Thank you!

Can't wait for this!

Wow, you’re quite a bit more organized than I am lol. I’ve been obsessed with trying as many combos as possible and have kept records of combos I’ve liked. I have not put ratings in different categories though.

Last time I was here I asked about using 6aq5 tubes. I went ahead and got some and I'm happy to report they work just fine and can sound great! I use a 5y3 rectifier in my kt88 firebottle to get the voltage down where it needs to be. I was a little worried about the screen voltage, the 6aq5 is only rated to 250 volts on the screen. I believe the firebottle puts 260 volts on the screen. Some other folks have assured me the 10 volts shouldn't be a big deal. So fr so good...

I have listened to Brimar, Mullard, and a French brand Miniatron. Also have some Telefunken as well but have not fired those up yet.

@straitwire or anyone else that may know, what is the power transformer on the Firebottle KT88 rated for? I know it's pretty beefy but wonder if it can handle output tubes that draw 2 amps for the heater. I'm guessing not but figured I'd ask.

What tube compliment are you planning on trying? List them all please, including the rectifier

Well, as usual, Dennis has been monitoring the thread and has relayed to me that the filament winding on the Firebottle KT-88 power transformer is rated at 6 amps, or in other words, will run ANY tube compliment you can stick in there.

He also reiterated that Inspire amps can be run 24/7/365 without any concern for the capabilities of the transformer. You essentially need to worry more about your tubes than the amp itself...:smoking:

I had ordered some N34 tubes for an amp coming to me this year and by accident/miscommunication I also got some N43 tubes. The 2 amp heater is what jumped out at me so I asked my question about the power transformer. Looking a little more closely they have a 4v filament so I won't be using the anyway lol. There's no way to make an adapter to make those work right?

Still, it's good to know that the transformer can provide 6 amps. Though I might be at the end of my tube rolling journey with this amp. The GE 6bg6ga and Raytheon 6f8g combo is an amazing combo. That and the cv1102 with el38 combo are my go to combos. I still have a few other tubes to listen to like the Telefunken 6aq5 but it's hard to have patience with new combos when you have stuff that you know sounds great.

Personally I wouldn't say you are at the end of the journey until you've also listened to some of the old standards, like US made Tung Sol or GE 6550s, or their British KT 88 counterparts. Yes they are expensive to buy, but if you have other toob rolling friends, they can always help you out with a loan or bring some by for a listening session.

I do this with Dennis all the time....

Yeah, I’m getting close to the end. I’m not going to pony up the money for real kt88, kt66, or ecc32 tubes. As it is I’m plumbing the depths of alternative options. I had never heard of the bl63 tubes but I’m glad I found them. While I haven’t had the chance to hear American 6550 I haven’t been impressed with the kt88 and 6550 I have heard. Plus, hearing a tube I don’t want to pay for would be the ultimate tease lol.

I do wish I could get a Firebottle KT88 with a 12v option, at least for the input tube. I’ve ordered a PP amp from another guy that will allow me to use 6v or 12v on either input or output tubes. I’ve already got a selection of 12sn7 tubes for my preamp including black glass round plate Tungsol and the so called bad boy Sylvania tubes. They live up to the hype:) I’m not about to pay the price for the 6sn76 equivalents though.