First time building a tube preamp

[reeeky2001]

So here I am in a record store looking at a Pioneer PL-600 (turntable), thinking to myself "You know, I should get rid of that old, $10 garage sale, piece of cr*p I bought 4 years ago." I go looking at the guys turntables, without a whole lot of money to spend (I was buying $75 in LPs), I found a PL-600 BD TT for $59.99. I get it home to find out that, unlike that piece of cr*p that I had, this TT doesn't have a preamp built in.

Then I logically decide, it's time to get a preamp. Then I get thinking about the different amps I've heard, and remember the warmth and quality of a tube amp I heard about 2 years ago. I remember seeing the lights and feeling the warmth of the amp.

So I'm browsing the internet looking for a decently priced preamp, and I don't really like what I see. Either its overly priced, or it shody workmanship. Thinking to myself, even if I spend more than other preamps, building my own is worth the venture into tubes.

Finally I think I found a design to settle on, diyparadise.com's Simple 5687 Preamp. Looking at the schematic and part list, it doesn't seems to be to daunting. Except for one thing... the transformer.

See, in all my other electronic ventures, either I've been able to get a wall wart, or power it from a DC battery source. Apparently, until I am corrected, this not so w/ tubes.

This is where I am, ask foring help. Where do I get a transformer for this board, or for any other project that needs such a large transformer? I can use digikey.com, but I don't know how to find what I'm looking for.

Thanks for any and all help,
Curtis Kinsey

[DigitalJunkie]

Well,
http://www.hammondmfg.com/5cpwr.htm
and
http://www.edcorusa.com/products/tra...pwr/index.html

are two sources I know of.

[Mikael Abdellah]

I second the hammond transformers. And while you're at it... buy a nice hammond chassis. They are just stunning. I have the one on the right beside me. The ends are solid walnut wood.

[Sonusthree]

Curtis,

Isn't it a PHONO preamp that you want? (specifically for your record player.)

The above circuit appears to be a regular line preamp without the necessary equalisation.

Regards,
Martin.

[reeeky2001]

DigitalJunkie and Mikael: Thanks for the transformer links and the recommendations. That's exactly what I was looking for. If there's any other manufacturers out there, I'd love to know about them also.

Martin: D'oh! You're right. I don't know why I didn't realize that. Ah, well I'll search for another design, but it still goes that I'll need a high voltage transformer.


So now that I know where to get a transformer, I guess I need to find a good Phono Preamp design. Would anyone be able to recommend one?

Thanks for any and all help,
Curtis Kinsey

[DigitalJunkie]

Hmm,not too sure about any phono designs..
But,I did just remember another source for transformers,and parts.. http://www.triodeelectronics.com/

[Sherman]

To purchase transformers just go to http://www.angela.com. Steve has all the specs online for all the Hammond trafos he sells and his prices are the best. (No affiliation, just a satisfied customer.) He also sells Hammond chassis, top plates and perforated covers.

Steve doesn't have online ordering, you have to call his 800 number or send a fax. However, lately he has been putting some of his inventory on eBay (it is priced a bit higher, probably because of the eBay listing and PayPal fees).

[reeeky2001]

Thanks for the recommendations and suggestions, now I'm not so lost in the dark about where to find transformers.

Now, I guess I'll look for a Phono Preamp, and I might have to make a post asking for someone to guide me to one.

Thanks again!
Curtis Kinsey

[zacster]

The thing that make a phono pre-amp harder than a line pre to get right is the hum and noise. You'll get the circuit to work well enough but then spend a lot of time chasing the noises down. It isn't impossible, just a consideration. Proper grounding, parts placement and shielding are key.

What I did in any case is build a tube line pre (Aikido) and built in a Creek solid state phono pre amp board that I pulled from an old Creek amp that will never have another phono attached to it. Kids don't appreciate vinyl. Maybe I could get something that sounds better, but for the amount of vinyl I use myself it is fine the way it is.

[dsavitsk]

Originally posted by reeeky2001
Now, I guess I'll look for a Phono Preamp, and I might have to make a post asking for someone to guide me to one.

My experience, and I don't know if others are similar, is that from the time I decide to scratch build something, to the time that it is actually done and ready to use can take months ... years sometimes. Additionally, as others have said, chasing down hum in a phono stage is particularly tricky.

I'd build something quick and easy to get yourself going (example 1, example 2), and then do a high quality tube one after that.

Also, there are a number of good kits floating around that might be helpful.
http://www.bottlehead.com/et/adobesp.../seduction.htm
http://www.diyhifisupply.com/diyhs_cole.htm