Phono Preamp Kits from Boozehound Laboratories ?
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olddude55
Super Member
I built a battery-powered Boozhound head amp. Nice kit, easy build. The LOMC I was using needed different impedance loading but that's not the kit's fault. I'm not knowledgeable enough to change the kit to the proper impedance.
I'm surprised Boozhound is still around. They had some nice line stage kits and I was thinking about building one but the website didn't work last time I tried.
I'm surprised Boozhound is still around. They had some nice line stage kits and I was thinking about building one but the website didn't work last time I tried.
ripblade
Addicted Member
I bought the MM stage from him last spring. Board is done, but I still haven't heard it. Case and PS are always stumbling blocks for me. The PS is not really a problem, but I hate drilling metal cases. And then there's the loading option: Should I install a 100k resistor and parallel another externally for 50k? What about cap loading? The options are endless...
MisterDK
Addicted Member
Well - I received a prompt reply from Jason, Mr. Boozehound. He is still shipping and has parts in stock. I’ll likely try one of his kits in the near future.
However, after reading threads about the Boozehound phono pre, I came across a link for a similar kit, from a seller in Canada - AM Audio. Very similar design and also based on the “Le Pacific” JFET circuit. The price was (very) right so I ordered one of those kits, a dual-mono using separate PCB’s for each channel. Hope to receive and built it while most of us are still under house arrest. I’ll post some pics and let you know what I think of it, once built.
However, after reading threads about the Boozehound phono pre, I came across a link for a similar kit, from a seller in Canada - AM Audio. Very similar design and also based on the “Le Pacific” JFET circuit. The price was (very) right so I ordered one of those kits, a dual-mono using separate PCB’s for each channel. Hope to receive and built it while most of us are still under house arrest. I’ll post some pics and let you know what I think of it, once built.
ripblade
Addicted Member
Dang! Wish I had seen that earlier. Would've been much cheaper here in Canada than to have one shipped from the US. I also like the active power supply filter....the Boozhound one is only passive.
The Slider
Active Member
It is a nice and simple no-feedback circuit, should sound really good with good capacitors and the right cartridge. Just note that without any cascoding on the input stage, I think the input capacitance will be rather high, so might sound bright with some cartridges that prefer low capacitance, such as the Audio Technica line.
MisterDK
Addicted Member
Got my “Le Pacific” JFET phono preamp kit from Canada and soldered the boards up today. Seems to be pretty decent quality.
Won’t know how it sounds for a while though; still need to order some good RCA jacks and figure out how I’ll mount everything and power it. This wants 24-28vdc so maybe a couple small 12v SLA batteries - not sure yet. I’ll post a couple more pictures and what I think of the sound quality when it’s all together.
Won’t know how it sounds for a while though; still need to order some good RCA jacks and figure out how I’ll mount everything and power it. This wants 24-28vdc so maybe a couple small 12v SLA batteries - not sure yet. I’ll post a couple more pictures and what I think of the sound quality when it’s all together.
Love those Russian mil spec K42Y and K40Y-9 caps!
MisterDK
Addicted Member
Most I’ve read about them, say they sound good. Some people don’t like PIO caps though. I don’t know - but I wanted to give one of these JFET “Le Pacific” circuit pre’s a try. Hopefully it’s not a waste of time and money, though it wasn’t expensive. Besides, I’d been wanting to dust off my soldering iron for a while..
The sealed Russian mil spec caps are good. They don't tend to dry out, like those old Jensen PIO. Their audio quality is most excellent. A bit more midrange warmth (in my opinion) that most polypropylene or polyester ones. As you can tell by the photo, I like to mix cap types in circuits, depending on what part of the unit they are going into & what ultimate audio quality I'm pursuing.
dogwan
Dogwan
I also ordered the same kit from AM Audio through their Ebay store. I was watching the kit and got a notification that they were selling the last 2 kits for $10 off so I pulled the trigger. With exchange and shipping it was still only about $70 so low risk.
I've already assembled the boards and in the same boat of wanting a chassis and a PS.
Wanna race to see who gets done 1st? (just kidding...)
MisterDK
Addicted Member
I also ordered the same kit from AM Audio through their Ebay store. I was watching the kit and got a notification that they were selling the last 2 kits for $10 off so I pulled the trigger. With exchange and shipping it was still only about $70 so low risk.
