Categories
Technical

Simple Tube Program EQ project

From the September 1947 issue of RADIOCRAFT magazine: an interesting ‘response equalizer’ project that looks to have great potential for use in the recording studio.  Download the complete article with schematics:

DOWNLOAD: ResponseEQ1947

You will need to download and read the article for complete details, but essentially this circuit provides the following functionality, with 7 controls:  4-position high-pass.; variable low-end boost with 4 selectable frequencies; 4-position low pass; variable high-end boost with 4 selectable frequencies; 10db overall gain with variable output trim.  And it does all of this with no inductors or transformers, and just one very cheap 6SJ7 tube.

To use this circuit in a complete studio-ready device, we will need to add several things:  First, an output stage capable of easily driving a 15k:600 output transformer.  I am going to try the very simple output circuit show above, taken from tubecad.com.

A 250-300v DC power supply (plus 6.3v filament power) will also be necessary; plus input and output transformers.  Once I get this all together, I will also need to figure out a good, silent bypass-switching arrangement.   Should be a good inexpensive tube eq project.   The overall application is very similar to the Pultec EQP-1A; this unit will not have as precise control due to the lack of inductors; but it will cost a heck of a lot less (likely $250 of parts verses $800 to build a Pultec).  Plus it allows one to boost and cut at different frequencies, which the Pultec does not offer.  Expect some build-notes, images, and audio examples here soon.

Categories
Early Electronic Music

Music Synthesizers in Popular Electronics 1972

Download a five-page article by David L. Heiserman on “Music Synthesizers And How They Work” from Popular Electronics magazine, February 1972.  Also included is a brief description and schematic for a ‘surf synthesizer’ project.

DOWNLOAD: SynthsPopElecFeb1972

Nice images of the Putney Synth and a Moog IIIc.  This article offers a very broad treatment of the subject, and it does not discuss music or music aesthetics very much; it is interesting though because it is intended for an audience with some technical savvy.  Everything in this piece can easily be applied to gaining a greater fluency with the software synths that we use today.

Naturally, any discussion of ‘music-synthesizers’ in Popular Electronics had to be followed by some sort of audio-synthesizer project; since this is 1972, the project is a Surf Synthesizer, aka a white-noise generator followed by a randomly-modulated low pass filter in sync with a VCA.  If you know what any of that means, you might could be interested in the schematic, which you can find after the link below.  I can imagine sitting at the kitchen table during the Nixon administration, carefully soldering this mood-enhancer while my wife macrames an Owl.

Continue reading “Music Synthesizers in Popular Electronics 1972”
Categories
Microphones Pro Audio Archive

Sennheiser 421 and 441 Dynamic Studio Microphones

Download three circa 1980 Sennheiser product-sheets for the MD-421-U and MD-441 microphones:

DOWNLOAD 421-U (color 4-panel): Sennheiser421_Color

DOWNLOAD 421-U (monochrome 2-panel):SennhesierMD421U

DOWNLOAD 441: SennheiserMD441

If you have spend much time in recording studios, you are probably familiar with these great microphones.  When we were kids first learning about recording, the 421 was the one ‘good’ mic that we had; we didn’t know exactly why it sounded so very much better than the assorted Shure, EV, and Realistic public-address mics that we had, but the difference was shocking.   A little while later I discovered the 441, which I find to be a less-exciting sound but still incredibly useful, especially when you want a really tight pattern and good fidelity (esp. under the snare).   Also good on the rack toms to reject snare and hat.   Stan Coutant’s excellent Microphone Data website has a download link for more current spec sheets on these models; I thought it might be useful to offer some earlier material here.

Categories
Connecticut Audio History Microphones Pro Audio Archive

AKG Acoustics Full-Line Catalog c. 1981 – Microphones Reverbs Headphones

Download the thirty-two (32) page 1981 AKG Acoustics catalog (9.8mb file):

DOWNLOAD: AKG_Acoustics_FullLine_Catalog_1981

Models covered, in text and photo (no specs), include: AKG C-422 stereo condenser microphone; C-33 and C-34 stereo mics; C-414EB. C-414E1 and C-414EM/p48 condensers plus S-421E1 control unit; C-450 System; C-535EN, C-567E, C-568EB condensers, D-300 series live sound mics; D-224E and associated dual-diaphragm mics; plus the proverbial ‘shit-ton’ more. AKG BX-20, BX-10, and BX-5 reverbs are included, plus a wide range of headphones including the K-40, K-41, K-141, K-240, and K-340 dual-system.

