Categories
Early Electronic Music Magnecord Recordings

Magnecord PT6 c.1950 used in contemporary music production

It never ceases to amaze me how many people navigate to this website as a result of searching for Magnecord tape-machine information.  Until I bought a pair of PT6 machines last year, I had no awareness of them; since then, I am continually discovering more and more evidence of the role that Magnecord played in mid-twentieth century broadcasting and recording in the United States.  Moreover, my two machines (previously owned by the University of Connecticut; purchased by me last year for $25/each) now work great after I performed some restoration work.  This is no mean feat for sixty-year-old tape recorders which were subjected to the harsh treatment of student-recordists for untold decades.  Anyhow, you can hear some early test-recordings that I made with the PT6 shortly after I restored them:  listen here and here.    Since I recorded that version of “Hallelujah,”  my two PT6’s  have been parked in the entryway of our studio Gold Coast Recorders.    Clients often inquire about them, surprised to learn that they are in fact functional; but it was not until last week that they actually got used on a session.   Take a listen to the track below and you can hear some of the wonderful music of Keith Restaurant.  Keith’s been a frequent visitor to Gold Coast since we opened our doors in April and he makes music that you might call minimalist, or noise music, or process music;  it’s inherently impossible to categorize.  With this sort of ‘organized sound,’ every listener needs to find his/her own way in.  The following piece is from a set he recorded called ‘computer music.’  You are hearing a single live take of several performers manipulating the harddrives and power supplies of live laptop computers, amplified with induction mics and guitar amplifiers.  The Magnecord PT6 is the primary recording medium, and several generations of re-amping and re-tracking (via our UREI 809 studio playback monitors) in the big live room at Gold Coast were layered to create the overall piece.

LISTEN: KR_CmptrMx_Track2.mp3

Since the sounds that composer Keith Restaurant organize in this music have essentially no reference point (I.E., none of them are sounds that you or I would have heard before), every element of the production process is incredibly important in creating meaning.  In this way, the Magnecord PT6, with it’s peculiar frequency response, distortions, and flutter, is being used in a very significant way; it is a primary component of the sound, rather than an ‘effect.’  This contribution is intensified by the multiple-generations of recording and re-recording via the PT6.  It is also interesting to note than even in the longer (4:00) piece, the PT6 deviated less than 250ms over 4:00 relative to the Pro Tools safety copy.  This is great news for anyone who wants to fold one of these into their working process.

You can learn more about Keith Restaurant at his blog.

 

Categories
Uncategorized

Interesting Audio-Technology Mini-Exhibit in Philadelphia

Walking around Philadelphia I noticed this shop-window.  Wow these people really had my number.   The shop is called Art In The Age Of Mechanical Reproduction (h.f. AITAOMR), which is a reference to a seminal essay by Walter Benjamin.  Benjamin was interested in understanding how our concept of value in art was altered by the new processes of mechanical reproduction (offset printing, phonograph records, etc) which became widely available in the early 20th century.  ANYways… AITAOMR is a fine shop with appealling apparel and lifestyle items offered for sale.   They also market their own line of rustic flavored boozes you can sample in the shop  (sold elsewhere at licensed agents).

Turns out that the shop-window display is part of an in-store exhibit of audio-technology that was put together by record producer/engineer Bill Moriarty, who has worked with popular artists like Man Man and Dr. Dog.    It’s a fun tactile display that foregrounds some of the crucial basic processes we use in audio work: editing, mixing, reverberation, ‘effects processing,’ etc.

The exhibit is up for a few more days; you can read more about it in Moriarty’s own words at his blog.

 

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Uncategorized

Exclusive Bonus Content (2) (aka: found in an old guitar case)

Teenage Pain

Is So Real

I purchased a chromed-the-fukk-out sixties no-name hollowbody for a few bucks at the flea mkt last weekend.  Nothing special, but marker’d inside the case was this piece of folk art.  Too bad it didn’t have a four-track demo of this kid’s music in there too.

Kinda reminds of the best haiku I ever heard:   “Fifteen.” Credit for this one goes to K.M.:

sitting in my room

metallica really rules

I am so angry

See here for more ‘exclusive bonus content.’

UPDATE:

SEE HERE for a film-version of ‘found in an old guitar case’

 

Categories
Custom Fabrication Technical

The Old ’76

My latest microphone preamp design is completed and sounding very cool… The Old ’76.

