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I'm finally going to start building again. I have three projects on the bench this winter: a guitar amp; 6V6 push-pull, a tube microphone amplifier/compressor and Shannon's eiclones.

If anyone has a good circuit to try for the compressor, speak up! I am currently thinking of something like an Altec 444B. Someone pretty respectable suggested that I could build a good one based on 6BE6 using grid, uhhhh idunno, 3? to control circuit gain. I like this idea as I have lots of 6BE6. I'll probably move this one down to tube 101 as I have a few questions about this subject in general.

As for the eiclones: I want to use KT88s and was thinking of the winged C as well as 6SL7 in place of 12AX7. I have read thru alot of the posts here trying to update on all the latest thinking but everything is so scattered it would take hours to distill it down to a few decisions. Shannons latest version of the manual is dated 2/27/06 which seems pretty long ago. Is there anything you guys would like especially to tell me before I begin? And keep it clean, nothing about where the sun don't shine etc, etc. (same to you buddy)
One thing is that it's not clear to me what to do with the jumpers if I want to use 12SL7.

Thanks in advance

Don

The castle lights are growing dim
There's no one left but me and him
When next we meet in Frightenstone
Don't come alone!

Make sure you get some of these RCA 12SL7's ... they are great ! Yellow_Light_Colorz_PDT_01

that's classy. cheaper i assume?

Those were from World War II when tubes were scarce. They released them for civilian "M-R" (Maintainance and Repair) They were supposedly rejects, but there is really nothing wrong with them. It came with a printed disclaimer in the box. Pretty cool piece of history. I got them from Fair Radio sales, who still types your receipt on a manual typewriter with a cloth ribbon.

Western Electric did a similar thing, they had tubes available for "civilian" use that were marked either "reject" or "sub-standard" which in all reality were perfectly OK.

/ed B in NH

dhuebert wrote: I have read thru alot of the posts here trying to update on all the latest thinking but everything is so scattered it would take hours to distill it down to a few decisions. Shannons latest version of the manual is dated 2/27/06 which seems pretty long ago.

All updated this morning. Squeaky wheel greased!

TomMcNally wrote:Those were from World War II when tubes were scarce. They released them for civilian "M-R" (Maintainance and Repair) They were supposedly rejects, but there is really nothing wrong with them. It came with a printed disclaimer in the box. Pretty cool piece of history. I got them from Fair Radio sales, who still types your receipt on a manual typewriter with a cloth ribbon.

I think the real reson for the marking was to discourage black-marketing and hoarding, or at least make black-marketing less profitable. Of course, the inventive types could do what Richardson used to do and sandblast or bleach the numbers off...