AKG USA was once-upon-a-time located right down the road from here in nearby Stamford, CT.  I think this is probably one reason that I have come across so many unusual AKG mics, headphones, and related literature at the flea markets and estate sales of Southern CT.   The AKG 414 microphone, in all of its variations, is a staple of the audio world and a staple of this website; longtime readers will recognize this as my ‘reference mic’ for audio examples.  It’s  not the most exciting sound but it’s a high-quality sound that many of you know and therefore I feel that (along with the SM-57) it makes a good benchmark.  ANYhow…  check out the crazy art-direction of the this catalog.

In addition to the awesome haute-’70s monochromatic earthtone backdrops (see examples in photos above), we have various ‘symbolic objects’ to characterize the products; King Tut represents the gold of the diaphragms;

…a crystal vase represent ‘clarity’ of the electret-condenser line;

…a ‘flower-in-vase’ perhaps suggests the ‘capture-of-nature’ promised by the dual-system electrostatic/dynamic K-340 headphone?  Dig in and enjoy.

Categories
Microphones Pro Audio Archive

Primo Microphones Circa 1980

Download the entire 12-page Primo Microphone Catalog Circa 1980:

DOWNLOAD: PrimoMicrophoneCatalog

Models covered, with specs and photos, include: Primo CMU-503 and P-77, P-88 ‘professional’ studio microphones;  UD-876M and UD-959 Live Sound mics; and a huge range of general-purpose stage mics including: Primo UD-905, UD-876, UD-866B, UD-871B; Electret Condenser models EMU-4520, EMU-4516, EMU-522, EM-518, EMU-4517; plus many more mics and accessories.

From what little information I can gather, these mics seems to have been made in Japan and then sold in the US by ‘primo,’ which also made telecommunications mics and/or mic elements.  I have never come across one of the these units.  Anyone?

Best half-tone cover image ever, btw.

Categories
Mixtapes Recordings

Winter 2011 Mixtape

It’s time for another compilation culled from the endless crate-digging.  This season’s harvest seems to have slant towards country-rock and psych-folk.  If you see me, ask me for a copy.

1. “Ohio River, She’s So Deep And Wide” by Winifred Smith.  From ‘Folk Songs Of The South’ by Winifred Smith.  RCA Victor #61100

2. “It Ain’t Easy” by Ron Davies.  From “Friends” A&M SP 8021

3. “Broken Hearted Blues” by T-Rex.  From “Tanx” Reprise 0598

4. “Dear Mary” by The Steve Miller Band. From ‘Sailor’ /Capitol ST 2984

5. ”Jamie” by Hedge & Donna.  From ‘The New Spirit Of Capitol’ Capitol #SNP-6

6. “Hope” by Mason Proffit.  From “Last Night I Had The Strangest Dream” Ampex A-10138

7. “Reflections” by The Chambers Brothers. From ‘New Generation’ Columbia C 30032

8. “Bad Night at the Whiskey” by The Byrds.  From ‘Dr Byrds and Mr Hyde’ Columbia CS 9755

9. “Innervenus Eyes” by The Bob Seger System.  From ‘The New Spirit Of Capitol’ Capitol #SNP-6

10. “In Your Life” by Tower.  From ‘Collecting Peppermint Clouds’ Technicolor Dream Records T.D.R. 002 (Originally a Decca b-side)

11. “Baal” by Exuma.  From “Exuma II (Air)” Mercury SR 61314

12. “The Joys Of Life” by Karen Beth.  From “The Joys of Life” Decca DL 75148

13. “Atlantis” by Donovan.  From ‘Barabajagal’ Epic BN 26481

14. “Take My Home Country Roads” by Olivia Newton-John.  From ‘Heavy Hits’, Adam VIII LTD # A-8010

