Monday, March 22, 2010

Oatley Electronics Jan6418 tube phono preamp















This JAN6418 valve based phono preamp is soon to be released by Oatley Electronics. It is a two stage preamp with FETs buffering each stage.

The cast Al enclosure has been finished in epoxy enamel hammered copper paint. The sound is excellent and noise is very low apart from a faint hiss. Music from your fav. TT will flow extremely well and I found it only took a few hours of play for the preamp to "come to the party" and sound relaxed.

In this build I have used the kits standard components but better parts would make an all-over better preamp.

Sunday, March 14, 2010

retro-thermionic Merlot with JJ KT88 Blue Glass















My son had ordered a valve amp. He wanted nothing on the top plate but valves and transformer. So a front plate holding the volume control and rear plate holding the speaker and input connections was constructed.

The amp is a two stage KT88 based single end UL amp (SE UL). The driver valve is the 6N1P. It is a common Russian valve quite capable of driving the KT88s. In this shot you can see JJ Blue Glass KT88s. I have tried EL34. 6L6, 6V6 and 5881 valves in this map with no bias change. In the EL34 range I have used Black Sables and Siemens (NOS) tubes. But I think over all the KT88 is the best. When this amp went to my son Sovtek KT88s were reinstalled. He was more concerned with the look than the sound.

This amp requires speakers with an efficiency of at least 90db to provide high volumes of music. SE UL amps provide exceptional sound staging, pin-point stereo imaging and a very natural sound. Though they only produce 6Wpc, through efficient speakers, good listening levels can be obtained.

Lookout for the Merlot Black top to be posted on this blog.

Wednesday, March 10, 2010

Portable Triode Headphone amp















You take a look at all those schmucks on the train listening to their audio-dead iPods and their super compress modern day pop/rap/crap/techo "musicless" MP3 files and cheap super "shitty" ear buds and think why? When they could be really listening to well recorded, non-compress, lossless music files on a pair of Phiaton MS400 close back carbon fibre and leather headphones and a Cowon S9 (for example) player and a portable Triode headphone amp.

Though there is an on/off switch no battery drain occures until there are plugs in all sockets and it is switched on. Pull out a either plug the power is cut. Battery life is about 100 hours.

The two experiences are worlds apart. THANK GOD!! What this weighty but musically beautiful instrument does is buffer/amplify between player and HPs. It uses tiny sub-mini pentodes valves (tubes) in triode config. It also has a HP driver chip (PT2803) which buffers the whole connection back to the player and DRIVES the HPs.

Ruining on a a couple of lithium 9V batteries it is truly portable and divine sounding. And they provide 6db of gain. But much better than that. Tell me how many of your audio savvy friends have one. Good reason to get one "rule"quick.