Tube phono pre-amp needed.

[SY]

For a power transformer, I'd look to surplus. Ebay is your friend. Herbach & Rademan had some likely looking candidates, too, when I was poking around earlier today. For new, Edcor is inexpensive and looks pretty good.

 

[EC8010]

For an HT transformer, look out an old bathroom light fitting with shaver socket. The (typically 20VA) isolating transformer can be used with a voltage doubler to give 320V. For heaters, look for any old EI transformer that hasn't been lacquered, take the laminations out, unwind the secondaries (counting the turns as they come off), measure the wire diameter and rewind for whatever voltages you need. Salvage common mode chokes from computer power supplies.

 

[chrisb]

If it's not too late to echo a couple of recommendations made earlier, I can highly recommend the Seduction. A buddy of mine built one a year or so back, as part of a now full Bottlehead system, and I've had the opportunity to hear, as well as several other much more expensive tube based phono/line stages (2 different examples of K&K, as well as the Hagerman Coronet) For my money the only FIY product that showed the Seduction the door was the multiple times more costly K&K.

If I hadn't previously finished my own scratch-built phono stage (for much higher cost in the end), I'd start with the base Seduction, and tweak with upscale component parts after a few months of burn-in.

As Eli noted, the base cosmetics of (any of) the Bottlehead products is not their strongest selling point, but the only limitation to customization is your imagination.

 

[phn]

Search this forum or google. Lots of them out there.

 

[Runco990]

For an HT transformer, look out an old bathroom light fitting with shaver socket. The (typically 20VA) isolating transformer can be used with a voltage doubler to give 320V. For heaters, look for any old EI transformer that hasn't been lacquered, take the laminations out, unwind the secondaries (counting the turns as they come off), measure the wire diameter and rewind for whatever voltages you need. Salvage common mode chokes from computer power supplies.

WHOA! Guys...... I am NOT in the wind-your-own transformer stage here....

That's a little too advanced for me. I'll leave that for later..... much later....

Looking for a suitable transformer that's in one piece, thank you.

Marc

 

[Eli Duttman]

Looking for a suitable transformer that's in one piece, thank you.

$18.97 gets you Allied Electronics stock # 227-0067, which has a 230-0-230 V. rectifier winding rated for 50 mA. of B+ and a 2.5 A./6.3 V. filament winding. Rectify the B+ with a 7Y4 or 6X4. The filament winding provides AC for the rectifier and also feeds a "full wave" voltage doubler made from 2X substantial Schottky diodes and 2X large 'lytics. Follow the doubler stack with a 7812 3 terminal regulator IC. 2X 12AX7s draw 300 mA. @ 12 V., which is easy for the IC if it's well heatsinked.

 

[Runco990]

If it's not too late to echo a couple of recommendations made earlier, I can highly recommend the Seduction. A buddy of mine built one a year or so back, as part of a now full Bottlehead system, and I've had the opportunity to hear, as well as several other much more expensive tube based phono/line stages (2 different examples of K&K, as well as the Hagerman Coronet) For my money the only FIY product that showed the Seduction the door was the multiple times more costly K&K.

If I hadn't previously finished my own scratch-built phono stage (for much higher cost in the end), I'd start with the base Seduction, and tweak with upscale component parts after a few months of burn-in.

As Eli noted, the base cosmetics of (any of) the Bottlehead products is not their strongest selling point, but the only limitation to customization is your imagination.

Still considering that. True, I can stuff it into my own cabinet.

Marc

 

[jduffy]

I dig phono preamp threads. Part science and part voodoo. Here's mine from a little while back. Some great info for sure. I'm working on getting my parts together so I can build mine.

http://www.diyaudio.com/forums/showthread.php?s=&threadid=97548&highlight=

Good luck with your choice(s).

 

[planet10]

I'm in late, but given the original question, this ready to go puppy for $250 has received universal praise in the media (i haven't seen or heard one)

http://www.needledoctor.com/Bellari-VP129-Tube-Phono-Preamp?sc=2&category=401

As the feedback RIAA & the low voltage supply have to compromise it somewhat, for not much more i'd personally get the Seduction and not just because the picture is better...

An externally hosted image should be here but it was not working when we last tested it.

dave