Do I have the correct tubes in my amp?

Hi. I'm sorry, but I'm confused.
I did check out the board threads on tubes and saw that tube choices were changed for some models of MM amps. It can't seem to find a definitive answer on this topic, but I'm going to try to ask:
I have:
a) MM 112 RD 100 (silver badge, black logo)
chassis # 2100 RD
b) MM 112-RP-100 (black badge, silver logo) chassis # 2100 RP
Both have EL-34's in them right now. Should one or both have 6L6's?
Thanks everyone.
LouLoomis
P.S. Sorry if this is a double-post...I tried to post this the other day and I may have just Previewed it instead of Posting it as well....I don't think it was posted, though.

thats a hard one,most rd/rp models did use 6L6's,but the really early ones did come out with el34's,the el34's kinda dried up for a long while so they went to the 6L6's,there is usally a white sticker in the back of the amp right under chasis,that has the right tubes to use on it ,hopefully that sticker is still there on yours ,hope this helps.

Hi. If the white sticker which lists the correct tubes should be visible without disassembling the amp (i.e. removing the chassis from the cab), then neither of my amps still has the white sticker(s).
Any other way to verify which tubes the amps should have?
Thanks a lot.
LouLoomis

no that sticker is usually on the cab ,no disassembly required .ok,does the amp seem to be working properly ?both these amps can be made to use the el34's it just took some adjustment,these amps are self biasing but the plate voltage would have to come down abit for the el34's.what I am getting at is if the amp is not making these tubes glow bloody red and sounds good ,the el34's are actully a better sounding tube then the 6L6s',I personally have been using kt88's in mine but mine ran the 6L6's ,if you went toi kt's it would probally be kt66's which i've heard are great sounding tubes.Marshall had the same prob at that time and went to 6L6's during that period ,then went to kt's when sales went down due to a loss in thier marshall tone later el34s'became availible again and they went back not because they sound better then the Kt's but because they were way cheaper.If you are looking for a bit more fender tone 6v6's could work as a simple substitute.The one sure thing is if that head is set up for 6L6's and you put el34's in it it will torch them in no time if you run at full power,half power you might get away with it.

The amps seem to work properly, but they both have intermittent crackling. I have a post about this re: the 112-RD-100. Now the 112-RP-100 is doing the same thing. It's not the guitar cables, etc. I've tested that.
I run my amps at half power generally. I'm just trying to see if the tube selection is causing the crackling and/or is otherwise the wrong configuration for this amp. I want my amps to last forever and want them to be correct in their tube configuration.
Is there anyway to check based on serial # to see what the correct tubes would be, based on chronological data?
LouLoomis

well the silver badge is a good indicator of it being pre-80's which would say the el34's are the right tube but the other is clearly 80's,the crackleing sounds coud be alot of things beside tubes,this amp might just need new tubes and a good cleaning ,if that doesn't do it it may need things like a cap job...ect

Hi Lou..
I have the HD 130 2x12 export version with the silver badge and the 12xa7...i got my amp over 20 years ago secondhand and it came with EL34's installed...i tried JJ KT 88's but even though they were good sounding,the tubes fell apart...! the base came away from the tube on three of them...could be something to do with the heat in the MM but i was disapointed to say the least as the 88's are pretty expensive this side of the pond...
At the moment i have JJ EL34's in the amp as it was either them or GT's which i'm not too fond of soundwise...the best results i've have with tubes for the MM was with unmatched Sovtek/EH EL-34's i bought off a guy at an outdoor market on a sunday morning many years ago...!!!!!
unfortunately the guy and the market are long gone so i took a chance on the JJ's based on internet reports...i will try something else the next time
Regards
Tony