Nest Theater Part Seven - 300B SET Amp Build 02Apr20-06Apr20 & 16Apr20

Sequestering... timing is everything. Earlier in the year I started to buy stuff to build an amp and it came together just as sheltering began. I built high efficiency horns for the Nest 'cause I intended to drive 'em with a low power single ended triode (SET) amp - which I have also now completed! The SET classic circuit is the least adulterated of any audio reproduction scheme... nothing is in the way - no feedback in amplification. Anyway... SET amps are also a freak fringe of audiophilia ~ even more so if you build your own to dial in the best parts. And "the best" may imply using 300B power tubes, a naked circuit, spectacular transformers, and high spec components like tantalum resistors. So, I'm ushering a full 8 watts of ultra-clean, ultra-quiet power with 300B tubes + special triple c-core output transformers to drive my ~8ohm high sensitivity DRC BLH + ribbon super-tweeter loads. I chose Audio Note Kits (ANK) to consolidate the far ranging supply chain (and save me a massive pain) and provide a decent chassis, it's the Kit 1 - 10th Anniversary Edition. It worked; I've built one of the most sought high-end 300B tube SET amps in the world. Here are the basic steps - basically 4 days of construction and test, but just finished as I awaited some final parts. The amp is awesome and I can hardly wait to deploy it to the Nest with the new DAC.

40 pounds of transformers arrive

The rest of the supply chain converges

Workspace ready

C-Core output transformers ready to mount

Main transformer and choke ready to mount

Transformers and preamp plate installed

Power switch and IEC receptacle installed

The working side henceforth

Ready to build three PC borads: power, filter

Hardwiring 300B bases

Boards completed and tested for fit

Interconnect wiring underway

Volume, input selector, speaker posts, and inputs installed and wired

All tubes present & accounted for
(bottom: pre-amp, middle: power supply, top: 300B output power)

DC voltages verified - 5, 70, 435volts!

Tubes, mostly Russian, loaded and ready for music test.

Front (without faceplate)

Rear

Fired up for the 1st time

Pre-amp section

Power-amp tubes.

Fired up and verifying @ night.

Happy Tax Day - Weird Day On PT And New YouTube Stuff 15Apr20

At least we got to defer. With a gap in the snow I hit the PT. Flows were back to ~500cfs and with a couple of very cold nights the emerging BWOs and other bug hatches were minimized. I had a number of fish on but missed landing all but one 17"er. Hmmm. The biggest was one of those situations heralded by the moment you know the vigorous head shakes allowed the beast to throw the hook (from the momentary slack) but then there's a nano-second delay and a re-hookup into it's body... at least I know the feeling now with a number of fish lost in this manner. The "side-haul" and pressure was too much and I lost that pig... the movie of the incident unfolds exactly like that though. Oddly too on the outing from Nature Center was a massive beaver beached and dead just below the 1st big weir upstream from parking... orange teeth! Then I feature some artists' new drops who bring their best in these unengineered, unattended, unteathered times.

Phoebe Bridgers just streamed live on Instagram for Pitchfork. "I'm such a boomer; I'm likin' the tech." It's a good stream with a tribute to John Prine as well as an all new song drop: "I Know The End." Black pajamas at home I guess...

Cody took his wife Elyse (decorated skier) down a sketch line in the Sawtooths... really fun on really bad snow.

And Grouplove played the YouTube space for a gr8 version of Deleter live.

Wheatus seems to release recorded live sessions often... no video. Great song though.

Alex Lahey won't be coming to the US soon but she did do an unattended, solo concert which was cool: Delivered Live.

The Fly Formerly Known As Bronx Now Purple Reign 12Apr20

A formidable Houstonite was unsatisfied I'd named a fly without musical reference... as that is what I most often do and he's unaccustomed to pattern breaks. Therefore, let it be here now known, the fly formerly known as Bronx midge is renamed Purple Reign midge. Here it is naked and alongside Jimi's Axe... it's performing well thus far in the early season - especially when small midges are hatching. Recipe: 2488H hook in #22 or #24, purple glass XS bead, UTC 70 purple thread, gunmetal blue XS wire, small Medora wing case, peacock herl thorax.

Big Fish Day - Matt DeBalski @ 11 Mile 11Apr20

Preceding the snowy weather, Matt & Daryle hit the 11 Mile section of the So Platte. Master fisherman Matt landed this beautiful 26" cutbow on a tiny purple/black bubbleback midge just upstream of the last bridge! Congrats for a gr8fish Matt... it kindoff matches your hog hat.

