300B vs. KT88 SET?

You can read the Art Dudley piece I mentioned online here

Marco

I am also interested in the difference between 300Bse vs. KT88se at some point the conversation seems to have jumped to 300Bse vs. KT88pp not sure why. I know more KT88pp amps exist then then do KT88se amps. But there are a few nice looking KT88se and EL34se out there Decware's model SE34I.2+ (www.decware.com ) and www.hifiandaudio.com has a fine looking KT88 se as well. In all of the se KT88 / EL34 amps I have seen the the KT88 / EL34 are interchangeable.

From the examples I have seen you can get:

5watts from KT88se with a 5K opt running with no nfb
12watts from KT88se with a 2.5K opt running with nfb
8watts from 300B running 3k with no nfb

I am sure other operating points are possible.

I had been running a cheap se 6N8P / 6P13P (the 6P13P is very smiler to the EL34 ) which I won at an headfi auction for $150. After 3 hours the output transformers get very hot. It's rated at 12W per-side. The opt are 2.5K load and they are run in UL (it's an ultra-linear se amp) to the 6P13P and it uses NFB (don't know how much).

Now just yesterday I picked up a 6J4P/300B it is a Jas Bravo 2.2. I have not looked inside so I can't tell you anything about the 300B other then what tubes it uses.

Now comparing the $150 se 6P13P to the $1700 300B, these two amp sound totally different it would be easy to pick one out in a side by side test. The 6P13P is not really a HiFi amp, it can't really do rock, lacks base slam and what base you do get is kind of lose.

The 6P13P does well with high/mids where the 300b jas does well with low/mid. Its like there is a window and each amp does well with a different part of the range. The 6P13P is more smooth and the 300B is clear however the 300B is dark I believe this is a trait of the 300B others will agree with.

I watch a lot of British Mystery movies (Inspector Morse mostly) with my amp. With the 6P13P when Morse is interviewing suspects the presents of a clock in the room ticking away is really clear his voice is better with the 6P13P. Deep background music is better with the 300B. For most of the episodes the 300B is more well rounded. But there is one episode called “Death Is Now My Neighbor” where I like the 6P13P better. I can site one seen where an organ and quire are playing in an Oxford college and the academics are filling in to take there seats for mass.

Before I got the 300B I had assumed it was going to be the sweeter sounding of the two set amps, I was wrong. That said, I would be interested to hair a KT88 se in a 5k opt non-feedback arrangement.

Leve
Long Island, N.Y.

I have both SET amps. Both are custom made with high quality parts. The kt88 SET amp is using Shuguang Treasure 'Black bottle" kt88-z output tubes and NOS Raytheon 6sl7 "red base" driver tubes and Sovtek 5ar4 rec tube. This is a stereo amp. The circuit is from JE Labs. The 300b SET is in mono block form. It has Sophia electric Princess 300B carbon plate output tubes and the circuit employs a 2 stage driver consisting of vintage type 27 and type 56 tubes. It uses tung sol 5u4g rec tube.

The kt88SET has better top end, sounds a little smoother. The 300b SET has better bottom end (not as slow) and mid bass. Both amps have that magical midrange that I love but the 300b is more lush and renders voices with a more realism. The kt88 does a real good job of projecting a holographic and realistic soundstage. The 300b does also but it is deeper with more air around the voices, it has a higher spooky factor, especially with the lights off. The kt88 SET is still a sweet sounding amp and does voice better than any other amp(besides my 300b amps) that I have heard, that include high end SS amps PP tubes too. both of these amps blows away my Single ended SS amp "Pass Labs aleph 3" amp. One thing nice about the kt88 Set amp is I can also roll tubes, I got a pair of vintage Telsa el34 coming.

Appears this thread is a decade old, yet this was my question as I educate myself as I embark on my "Tube Audiophile" journey. I'm guessing I'm going to need 2 amps; a 300B, and a "rolling amp (KT66-KT150)". 

I own a pair of Klipsch Forte III's powered by an Onkyo AV receiver, that I'm planning on selling/trading-in. 

The Forte's will easily be driven by a 10w SET and many enjoy rolling 300Bs though it is not an inexpensive hobby.  You will find their are a surprising number of new 300Bs available that sound quite different.  

I am not sure what the benefit of a KT 66-KT150 amp would be as you don't need the power.  The only benefit would be the opportunity to roll relatively inexpensive tubes rather than the pricier 300Bs.  

Picking the exact SET (PX25, 300B, 845, etc...) to get the right sound profile for your taste is probably an interesting place to start.  300Bs will give you most flexibility for Tube rolling but have a specific sound profile that may or may not appeal to you.