MESA 400 REPLACEMENT TUBES

[tombowlus]

OK..gigged with it last night, and I'm STOKED. THAT, was the greatest bass sound I've ever gotten. A Mesa 400+ with Reflektor/Svetlanas through a Berg NV610, is tone NIRVANA for me.

Sweet!

 

[John D Harris]

I am still curious to hear from anyone who has used both 6L6's and 6550's in their Bass 400. What sonic differences did you encounter?

Also, does anyone other than me think that the 400 sounds more clear, open and articulate than the 400+, which sounded more girthy, and bottom heavy? I have tried the 400+ in three different stores, and the 400 only in my home, so that's not apples to apples, but I was able to use some of the same cabs that I heard in the store (but different basses).

Tom.

BUMP THIS!!!

OK; I'm curious about this as well.

Anyone?

 

[tombowlus]

BUMP THIS!!!

OK; I'm curious about this as well.

Anyone?

I recently found an outfit that seems to be very qualified amp techinicians, and they have a tube guy who builds his own high end tube amps and seems to know his stuff. Thanks for the recommendation, Bob! They will be installing bias trim controls (for each tube pair) in my Bass 400 and my Trace Elliot Quatra Valve. I spent some time talking to him about the 400, and I had the original Boogie manual/schematic for him to look at. He said that while their implementation is a bit unique, and not really what he would do for an amp driving 6550's (noting that the output transformers are a bit on the small side), the way the Bass 400 is laid out, he thinks it is more well suited to driving 6550's/KT-88's than 6L6's. He commented that it looks like they wanted you to be able to overdrive the power tube section, but placed some safeguards in the chain to help prevent meltdown.

Time will tell how this works out, but as always, I will report back!

Tom.

 

[John D Harris]

Cool!

I'll be interested on how it compares to the TE Quatra Valve and V8 heads when you get it running.

 

[schnake]

hello,
do you know if JJ KT88 will fit to mesa 400 head (size ...) ?
Are they really better than SED 6550 (less expensive) ?
is somebody knows the biasing values for 6550/KT88 ?
thank you !

 

[sbakker]

hello,
do you know if JJ KT88 will fit to mesa 400 head (size ...) ?
Are they really better than SED 6550 (less expensive) ?
is somebody knows the biasing values for 6550/KT88 ?
thank you !

They fit !

 

[schnake]

hi everybody !
Not only KT88 fit perfectly in my mesa bass 400 but the tone is awesome ! The shop which sold me the tubes give me 32mA biased tubes and it works perfectly ...
bye

 

[chaosMK]

Nice. Is the difference in output that great? Right now I run my Bass 400 at around 7 Master (running both channels on the inputs at 7/4) to get the volume that I want out of 2 4x10 cabs. Much higher than that I break up.

 

[oZZma]

I just scored a Mesa 400 in great condition - and with the Mesa shock mount rack, thank you very much! - off ebay, so suddenly this thread becomes much more pertinent to me!

hoodadoo, what did you end up doing (if anything) about tubes?

And for those of you who have tried both 6L6's and 6550's in a Mesa 400, can you tell me how the two options compared?

Thanks, Tom.

Funny how many threads have been written about these two heads but you can't find a comparative demo anywhere in the web!