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RE: NYAL OTL3

An update.

I first checked all the diodes with my Fluke multimeter to see if anything was obviously wrong, but they all tested good. (A number of them were replaced by George Kaye when I had my OTL3's checked/upgraded about ten years ago.... Would have sent these to him already for repair, but he's a busy man.)

FYI: I attached a speaker while doing all the following work on the OTL3 per the input from "rhinohifi714" and never heard a sound.

I first took every tube out of my other OTL3 I just setup to see if they would work in the "other" one, but they didn't with V3 6LF6 turning red after the plate current had finished its slow/smooth rise to steady state.

Turned the plate current down 30% from the 300+/-25mA target per RAM Labs recommendation and placed a matched sextet of 6LF6 RAM Lab tubes I bought a long time ago into the OTL3....the V3 6LF6 turned red after a bit. Nara mentioned he changed/moved tubes around to eliminate the red glow from V1 (vs my V3), so I tried the same thing with these tubes and found a combination that worked .... at ~210mA (tgt-30%) plate current.

After new tube warm up, RAM Labs recommends bringing to target-20% then look for any plate glow in a dark room. If a glow, reduce to eliminate (I did, set plate current to ~220mA w/o any glow). [If no glow, RAM Labs recommends to leave at target-20% for 10hrs of use, then raise to target-10% for 20hrs of use, then bring to target. Check at 100hrs, then every 1000hrs after that.]

I put in the 6FS5 phase splitter and finished the setup (85V bias), with the plate current hovering ~230mA but without a glowing V3 6LF6.

After 10hrs of music (I hope!) I'll have another update.

Thanks to "rhinohifi714" for your help.




Edits: 03/24/14 03/24/14

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