Active preamp with the Firebottle KT88?

[Isaacc7]

I have been using a Schitt Freya+ with my KT88 Firebottle amp ever since I got the amp. My DAC (a Topping D90) outputs 4.4v over its balanced connection and so the passive mode of the preamp works well. I noticed that the active section took away some detail and shrank the depth of the sound stage. Normally I would jump right into tube rolling but the Freya+ has the tubes recessed making it a pain to swap tubes and impossible to use my 7n7 tubes without resorting to using socket savers in addition to the adapters.

The obvious solution was to buy a new preamp! I had turned 50 this year and decided to treat myself to a pricy preamp. I decided on a Supratek Cabernet. It seemed to have what I was looking for in a design and is certainly well liked. I even had Mick customize it so I can use both 6sn7 and 12sn7 tubes. The best 6sn7 tubes have become incredibly expensive, the 12sn7 versions are still obtainable.

Long story short, I can't get the system sounding better with the preamp in the system than I can without it. No matter which tubes I use in the preamp or the amp I end up losing detail and often times have other sonic compromises.

The thing is that I have never needed more gain. So what was I hoping to accomplish with another gain stage? Some extra tube magic? That doesn't make any sense. None of this is a knock on the Supratek, it's just that I don't think I needed another piece in the system. I am very happy with the system with the passive preamp.

Dennis is now making a really sexy preamp that I totally would have bought if it had been available earlier in the year. I'm pretty sure I would have the same problem though. Those of you that have bought or are thinking about buying it, what is it that you're hoping it does in your system?

I'm keeping the Supratek because I'm an idiot audiophile lol. I will be trying some solid state amplifiers (shock, horror!) in the nearish future and I think it will be a great compliment to them. Gotta have some tubes in the system after all

[joel_hifi]

I have a Supratek Grange on order, will complement my Fire-Bottle KT88 as well as the solid state Goldmund Telos 280, amongst others

[Isaacc7]

Originally Posted by joel_hifi

I have a Supratek Grange on order, will complement my Fire-Bottle KT88 as well as the solid state Goldmund Telos 280, amongst others

Whoa! The Grange is a sweet machine! I got rid of my LPs a long time ago, I wonder if I should have gotten rid of my active line stages long ago too. I'll be interested to hear how you think the Grange works with the Firebottle. Also want to hear how it pairs with the solid state too!

[Isaacc7]

If you read my tube rolling thread you'll see that I feel like I'm getting a good feel with how the KT88 Firebottle amp changes with different kinds of tubes. I'm still going a little crazy when I add my active preamp though. It changes in ways I can't figure out.

I loved the Sylvania 6sl7wgt/Sylvania 7c5 combo so much I decided to try it with my new preamp. I put in a pair of grey glass 14n7 tubes and WOOOOSH! Super smooth and lush. Just creamy sounding. Voices were hauntingly real and massed strings were just a dream. But there was no bass. The entire sound changed radically and the bass was MIA. This preamp uses output transformers so it shouldn't have any weird loading issues so what's going on?

I realized that I had yet to break out the expensive tubes I had starting hoarding for this preamp. I found a NOS tube of the "bad boy" Sylvania 12sn7 tubes. Time to see what the fuss is about. Ooh, that's nice! Lushness retreated but vividness got cranked up. Bass is a little better. On a whim I replaced the 6sl7wgt in the amp with a tall 7n7 and I got back a lot of the bass and lost a lot of the lushness.. Now I feel like I'm getting the "rightness" of the 6sl7wgt/6v6 combo but the sound is bigger and richer.

This is what I had in mind when I splurged on this preamp! I'm still scratching my head on the tube combos and how things are working together. The tube compliment on the amp sounds totally different with a passive preamp vs. the active. Hope I'll be able to figure out the pattern.

[Analog Addict]

Do yourself a favor. Why mess with less when you can have the best. Buy the LP-2030...

[Isaacc7]

Originally Posted by Analog Addict

Do yourself a favor. Why mess with less when you can have the best. Buy the LP-2030...

I’m still enjoying this one lol. The LP-2030 looks really good from an audiophile/sound perspective but is missing some features that I value. Remote control is the big one but I also like multiple sets of outputs including balanced connections. Speaking of balanced connections, having output transformers means I can drive more kinds of amps easily.

Still, that tube compliment on the LP-2030 is sexy as…

[Isaacc7]

OK, think I have settled in with using an active preamp with my Firebottle KT88. While I have not been able to reproduce the sheer clarity and transparency that a passive preamp does, I do love what my Supratek is giving me with the right tubes. Everything is bigger, lusher, and for lack of a better term, there is a sense of heightened presence to instruments. The sound is addictive. So yeah, the preamp is likely only adding distortions so isn't as "accurate" as a passive but <shrug>.

I've found the input tube on the amp makes a big difference and like I posted above you can't really predict how it's going to work beforehand. Going back to the tall bottle 7n7 on the input has proven to be the best tube I've found so far in my system. The bass I was missing with the 6sl7wgt is back.

As always, the other thing that leads to better sound is better tubes. Unfortunately I've found the usual expensive suspects to live up to the hype. Both the round Plate TungSol 12sn7 and the so called bad boy Sylvania 12sn7 make an obvious improvement. I'm also really enjoying some of the tall 14n7 tubes as well.

[Isaacc7]

A quick follow up on my active preamp situation. The combination of the Supratek preamp and Firebottle KT88 is sublime. for the longest time I seemingly couldn’t get any bass out of the combo. Or at least I was getting a lot less than with a passive preamp. I don’t usually give much credence to burn in but it’s the only explanation I can give.

My favorite combo is round plate Tungsol 12sn7 tubes in the preamp and a tall bottle JAN Sylvania 6sl7 input with Sylvania 6ez5 output tubes and RCA 5u4g rectifier in the Firebottle.

So yeah, while I could get adequate volume with a passive preamp, a good active can add a lot to your system.