True triodes [300B, 2A3, PX4, PX25,PP5/400 etc, etc] when used in a circuit that impliments them properly do not suffer the drawbacks experienced with most Tetrodes, and pentodes, connected as triodes, as we see in amps that have the switching facility fitted to turn Tetrodes, or Pentodes into triode operation, therefore its not a fair comparison.
From what I have seen with many amps that have these switching facilities fitted, it has been added to make a sometimes unlistenable amp on some types of music, listenable, when switched to Triode mode, either way, IMHO both operating topologies are compromised in many of these designs.
A...
"Today scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality"
Nikola Tesla
Its now a conspiracy theory to believe that the Immune system is capable of doing the job it was designed to do.
A fish is only as healthy as the water its swimming in ! [Dr Robert Young]
www.tubedistinctions.co.uk
Matthew 5:10
Location: East Riding of Yorkshire these days
Posts: 4,779
I'm Shaun.
OK, so just what is it about the 300B that makes it sound so incredibly..... whatever the word is, but definitely sublime...? And, how is it that even when the 300B is wired for push pull operation it is still so bloody pure and airey...?
Yes, my experience of the 300B was a WAD 300B PP back in the day by Nick Lucas but the sound was so damn spacey and airey. Yeah, bass was a bit elastic band but that midrange vocal and treble was sublime.
I also owned an Audion 300B SE amp which was excellent but maybe not quite as good as the WAD. The WAD seemed better suited to a larger range of music types.
Location: East Riding of Yorkshire these days
Posts: 4,779
I'm Shaun.
I'm guessing that the operation of amps like my current one is purely down to personal taste as it sounds extremely good in either mode unless of course you prefer less treble and a more intimate vocal for say jazz and then triode sounds better. I mean, would anyone listen to jazz with a 250 Watt per channel tranny amp...? Would there actually be any benefit...? It seems to me that once again this is displaying the hi-fi hobby and its quirks or maybe our quirks.
Location: East Riding of Yorkshire these days
Posts: 4,779
I'm Shaun.
Location: Seaford UK
Posts: 1,861
I'm Dennis.
From Shaun;
"I mean, would anyone listen to jazz with a 250 Watt per channel tranny amp...? "
Well I was listening to everything on just such, and it was to me very good, (ATC SPA2).
But, having never experienced the 300B ethos, I may really be missing something and be in a contracted and deluded world of my own. I used EL34 and 84 amps up until '70, and have been SS ever since.
If I were a multi, multi, millionaire, I would buy it all and with a vast mansion try everything, with 100 audiophiles having a long stay in the many spare bedrooms, and helping to evaluate it all and come to conclusions by consensus.
We could do lots of measurements and DB AB testing, and thrash out the state of play.
Think of the numerousness of the combinations.
This would for me be a better use of time than swanning around the world in a yacht and driving a Lamborghini.
Hi Shaun,
True Triodes are very linear, and produce predominently low order even harmonics, which our ears like, therefore; it is not unusual to find on test that some of the well known, and therefore well loved triode amps have distortion levels as high as 10% or more, which would be intolerable with many solid state and pentode amps. And because of the distortion characteristics of triode amps, very little to no feedback is often required, which helps in allowing that ledgendary, magical mid range of Triodes to shine through. Unfortunetly though there are drawbacks; as stated bass frequencies are often compromised, or severely underdamped, also; triode amps are very inefficient when compared with Tetrode/Pentode amps.
A...
"Today scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality"
Nikola Tesla
Its now a conspiracy theory to believe that the Immune system is capable of doing the job it was designed to do.
A fish is only as healthy as the water its swimming in ! [Dr Robert Young]
www.tubedistinctions.co.uk
Matthew 5:10
Location: East Riding of Yorkshire these days
Posts: 4,779
I'm Shaun.
Once again Anthony, many thanks for the reply. The WAD 300B amp I had back around 1997 did indeed have a feedback switch for on or off (obvious I guess) and with feedback did have a lot more guts and oomph but lost almost all of the magic. Once again I guess a case of meat and poison. If I only had the system I have now with that pre/power combo I think the sound would be my ultimate. It is not the case though as that was quite some years back. I still remember that classic air and midrange vocal though.
Location: East Riding of Yorkshire these days
Posts: 4,779
I'm Shaun.
Even with my present Prima Luna combination in triode mode the vocal sound on female jazz is bloody astonishing. The only problem though is that triode mode removes that extra air and sparkle thus leaving me here, not quite able to make up my mind. I guess it all depends on mood at the time. In the darkness of a winter evening triode wins through easily but listening to Deadmau5, maybe not.
I made a few amps earlier on in my career that had Tetrode/triode switches fitted, but I also fitted feedback switches, so that the feedback in either mode could be reduced, I also fitted a variable control that would only reduce the feedback at low frequencies, this tended to act in a similar way to a loudness control.
Anyway, glad my ramblings have been of some interest.
A...
"Today scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality"
Nikola Tesla
Its now a conspiracy theory to believe that the Immune system is capable of doing the job it was designed to do.
A fish is only as healthy as the water its swimming in ! [Dr Robert Young]
www.tubedistinctions.co.uk
Matthew 5:10