Royal Vocal Amp 90 Mystery

[AndreH]

I picked up this Royal Vocal Amp 90 with a 2 x 12 Elk cab for the absolute bargain of $240 on Facebook Marketplace.

I've been unable to find any information on this amp online.

There is quite a bit of hum as well as crackling on some of the inputs, so I'll probably re-cap the filter and coupling capacitors.

The output stage is a classic EL34 push-pull.

The input stage is something I haven't seen before.

There are 6 12AX7's, one for each channel as well as a phase inverter feeding the power stage.

I can see someone has been in here before and made a mess of the spring reverb wiring amongst other things.
What's new to me, is the addition of an AC126 Germanium PNP Transistor for each input channel, first time I've seen them in the wild, had to Google the specs.

Has anyone come across one of these amps? 

Any information, schematics, clues would be greatly appreciated.

[RoadShow]

I did a quick search, and while the "90" was a dead end, I did find these for "Royal Vocal Amp".   Perhaps if you double back on these you can find better leads.

https://www.youtube.com/watch?v=MtHIYxh4law
https://reverb.com/item/86622040-royal-vocal-amp-60-packed-with-tubes-bring-the-thunder
https://www.mylespaul.com/threads/why-would-anyone-buy-a-royal-amp.47357/

[dogburn]

The components, especially the resistors, point to it being made in Japan, probably in the 60s. And the amp listed on Reverb that RoadShow linked to confirms that. If no schematic was included inside the cab, then it may be near impossible to find one for the amp unless it was also sold under a different brand/model name. You may just have to trace out the circuit yourself (part of that would be easy since it looks like most if not all the mic channels are the same).

[AndreH]

The components, especially the resistors, point to it being made in Japan, probably in the 60s. And the amp listed on Reverb that RoadShow linked to confirms that. If no schematic was included inside the cab, then it may be near impossible to find one for the amp unless it was also sold under a different brand/model name. You may just have to trace out the circuit yourself (part of that would be easy since it looks like most if not all the mic channels are the same).

 
Good spot, amp was manufactured in Tokyo.

[RoadShow]

The components, especially the resistors, point to it being made in Japan, probably in the 60s. And the amp listed on Reverb that RoadShow linked to confirms that. If no schematic was included inside the cab, then it may be near impossible to find one for the amp unless it was also sold under a different brand/model name. You may just have to trace out the circuit yourself (part of that would be easy since it looks like most if not all the mic channels are the same).

 
Good spot, amp was manufactured in Tokyo.

Note: 220-240V on the back