Curious about Holzer/Haeco history.

[Bo Hansen]

Since the 1960s, I have heard of Howard Holzer, Haeco/Holzer Audio Engineering Company. (Van Nuys, California ?)
The reason for this is that one of the old well-known recording studio here in Sweden called Metronome Studio, had equipment from Haeco, partly in the form of cutting equipment and also Holzer discrete op-amplifiers included in their old home-built mixing console along with Disa tube amplifiers.
This console was replaced and was scrapped in the early 1970s, when they installed a new Neve console.

Today it is difficult to obtain information about Holzer/Haeco, it is written almost nothing about this old business on the web, the only thing I can find is some info on a "CSG" compatible stereo generator, a stereo/mono signal process used for disc cutting, and a few short lines of text, in connection with an article about A&M Recording Studios.

I'm most curious about Holzer discrete op-amplifier, they are integrated in a module with a "male noval tube socket" as connector.
Read somewhere that John Stephen (Stephen tape recorders) made a similar op-amp that was pin-compatible.

The old home built Metronome console is gone long ago, and even the engineer who built it, so there is no information to find there.

Is there anyone here on this forum, who knows something about this op-amp, you might have an old brochure/datasheet or a schematic of the circuit in the module.
I am also interested in additional information regarding Howard Holzer and his company Haeco.

Btw,
As John Stephens op-amp is supposed to be like, is of course info on this also interesting.

Best from
Bo

 

[gridcurrent]

Howard Holzer was a maverick, a forward thinker.
In the 1960's, his focus was disk mastering and sold a number of his cutting systems to RCA Victor and Capitol Records.  The power amplifier was based on 6146's, screen supplies regulated, B+ approx. 750 VDC.  Like Westrex but unlike Neumann, there was provision to monitor the cutter's feedback coils.
Attached is a photo of the feedback amplifier.
The cutting amplifier had issues.  RCA commissioned their Princeton Labs division to analyze and recommend fixes for the record division.  Incidentally, one of the remedies was to replace certain 12AT7 voltage amplifier stages with 12AX7a,  noteworthy for those 12AXa haters.
Howard was one of the first, if not the first, to advocate the use of digital delay in place of a preview machine, circa 1976.
Haeco was also a distributor of Scully and Dolby; in the late 60's that combination was a essentially a license to print money.
It is my understanding that the Haeco and Stephens plug in amplifier modules were originally sourced from the same supplier.
Beno May of Grundman Mastering was employed by Howard, he is the definitive source.

 

[Bo Hansen]

Gridcurrent,

Many thanks, very interesting information, appreciate this very much.

I will try to find Mr. Beno May.

--Bo

 

[mjrippe]

Besides the CSG there is a phono preamp currently on ebay (http://r.ebay.com/ke2sH5) the seller may have some knowledge about Haeco as he is an old school engineer.

In addition, we have some Haeco EQs here at the studio.  They are basically Spectra Sonics 500 eqs with those damn plugin opamps which we do not have.  A couple have been modded into passive eqs.

 

[mutterd]

Yeah I have a copy of a Spectra Sonics 500 EQ that was made by Holzer.

Black PCB stock, I was told they came out of one of the A&M consoles...

I have 2 or 3 different fakes of the Spectra EQ's - none even close to the build quality of the original, but his is the least crappy of the bunch.

 

[Gold]

The Haeco cutter heads are still in use by many. Grundman uses them. They are Westrex guts in a Haeco case. The story I heard is that Otto Hepp who built some if not all the later Westrex cutter heads built them in the same lab off hours.

He made many boxes for disc cutting and I believe he made a primitive automation system for Sully lathes.

 

[gridcurrent]

.

 

[gridcurrent]

the SD-240 cutting system was allegedly based on a Crown DC-300.
interesting that groove depth was adjusted via intentional amplifier DC offset into the drive coils.