15. “I’m Losing You” by Dwight Twilley.  From “Sincerely” Shelter SRL-52001

16. “My Love” by Paul McCartney.  From the 7” single Apple #1861

17. “August Day” by Hall & Oates.  B-side to “I don’t want to lose you” RCA PB-11424

18. “I Go Crazy” by Paul Davis. From the 7” single Bang # B-733

19. “Only With You” by The Beach Boys. From ‘Holland’ /  Captiol MS 2118

Follow the link for more information…

Continue reading “Winter 2011 Mixtape”
Categories
Connecticut Audio History Recordings

Bridgeport CT Punk Rock 1985 : : : update : : :

Came across this 1985  7″ at a yard sale this past summer.  The band is called ‘Rude Awakening’ and the A-side is “Teenage Suicide.”  The label tells us that it was recorded at Downstairs Studio, Bridgeport CT.  Label is Incas Records, whom I believe I had some contact with some years ago when I was scouting for some re-issue material for Anthology Recordings.   ‘Teenage Suicide’ is sort-of punk-opera with lots of different sections, changes, etc.  My pick is the B-side “Wanted” which has a classic Johnny Thunders vibe.  Check it out:

LISTEN: Wanted

Update: Tom Boudreau, writer of ‘Wanted’ and guitar-player for ‘Rude Awakening’ got in touch with PS.com.  Here’s a few words from Tom about the band and the studio:

“(re: the) Rude Awakening 45. That was a few lifetimes  ago. Roughly 25yrs later i can report that we sadly lost my brother / drummer in 05 due to complicated health issues / diabetes. I am still in contact with Joe Stoner (vocals).  Sean (bass) is still local and we have crossed paths over the years.  Joe wrote the A side and i wrote the B side of that record.  All 4 of us built the music. I do not have any contact with Sam Eckhardt who owned and opperated Downstairs Studio. This was an 8 track Tascam board, 388 1/2″ reel, 2 room facility in the basement of Davidsons Fabric in Downtown Bridgeport. A lot of bands recorded there in the mid-80’s. Currently i have a small project studio in my home.  I still have contact with Incas (Records). I have done some tape to cd transfer for them including ‘Ct Fun’ which was a compilation done with many bands from the times including Rude…

Tom Boudreau
www.boneheadstudio.com”

Thanks for getting in touch Tom!  The Davidsons building, btw, is still present in Downtown Bridgeport.  It’s just one of another abandoned buildings in the largely derelict downtown of this once-great city.  The huge painted ‘Davidsons’ signage is clearly visible to all who approach the bus/train station from the North.  I’ve asked Tom for some pics of  ‘Downstairs Studio’; if any arrive I will post them here.   BTW, nice to get a solid, concrete examples of one of the hundreds of busy, active Tascam-based project studios of the early 1980s.  See this previous post for more on the Tascam revolution.

Categories
Early Electronic Music History Publications

Out-Of-Print-Book Report: History Of Music Machines (Smithsonian)

Came across this obscure volume in a rubbish bin several years ago.  Published by Drake Publishers in 1975 and billed as being ‘Prepared By The Smithsonian’ (No author attributed), “(The)History Of Music Machines” (hf. ‘HOMM’) is a b&w hardcover gift/coffee-table book which presents a fairly interesting survey of the history of reproduced sound.  Several copies are available for just a few bucks at amazon. 139pp.

From the introduction (by writer Irving Kolodin):

“Over the years, the debates have continued about the pros and cons of music machines, the impact of their existence on the habit patterns of society,…. their influence for good and evil on taste…  As for taste, it has been driven to the wall, and all but through it, by exploitation of the music machines’ potential for serving the lowest common denominator.  Whether in records, or in radio’s reliance on the Top Forty -those loudest, hardest, often cheapest appeals to the beetle-browed-  selectivity has since foundered on the rock of commercialism.”

