Sunfire Preamp Tubes

Every brand and tube type will sound a bit different in a different circuit, so it can be tough to draw broad conclusions. It’s extremely subjective... your spicy might be my hot. 

I have some EH 12BH7As that I love, but it’s no guarantee that their other tubes will do as well. The EH EL34 output tubes sound nice in my amp, but I don’t love what they sound like.

I also have some new issue Russian made Mullard CV4004 tubes in my preamp that are pretty incredible in their price range.

Gold Lion is another well regarded name....love their KT66, but haven’t heard any of the others. They’re higher in price for sure.

Same goes for the TungSol 7581A output tubes...love those, but have no idea what their other tubes are like.

I’ve also had some JJs, Nesstone, and Shuguang that worked well and liked, but that I didn’t love.

At some point it’s just a roll of the dice, but it’s all part of the fun of dialing in exactly what you like. Good luck, and let us know what you end up with.

Hi Allen. I'm going thru the same thing at the moment with my sunfire vaccuum tube.  Had one channel develop a hiss and pop / crackle for the first time since 2005. Been using this pre amp daily since buying it new that year. Wondering if you went any further with upgrades?

Hi,

I feel you pain! In my case, what I have learned, the popping sound can be caused, more often, in the power supply of the amp rapidly discharging when the power is switched off, especially if the preamp is turned off first followed by the amp. The rule of thumb I follow, preamp on first followed by the amp(s) and the amp(s) off first followed by the preamp. Also for the preamp, I upgraded the tubes to Mullard CV 4004/12AX7's, they really made an appreciable difference, all three, about $85.

Secondly, capacitors going bad can also cause this to happen and in that case it doesn't really matter what is turned on when. I have two Carver amps and both suffered from the failing capacitors at different times, about five years apart. The second one is going in next week to resolve the capacitors. 

As to the hiss, in my case, after way too much investigation, testing, and consultation with a variety of people smarter than I, and my repair guy, I purchased an $8 noise gate from Amazon, no more noise. What I kept comping back to was dirty power. I live in a condo and all of the wiring has a lot of noise.

Not sure where you are but there are only three places I would send my equipment, in order of preference. I hope this helps, let us know what you decide and how it works out!

www.ampexperts.com, www.nelionaudio.com, and www.carveraudiorepair.com

Cheers

Thanks Allen. I am going to check into those, I appreciate your response.