The Old ’76 is a novel three-stage design; it’s not based on any past or current production microphone preamp.  That being said, the circuit is nothing revolutionary: an input transformer (in this case a UTC O-1, as I was temporarily out of Jensen 115s) connects to an RCA 76 tube, biased in textbook (or, at least, RCA-Receiving-Tube-Manual-book) fashion; volume pot follows and then on to a 6SL7 tube with the first stage plate directly coupled to the grid of triode 2; the output is a cathode follower with a Solen cap and onto an Edcor output transformer.   The pushbutton switch (with associated pilot lamp) activates 48V phantom power.  Overall gain is approx. 60db and response is flat 50hz – 18khz.  I am betting that the slight high and low end roll off is due to the UTC O-1; the next build will use my customary Jensen input transformer and we should see 25hz-20khz flat response.

76 tubes were often used in ancient console radios with a large tubular shield positioned around them; the reason for this became quiet clear once I had finished my piece; before I added the above-depicted aluminum plate between the 76 and 6SL7, I was getting some unpleasant ringing on very high frequencies.

I had wanted to build a mic pre with some of these very old two-digit designation tubes for some time now.  Hi-Fi fans seem to love the 76 tube, so I figured there was probably something worth investigating.  76 tubes are readily available and pretty inexpensive; it is a bit of a challenge to find the 5-pin bases that they require though.  AES sells only one 5-pin base, and it’s expensive and oversized.  My prototype unit here used an older Amphenol socket that I dug up somewhere.

Some other miscellaneous design notes: B+ rectifier is a 6×5 tube; hammond 15mh choke was used in the B+ chain; DC filaments, as usual; the phantom power supply has a slow ramp-up when activated; the three-pole phantom switch 1)connects the 48v supply to the main power supply; 2)connects the phantom indicator lamp to the 6v supply; and 3) connects the 48v to 6.8k resistors that actually connect to the mic input jack.  I find a three-pole switch necessary in these instances because there is some ‘drain’ time involved when phantom is turned off, even with a bleeder resistor; disconnecting the 48v right before it hits the mic jack provides 100% assurance that you (I) won’t melt that BK5 ribbon (again).

An A/B test of The Old ’76 vs. the usual API 512 will be posted here in the next month or so.

 

Categories
Microphones

The Mics of ’42

Download a four-page catalog scan of the microphones of offer from Allied Radio in 1942:

DOWNLOAD: Mics_Of_1942

Models covered, with photos, text, and some specs, include: Astatic T-3, JT-30TT, GT-3, N-30, and DN mics; Shure 708-A, 750-B, 730A Uniplex, 55c, 55a, and 555 Unidyne, Shure 7A, 705A, and 70H Crystal microphones; Electrovoice 630, 640, and Cardax dynamics, and V-2, V-1 ribbon mics; Amperite PGL Dynamic and RBHK and RBMK ribbon mics; RCA MI-6205 Aerocrystal Microphone; Bruno WS, SS, and HS high-impedance ribbon mics; plus more.

Bruno Microphones Circa 1942

Astatic Crystal Microphones Circa 1942

Electrovoice and Universal Crystal Microphones of 1942.   The most primitive of microphones.  I recently got the chance to use my ancient Lifetime Model Six Carbon mic on a contemporary vocal session.  It actually worked out great.  This is ATLANTIC CITY, my studio project with T.W.  LISTEN: Ten Past Midnight

Electrovoice and Amperite Ribbon Mics c. 1942

Shure Cardiod Mics c. 1942

Categories
Antique Hi-Fi Archive

Mystery Amp Circa 1955: Mystery Solved. Anyone have a schematic?

*UPDATE NOV 2016:  please read thru the comments section!  In all likelihood, this is in fact an original Mirko Paneyko piece, which means I am a huge A-hole for selling this thing for $180 on eBay in 2012. I only learned about MP in 2016 via a huge collection of old journals I purchased.  He was a titan in the audio field, and certainly one of the most interesting historical figures in the Bridgeport area in the mid 20th century.  Read his NYT obit here. – ED

  I picked up a big pile of old audio equipment this past weekend; notable items included a Shure Level Loc, a massive Bogen tube pa head, a kit-built Acrosound ultralinear 5881 amp, and a Gibson acoustic gtr case from the early ’60s (no gtr).  Also included was the mono amplifier shown above.  It’s a push-pull amp, cathode biased 807s, with 6SN7 driver and phase inverter; there is also a 2x 12A_7 preamp section with this ‘remote’ control section attached via 10′ of cabling…

