Original Marshall Tube Identification Question - JCM 800 4010 (2204 Circuit)

[Jecarroll7]

Picked up an all original JCM 800 4010 combo from the mid 80s that looks like it has the original tubes.

My question is who made the tubes. The three preamps have only ECC83 on them, not other markings, long grey smooth plates.

The EL34s are also grey smooth plates, no markings at all.

The tubes look like telefunken tubes but don't have the telefunken markers on the bottom of the tubes.

Haven't found much online about Marshall tube vendors in the 80s, Any ideas?

[nickb]

I've found this useful. Maybe it will help eBay Guides - The Tubeking's Guide to NOS and Vintage Audio Tubes

[wyatt]

The power tubes are probably East German RFT. They were the stock tube in Marshalls for years until the plant closed when they reunified Germany. They often aren't labeled or are labeled for Western companies (a weak gesture to avoid the stigma that both the US, UK and NATO military equipment was relying on tubes from East Germany). At the time they were the last large manufacturer of EL34's in the world, Marshall had to switch to the Sovtek 5881 for a few years.

The preamp tubes are probably EI. They have longer plates than the RFT 12AX7's. These were stock tubes in Marshalls for years until they were caught up in the embargo during the Balkin Wars (NATO eventually bombed the plant so that it wouldn't be to produce weapons). This is when Marshall made the switch to Chinese preamp tubes.