Categories
Custom Fabrication

SuperHugh: studio instrument preamp

I tried to imagine the sort of custom instrument preamp that a top session player might have brought to a studio in The Seventies. Similar in principle to an Alembic F2B (part of many top players’ rigs for decades) but with many crucial improvements, this compact all-tube preamp starts with a classic Fender blackface low/mid/high/bright/vol feature set but adds the following: *master volume, *hi shift, and most importantly an additional output stage that can reliably drive a 10k input at high levels with no frequency loss.

I learned a ton about the idiosyncratic Fender eq circuit by listening and fine-tuning this unit; the various compromises and ‘sweet spots’ that one can find with different cap and pot values. Basic three-stage filter power supply (output stage at 2nd leg) and c/t grounded AC heaters proved more than sufficient; the thing runs dead quiet (zero hum) other than a minuscule bit of reassuring hiss, as i used all NOS 1960s Allen Bradley carbon-comp resistors throughout (which id never do for a mic pre, but for vintage guitar/bass tone its part of the package, i think). The output stage runs at 350 volts, and the input and makeup stages are around 215, allowing for tons of headroom.

Above: the unit with the top cover removed. You can see the sub chassis with the 12AX7 and the 6C4 output driver; a huge Aerovox output cap; and the rugged fiberglass turret-board point-to-point construction.

Above: another internal view. All of the hardware bits are DakaWare, API, and Smith NOS parts from the 60s and 70s, all from my inventory. Signal wiring (orange) is stranded silver 22ga wire and the ground wire (green) is 18ga solid copper.

How does it sound? With bass guitar its absolutely magical- every classic electric bass sound is just there at your fingertips; very inspiring to play thru. Really sounds like a ‘finished’ bass track with no additional processing. The whole package is compact enough to fit in many gig bags.  As for the name? “Super” as the circuit owes much to my beloved Fender Super Reverbs, and “Hugh” as an homage to one of my all-time favorite session greats Hugh McCracken.

Categories
Altec Custom Fabrication

Altec 436C style compressor build #2

I’ve serviced and modified many Altec 43X-series compressors over the years, but I think this may be only the 2nd one I’ve built entirely from scratch. Styled more like a Federal AM864, this unit incorporates many of the tweaks and modifications that I have come to like in these machines. Here are some images of the build.

Couple of things to point out in the photo above. Note the larger “Octal” tubes (6X5 rectifier and 6SN7 output amplifier) on the left side. I like octal tubes, as the larger sockets are easier to work with, so space-permitting I tend to use them. The original 43X used a solid-sate rectifier (with a voltage doubler) but I used a more conventional full-wave supply with a rectifier tube since it suited the look better. The 6SN7 output tube was a nice choice as there are so many variations of this tube available. It’s a direct sub for the 6CG7 in the original Altec.

Also note: behind the meter is a ‘meter null adjust’ pot. I can’t recall how this was handled on the original Altecs, but this mod is a common one shown on many internet schematics of the 436. Also note the large pot to the left of the meter. This is the Gates Sta Level output trim control (-6 to -14db cut) that I detailed on this site years ago. A worthy and necessary addition!

You can also see the enormous output transformer in the center: a massive potted unit built for Daven, likely by UTC. originally built for hi-end test gear, it is ultra hi fi and handles more level than this thing will ever see.

Above: some detail of the meter. I was motivated to build this thing solely because I found that original Altec panel meter at a hamfest for a buck. Seemed like it needed a 2nd life… Also check out that finish on the panel! That’s about 6 layers of paint and 3 layers of clearcoat, sanded between each coat. The knobs are all NOS 1960s DakaWare, acquired from Park Distributors in BPT CT (RIP).

Above: the UTC A18 input transformer, which has similar specs / ratio to the Peerless plug-in unit that an original Altec would have been outfitted with.

Above: the completed unit on the bench. The input pot is a really nice dual-gang 50K 1-watt sealed unit; I got several of these from Park before they closed. I cant imagine that any pot like this is available today for under $50. Good find. Running the length of the unit to the immediate right of the turret board is the heavy copper ground buss. Every ground in the machine connects here, and only here, and the ground buss meets the chassis at only one spot – the input jack. I swear by this construction technique. I’ve rewired a lot of old cheap tube guitar amps with this addition and the improvement in noise floor is remarkable.

