Boozhound Labs Phono Preamp Kit

IMG_0426I know.  The grey box above ain’t much to look at in the abstract.  But, it’s what’s inside the box that we are concerned with today.  Jsn at Boozhound Labs (hf ‘BHL’) sent me one of his new “JFEt Phono Preamp Kits” to check out, and I’m glad I did.  It was a quick+ easy project that has greatly improved my LP listening situation in the living room mini-system.

IMG_0455Above you can see the BHL preamp right beneath a little stereo power amp (with A/B input select and a stereo volume pot).  The power amp is a design that I have built dozens of times for clients: a single 6SN7 is shared to provide one voltage-gain stage per channel, with each channel using a 6L6 (cathode biased) class-A to provide approx. 8 watts of power to each speaker.  Just so you know where I’m coming from, here’s the complete setup:  ADC QLM 30 mk III cartridge mounted on a Technics 1200 table, then into the BHL, then to the SE 8-watt power amp, and finally to JBL 18ti speakers.  Very circa-1980.  The other input of the power amp is connect to an Apple Airport Express so that I can stream music off the iPhone or the macbook.  Certainly not an audiophile setup, but I’ve never found it lacking.

IMG_0425The BHL kit ($89 direct) comprises the board that you see above, all the parts to stuff the board, instructions, and a bunch of good quality wire.  I supplied the Hammond steel chassis and bottom plate and the vintage-style lamp holder and big power switch, plus a $13 24v switching power supply from eBay, some El Cheapo-brand dual RCA jacks, a binding post, and a goofy old Amphenol connector to mate the power supply.

IMG_0427Note that since this thing is running at 24V, I had to try to find a 24v bayonet bulb for the vintage-type jeweled-lamp.  Don’t use a 6.3V bulb from yr parts drawer here!  It will not end well.  Luckily, MCM electronics had 28v bayonet-base bulbs (the closest value that I could find to 24v) for just a few cents.  Anyhow, I went through this trouble since I wanted the BHL preamp to match the appearance of the power amp perfectly, but you could easily build this board into whatever you want.  Here’s a dude on Instagram who went for more of an ultra-modern/brutalist look for his build.  Point is, you can do whatever you like as far as the visual aesthetic yr after.   I probably spent about $50 for the non-included components for my build.

The circuit is super-simple and it’s very very easy to assemble. The BHL site has a transcript of the directions that come with the kit if yr curious.   It took me less than an hour to solder all the parts together.  As Jsn explains on his site, “This is just about the simplest circuit possible that will accomplish what we need – reverse-RIAA equalization with gain. This is 2 JFET gain stages with a passive (no feedback) RIAA equalization network sandwiched between them.”  Simple as it is, the components included are of a very high quality.

Now, I was replacing a very cheap phono preamp with the BHL (I had been using a $50 Rolls VP29), so keep that in mind – but here were my initial impressions, which the past month of 4-hour-per day listening has proven to be (subjectively) correct:

*The sound is very good; the low end is a bit more even and less ‘rolled off’ versus the ROLLS preamp.  Vocal-area midrange is a bit more forward.  The high end seems to sound about the same, but the cartridge/LP is probably the limiting factor as far as treble.

*The biggest improvement is that the self-noise of the BHL is so much lower.  And there is less hum.  So overall there is really a huge difference in terms of background noise, which just brings out so much more detail in the music.  And honestly, I never even thought that my ROLLS preamp was noisy until I installed the BHL.

*Gain is a little lower than the ROLLS that it replaced (maybe 2 or 3 dbs).  Not ideal, but not a huge deal.

Full disclosure, and maybe this is unnecessary: Jsn provided the kit to me at-cost.  That being said, at the street price of $89 I do still think it is a very good value.  If yr thinking of testing the waters of Audio DIY (and you like listening to LPs…), I could not think of a better place to start.  Jsn is a great guy, and it was his old BHL blog that was one of my greatest inspirations in starting PS dot com; so if you dig this website, support the dude and get yrself some upgraded sound in the process.

