TDA1541A Balanced DAC, part 2

I'm listening now to Andrea Bocelli's Amore album, right now Estate's is playing, using balanced TDA1541A-S1 DAC and it's direct heated triode output... the sound makes you really enjoying the Andrea's emotion... man... I have to write this instance..:). There were few moments like this when you're deep in to music you're listening, really caresses my ears and you forget about analyzing music, let alone measuring he he..I lost my measuring urge :). I'm just going to enjoy it before this DAC moving to it's new home.
Damned!!.....that voice of  Christina Aguilera...what a talent!..what a waste in her pop music!...and just past midnight here, the volume knob barely at 9 ...Somos Novios......., my ears were tickled nicely here :)


It's have been almost 2 weeks since I have boxed up brother Y's balanced DAC and fired it up. Before that I use his DAC - Jfet - LME49720 opamp board and the little DHT bugger in my DAC box with the famous Salas shunt regulator.

I should mention that a few weeks back we have had a very nice blind test session. I for sure have participated, bringing this balanced DAC. The result? well a mixed bag really. I've heard 2 to 4 very beautiful sounded DAC there. A matter of taste though, only 1 of my favorite made it to final. The winner is a humble AD1955 DAC..congratulation ! here is the pic of my box with brother Y's boards.

There are the 4 Salas regs, at center the TDA1541A-S1, the DC coupled single ended Jfets, next to it is the balance-single ended opamp converter (with bit of gain) that going to ..yup, a pair of direct heated triode :). a very nice sounded ones those little buggers !, I did not believe my ears when listened to them the first time. I've made both anode & cathode follower/CF, the above is CF. Heater cathodes were battery powered. Why DHT output? I'm quite bored actually doing another 9 pin tube things, maybe octal tubes will be nice but I'm daunted with so many choices and what if the sound is not right...

Now in new box, not as large as mine, standard thin steel box, but modified with 8mm thick aluminium face plate and 2mm rear plate

Anti clockwise from top left : 2 EI trannies for digital supplies, 1st 2x Salas board, DAC board, 2nd 2x Salas , SE Jfet's, opamp with LM317-337regs for supply up to +/- 17VDC, DHT DC heater (modified Tom Ronan's supply), DHT board with supply, analog transformer (both high voltage, 2x 10V for heater and 18V for opamps). At center are cap banks for opamps.

This project to me is the most difficult and challenging, but worth the effort. This is my many "first-time" experiences with balance topology, first with I2S splitter, first  balance- SE opamp, all including Salas board were custom designed and CNC'ed, and yes, first time DHT and I highly recommends you guys overcoming that famous DHT hum with DC heater!. very frustrating and yet rewarding ..completely gone? nope, but I remembered 'complaining' friend's DIY DHT amp..now I have experienced it coming with that "low' hum is admirable!.

Thanks for reading....thanks to brother Y for the challenge, may the emotion be with you!

now on : Solamente Una Vez (oh my...Stevie Wonder just great with Andrea..), Sony CDP950 digital out, TDA1541A-S1 balanced DAC-DHT tube out, Aikido pre amp, Aleph J clone tweak nr.xx, Scanspeak Elan