“Empire” - my super F5

The last and possibly the best F5 ever. There was another F5 which also appeared to exceed the others with performance. It also had the Mundorf MLytic audio grade caps. In this build I increased the filter caps to 132,000uf and upped the power tranni to 300VA. Keeping the Cat5 solid core twisted pair for hookup wire and the standard compact enclosure. This build is very similar to the others with the filter caps well snubbed with larger and small poly caps. 

The BIG difference here is the use of 1W carbon film resistors. The Jim's kit comes with Fishey and Dale resistors which normally I would use. Not this time. Also this Jim's board, like the build before, uses his double weight brd. with two 100uf Elnas on board and other components. The sound is hyper 3D and incredibly transparent with extended deep bass and startling dynamics. The whole sound is one of earthiness and richness. The use of carbon film is a controversial one. All negative comments about the use of carbon film Rs come from those who have never used them in a build or/and have never heard them. I like to buck the trend especially when I know what I build will exceed what others can contemplate. And exceed in performance.

“Mimic-Magic” - MM phono stage

 

Yet another Mimic and this time combining all the components I thought have sounded good in other Mimics. That’s what makes it “Magic”. Another in these more hobby looking enclosures mainly because I had them on hand. 1/4W carbon film resistors, PIO output caps, MKP and poly caps and the same OPA2134 chip as in all Mimics. Smooth and warm sounding with my Garrett P77i. 

“Mundor/F5” - Pass F5 inspired with advanced boards

 

I was vey impressed with last F5 I built using Jim Audio boards. The amp sold before a I could start construction. The build was a big step up from the F5 before by upgrading the filter caps to 88,000uf of Mundorf MLytics and the toroid tranni upgrade from 160W to 300W. The total presentation of that amp was beguiling.

Here is my build based on what I thought maybe the best amp I have ever heard. Ounce more 88,000uf of Mundorf MLytics audio grade caps at over $300 for caps alone. Same upgraded Jims brds. and as before all Cat5 twisted pair hookup wire. This amp shines. Given the right music you are challenged to think something so compact and unassuming can generate such presentation. It’s a 25W Class A simple amp. Bass goes easy to 30Hz, mids are transparent and treble clean and controlled. Compact and astounding. 

“3D” - Three channel Class D amplifier

 

I completed a three channel Class D power amp for another SNA member. 1X 150W and 2X 180W Tripath amp modules, 500W PS with Mundorf MLytic caps - 2X 22,000uf and EVO oils on the input. I sent the amp off without taking any images and had to ask the new owner for a few picks.

"Shadow" - SRPP 12AX7WA Sovtek preamp

 

Just finished this compact tube preamp with Sovtek NOS NIB 7025 (12AX7WA). Again on a jiffy box - “Shadow” - this time is an ironstone epoxy enamel finish. All metal film Rs and PIO output caps with silver plated fine copper hookup wire. Two inputs. SRPP topology. External PS is a Radi0kit kit for 12V and  250V DC. The preamp is absolutely dead quiet. No snap, crackle or pop.

"Shu" - CV-181-Z and Golden Dragon preamp

 

For quite a number of tube preamp builds of late I have been using SS rectification. Coming across a new Golden Dragon 5U4 rec tube and new Shuguang CV-181-Z (6SN7) dual triode in my stash changed all that. Most of my builds of late have been SRPP but I started with single stage tube preamps. Time to revisit that and time to revisit tube rectification. You have to have a power tranni which will support a 5V filament at sufficient current for the rec tube and also have sufficient high voltage current support. The Hammond tranni I had hand on hand for many years (and this includes how long I have had the tubes) will do the job easy. In a big push through these many lockdowns to use up expensive parts in "da lab" and even having the cast Al chassis I knew I should go ahead.

Epoxy enameled sprayed cast Al enclosure with Hammond power tranni and heavy rubber feet makes a good start. Ceramic tubes sockets, silver plate fine copper wire in the signal path and a Pi X 4 filtration PS make the basis for a great tube preamp. I could have used some stock metalised poly output caps but I ordered Mundorf EVO oils for the output. Glad I did. The PS is CRCRCRC with the final cap a 4uf PIO. All filter caps are snubbed. 

Two selectable inputs and one out. Silver soldered signal path with fine silver plated wire and all carbon film resistors plus the excellent 50 Year Treasure ceramic based and gold pinned tube (CV-181-Z) make for real good music. Rich, smooth and soulful. 

"Priory" - tube Headphone amp

 

From the COVID lockdown last year I made a real push to use as many parts I had on hand as I could to build them into working pieces of sonic art as possible. Not just cheap passive parts but expensive tubes and transformers. I had two Hammond low power high voltage trannies, a Svetlana 6AS7 and cheapy 12AU7 plus a beautiful base and most other parts to build either a preamp or a tube headphone (HP)  amp. Take a look at what I decided.

This is the seventh tube HP amp I have built. This includes three Bottlehead amps for others from kits. This excellent build includes;- A beautiful Cypress base, Hammond power tranni, Svetlana 6AS7, Alps Blue Velvet pot and 4oz gold plated knob, very low noise SS rectification and 330uf of storage capacitance plus a 5H Hammond choke. Not only is the double Pi PS choked but has Ultra fast/Soft recovery diodes. All components in the PS are fully snubbed with poly caps. The amp is super quiet.

Of course all point-2-point wiring and no shielded wire or PCBs. All signal wire is solid core Cat5 copper. WBT silver solder used throughout. Only one capacitor in the whole signal path as the 12AU7 driver tube and the power tube are directly connected. To get that extra deep "full" sound I used 1W carbon film resistors. Every time I have used carbon Rs in any build I always get a richer warmer sound. Its the same here. 

This HP amp produces the most textural, deepest warm sound I have heard in my HP amps to date. Reverb just extends for ever. And to think the passive components are very basic. But there ae some tweaks - the 400uf output NP cap has a 0.1uf Russian PIO cap snubbing (or by-passing) it. Every electrolytic has a poly subbing it. The amp is dead quiet, only the music gets through.