Jesus Irving.  Don’t mince words buddy.  Tell us how you really feel.  Note how he allusively slips ‘Be(e/a)tle’ and ‘Rock’ in there.  Nice one.  ANYhow. Reactionary sentiments asides, HOMM is basically a chronological series of photos with explanatory captions.  I find it interesting because it does not attempt to parse recording devices, electric instuments, synthesizers, amplification equipment, choosing instead to include all of these very different (in my mind, at least) type of equipment into the totality of ‘music machines.’  This suggests the view point that music is either made ‘by man alone’ or somehow made ‘by machine.’  It’s an interesting idea.  A very outmoded binary opposition, certainly.  Here are some highlights.

The multiphone, a wax-cylinder jukebox from 1905.

The Stroh Violin.  DS mentioned  last week that he had seen a band in NYC recently that performs exclusively 1900-1930 music on all period instruments.  ‘One of those Violins with the victrola horn’ is apparently employed.  Now we know that this is called a Stroh Violin.

The much-loved Magnecord PT6 gets some praise.

HOMM ends with some (even then very-dated) images of Electronic Music Studios. Above we have the Columbia-Princeton Studio circa 1959 (see my previous post) and below some rare images of the circa ’65 studios at the Catholic University of America.

(footnote: a nod to EKL, originator of the ‘out-of-print-book-report’ in her PARFAIT series)

Categories
Connecticut Audio History

LOFT recording consoles circa mid 1970’s: UPDATE

Pictured above is the very first recording/mixing console made by LOFT (Loft Modular Devices, Inc.).  It is a model 440.  LOFT was a manufacturer of Pro Audio equipment in Manchester Connecticut active in the 1970s.  In 1980 LOFT became Phoenix Audio.

Here’s a close up shot of a Loft model 440 console.  From the first picture, the Tascam 80-8 mounted in the desk to the right tells us that these were boards aimed at the professional project studio/demo studio market.

Another close-up image of a 440, this time a series 2.  These images, and all that follow in this post, come courtesy of LOFT founder Peter Nimirowski.  Peter got in touch with PS after we ran this earlier post which mentioned some of the LOFT outboard gear.  Peter has this to say about LOFT’s consoles:

“Loft … made two series of mixing desks.  The 440 Series  used a Microtran Transformer in the mic pre-amp. This console was probably one of the first low cost professional desks. My understanding is one is in use in CT another in Calif.    (Regarding) the 800 Series: we only made a handful of these boards. This was at the crossover point from Loft Modular Devices to Phoenix Audio.  (We) tried to make the leap into the pro studios. The first console used Allison’s Trans-Amp in the pre-amp circuit. Consoles after that used our own transformerless pre-amp design.  John Roberts was responsible for all Loft and later Phoenix Audio circuit designs. A truly brilliant designer. The consoles were manufactured mid to late 70’s. By 1980 LMD had become Phoenix Audio which did not manufacturer any consoles. When I together with Richard Federman started LMD it was a result of wanting to build a recording studio, not a manufacturing company. At that time except for API, Quad 8 and Maybe Neve, there really wasn’t much of a choice in affordable mixing desks. As far as technology, the first IC op-amp the 709 had just been developed. PC boards where just coming into existence. LMD manufactured all PCB in house. I designed and built the etching system. Everything was done in house.

Thanks for getting in touch Peter.  Here are some images of the later 800 series console, again from Peter’s archive.

Categories
Technical

Gately EM-7 Mixer and EQ-7 4-channel Equalizer Unit

In a previous post, I included the scan at left from a 1969 issue of the AES journal.  It’s an ad for the Gately Electronics EM-7 4×2 mixer and EM-7 4-channel equalizer.  At the time I had hoped to find one of these little setups, and sure enough,  one of the EM-7 mixers came along on eBay.  I checked the sellers ‘completed listings’ and saw that he had sold the companion EQ-7 equalizer unit earlier.  I contacted that buyer through eBay, indicating that I was interested in the EQ-7 should he decide to part with it.  Sure enough, he did.  So I was able to get an EQ7 as well.

All in all it turned out to be a great deal.  It was a bit of a pain in the ass to get these things working, but at the end of the day I ended up with 4 fully discrete mic preamps with discrete EQs, all running on 48v, and all with UTC input and output transformers.

This post will get a bit technical, so follow the link below to read on…  CLICK TO CONTINUE….

Continue reading “Gately EM-7 Mixer and EQ-7 4-channel Equalizer Unit”