After a little cleaning, the amp actually works fine if I remove the ‘remote’ and input directly into the final 12AX7 stage prior to the phase inverter.  As far as actually using the remote, well, I can’t quite figure out what sort of patching needs to be inserted with the two RCA jacks and one RCA male plug coming out of the face of this thing.  It’s a little bewildering.  If anyone can tell me who made this amplifier, I imagine I could find the schematics somewhere.  There are no markings on the unit anywhere besides an inked serial number inside the chassis and the letters ‘MP’ on the remote.  I am sure that this is a factory-wired unit, as there is tamper-paint on every solder joint.  BTW, I added the on-off-switch and the IEC socket on the side, so don’t let those two details derail your ID’ing efforts.  I am guessing that this a circa 1955 unit as the 12AX7 was only introduced in 1953, and the 807 craze was in the process of winding down by ’55…  so we’re likely looking at a unit made between 1953 and 1958.  Any ideas, please let me know.  This thing is 95% of the way to full operation and I’d like to get it running strong again.  It’s a tremendous looking piece, and it has a lot of volume.

*************

*******

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Updated: the mystery has been solved.  This amplifier was built by the Saulnier Music Service of Columbus, Ohio; so sez the son of the man responsible.   Read the comments section for the full story.  I am still in a need of a schematic (or even just a manual?) for this thing so that I can figure out what do do with the assorted preamp jacks n’plugs.  According to our poster, this circuit came from a transformer manual; which would likely mean a Stancor audio-manual circa 1954.  Anyone?

Categories
Uncategorized

(Updated: Link To) Live Radio Show: The Ladies of Psychedelic Folk: 11/14/11: 89.5 WPKN:

Monday November 14 2011: Tune in tonight to WPKN 89.5 on yr FM dial in Southern Connecticut/Northern Long Island: or listen live in high-quality at www.wpkn.org.  I will be appearing as a guest on Steve di Costanzo’s excellent program ‘Radio Base Camp’ presenting a show I’ve put together on the Ladies of Psych-Folk.   We’ll be listening to some classic and lesser-known gems from the late 60s, as well as more recent artists who have drawn inspiration from that era.  Steve had me on air back in June; you can check out that show here. Hope you enjoy the show.

UPDATE: Steve has added the show to the WPKN archives.  You can stream it until (insert personal favorite apocalyptic event) at this link.

Categories
Uncategorized

Open Studio Event 2011

This coming weekend: November 12+13 2011: we will be having another Open Studio event at our arts building in historic Bridgeport CT.  Forty artists and fine craftmakers will open their studios and exhibit their work and their work-practices in our century-old lace factory, and this is only one part of a larger Bridgeport Arts Trail going on that weekend (read some media coverage of the event here).   Believe-it-or-not, our dusty lil post-industrial town features not one but three very large art-space buildings, and there is some fantastic work to see (and hear…).  After you’ve come by to listen to some of my Recycled Champs, the Model 22277 hi-fi amplifier, and my latest development in all-tube mic preamps (w/ ancient RCA 76 tubes), be sure to check out the work (and amazing studio) of the photographer Tom Mezzanotte, world-renowned quilter and textile artist Denyse Schmidt, and all the odd characters that have assembled in this strange+semi abandoned place that we call BPT.  If you’re lucky, you might even get to commission some print-on-demand work from my wonderful wife E., who will have numerous print-publications of her work for sale.  Details and directions below.

Categories
Custom Fabrication Uncategorized

A couple of recent guitar amplifier builds *Revised (2)*

Cassius #10; aka #10 in the the ongoing series of Fender Champ-derived guitar amps built into recycled ‘found’ vintage speaker enclosures.  See here and here for some of the earlier examples. #10 is already sold, but will be avail for examination at the upcoming Open Studios event at our building this coming weekend.  Cassius #10 is my first ‘Cassius’ with an EL84 output tube: it’s basically the front end of a tweed fender champ married to the power stage of a Vox AC4.  Add a nice full-range 8″ Alnico HiFi driver and holy shit does this thing sound great.  Solid-state rectifier, no choke, extra filtering stage in the power supply.  Output transformer is from a 1950s R GE HiFi console; all other parts are new.

Of all the pieces that I have posted on this website this the past year, the one that gets the most page-views is still my scan of the 1970 ORANGE amplifiers catalog.  I’m much more of a large-combo-amp guy then a stack-guy so i’ve never owned an actual vintage Orange amp head.  That couldn’t stop me from building one though.