Nest Theater Part Six - DENAFRIPS R2R DAC 10Apr20

My DENAFRIPS Pontus DAC arrived from Singapore and I had to check it out before taking it up to the Nest Theater for intended installation there. I also disinfected it. DENAFRIPS stands for: D-ynamic, E-xquisite , N-atural, A-ttractive, F-idelity, R-efined , I-ntoxicating, P-ure, S-ophisticated... do you think this Chinese company was marketing to me? While I am not many, or any, of these things, my Pontus DAC is. I did buy the unit sight unheard so I was a smidge nervous but read plenty prior to buying. This DAC is a classic resistor ladder design (vs delta-sigma) and not unlike my Schitt Gungnir multi-bit DAC used in my Blodgett headphone system. In fact my test setup used JRiver on Mac spitting bits through USB to the DAC then unbalanced analog audio was sent to the Schitt Mjolnir 2 tube power amp (not shown), which drives my Mr Speakers EtherC Flow cans. An unbalanced test is righteous as SET amps (one is pending from me for the Nest) are single-ended by definition.

The Pontus is very musical, not a hint of reproduction being digital or shrill - this is exactly what I was seeking. Big sound stage and nice, powerful, organic bass & sub-bass - better than the Schitt in these regards. High frequencies are sufficiently resolved and seem accurate. I don't do technical measurements and perhaps these impressions aren't the way to judge but how it sounds is how I use it.

The thing is really heavy, for a DAC, with a separately encapsulated linear power supply bringing most of the weight (along with a finely built case). Components throughout are excellent. Pontus is dynamic and non-fatiguing despite I can hear everything well. I haven't used oversampling mode but I did test the inputs I intend to use.

I did plenty of a-b compares to the Gungnir MB and I think the Pontus is better in all regards except price. The Chinese are gonna be able to do more strong things in the audiophile realm I'm sure. Pleased. Recommended.

UPDATE... Since I have some time I reinstalled the Pontus in my Schitt stack and did a righteous dive on the other aspects of the Pontus. Here I'm using the balanced (XLR) outputs of the Pontus to the Mjolnir 2's balanced inputs. My headphone setup is balanced all the way to each ear. The Pontus is awesome - I got an even more visceral feel, especially at the low end. It's a lot more fun than the Gungnir MB DAC - I can't keep it in COS though as it needs to center the Nest Theater. On to DSD capabilities...

Holy shit! I have a modicum of material in SACD form which I had ripped to .dsf files, I rarely use it as the Schitt DAC and Woo DAC both eschew DSD conversion... my Onkyo portable plays them well. But now, wow, my Nest Theater will be able to replay these files; it's great! I got the Pontus up to DSD256 no problem and all the DSD files I own sound great - but of course these are great recordings and artists from the outset. It's expensive to buy DSD material but it may be worthwhile in cases where one really likes a recording. Normally I'll still do 96KHz/24bit and be plenty satisfied but it's great to know Pontus goes the additional mile. I played tracks from all these albums and just wow. The only thing I could not do was digitally filter for my headphone frequency abnormalities using DSP ~ yea, there aren't many errors in the EtherC cans anyway so the sound is fantastic. I also tested oversampling mode on normal PCM files - can't say I'd recommend it - seems like potential adulteration to me. I can't wait to get this thing rolling in Silverthorne. PLEASED. RECOMMENDED.

Aural enhancements provided by Arlo.

Gettin' Out & Leslie's 70th

Kala & I are getting out on the AFA hiking pretty often. We've discovered a number of new trails and we've wandered off trail too. Keeps us sane and the AFA is a lot more sequestered than Blodgett Open Space where recently Kala counted 50 cars! Get out, spread out.

Our good friend Leslie Wilke celebrated her 70th birthday and we were on point for the online virtual gathering of her family and friends. It came off well. Many attending built Leslie's Sunrise cocktails, a libation I prepared for her previously and resprised on this auspicious day. Another cocktail made for virtual happy hours with the CoWW and family is the Rum Quarantini - a mule variant also shown below.

Recipes for this and the recently used Rum Quarantinis are provided below.
Leslie's Sunrise...

• 1 pt Galiano
• 1 pt Creme de Banane
• 2 pts Anejo Tequilla
• 1 tbsp Cream (if pt = small jigger)
• 1 pt OJ
• Splash of grenadine 
• Shake over crushed ice into martini glasses and splash in grenadine.

Rum Quarantini...

• 2 Aged Rum (I’ll use Pyrat reserve)
• Juice of 1 Lime (~.75)
• Juice of 1/2 of Cutie Orange (~.5)
• 1-2 Ginger Beer (preferably Cock & Bull); BTW, never buy diet Ginger Beer
• 1 tbsp maple syrup
• 1 dash Angostura bitters
• Orange peel twist 
• Shake all but Ginger Beer over ice, pour over ice in tall glass then top with GB and fold in.