lorne
Sonic Lizard
I'm updating this thread — a follow-up that seems imperative considering some recent successes.
To my satisfaction, I finished my experiments with the Haller passive attenuator circuit. There was more to do, but I elected to get on with something else — something as simple as cooking bacon and eggs. The answer was a circuit mentioned a few times on this thread and a couple of others: http://sound.westhost.com/project01.htm Good on ya' Rod Elliott from down-under. Love the site!
I used the familiar, (here in Japan) inexpensive, 'B' type/linear pots from Cosmos. In fact, I used the same box-up as in my last Haller rendition that you can see in Post #2. I just stripped out the wiring, then rewired the bits as shown on Rod's site.
I liked what I heard ... just as much as with the Haller circuit. But, this time, volume control in combo with my rigs was better. And thus I used this little box for months. And then the day arrived when I boxed up a fresh Monica-3 DAC and made a 24 Volt linear power supply for it. You can go over to DIY Paradise see see what Monica-3 is all about, or read the review on TNT Audio. The point here should read: I was mightily impressed at how I seemed to be getting the natural, raw, and unalloyed talents of Monica right to my Trio/Kenwood mono-amps. What a treat! And then ....
OK ... so there is never, or very rarely, a free lunch. I seemed to be walking back and forth adjusting the right and left pots for balance all the time as tracks came and went. It seemed worth it. It was worth it! But, nevertheless, I began scheming — again. Cut to the chase:
I dug out an old tube preamp that I'd not used for some years ... a Melos GK-1+1. I had already modified and rebuilt the outboard power supply before parking this unit — despite it's promise and potential. It was just not measuring up in some way that I could not put my finger on. Please read on ....
I set everything up and put the Project 001 passive attenuator on the Melos' Tape Out RCA plugs. The result: stunning, gobsmacking, shinjirarenai! Detail, dynamics, timing, tonal and channel balance — all there! Now here is the interesting bit: the Melos uses a very nice pot — an Alps something or other if I remember. Balance settings are made by switching through resistors — no resistive pots! My friends, care was taken in the now defunct Melos factory in regards to gain and attenuation. But, by cutting out the internal circuit and using the Project 001 passive attenuator on the line level Tape Out facility, the entire rig has made a lovely important leap — the best sound this guy has ever had in any of his listening venues over the last 20 years!
As ASOK has reminded us above, these passive attenuators are very system sensitive/specific. In my case all is more than well! You passive freaks might try the same approach and see what you get. If you have a decent active preamp, try putting your passive attenuatore on a line level out and listen.
To my satisfaction, I finished my experiments with the Haller passive attenuator circuit. There was more to do, but I elected to get on with something else — something as simple as cooking bacon and eggs. The answer was a circuit mentioned a few times on this thread and a couple of others: http://sound.westhost.com/project01.htm Good on ya' Rod Elliott from down-under. Love the site!
I used the familiar, (here in Japan) inexpensive, 'B' type/linear pots from Cosmos. In fact, I used the same box-up as in my last Haller rendition that you can see in Post #2. I just stripped out the wiring, then rewired the bits as shown on Rod's site.
I liked what I heard ... just as much as with the Haller circuit. But, this time, volume control in combo with my rigs was better. And thus I used this little box for months. And then the day arrived when I boxed up a fresh Monica-3 DAC and made a 24 Volt linear power supply for it. You can go over to DIY Paradise see see what Monica-3 is all about, or read the review on TNT Audio. The point here should read: I was mightily impressed at how I seemed to be getting the natural, raw, and unalloyed talents of Monica right to my Trio/Kenwood mono-amps. What a treat! And then ....
OK ... so there is never, or very rarely, a free lunch. I seemed to be walking back and forth adjusting the right and left pots for balance all the time as tracks came and went. It seemed worth it. It was worth it! But, nevertheless, I began scheming — again. Cut to the chase:
I dug out an old tube preamp that I'd not used for some years ... a Melos GK-1+1. I had already modified and rebuilt the outboard power supply before parking this unit — despite it's promise and potential. It was just not measuring up in some way that I could not put my finger on. Please read on ....
I set everything up and put the Project 001 passive attenuator on the Melos' Tape Out RCA plugs. The result: stunning, gobsmacking, shinjirarenai! Detail, dynamics, timing, tonal and channel balance — all there! Now here is the interesting bit: the Melos uses a very nice pot — an Alps something or other if I remember. Balance settings are made by switching through resistors — no resistive pots! My friends, care was taken in the now defunct Melos factory in regards to gain and attenuation. But, by cutting out the internal circuit and using the Project 001 passive attenuator on the line level Tape Out facility, the entire rig has made a lovely important leap — the best sound this guy has ever had in any of his listening venues over the last 20 years!
As ASOK has reminded us above, these passive attenuators are very system sensitive/specific. In my case all is more than well! You passive freaks might try the same approach and see what you get. If you have a decent active preamp, try putting your passive attenuatore on a line level out and listen.
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