Lazarus Cascade Basic Preamp - What type of tubes?


I have a Lazarus Cascade Basic tube preamplifier and do not know what type of tubes it uses. There are four tubes of the same type, but there are no markings to indiciate the tube type. Thanks for any help or information you can provide.
valhalla
I had one for a very short time, four tubes mounted horizontally. I'm pretty sure they're 6DJ8's (6922's)
Absolutely DO NOT put 6DJ8 tubes in this preamp! It uses 4 12AX7 or equivilent(ecc83, 7025, 5751) I have this preamp and this info is direct from the owners manual.
Does anyone have schematics for it, Trying to restore one but can't find anything on it, A photo or anything from an original would be much appreciated, Thanks