolling. There are some new PrimaLuna products coming out that will use 12AU7's and 12AX7's come January.

There will be a tube headphone amp that can be run two different ways. And incredible phono stage designed in a way I've not seen before. And a DAC that is all-tube, dual mono, tube rectified, and uses a tube to address jitter (only found in PrimaLuna)

They are in prototyping now. I won't say anything more. I was supposed to keep my mouth shut.

Hi David256 if you look at many products that use tube sockets they are mounted onto PCB's, and it's not uncommon to have that same PCB have the power transformer attached to it. PrimaLuna tube sockets are mounted on to heavy-gauge fully ventilated standoffs. The chassis is so heavy I don't think there's a lot of microphony going on.

It's so easy to demonstrate. You can whack the hell out of the chassis and hardly a peep will show up anywhere on any PrimaLuna component. Compare that tube a number of preamps where you simply flip a switch and it rings through the speakers.

I do like composite sockets too. We used some killer ones when we built the Ah! Tjoeb CD player that were da bomb. But the ones we use never fail (well, maybe one) so that's what we're shooting for.

On the microphony question, I've found that tubes can lose a little air and harden up with dampers SOMETIMES. Every case is different. Some microphony CAN be good, evidenced by the sound degrading if it's removed. Is it a distortion artifact? Maybe. But that's one of the charming aspects of tubes. If distortion were the end-all be-all buy an Aragon. They are electrically perfect.

If the tube is already low in microphony, and the circuit isn't a silly one (like this idiocy of 27dB of gain in a preamp), and the socket isn't mounted to a PCB, why bother. It should be done on a case by case basis. What ever sounds best. They cost nothing so why not.