@wig I am looking for 300b Zero NFB amps myself and the Otoman labs amp might be the ticket. Since most in US will be buying blind, could you describe a bit more of your experience with these amps ? What preamp are you pairing with it ?
300B Tube Amps with 15/16 Watts Per Channel?
Felix Audio makes the dual 300B amp "Lybra"--are there any other manufacturers of that gear?.Does anyone have experience using two each 300B tube amps modified to be two monoblocks with 15/16 watts output power each? If yes, did you hear any difference in the exquisite 300B sound other than more power? All experiences and thoughts appreciated. (Yes, expense is already noted)
16 responses Add your response
I had some 300b PP Zero NFB Mono’s with 20 Watts @ 4 ohms built by Ken Uesugi of Japan and they sound stellar and the price is a STEAL; my inter stage transformers are silver and made my Luxman which are different than the ones show in the link below: https://otomon.net/products/detail/72 I have been using mines for 11 months and they have been rock solid Wig |
Don't listen to @brianlucey 😝, I am struggling to remember if I bought his used pair of Allnic A6000 monoblocks. I could be wrong! This much I will admit: i neglected to mention the model in my previous post, I couldn't be happier with the transaction, great packaging and like new condition, he is correct regarding running two pairs vs quad 300bxls, they are meticulously crafted, and we're very impressive driving anything, but between the heat, retubng expense, and that they were IMHO almost too clean, aiming for superb dynamics trading something in tonal colors, and some delicacy with micro-dynamics. I believe the feedback design might be what caused this. |
Art Audio Diavolo Copper Ref SET. Verdantaudio.com I think it maxes at 13wpc, but you must use the EML 300BXLS. You would need to discuss having the amp wired to the higher voltage psu transformer windings and bias circuit adjustment for that tube to get the higher wattage. The Western Electric 91a Boasts 20wpc with their 300b and special circuit and solid-stage rectification, (I prefer tube rectification for SET), but that 20wpc is at 10% distortion which is an order of magnitude more than necessary to get the 2nd/3rd harmonic distortion which provides the euphonic magic along with that floaty liquidity and palpable midrange and eerie micro-dynamics . I don't do parallel SET (anymore) after owning the ALLNIC (Quad-Parallel 300bxls monoblocks which will give you 60wpc, but only by using quad-pairs of eml 300bxls (KR AUDIO BXLS MAY ALSO WORK). $25k New or $10k-15k used and theg are made in S.Korea). I don’t recommend parallel-set because it’s not as pure sounding lacking some magic (though better than pushpull or ultra-linear or the phony triode-mode by disabling 2 stages using a pentode) , very expensive, it’s a class A amp with massive heat output aka a space-heater, retubing is way more expensive especially for EML or KR 300bxls. I’ve done all of this before. Do you like running the ac in winter all the time? i now own a muzishare R100 805 model Don’t be confused the 300b is only a Driver-tube for the 805 triode) It produces a real 50wpc and for the money or 4x the money, I really love it. I run TOTL Psvane Acme 805 ($650-$850 ebay) and its the best bang for my buck ive ever had with a SET AMP. It Drives my Legacy Audio Whispers XDS dual-open-baffle speaker exquisitely . Specifically it drives each speaker’s 4x 7” mid-woofers, and the dual AMT custom midrange and tweeter. The open-baffle 15” bass drivers (humblebrag, all eight of them) are actively powered by 500wpc ICE Class D amplifiers. The speakers are 4ohm 94db.
|
If you don't mind assembling a kit, Bottlehead makes a 300B model called the Kaiju that can be configured to work as a 16W monoblock amp. I have the Kaiju configured in stereo mode and am very pleased with its sound quality. I can only imagine that the Kaiju in monoblock form would sound just as good or better, but with more power. Bottlehead kits are very complete with superb instructions, which makes for a relatively easy build. |