Above, my version of an Orange Graphic 80.  Two EL34 output tubes, two 12AX7 preamp tubes, effects loop, variable low-cut filter, adjustable ‘fixed’ bias.  Unlike an actual Orange Graphic 80, I used a high-voltage mains transformer and a 5U4 tube rectifier (Orange originally used a voltage doubler and a diode bridge).  I also used a slightly different supply for the grid bias voltage as my Hammond power transformer did not have a bias winding.  For the output and choke transformers I used pulls from a beat 1950s RCA PA head; it was rated at 30 watts (7027 tubes) so we’ll see how long this output transformer lasts….

The most unique feature of the Orange amps is the bit labeled ‘filter’ here; Orange called it the ‘F.A.C’ control; it’s simply a 6-position high-pass filter that follows the coupling cap before the phase inverter.  It’s composed of a 6-position rotary switch with 5 carefully-chosen caps strung in series between the taps.   Simple as it is, it does make for a much more versatile amplifier.  I recently built this circuit into one of my Cassius amps (already sold) it worked great there too.

Above, the preamp wiring. 

Want to know more about building your own Orange Graphic from scratch? Follow the link below to READ ON…

Continue reading “A couple of recent guitar amplifier builds *Revised (2)*”

Categories
Altec Microphones

Studio test of obscure circa 1965 Altec dynamic microphones

L to R: Shure SM57; Altec 684 Omni; Altec 682 Cardiod; Altec 683 Cardiod

Altec made a great number of different microphone models in the 1950s and 1960s.  A certain few of these are still widely used in recording studios today: most notably the 639 ‘Birdcage’ dual-element microphone (see here and here) and their various small diaphragm ‘Laboratory’ condensers (see here, here, and here).

During this period Altec also made a variety of conventional-looking dynamic microphones, some of which have quite good specs on paper.  Today we’ll be having a listen to the Altec 682, 683, and 684.

I’ve prepared three stereo audio tracks which all document an identical solo guitar performance which we tracked in the big room at Gold Coast Recorders.   In each of the three tracks, you will hear a new-ish Shure SM57 in the left speaker, and the selected Altec mic in the right speaker.  I chose an SM57 as a reference because it is a microphone that most of us are very familiar with and it is often used to mic electric guitar amps.  I placed the mics a big further back than I would generally use a dynamic-mic on a guitar amp in order to minimize any differences that might result from the slight variation in mic placement in relation to the amplifier.  All signals were taken from the microphone into identical Sytek mic preamps and then directly into Aurora Lynx convertors and into Protools.  No processing whatsoever was used other than minimal Digidesign MAXIM on the bounce-buss to ensure strong playback level; it was taking off 0.3db at most.

Levels were matched initially by running a 1K tone into the guitar amplifier and then fine-tuned on playback to within the tightest possible margin.  The 684 Omni required 30% more gain to reach an equal level; the other three mics were within 5% or so of each other in terms of output.

Alright now that you’ve seen the setup, here is the audio:

SM57 vs Altec 682: SM57L_682R

SM57 vs Altec 683: SM57L_683R

SM57 vs Altec 684: SM57L_684R

Have a listen and draw your own conclusions.  My quick assessment: the 682 sounds pretty similar to the 57, but IMO a lot prettier, a lot more detailed, and just more presentable in general.  The 683 sounds thinner than the 57; bass is notably lacking and there is an aggressive character to the mids.   Not sure that I would ever select this mic for anything.  The 684 sounds like… an omni mic, so it’s not a valid comparison to a 57, but it does sound pretty decent as an omni.  Might make a good under-snare microphone.

All of these forgotten Altecs are available cheaply on eBay from time to time.  I’ve never come across one at a flea market or swap meet, though, so I don’t think they are very common.  From what I can tell from my limited sample-pool, the ‘A’ designation after the model-number indicates that the mic uses an XLR5 (rather than the current standard XLR3) connector.  If you get one of these ‘A’ designated mics, you will need to find an XLR 5 female jack.  Wire an adapter to XLR 3 as follows: (XLR5:XLR3) 1:1, 2:3, 4:2.   The ‘B’ designated mics seem to have our current-standard XLR3 jacks.  Again, I am not 100% about this distinction, so check closely before buying if you don’t wanna be soldering adapters.