Boozhound Labs

Kinda Miss My Camaro

CamaroFuzzTopCC copyAbout 10 years ago I had a dark purple 1986 Camaro Berlinetta with a 305 and the digital ‘knight rider’ instrumentation panel.  I bought it for $775 (only 83k miles!) from an old lady who grumbled, “don’t kill yourself Don Johnson” as she handed me the keys.  Except for one odd incident in which the car would simply not turn off,  it was 100% reliable and I loved driving it.  I sadly had to sell it because I lost the parking space it slept in.  I was poking around the ole MacBook today trying to find some pics of it, and there ain’t even one!  I guess that 2005 was maybe riiiiiiiight before the era of ubiquitous photography of every single fkkn facet our goddamn lives, and maybe I’m better off for it.  Maybe Camaro is just better off living in my midnight-blue tinted memories.

Camro_Fuzz_insideWhile I couldn’t find any Camaro car pics on the laptop, I did stumble on the above-depicted germanium Fuzz Face ‘clone’ that I decorated with a mid-seventies Camaro badge.  I buy these old chrome auto badges in lots at the flea market; if yr patient, you can get em for a buck or two each.  Anyhow, this is one of the only guitar pedals that I ever built and it turned out great, despite the fact that I simply used whatever old NOS RCA germanium PNP transistors I had around, without so much as even looking at the data sheets.  I just tried a few different types until the thing sounded like a Fuzz Face, and voila.  One cool detail: in the image above, check out the massive mil-type chassis-mount oil cap (far left) that I used as the output coupling cap.

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Above is the very simple schematic that I apparently pulled from FuzzCentral.  Much like my Camaro (the car), my Camaro (the fuzz) was sold off many years back, and yeah I kinda miss it.  Can’t keep em all…

Tonight: 3.12.14: Live DJ set at Firehouse 12, Neu Haven CT

photoHow y’all doing out there in internet land////

Tonight I will be taking a dip into the murky waters of real life social interaction with a 4-hour DJ set at FIREHOUSE 12 in New Haven CT.  I’ll be trading off with my good old pal JBW aka SWAY with a night full of weird dark old rock punk and soul.  And maybe some electronic terror if you stay late enough.  You can check out my instagram to see some of the recent-findings to be spun up tonight.

45 Crown Street, New Haven CT. 9P -1A

Come on down and hang out with all the regulars and irregulars.  No cover.

The Quad-Eight RV10 outboard spring reverb unit of 1972

QuadEight_RV10foto_vanleerJust about a year ago I published an article entitled “Obscure Mechanical Reverbs of the 70s.”  Included in this this survey was the Quad-8 RV-10.  Now, y’all know how much I love spring reverb (also here…), so I was pleasantly surprised when I received a phone call from one J. VanLeer (his photo at left), who claimed to be the inventor of this obscure device.  In VanLeer’s words:

“When with the HAMMOND ORGAN CO. I worked on spring reverb tanks – after HAMMOND closed, these were made first by GIBBS, and OC ELECTRONICS than ACCUTRONICS who sold out to BELTON (Korea) and now a Chinese firm MOD makes spring tanks. The RV-10 still sounds the best ’cause it makes use of 4 different (length, diameter & wire gauge) rather that 2 or 3 with only difference in length.”

Vanleer patented this unique twist on spring-reverb technology and then apparently leased said license to Quad-Eight.  By his reckoning at least 357 of these units were sold. VanLeer sent me via post the original product-sheet for the RV10.  I reproduce those here for your edification and downloading: QuadEight_RV10

QuadEightRV10QuadEightRV10_0001Below are some photos of the interior of the RV10 (from an eBay listing that ended in January 2014 at $446).  The parts and build quality is extremely high – with hefty input/output transformers, and a UTC O-series (inside an O-17 case), which I presume is the recovery-pickup transformer.

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ed. note: Mr. VanLeer had quite a long and interesting career as an innovator of electro-acoustic devices; click here for an article about his career (use Google Translate to translate into your own reading language).