Advice on phono preamp kit

laotzu61

I would really like to get involved in electronics/audio kit building over the winter, and would appreciate any advice on a decent phono preamp kit; tube or solid state. something in the 200.00 range. thanks.

mhardy6647

Solid state - can't beat the Hagerman "Bugle" for price/performance ratio. I have one myself.

Vacuum tube - Hagerman's "Cornet" is superb but a tad pricey; Bottlehead's Seduction is good and less expensive (although not as much less expensive as it used to be); I have one of these, too.
There are a number of good options in vacuum tube phono preamps; some of them get pretty 'spensive.

www.hagtech.com
www.bottlehead.com

mhardy6647

Re: Bottlehead. Das Ding an sich

strider

The Hagerman Bugle was the first kit I ever put together. Pretty straight forward, voltages are MUCH lower then a tube based phono pre. Runs off of batteries so there's not even a power supply and associated wiring to worry about. If you factor in a case, may be looking at $125 as a realistic number.

Far as tube based kits, I've built one of Glassware Audio's vacuum pre amps and have been very happy with it, although the documentation with the kit is geared towards someone a bit more experienced then myself. They offer a few different phono pre amp kits, but only one is in stock currently:

http://glass-ware.stores.yahoo.net/tetrasansps.html

In my opinion, you'd be blowing your budget out of the water if you went with a tube based kit. With transformers, casework, and tubes I'm probably in the $500 price range for my pre.

laotzu61

thanks, guys. i'll check them all out.

Big Dawg

+1 for the bottlehead also think this one is worth a look:

http://www.tubes4hifi.com/PH15.htm

laotzu61

Big Dawg wrote: »

+1 for the bottlehead also think this one is worth a look:

http://www.tubes4hifi.com/PH15.htm

thanks, big dawg. a little pricey for me right now, but i will check it out. that puppy looks sweet! also may have to adopt the sites signature for my mind--"the path of least resistance is thru a vacuum"

jcaut

I don't know what your goals are, sound quality wise, but if you go solid state, you don't have to spend a lot to build a high performance phono pre. I'm attaching a picture of one I just finished. The circuit is the VSPS (very simple phono stage) from RJM Audio. It's a simple, low parts-count unit, based on a dual op amp and using single stage, active EQ. I powered mine with a split +9V/-9V supply using two 9V batteries, and placed it in a metal can for shielding. The op amp I'm currently using is a BB OPA2132, but other op amps can be used. I'm quite impressed with the sound quality, and especially with how quiet it is. My points of reference are the phono stages in various receivers and pre-amps I've got or had, including older Pioneer, Marantz, and Carver gear.

It's not really a kit, but it's quite easy to assemble and the parts cost is pretty minimal. I scavenge a lot of film caps from old electronics, but even buying new parts, I don't think I'd have more than $30 worth of parts in the one pictured.

For anyone who uses a turntable and vinyl records, phono preamps are a great way to get into DIY electronics, because they don't have to be expensive and you really can hear differences. Don't know if you're a guitar player, but I'm also having a blast with DIY guitar effects, and little LM386-based battery powered guitar amps.

laotzu61

thanks, jcaut! i will check out their site. this looks like a good starter to get some experience with.

ViperZ

Just a side note. If you're just starting electronics / kit building, a preamp build, and especially phono preamp, is the hardest thing to build properly. The signals traveling through the phono preamp are 100s times smaller in amplitude than in regular preamp and power amps, so everything has to be perfect - soldering, wiring layout, shielding, etc etc - to get a good result out of a phono preamp.

mhardy6647

The above statement is very true... but... that being said, the solid state (IC) based breadboard suggested a few posts before has the great advantage of battery power - power supply noise rejection (and induced hum from the power transformer) is a non-issue. Shielded cable (or even twisted pairs) will probably get it quiet enough for the ca. 2 to 10 mV average signal levels of most MM phono cartridges. Just make sure everything can be grounded together, or the grounds can easily be lifted, in case of hum :-)

I.e., the bar is about as low as it's gonna get for a simple, battery powered IC OP-amp based phono preamp/EQ breadboard, even for a novice!

Vaccum tube preamps (even line-level circuits) are notoriously tough to get quiet. Gary Kaufman www.the-planet.org built the RCA Receiving Tube Manual (12AX7-based) phono preamp some years ago. Gary knows his stuff, and it sounded good, but he said it was nigh-on impossible to get it quiet.

You can get some flavor of the topic (for line-level preamps) from his pages:
http://www.the-planet.org/linestage.html
http://www.the-planet.org/linestage2.html

(FWIW, that little blue one on the second page was on loan at my house for a while a few years back)

laotzu61

thanks for the info, guys. and the links.