I've already assembled the boards and in the same boat of wanting a chassis and a PS.
Wanna race to see who gets done 1st? (just kidding...)
I just ordered a few RCA jacks (inexpensive ones, not super fancy) and am presently charging a pair of 12v SLA batteries. I have a wooden box I’m planning on using to put the boards into; batteries will stay outboard.
Not racing, but mine should be ready for testing in about a week, I think.
dogwan
Dogwan
Found a chassis yesterday on Craigslist for $10. Old security camera switcher from the 80's straight out of the Washington St. Liquor Control Board surplus.
I stripped it out and rummaged through my parts bin. Turns out I had everything I needed to build PS. I was able to use the transformer that came in the in the chassis by changing the primary to 220v config which dropped the secondary from 27v to 13.5v. I then built a full-wave rectifier/voltage doubler with Schottky's and some beefy capacitance, which then fed a 24v linear regulator with some additional smoothing capacitance on the output. I got really nice low of 0.4mv of AC ripple. My only quibble is that I'm only getting 23.5vdc both loaded and unloaded. Might just need a new battery in my DMM. Doesn't seem to be an issue.
Here it is all assembled and running in. Excuse the spring clamps, I am gluing a copper plate on the front to cover up all the switch holes. Also the top cover is drying after I painted it. The square in the middle is some chassis dampening sheet to make it feel more solid
All in all it's sounding pretty good. At first there was some minor hum, but after the 1st side of an album it diminished to almost nothing? I'm sure it will get even quieter once I can bolt the top on too. So far have made it through about 2 hours of playing. At first it didn't sound very good. Now it's smoothing out noticeably. I understand that these Russian PIO caps need a long time to break in. I think I read that 100 hours minimum before you can judge them. 300 hours before they come into their own. Wish there was an easy way to break in a phono stage! The low level signals seem to take forever. I can almost hear it changing song by song right now.
I will post more pics once I get it to final assembly.
I stripped it out and rummaged through my parts bin. Turns out I had everything I needed to build PS. I was able to use the transformer that came in the in the chassis by changing the primary to 220v config which dropped the secondary from 27v to 13.5v. I then built a full-wave rectifier/voltage doubler with Schottky's and some beefy capacitance, which then fed a 24v linear regulator with some additional smoothing capacitance on the output. I got really nice low of 0.4mv of AC ripple. My only quibble is that I'm only getting 23.5vdc both loaded and unloaded. Might just need a new battery in my DMM. Doesn't seem to be an issue.
Here it is all assembled and running in. Excuse the spring clamps, I am gluing a copper plate on the front to cover up all the switch holes. Also the top cover is drying after I painted it. The square in the middle is some chassis dampening sheet to make it feel more solid
All in all it's sounding pretty good. At first there was some minor hum, but after the 1st side of an album it diminished to almost nothing? I'm sure it will get even quieter once I can bolt the top on too. So far have made it through about 2 hours of playing. At first it didn't sound very good. Now it's smoothing out noticeably. I understand that these Russian PIO caps need a long time to break in. I think I read that 100 hours minimum before you can judge them. 300 hours before they come into their own. Wish there was an easy way to break in a phono stage! The low level signals seem to take forever. I can almost hear it changing song by song right now.
I will post more pics once I get it to final assembly.
MisterDK
Addicted Member
ETI_5000
Super Member
Nice recycling.
I've been caught by that a few years ago, while recharging a car battery - the voltage readings I was getting didn't make sense, until I worked out that the DMM battery was flat. Then I spent about 15 minutes trying to find batteries at the local supermarket, which is within a block of where I live, and finally gave up looking and asked a staff member - hidden behind the counter!
I wasn't having a good day...Use shielded cable for the inputs (especially) and outputs, which will lower hum pickup from the transformer. While it is a bit fiddly to use, it’s worth it for the extra quietness.
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MisterDK
Addicted Member
I’m just waiting on the RCA jacks, then I’ll put mine together. Got two wooden boxes to pick from; will probably use the bigger one and stain it to about the color of my turntable. Planning on using these two 12v SLA batteries. They’re fully charged and about 25v, as seen here in series. Battery box will sit on the floor, ‘bout 4’ away from the preamp.
