Could this be modified for use as mic preamp?

[Sweetfoot]

I scored this ceco 1019 video amplifier. Can anyone tell me if this could be modified to be used as a mic preamp? It looks like very early transistor tech, maybe 60s or even late 50s era, but seems to be made with high quality components. I can’t seem to find anything about it online.

 

[C.B. - Boudio]

Only the schematic will tell, I think.
But, first and foremost, video signals (usually) work with very high frequencies, which, I think, may also explain the uncommon wiring layout.

 

[Brian Roth]

From the pictures, I really doubt that unit would be useful for audio. It appears that unit was designed for composite video as used in Ye Olde analog video systems....NTSC in the USA. The EQ pots were intended to compensate for cable losses within a facility. Also, these devices were essentially unity gain with 75 Ohm input and output impedances.

Bri

 

[Sweetfoot]

Thank you all for the responses! Looks like I'll end up parting it out and building something new in the chassis. Maybe I can reuse the transformers and germanium transistors in another project

 

[Brian Roth]

Looking at the photos again.....that might use Nuvistor tubes. Not really useful for audio.

Also, one of those metal "transformers" might be a filter choke.

Bri

 

[k brown]

Looking at the photos again.....that might use Nuvistor tubes. Not really useful for audio.

Also, one of those metal "transformers" might be a filter choke.

Bri

As far as Nuvistors for audio - users of the Ampex MR-70 may beg to differ.

And this (FWIW); post #12: https://gearspace.com/board/high-end/13067-u47-vf14-versus-nuvistor-tube.html

 

[Brian Roth]

As far as Nuvistors for audio - users of the Ampex MR-70 may beg to differ.

Good point! The MR-70 was a "last hurrah" for pro tape recorders using vacuum tubes. Much of the design work was done by John (Jay) McKnight who went on to start Magnetic Reference Laboratories. MRL became the standard for alignment tapes, even to the current times.

Bri

 

[k brown]

Good point! The MR-70 was a "last hurrah" for pro tape recorders using vacuum tubes. Much of the design work was done by John (Jay) McKnight who went on to start Magnetic Reference Laboratories. MRL became the standard for alignment tapes, even to the current times.

Bri

Also, mechanically one of the finest tape machines ever made.

 

[Sweetfoot]

I'm not familiar with nuvistor tubes, which components look like nuvistor tubes to you?

 

[13engrsapper]

They look like chubby TO-5 transistors, usually with 5 pins. You will also find them in some microphones AKG c12a/b come to mind. There are several SDC nuvistor mics too... and a stomp box or two. They are cool little devices. They can withstand something like 1000 G's while running - not your typical vacuum tube. HI-FI guys use them too.

 

[Brian Roth]

What made me wonder about the possibility of nuvistors in the design were the many wiring leads exiting the power transformer and the 150 uF/150 Volt electrolytic. Shrug....just a guess on my part!

Bri

 

[C.B. - Boudio]

Aren't they incapsulated or something in those black round things?

 

[Brian Roth]

Aren't they incapsulated or something in those black round things?

Looking again, I think @13engrsapper may be correct. Oddball transistors like that are before my time; I noticed a 1961 date code on one of the lytics!

Bri

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