Retubing an ARC VT100 mkll

Gary,

Is the ARC VS 115 wired in triode?? Regardless, thanks for the advice anyway. The 6H30 audio tubes were pushing between 4 and 5K hours too. So I retubed the whole VS 115 batch.

As an aside, I just ordered a retube set FROM ARC for my ARC Ref 5. There's probably over 3K hours on the 6550 C and 4 to 5K hours on the 6H30s.

Not sure what I did makes sense, i.e., buying VS 115 tubes from Upscale Audio and Ref 5 tubes from ARC. The thought process is that "ARC grade" matching might be more critical in the line stage than the amp. That's probably not a valid assumption, but it's a done deal. In any case, as stated, the KT-120s bias just fine and the amp sounds great, so I'll just have to "suffer" [sic] with the Upscale Audio tubes in the amp -- NOT.

Next time let me know BEFORE you buy your tubes. I can help.

No way the vs115 is triode. 4 tubes push pull per ch will not get you 110wpc even if you push B+ all the way to 550v.

Thanks Gary -- will do.

Gary and Johnsonwu -- I'll probably regret this question, but what is the significance of a triode amp? Btw, with KT-120 tubes, the VS-115 can push out 130 wpc, but my ears would bleed if I pushed my amp and speakers that hard.

Thanks again,

Bruce

Triode-wired tubes give a more refined sound. Richer in inner detail as many would call it. I would describe the sound as more linear, the microdynamics of low level passages are better preserved so you wont spent time hunting for the right listening volume.

In pentode or likely Ultra linear in the VS115 config, you get better bang for the buck esp in the dept of bass dynamics. if you like gut punching bass, keep it as it is. If you love violins, female vocals, and choral music, AND your speakers are 89dB/W/m or better, go triode.

Triode-wired tetrode or pentode tubes can last longer assuming same B+ and bias in both modes.

Many amps can be rewired to run the power tubes in triode mode. Pull the screen grid input resistor and connect the screen grid to the plate via a 100Ohm flameproof resistor. But it really depends on whether the biasing circuit has enough range to get the tubes biased to the 55-65mA per spec after triode conversion.