Mesa Recto owners read this (esp Troy!)

[OklaStrat]

Guys -

I got to thinking the other day about our Mesas (yeah, I'm back in the single recto family) and am getting sgme info from Bob at Eurotubes. Here's what may be going on:

He can supply KT88s for Dual Rectifiers that bias properly. So... I sent him an email asking about single rectos. What does the KT88 do for us? It gives more bottom end... and a tighter tone. I also asked him a few questions about EL34s in the proper current draw for those of us with series I amps, and also 'hotter' 6L6s since mesas are biased cold from the factory. In other words, tubes that will be biased hotter than Mesa tubes without having to adjust the amp.

Hope that makes sense.. I'll post what Bob shares with me later. I'm also going to check the bias on my Recto and also voltages tonight if I get a chance, and see if it's already wired socket-wise to use EL34s.

Pete

[Troy from VENTT]

Re: Mesa Recto owners read this (esp Troy!)

Sweetness! Keep me informed Pete! [img]images/icons/smile.gif[/img]

[Troy from VENTT]

Re: Mesa Recto owners read this (esp Troy!)

hahahah Pete, I have the feeling I'm gonna benefit GREATLY from you owning a Single Recto now! Muahahaha! [img]graemlins/laugh.gif[/img]

[OklaStrat]

Re: Mesa Recto owners read this (esp Troy!)

Well, I put a DMM on the boogie... got some interesting results. 448 volts on the plate, and 21ma bias. This isn't very good... should be between 26 and 32. So... it's off by about 20%. This is with the new boogie 6L6GC tubes.

So, I took a matched pair of NOS TungSol 5881s (about $60 a pop for unmatched singles at some tube resellers) and the held 444 volts, and 23ma. Better. They sounded a LOT thicker/richer than the stock craptacular tubes. Now I'm on the hunt for a schematic, or if I get really froggy I'll trace the circuit until I find the bias resistor. Or, I'll chicken out and take it to my amp tech guy and have him do it while I watch [img]images/icons/grin.gif[/img]

I put an EL34 in there, and the bias current dropped like a rock. No way in hell are we going to be able to put em in there stock.. the amp *will* need a mod.

Pete

[bstsuccubi]

Re: Mesa Recto owners read this (esp Troy!)

hey troy

forgot to thank you for the offer on the single rect. on the old board

I came across an old jcm900 combo that weekend, but thanks for the offer!

[thingman]

Re: Mesa Recto owners read this (esp Troy!)

kt88's in my DR huh?

I gotta try this out!! [img]images/icons/grin.gif[/img]

[Explorer77]

Re: Mesa Recto owners read this (esp Troy!)

so i can get el34s from thsi guy and they wont require my whole amp being torn apart and rebiased ?

[Tetsuo]

Re: Mesa Recto owners read this (esp Troy!)

I got JJ's from Bob for my Tremoverb. Matched set of 6L6 and EL34 (2 each) grat deal great service. Real happy with it. I still am not the biggest fan of boogie though but they did improve the sound

[hpets]

Re: Mesa Recto owners read this (esp Troy!)

I thought Okla said it would need a mod to use EL34's [img]graemlins/scratchhead.gif[/img] .
hpets [img]images/icons/smile.gif[/img]

[Tetsuo]

Re: Mesa Recto owners read this (esp Troy!)

Well maybe but the ones I have (and I am not sure about single recto's I ahve a dual tremoverb) you just needed to flip the bias switcha nd off I went. Although Bob at Eurotubes does suggest adding as trim pot on most boogies

[Tetsuo]

Re: Mesa Recto owners read this (esp Troy!)

Oh and Olka wasn't talking about Eurotubes eitehr. Bob tests all his tubes prior to shipping and matches his sets. Only good if you want JJ's though

[Piranha]

Re: Mesa Recto owners read this (esp Troy!)

Pete, the RCA Blackplate 5881(6l6) is the one for your amp. Good luck!!!

[OklaStrat]

Re: Mesa Recto owners read this (esp Troy!)

I have a few blackplates and tried em... I really like the tungsol 5881s so far. Also tried a pair of sylvania 6L6GCs... the tungsols rock.

Pete

[toejam]

Re: Mesa Recto owners read this (esp Troy!)

KT88s are pretty much the same as 6550s, aren't they?

[Soloist1]

Re: Mesa Recto owners read this (esp Troy!)

Most Tung Sol's are made by Mullard Pete. I bet you got some Mullard ones. ][ :o )# Explorer77 I responded in your other post but I'll respond here also. The tubes I got for my Mesa 20/20 are the JJ's that you can also get from Eurotubes. You do not have to rebias your amp if you tell him what you have. He'll get you a set of tubes that fall in the bias range for your amp. They sound great in Mesa gear. Better than the Sovtek's Mesa will send you if you buy direct from them.

[ December 05, 2002, 01:26 PM: Message edited by: Soloist1 ]