Eurotubes KT88/E34L Tubes

I remember on the HC forum people were using this combination in the RM100 heads. Anyone here have experience with this that can share a little info on how it effected their tone? Also, I ordered an RM4 with a VHT 2.90.2 really for the use of the KT88's, but is the VHT power section better than the Randall, when really I'll be using the same sorta tubes in it? I'm not really that interested in a rack setup, and if this'll do the same thing I'd stick with the head and Bob's recommendation with the 88's out the outside and 34L's on the inside. Any help would be appreciated, thanks!

- Irfaan -

Jimosity is running a VHT poweramp with an RM4 on those sound clips he recorded of the modules and using KT88's. His tone sounds killer!! I really want to check a set of them out in my RM100. I am currently running a quad set of Groove Tube 6L6 GE's in my head and they sound very good. I prefer them over the JJ E34L's that came stock with my amp. I would imagine you could get a pretty comparable tone with the RM100 loaded with KT88's as with the VHT poweramp.

I actually just changed my order from an RM4 to a RM100. I really don't want to deal with a rack and I got a very in depth e-mail from Bob @ Eurotubes about what tubes I could go with. I'll actually post it here, there's some good info:

Hi Irfaan:

So maybe a little description of tubes in general will help. The standard EL34 is just like the old European EL34's. These are a bit soft with a shallower low end and a smooth breakup with a nice crunch. A typical high quality EL34.

The JJ E34L's provide a deeper low end and are more aggressive and punchy than an EL34. The E34L is tighter with slightly more headroom and power with a more aggressive crunch. A great tube for rhythm and solo work.

The JJ KT77 is not quite a tight as the E34L but tighter than an EL34. The 77's have even a bit more low end extension than the E34L's and they have a nice sizzle in the top end that is not brittle. The clean tone is very fat and full and the crunch has more of a chunk to it and it's very punchy but not quite as aggressive as the E34L. A great tube for rhythm and solo work.

So for a comparison the JJ 6L6GC's have about the same low end as the KT77's but are a cleaner tube with a later breakup and they are not as mid range heavy. More of a traditional Fender type tone. The 6L6GC's are a better way to go if you scoop your mids and these are a great tube for heavy rhythm and melodic drop tuned Metal.

The JJ KT88's provide more low end thump than the JJ 6L6GC's and are a little more like an E34L in the mids and highs. The 88's have a very aggressive and punchy tone that is FAT. It's kind of like a cross between a huge 6L6 on the bottom and a very big E34L in the mids and highs.

I have customers using the KT88?s in the outside sockets and EL34?s or E34L?s and even KT77?s. The RM100 is pretty versatile that way. The bias on the 88?s should be between 50 to 55mA where all the rest of the tubes should be between 35 to 40mA.

It?s impossible to give you an answer on your question simply because I don?t know what preamp you would be using with the 2/90/2. The VHT is a punchy amp and will hold it?s own against the RM, no doubt but it?s not as versatile.

Thanks

Bob

Well, in 2 weeks I'm going nuts experimenting. Big thanks to Bob @ Eurotubes also. I'm probably going with the E34L and KT88 thing, but I'll mess around and post my results, and hopefully a video or two if I can

I've communicated with Bob via email as well and he is very cool. No wonder I like my 6L6 GE's better than the E34L's for downtuning. The KT88's sound interesting though. I already have a quad of E34L's so maybe I just need to get a pair of the 88's and put them on the outside along with 2 E34L's on the inside. I was also talking to this dude at The Tube Store and he told me that the TAD 6L6GC-STR's work really well for new-metal. I may consider trying a set of those. Man this sh!t gets expensive especially when you start looking at the KT88's or the 6550's!! Thanks for that info man, very informative.

Correct me if I'm wrong but I thought I read somewere thatthe buis range on the RM amps was only 25-45 mA. If this is true it would be difficult to use KT88's if they require a buis of 50-55 mA :?:

Hey MetalMajik you are right, im curiuos at this too, the RM100 manual refers to bias from 25mv to 45mv and the kt88`s needs at least 50mv,

can anyone confirm that?, its posible to run 50mv in the rm100?

That is probably a question we would have to call Randall about. I see that in the manual too. Hmmm.

I'm now completely confused. I know that the Randall RM80 uses 6550 tubes. Many of the tube websites list KT88 and 6550 tubes together, in fact, Eurotubes.com says that the KT88 works in any amp that takes a 6550. If the buis signal IS limited to 45 Mv I' m sure its probably not too dificlut to have the amp moded to increase the buis range.

Hey, How y'all doing?
I just recently acquired a Rm100 head too and was wondering if anybody found out about biasing the kt88's with other tubes. I was thinking of running them with my ruby el34's for real gigs and use a pair of 6v6s at home since i heard they work great on killing some db's off. Has anybody tried these?

now I don't have any of these amps and if I got one it would probobly be just the power amp as I like my Peavey preamp

but as for your quandary about the tubes and biasing it is possible to run a tube below the suggested range of the tube it is called cold biasing and is a common problem in Peavey 5150/6505 amps as well as some of the Mesa Dual and Triple Rectos, what the underbiasing causes is normally crossover distortion and normally is a bit buzzier and is in most cases responds less to dynamics but it is not detremental to the tubes or the amp some people know this and find it very troubling others know and don't care and some people have no clue and are perfectly happy but everyone is different