Cory's Phase Linear 2000 Ser I Unit #2

[laatsch55]

Joe, here is where we were deep into that one night, but it was all about replacing the LF-351 with the OP 134A.---http://forums.phxaudiotape.com/showthread.php/2839-Cory-s-Phase-Linear-300-Ser-II/page5
I was sure we ruminated on the 4136 too, just can't find it right now. On the 4739's are they as oddd as the 4136?

 

[laatsch55]

Swapped out Z3, the RC 4136 with a Brown Dog adapter with 2-Burr-Brown OPA134's. Managed to stretch the low frequency response a bit.

 

[Gepetto]

Joe, here is where we were deep into that one night, but it was all about replacing the LF-351 with the OP 134A.---http://forums.phxaudiotape.com/showthread.php/2839-Cory-s-Phase-Linear-300-Ser-II/page5
I was sure we ruminated on the 4136 too, just can't find it right now. On the 4739's are they as oddd as the 4136?

Hi Lee, the 4739 are decompensated versions of the classic 741 op amp. The 739 was one of the first volume op amps to hit the market and were considered wideband at the time because you could tailor the bandwidth with 3 or 4 external components. I used 739s as the tape head amp first and second stage on a NRZI and PE 9 track tape transport that I designed back in the very early 80s. They are very versatile devices but no where near what op amps are today.


The 4136 was the first quad 741 based op amp to appear on the market. Raytheon did not get the pinout right and this 4136 op amp eventually died out and was replaced by other quad op amps that got the pinout right.

 

[laatsch55]

You designed a tape transport?????

 

[laatsch55]

A sutable sub for the 4739??

 

[laatsch55]

Cory, the 2000 is going out in the morning. I'm shipping it with the Brown Dog/ Burr Brown combo in place of the RC 4136. It polished up beautifully. All in all a great looking piece of gear.

 

[BigSkyCory]

Ok. What about the 4739?

 

[laatsch55]

There are sockets on the board now Cory. If a suitable sub is recommended I'll try em in my 2000 SerI and Ser II's and then send ya some.

 

[laatsch55]

Cory, tracking number Fed-Ex--962223115001637

 

[Gepetto]

You designed a tape transport?????

That is what I did throughout the 80s and into the early 90s...

 

[Gepetto]

Ok. What about the 4739?

The 4739 is a unique beast, would have to look at it carefully to see if there is a likely sub or not.

 

[laatsch55]

Was your tape transport any good?? I'm assuming it was a data type setup, not zaudio.....

 

[Gepetto]

Was your tape transport any good?? I'm assuming it was a data type setup, not zaudio.....

We thought so Lee. Yes it was high density digital data recording, (7 and) 9 track high-speed, reel to reel, 1/2" start stop tape transports.

We sold to most of the OEM computer manufacturers of the time. The latter products were all serpentine high track density 1/4" data cartridge type transports.

 

[jbeckva]

We thought so Lee. Yes it was high density digital data recording, (7 and) 9 track high-speed, reel to reel, 1/2" start stop tape transports.

We sold to most of the OEM computer manufacturers of the time. The latter products were all serpentine high track density 1/4" data cartridge type transports.

Wow... Too bad you weren't here a little sooner! Larry really wanted to see about what it would take to make a circa 2010 tape deck, with tubes (of course). I was thinking how cool it may look... not a typical four-corners box, but instead something like Larry's Cary's.. where the transport would be centered, but enclosed just enough to cover the transport itself, and on top of a heavy "base" with tubes flanking either side of it. Hmmm, indeed!

 

[laatsch55]

Was controlling tape tension a hairpuller??

 

[Gepetto]

Was controlling tape tension a hairpuller??

Was vacuum column on the higher speed (125ips) and tension arm on the lower speed (75ips and lower). We had the only 75ips tension arm tape transport on the market. That one was a tricky servo to do.

 

[laatsch55]

Were there mechanical aspects to the tensioner that weren't consistent??

 

[laatsch55]

So you are no stranger to flux and bias...

 

[Gepetto]

Were there mechanical aspects to the tensioner that weren't consistent??

Not sure I follow what you mean Lee?

 

[laatsch55]

In the manufacture of the tensioners, were they consistent in their operation??