Never being satisfied for long I have been working on a new moving coil phono stage the Hypnotoad Moving Coil Phono Stage. Here is the first working prototype, well the only one actually. It worked first time I fired it up to my surprise and I only finalized the design last night. As you can see I had a few different options on the PCB and some of the component values were changed after I etched the PCB.
It's super simple to build, is dead quiet and has plenty of gain which can be adjusted easily to suit different carts. I used the trans-impedance concept for the input stage as I believe that it's the best way to go. Makes me wonder since the idea has been around so long that it hasn't been used a lot more.
I nearly went with a non-inverting output stage but changed my mind as I realized it would be out of phase. I have a personal preference for active equalization as well so that's the way I went.
RIAA is accurate, less than 0.4db deviation.
2 x OPA2134 dual circuit op amps.
Very few caps in the signal path and bypassed output caps.
Only 10ma's current draw.
Runs very nicely on 9v batteries at the moment but will try it later with my lantern batteries setup which seems to always sound a bit more authoritative on my other stages.
Right out of the blocks it sounded special, the bass was a tad heavy and the highs a little laid back at the first needle drop, but after only a couple of hours it's opening up nicely. So nicely I am thinking I don't need to change a thing, yeah right who am I kidding.
I did a comparison between it and the Phonoclone 3 and even though the PC3 is a fierce contender and the best phono stage I have heard. That was up until now, the HTMCPS has a slightly more forward sound stage compared to the PC3 with a slightly smoother more open sound to it. It's like another veil has been lifted from the sound.
I am listening to The Carpenters and Karen's voice can be a little harsh on some systems but it's as sweet as sweet and this is only after a couple of hours use.
It's super simple to build, is dead quiet and has plenty of gain which can be adjusted easily to suit different carts. I used the trans-impedance concept for the input stage as I believe that it's the best way to go. Makes me wonder since the idea has been around so long that it hasn't been used a lot more.
I nearly went with a non-inverting output stage but changed my mind as I realized it would be out of phase. I have a personal preference for active equalization as well so that's the way I went.
RIAA is accurate, less than 0.4db deviation.
2 x OPA2134 dual circuit op amps.
Very few caps in the signal path and bypassed output caps.
Only 10ma's current draw.
Runs very nicely on 9v batteries at the moment but will try it later with my lantern batteries setup which seems to always sound a bit more authoritative on my other stages.
Right out of the blocks it sounded special, the bass was a tad heavy and the highs a little laid back at the first needle drop, but after only a couple of hours it's opening up nicely. So nicely I am thinking I don't need to change a thing, yeah right who am I kidding.
I did a comparison between it and the Phonoclone 3 and even though the PC3 is a fierce contender and the best phono stage I have heard. That was up until now, the HTMCPS has a slightly more forward sound stage compared to the PC3 with a slightly smoother more open sound to it. It's like another veil has been lifted from the sound.
I am listening to The Carpenters and Karen's voice can be a little harsh on some systems but it's as sweet as sweet and this is only after a couple of hours use.
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