Categories
Custom Fabrication

Classic RCA riaa phono preamp / module-style

I’ve been developing an all-tube rotary-knob DJ console for the soundsystem at Berlinetta Brewing. One idea I decided to experiment with was building the 4 channels of phono pre amps as little plug-in modules, similar to theatre soundsystems of the 1940s and 50s. This would, in theory, allow me to make just 5 of the modules and have “zero downtime” if/when a channel failed. Anyhow, I made one as a demo, and man what a pain in the ass! The device you see above and below uses the classic RCA circuit from their receiving tube manual RC20 plus an additional 6c4 cathode-follower output stage, all built in a tiny grey Hammond box. All i/o and power (300vdc B+, 7vDC heaters) are on an 8-pin Jones for maximum “fake historical authenticity.” It worked out fine, sounds great, very low noise floor, but it’s just too fussy working in that tiny 4x2x2 inch box I will probably end up going with a different solution. Still an interesting possibility though…

Categories
Custom Fabrication

Fairchild 663 Optical Compressor circa 1965

I was recently given this circa 1965 Fairchild model 663 optical compressor module. This unit was sold as part of their modular console range of the era. It requires 7V A/C power and it has a completely passive audio path! Seems incredible, but it’s true. Here’s what I did to ‘lunchbox it’ for standalone use in the studio. More details soon…

Categories
Custom Fabrication

“Detroit Boxes”: Motown-style transformer DIs

Detroit Box #001 featuring UTC Ouncer Transformer and O-17 magnetic shield

Last year I found myself with an excess of nice vintage 1:10 and 1:12 audio transformers, so I figured I would make some “Motown”-style passive DI boxes and see how they sounded. I built all of these using genuine 1960s era transformers, NOS Allen Bradley carbon-comp resistors, and NOS vintage hardware components in order to make something that ‘looked and felt’ like the sort of thing that a studio custom-shop would have built in that era. These aren’t copies of the Motown box – that piece used a particular model of transformer which I did not use, and I had my own aesthetic directions to pursue – but like the original units, they have that higher 1:12 ratio, variable defeatable pad, bi-directional operation (for use as a ‘re-amp’) and ground lift switch.

In the past I generally built my DIs with 1:5 or 1:8 ratios, so I was curious to see if the higher ratio gave a more open, detailed sound while still allowing for a sufficiently good signal-to-noise ratio. After building a half dozen of these things, I can say that yes they sound great. Here are a few examples of the units I built.

#005, again with a UTC O-series and shield
#006; this one features a large Thordarson 1:12 transformer
Categories
Uncategorized

WESTON MODEL 862 VU METER PANEL ART (1946 VERSION)

I recently needed a pair of working Weston 862s. I only had one busted one, and a pair of 861s with different gfx that Weston OEM’d for some other firms. So i’ve scanned the 862 panel at 600DPI and I am going to attempt to print and re-cover the panels in the 861s. Wish me luck! Here’s the art at 600DPI if anyone else needs it:

Categories
Radio Shows Uncategorized

P/S Radio Show 12.11.2019 – link to listen from archive

This month’s P/S Radio show has already aired, but you can listen to the program via this archive link thru Jan 10 2020. As usual this show is broadcast 100% from vinyl. Check it out while you can, some incredible rarities here.

  1. The Gentrys HELP ME
  2. Cat IM GONNA HIJACK A PLANE TO CUBA
  3. Claire LePaige RENDEVOUS EXPRESS
  4. Sex LOVE IS A GAME
  5. Damon POOR POOR GENIE //// set break ///
  6. Irwin Goodman KADUN KASVATTI
  7. 3-Hur-El SEVENLER AGLARMIS
  8. Osibisa SURVIVAL
  9. Juan Carlos Caceres LOVE ME NOW
  10. Del Shannon SHE WAS MINE /// set break ///
  11. Groundhogs BLACK DIAMOND
  12. Fat Mattress NATURALLY
  13. The Steve Miller Band KOW KOW
  14. Aphrodites Child THE 4 HORSEMEN
  15. Man THE THUNDER AND THE LIGHTNING /// set break ///
  16. Catherine Ribeiro and Alpes AME DEBOUT
  17. Il Volo IL CALORE UMANO
  18. Le Orme ALLIANTE
  19. PFM IL BANCHETTO
  20. Peloquin Sauvageau STERILIZATION ///set break ///
  21. Funkadelic CAN YOU GET TO THAT
  22. Ronnie Stoots BYE BYE DARLIN (no YouTube version available)
  23. The Gentrys JUST GOT THE NEWS
  24. Francoise Hardy PUNTO (no YouTube version available)
  25. NRBQ RIDIN’ IN MY CAR /// set break ///
  26. The Mystic Number National Bank IT WILL BREAK YOUR HEART
  27. Witchita Falls GOING TO OHIO (no YouTube version available)
  28. Ken La Brie LISTEN
  29. Fever Tree TIME IS NOW
  30. Hector MEIRAN LAULU
  31. St James Church Stratford SEE ME FEEL ME (WHO cover) (no YouTube version available) /// set break//
  32. Charlie Kaman and Sons PRATLING POND BLUES (no YouTube version available)
  33. Blues Magoos TONIGHT THE SKY’S ABOUT TO CRY
  34. Breakout MODLITWA
  35. Catherine Ribiero LE PETIT FILLE AUX FRAISER /// set break///
  36. Sven Grunberg HINGUS (excerpt)
Categories
Uncategorized

NBC Custom SpectraSonics mini console circa who knows

PS dot com reader Frank B sent in these pics of his SpectraSonics console. This 6×2 board was custom built for NBC Television in the late 60s or 70s. Here’s Frank’s description of it:

“..its one of a kind…6 preamps and two 610 limiters plus some high pass filters. It was built for nbc-tv. Im guessing this is the only one in existence….The wiring for the patchbay is unique and crazy. “

Interestingly the comp controls are located on the rear of the unit and the compressors have their own points on the bay. Frank, I am curious what that other board you have to the right of it is!

