Rabu, 29 Februari 2012

Audiophile Last Frontier? Phono thingies, Azur 540P tweak

What I called last frontier here is in fact returning to old format : vinyl. While today and in upcoming years the CD life is on a count down to and end.

Ironic isn't it? media format that was 'killed' by CD has since experiencing revival once again and this time I think for forever. There are new pressings both 45rpm 180gr disks, 33rpm of relatively new artist. Also there are so called Remastered ones, of course from old but still selling artists.
 
Why? Not just nostalgic I think, there are qualities in vinyl that sets them apart, even new young generation who never heard vinyl before begins appreciating the vinyl, spurred by many 'indie' bands that issues that odd media. A Retro-Cool aspect might play a role here, but old die hard audiophile always know better things :). Read here my write up on the 'perfect sound forever vs vinyl'. I was pleasantly surprised that young people aged 20-30 years old are enthusiastically digging old records, looking for 'roots' of today's music. They looks for van Morrison, Jimi Hendrix..., Neil Young,..hell...they even look for Miles Davis's Bitches Brew !...some roots they look for :).

For me it's just a returning audio life cycle. I always loved the sound of old vinyl, no CD beats a good set up turntable-cartridge-phono pre and a good pressing, preferably all analogue ones.

Unfortunately, we're living in digital world, so most of the new pressings and remastering were done in digital domain. But how about the groove and the needles? Aren't they analogue? Yes, they're full analogue, but the groove cutting head is driven by an amplifier with industrial DAC, and thank God, with no less than 24 bits resolution. So you always can expect better sound of new pressing than the CD :).

So, what next? get those friendly priced turntables, get a cartridge, MC or moving coil type is better, MM or moving magnet if budget is tight, and last but not least, a Phono pre amplifier if your pre-amp do not have phono input. But a separate phono pre is better though :).

Some years back I've bought this Cambridge Azur 540P MM phono pre. Very basic and so-so sounding, but the DIY soul in me got that itch, I want to tweak it to the max possible, that includes adding a MC input!. here are the story.

before tweaking, all standard cheap components, there are 2 op-amps, the famous 5532 they're replaced by Burr-Brown OPA2134 and the final op-amp is the sweet LME49720

After some tweaks, my tweak reference is from VinylEngine, check out page 28 and on
and also after adding a separate MC input in this small box, using Salas Simplistic NJFET MC gain stage, many thanks boss! . This hard wired MC gain stage is using the now rare quad match Toshiba 2SK170BL jfet's, the output of this stage is directly goes to the MM input through a switch.

this one is still fed by 2x 9V battery, does not last more than 7 disks, so next step is adding separate power supply for MC stage, here testing a pair of output capacitor :
And I let this combination quite a while before my last tweak :)

Last tweaks were replacing BB-OPA2134 with LME49720, C out to stacked blue Siemens 0.33uF, 11 pieces per channel, no big film capacitor will go in this small box!..and after some discussion with my DIY audio guru, Mr DWA, the diode's are replaced with schottky type, the blue Elna RE3 is replaced by Phillips 10.000uF/16V, last but no least, the 2SA970 transistors on the MM input will be replaced by even rarer Toshiba 2SJ74 :)...hmmm..yummy,...thank you pak Dhe!..

and now spin that disk , sit back and relax :)

Thank you  for reading !

in the pipe line :
Vinyl, new pressing vs digital mastered-direct metal mastering vs pure analogue...