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Want more high frequency extension

I like my current set up, however, I find the high frequency extension to be lacking. Any thoughts on how I can achieve more extension? I was thinking one of two areas, preamp change or tube rolling in my amps.

I currently have an Audible Illusions L-1 with Bugle Boy 6922 tubes. I was thinking of maybe trying a passive pre like a Placette or trying a SS pre. thoughts?

Alternately, I was thinking of rolling out the stock tubes in the Six Pac's. Right now they are Rubey Tubes El34's for the output tubes, Electro Harmonix EL84EH for the current source, and Westinghouse 12BZ7 for the gain/phase inverter. The amps will also take KT-66, KT-88, 6550C, KT90 and KT-99 in the output stage and 12AY7 and 12AX7 for gain/phase. Any tube replacement that will provide more extension?

Thank you in advance
mattybumpkin

Showing 3 responses by mattybumpkin

mattybumpkin OP
590 posts
 
Trejla,

I am running Green Mountain Europa's. Eldartford, the amps are zero feedback design. Hey, I'm 39 and holding, not that old!

Thnx,
mattybumpkin OP
590 posts
 
Thank you everyone for the responses.

I am sure my hearing is still good even though from reading the posts here it sounds like I have one foot in the grave. Who should I leave my rig to in my will?

I think I will begin to roll some tubes in the amp first, and if that still doesn't float my boat maybe I will try another pre.

Trelja, I would be curious to hear your impressions of the EL34 tubes you just got. I was thinking of trying the EH EL34's, supposed to have more sparkle up top. I know the comments you mention about the Cary V12 and the attempts to use the other tubes like KT88, etc. I wonder though, the Six Pac's are different circuitry than the V12I that was mentioned in the other thread. The new V12R is supposed to be the same pretty much as the Six Pacs. I wonder if this would make the outcome different. I'll ask Dennis I guess, or Kevin at Upscale. KT88's are more extended than EL34's, yes?

Regards,
mattybumpkin OP
590 posts
 
Oh,

Tvad, I did roll back into the AI L-1 some EH 6922 that I had. It did provide some extension. Thank you. I may try to hunt down a pair of the Siemens you mentioned.

Regards,
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