Any of yall got a custom mini-console by a big maker like this? Let us know!

Categories
Uncategorized

ADM Console History Part IV via former manager G. Frudd

(L to R) Sheraton Shook (ADM GM at the time); Brian Phelan (cabinet shop foreman, later Shop Foremen); G. Frudd; Robert Bloom (owner)

G. Frudd worked at ADM technology from 1976 – 1989. He sent us the photos above and below. These document some of his work at ADM during that period. Frudd started at ADM as the “console fitter,” previously having worked as a tool & die maker.

Frudd went on to run all of the mechanical shops- machine, cabinet, engraving, and fitting, eventually becoming the Mechanical Engineering Manager. Frudd was directly involved in the design of all consoles and rack products during that period.

An ADM 1600 built for NAB 1981

G. Frudd: “In my time at ADM we transitioned the product from wood cabinet based to metal and extrusion based structures. It was a great and exciting place to work. After ADM’s demise I went on to be a mechanical designer and product line manager at several companies in the lighting and automation industries.”

The two images above are burn-in racks for console modules.

An extender-board test fixture
An ADM 1600 console circa 1976
An AD-800 console built for NAB 1981
An ADM 2400 console circa 1980
An ADM-800 circa 1978
An ADM Stereo radio console undergoes testing, 1978
Cabinet fabrication for an ADM-3200

Thanks for sending in these great images GF!

For previous ADM coverage on P/S dot com, check out these links:

Catalog images and a TON of comments – click here

The 1981 Glen Glenn Sound console – click here

The ADM / FINE console – click here

Categories
Radio Shows

STREAMING NOW: Preservation Sound Radio 6.12.19: USSR + Eastern Bloc Vinyl

Really excited to share this one with y’all: it has been a dream of mine for many years to assemble an all- USSR + Eastern Bloc Rock/Prog/Funk show.

Click here to stream the show (until July 12, 2019)

Tracking down all these records (everything is from the original 70s+80s vinyl LPs) took some doing but it was worth it… there is so much obscure and frankly incredible material on Melodiya, Amiga, and the various Czech and Polish and Hungarian labels from the Iron-Curtain days. Here’s the set list, and where possible I’ve included a YouTube link- it’s very hard to locate this stuff on YouTube, or anywhere else, as many of these files are posted using only Cyrillic characters. A few other caveats: I had to rely on Goggle Translate for the song titles and the artist names, so I can’t say for certain if any of this info is 100% accurate. At the very least though, it should provide the motivated crate-digger with some basic starting points for tracking down some of these records. Enjoy –

  1. Funny Children “Our Song”
  2. Romance For Lovers OST (Alexander Gradsky et al) “Search”
  3. Alla Pugacheva “Tambourine Shaman”
  4. Omega “After a Difficult Year”
  5. Gunnar Graps + Magnetic Band “Our Lawyers” /// SET BREAK///
  6. Alla Pugacheva “Sonnett” *Sampled in 50 Cent’s ‘Piggy Bank’*
  7. Sigfried Walendy “Papa Joe”
  8. Sofia Rotaru “Road”
  9. Magnetic Band “Troubadour”
  10. Iberia Ensemble “Traveling” /// SET BREAK///
  11. Plastic People of the Universe “Toxic”
  12. The Young Seven “Letter Father”
  13. Ensemble Singing Hearts “Where to find love”
  14. No To Co “Sunday”
  15. Omega “Ten Thousand Steps” /// SET BREAK///
  16. Electra “The Rooster with the Red Comb”
  17. Alla Pugacheva “Fully Around The Sages”
  18. Psycho “Nomina Sunt Odiosa”
  19. Hungaria “Steffi Come”
  20. Studio 66 “Not A Student” /// SET BREAK///
  21. Funny Children “Always Away”
  22. Gunnar Graps + Magnetic Band “Money Wall”
  23. Ruja “It’s here you were born”
  24. Puhdys “Doors open to the city”
  25. Omega “Girl with Pearls in her hair” *Sampled in Kanye’s ‘New Slaves’ ///SET BREAK///
  26. Czelaw Nieman “Pebble”
  27. David Tukhmanhov “Mentally Enter Your Cabinet”
  28. Arsenal “The Tree”
  29. Electra “The Smile” (2nd half of song)
  30. Yacheslav Ganelin “Devil’s Bride O/S/T”
  31. No To Co “Dimi” ///SET BREAK///
  32. Vitamin “(title uncertain)”
  33. Karat “The Blue Planet”
  34. Vaclav Neckar + Bacily “Time Machine”