Aux. Sound Input on RCA 245 Amp Sets

[RolandVV-360]

Recently, in the pursuit of the ability to listen to Radio Dismuke on a period machine, I stumbled across a peculiar method to non-invasively plug in other components into the set. This will work on any Victor Phono/Radio with the revered RCA 245 amp and Victor radio receiver (i.e. the Victor RE-45, RE-75, and RE-156). From what I have seen, most other folks have been completely disconnecting the dedicated receiver Jones plug cluster from the amp and plug in individual US wall plugs, inserting one for each function: sound input, ground, and most importantly, the power switch. Using this design, the power switch must must be wired into the Jones cluster manually since the receiver contains the power switch, which is wired in through the Jones cluster. I attempted at this method, and although it did work, it took time, effort, and a good amount of visual research on youtube, watching short, poorly recorded videos of people who had done this same thing. This put me on to making a simpler method for those who do not have the resources or time to complete such a task. I left all of the Jones clusters connected, and rather pulled out the phono jacks from the receiver. I used the speaker wire from my 7-30, which has the same thin pin plug as what is used on the 245 amp pairs. This was then plugged into the phono connection and wired into a connector, as not to splice my only 3.5mm aux cord, which was also wired MacGyver’d to the connector.

This design can be improved upon simply and solely by creating a more reliable connection between the 3.5mm cord and the phono jacks. This could possibly be done by soldering the ends of the phono jack wires to RCA jacks, making the connection more reliable. Or you could do away with the conversion entirely, and splice a 3.5mm with the slim phono jack cord.

I can only be sure that other folks have accomplished this before, but I felt the need to share the knowledge with the fellow collector, and also preserve it for the collectors and the curious after us.

[phonojim]

The victor R-32 is a radio only version which uses the same tuner and amp components as the RE-45. It has the (unused) phono input on the rear of the tuner chassis.

Jim

[RolandVV-360]

The victor R-32 is a radio only version which uses the same tuner and amp components as the RE-45. It has the (unused) phono input on the rear of the tuner chassis.

Jim

Did the R-32 tuner have the transfer switch as the phono models did? I would assume it would, for the purpose of plugging in one of the consumer RCA tabletops offered at the time.

[phonojim]

I can't say for sure, but I believe the 2 are the same electrically. IIRC, the R-32 and RE-45 both have the same schematic. I have not yet attempted to overhaul my R-32, so I really don't know about its operation. If you know of a source for a clean copy of the schematic, please post a link. The only ones I have seen are poor copies which are almost impossible to read.

Jim

[RolandVV-360]

I can't say for sure, but I believe the 2 are the same electrically. IIRC, the R-32 and RE-45 both have the same schematic. I have not yet attempted to overhaul my R-32, so I really don't know about its operation. If you know of a source for a clean copy of the schematic, please post a link. The only ones I have seen are poor copies which are almost impossible to read.

Jim

I've been using American Radio History's transfers of the 1929-1930 service manual for schematic research, as well as general electronics dissection. Scroll to page 564 on http://www.americanradiohistory.com/ARC ... 9-1930.pdf and you will find a legible schematic for the R-32. I've found that although the RE-75 was equipped with the 245 amp and Victor designed tuner, the design is slightly more complicated, with several differences mostly in the tuner. In the end, this doesn't matter, since the schematics used in the service manuals always referenced the simplest design of the given amplifier, as used on the R-32 and RE-45.

[phonojim]

Thank you for the link. This is the first time I have seen a readable schematic for this unit. My R-32 appears to have the radio/phono switch installed, although I have never had the set operating to know whether or not it is actually working, although I assume so, since the phono input is present on the back panel.

Jim