Elrog 300b vs we300b

@david_ten  At some point after Acme 300B fully burned in I'll return to Coincident 845 in system and compare present Shuguang Black Treasure 300B as driver vs Acme. Based on 6moons review of Coincident monoblock 845, Linlai Elite 300B  vs can't recall cheaper tube as drivers made obvious difference to reviewer. 

@david_ten

Arthur Loesch tracked me down at the CES a few years ago, and as we chatted and toured the rooms at the Alexis Park, he mentioned that most DHT’s sound alike - if driven by a low enough source impedance and a powerful driver with *lots* of current. It’s when they are driven by feeble 5-8mA driver tubes that the characteristic 45, 2A3, 300B, or 845 signature appears. In other words, you’ll get loads of that 300B sound if all you’re using is an RC-coupled 6SN7."

The esteemed SET maven Arthur Loesch (Haven’t seen his name in quite some time) seems to be making 2 points.

1 DHT tube require a high current driver tube to obtain optimal performance.

2 If this driver tube requirement is met then there’s little (If any) sonic signature distinctions amongst the DHT tube choices.

Well I do know that the builder of my Coincident Frankenstein 300b SET specifically chose the 6EM7 as the driver for the 300b output tubes. Citing the 6EM7 has far greater (Max of 50ma per data sheet) current capability compared to the 6SN7. He said this is exactly what a 300b tube needs to display its full potential. Also the late Roger Modjeski said the 6EM7 had enough current and power it could function as an output tube driving a speaker load.

He in fact subsequently built a 6EM7 SEP amplifier that produced 2 watts per channel (Equal to  a 45 tube). Point being if it can drive a speaker impedance, it can drive a DHT output tube. So Mr. Loesch may have a very valid point.

As to his 2nd point, I just don’t know. I’ve compared numerous 300b brands in my Frankensteins (With high current 6EM7 driver tube) and could very easily and clearly hear sonic character differences between all of them. Now granted this was using only the 300b . Whereas Mr. Loesch was comparing different DHTs (45/2A3/300b/PX 25 etc.) to each another.

As always the world of tubes is interesting and even fascinating.

Charles

@sns Thanks for your responses. Looking forward to your findings when comparing the Acme and Shugang in your 845 amp.

@charles1dad Thanks. I’ll reach out to Scott to find out his thoughts on his choice of driver tubes (7A4 x2 with OC3 x2 and OD3 assisting) for my 2A3 amps and what he thinks of Loesch’s points.

I have been playing around with a whole range of driver tubes on my WAvac EC300B. There are audible differences that are of the same order of magnitude as output tubes. Specifically Jan Philips 7581a: very resolving and fast, yet slightly harsh in the treble. Svetlana Winged-C 6L6GC: very harmonious, sweeter than Jan Philips 7581a, yet most depth of soundstage, Tungsol KT66 (actually really 6L6 GC with 900mV heater current): deepest bass, very powerful but slightly sluggish. These were the best of the lot; JJ, GE and RCA black plate are fuzzier and less dynamic. I have not yet tried the Tungsol 6L6GC reissue but am intrigued because of the strong KT66 performance. As mentioned mixing and matching driver and power tubes gives additional mileage. 

@david_ten

I’m pretty sure Scott is familiar with Arthur Loesch and I’m very curious to know his thoughts regarding driver tube attributes (Particularly the high current aspect). Given Scott’s expertise I suspect he has a strong opinion one way or the other.

Charles