"Clarity II" - LJM Class AB power amp

 

This was a slow burn build. I had completed the amp section but no PS. After completing two commission jobs I could finally complete the amp. The compact enclosure for the amp was built around two heatsinks I had had for years and the enclosure for the PS the same. Caps standing out of the top of the PS I was given years ago and are Nippon Chemi-com. Total capacitance is not large but is well snubbed and the amp is quiet.

Two fast diodes provide rectification and four 3.3uf polies snub the bigger caps which are 3900uf each. Tranni is 160VA so the amp is capable of 80Wpc. The LJM Class AB modules used are rate 120W and are all bipolars. I like the sound of bipolar transistors and these modules contain nothing else and are very inexpensive. 

A local metals provider cut the plates for the amp to my specs and after a lot of drilling and tapping came together well. Three large gold plated brass cones balance the amp and add to the looks and improves the sound. An umbilical cord connects PS and amp using a large XLR connection. DC offset for these modules does not require adjustment and is extremely low.

The sound is super clear, detailed and expansive. Bass extends just beyond 30Hz the limit of my speakers. Regardless of type of music played it comes through, clear and uncluttered. After hours of listening the amp is still cold. I believe the amp would have no problems driving low efficiency difficult speakers. Very pleased with both the looks and the sound. 

German made EL3N - “Puissance” - triode strapped amp

 This time with a German made EL3N NOS NIB, new Svetlana 6N1P and Sylvania 5U4GB NOS NIB.

Interstage caps are Mundorf Supremes which I have used in a number of amps. Big and expensive but sound good. Hammond power tranni and Asian OPTs. The OPTs were meant to have the UL tap but didn’t. This amp then is triode strapped. Base is heavy and of blonde fine grain timber. Top plate is 2mm Al.

The EL3N sockets are made in Japan and are CNCed from a block of teflon with phosphor bronze contacts. Again expensive. PS is double Pi with 247uf of caps and a 5H choke. Total current drain is low and just over 20mA. The sound is big and warm with lots of drive. Though triode strapped it sounds very similar to my French tube SE UL version

6N3 + TDA7294 integrated amp.

A completed tube and chip integrated. Fast and crisp. Absolutely dead, dead quiet thanks to CMRR. 80Wpc, 300VA power tranni, choked power cord, rodium RCAs, RFI/EMI power filter, heavy duty speaker binding posts and 2U 19” rack mount. At the members request a low filter switchable cut of 6db at 150hZ. Also a 24 step step attenuator. 

“Piccolo Pro” - 6J1/5654W small tube preamp

 

A new 6J1/5654W tube preamp nestled into my system. Sounds as good as the last one which sold. Upgraded this build here with wood cheek chassis, three inputs and remote control. Colour is Ocean Blue hammer tone. All silver plated copper wire for hookup. Called this one “Piccolo Pro” due to the upgrading from the original Piccolo. 
 

Perfect at first switch on. I have both 6J1 and the higher performing JAN GE 5654W tubes. Much better with the JAN GE 5654W tubes. Works with a 12VAC 1A wall wart. 

“La Technique” - French made 1957 EL3N power amp

 

Inspired by the look of these vintage French made EL3N tubes - NOS NIB - with their red cumberbun and rarity I was compelled to build an amp. Also looking for something a little different I built on a Hammond wood cheek chassis. I already had the external PS with tube rectification from my “Xfi” amp and had listened to these new tubes in a 6L6 amp. 

Staying with a traditional black look with classic wood cheek sides and the showy tubes in black and red this amp was always going took stunning. The OPTs are 5K Asian and add that to German Mundorf Supreme interstage caps on a Canadian chassis you have a true international components mix. The driver tube is a new Svetlana 6N1P, resistor selection is carbon and metal film with wire wounds for Ck. Also a mix of NP and standard electrolytic caps with all Cat5 solid core hookup wire characterise the sound. 

Compared to my many SET amps, “Xfi” being a good example, this amp has a fuller, richer, bassier sound. As with all my other SE UL pentode amps this one has PRaT. I find drive and rhythm a hall mark of pentode based amps and “La Technique” no different. I love the look and are ecstatic about the full bodied sound. Add to this the amps heart is French made vintage tubes is a bonus. 

“Piccolo” - 5654W compact tube preamplifier

 

This smart looking and compact tube preamp uses (matched) JAN GE 5654W tubes. The kit is sold with lesser performing 6J2 but here they have been upgraded. The enclosure is Hammond extruded anodised Al smart looking enclosure. Three inputs are selected by two front switches. The black knob is a large anodised Al type with a good feel. All internal components are of very good quality. 
 

Power is via a 12VAC 1A plug pack and connects to the preamp via a two pin locking connection. Internally HT is generated to produce a dead quiet preamp. Under test up to 90% max volume there is 0.0mV of noise. At 100% volume, 0.4mV of noise. Input impedance is 100K. The blue colour when on is a pleasant glow and the filaments fire is also easily seen. Tube rolling is possible. 
 

From such small tubes I didn’t expect how good sounding this preamp could be.

“Iron Stone” - OPAMP based MM RIAA phono preamp

 

I bought the last six Jaycar LM833 dual OPAMP based MM phono stage kits. This is the very last. Two were resold and four assembled and three sold so far. Where the previous “Player” was enclosed in an expensive Hammond extruded anodised Al enclosure this one cleverly hides in a strayed plastic enclosure. Colour is Iron Stone and thus the name for this final build. The paint is durable epoxy enamel on an etching primer. 

The last two builds are powered by an external 12VAC wall wart. There is excellent power filtering and +/- 12V regulators on board to ensure a dead quiet MM phono stage. The RIAA EQ is a mix of passive and active plus there us a buffer gain stage. The front knob controls gain not volume though more gain means more volume. Input impedance is 47K. Internal components are most NP caps and metal film resistors. The inside of the enclosure is heavily lined with bituminised Al foil which is earthed. The foil shields the inside from stray electrical interference and the bitumen damps any resonances. 

Overall the sound is transit quick, very clean and extremely detailed. The LM833 OPAMPs have bipolars transistors throughout which provides a rich warm tone though any similar OPAMP can be used. For example an OPA2134 can be dropped in. I find this FET/bipolar OPAMP not as warm and the bass not as full. Im staying with the LM833.