Hifi, why bother?

[Diabolical Artificer]

I've been mucking about with valves these last few months trying out various OP stages, the OPT is very well made, lots of iron, interleaved layers of windings, 4 807's in parallel PP. I've tried AB1, AB2 and extended class A and tested the heck out of every circuit change and come to the conclusion that more THD sounds better, so why bother with hifi?

A short appraisal of each type of OP stage - Class AB1 UL PP, tested excellent on test gear, very low THD, excellent frequency response. Music test, sounded cold, left me decidedly underwhelmed.

AB2, this took some fettling, two 807's this time as per datsheet, we're driving the grids of the 807's direct, no coupling cap, no grid leak from cathode followers, so an extra stage, more phase shift. Tested awefull at first, THD over 5%, F response still ok ish. Music test, ahooo!, now your talking, sounded bloomin lovely, all sparkly, great bass, clear highs and mids.

Extended Class A - two 807's connected as triodes, two as beam tets, these biased off at low volume, but SW on as more power is needed. I got this wrong too at first, big AC imbalance into the OP stage and applied PFB instead of NFB, tested awefull, over 8% THD at low levels, 10% at full whack, F response terrible. Music test, sounded absolutely lovely, big smile all over the mush, skanking about yon living room to 70's classic roots reggae, but everything sounded good on it.

So, nothing new here, we all know a bit of 2H sounds nice, but 8%! Nuts, so, I'll pose the question again, why bother with hifi?

Andy.

[ppppenguin]

If it's what you like, then listen to it. But I know you wouldn't make audiophool claims about it like some might.

The great Eckersley said, c1930, "The wider you open the window, the more the dirt flies in"

[Mark Hennessy]

Of course we like distortion. But it has to be right sort of distortion. Which you've got with your design, albeit the expensive way.

You could get much the same effect using a low-distortion, state of the art solid state amplifier and some signal processing ahead of that. That processing might be tricky to achieve, but it would be feasible. This is a standard technique in recording studios - there's huge market for DAW plugins that add the desired types of distortion to give an analogue "warmth" to a modern recording. And people still use vintage mic pre-amps and compressors, or bounce stems out to an analogue tape machine. All commonly done - if anything, more so these days.

In the recording studio it's part of the artistic process. Doing it in your home - and applying the same broad brush to all recordings - is a matter of personal preference, but there are plenty who would find it an insult to the engineers who made the original recording. BTW, I'm not expressing my own opinion either way here - please don't think I'm having a dig at you.

I'd be tempted to try letting your amps drive a dummy load and then pass that through a solid-state amp. You'll get most, perhaps virtually all of what you're hearing right now - but you might need to play with the dummy load so that it looks more like the impedance curve of your speakers. Having done that, you could add a control that lets you mix between the "enhanced" sound from the valve amp and the "clean" sound before. Easy in theory, a few challenges to solve in practice. But quite doable. It would give you a convenient front panel control which you could label "Niceness", allowing you to choose your poison, according to the recording...

If the idea of running a valve amp into a dummy load just to get the right sort of distortion sounds like heresy, it's a common trick in the recording industry to allow guitar amps to be turned up to their optimum point for a required sound: https://www.thomann.de/gb/attenuators.html

To be honest, it might be worth investigating studio gear. What you clearly crave from your system is a modification of what the artists intended, and doing this at line level is whole lot easier and cheaper than building huge valve amps. To start with, investigate vintage compressors and poor quality audio transformers which can make "nice" distortion if you're lucky. Lots of options, all far cheaper than typical audiophile tweaks. Put it in a nice box and you'll make your millions selling them!

[Murphyv310]

I'll stick with my home build stereo Mullard 3-3.
It's never pushed to max and I enjoy the sound from it. It drives two Tannoy speakers fine.

[valvekits]

I bet you have enjoyed going down your learning curve though Andy.
These days wearing glasses for my computer monitor has become obligatory. I just use Poundland ones and found that usually 1.25X or 1.5X will do. But then I got clever and found that my left eye is optimum at 1.5X and my right eye is optimum at 1.25X. So I popped the lenses out and re-fitted them to suit my requirement. I suppose a bit like tuning up your hi-fi for best performance. The result was I couldn’t use them as they made me feel nauseous. I suppose it’s what goes off between your ears that really counts.

Eddie

[BusyBee]

My view is often 'simple is best', although going too far with DC coupling at one time probably gave the worst sound of all. I am probably happiest with straightforward valve or transistor amplifiers, both in making and the sound of. Obviously processing to the max will give theroretically whatever you want but there is generally no need. I suppose what I would really call the silliest thing of all (at least to me) is that complex processing circuitry, due to modern production methods, can possibly be far cheaper to implement than traditional designs.

This is an interesting thread. It does remind me about completing my transistor amps. previously posted, to which I have done some exploratory work with using miniature valves in a preamplifier circuit. I would have trouble giving concrete reasons but my feelings would be to use a valve preamp to drive a solid state output rather than transistors or IC's to drive a valve output, hence being able to keep to lower voltage and easier to manipulate output with devices and low impedance to directly drive speakers. This would also have the ability to have lower voltage valve feed (perhaps pretty much the same as the power amp stages). As mentioned / implied, useful valve type conditioning can be implemented early in the chain. If / when I get there I will share results.


Tracy

[ppppenguin]

.....Having done that, you could add a control that lets you mix between the "enhanced" sound from the valve amp and the "clean" sound before. Easy in theory, a few challenges to solve in practice. But quite doable. It would give you a convenient front panel control which you could label "Niceness", allowing you to choose your poison, according to the recording...

First a loudness control, now a "Niceness" control

"With the tone controls at a single touch, Bel Canto sounds like double dutch"

alternative version on some recordings...

"With the tone controls at a single touch, you can make Caruso sound like Hutch"

[Amie]

....8% THD at low levels, 10% at full whack, F response terrible. Music test, sounded absolutely lovely, big smile all over the mush, skanking about yon living room to 70's classic roots reggae, but everything sounded good on it.

So, nothing new here, we all know a bit of 2H sounds nice, but 8%! Nuts, so, I'll pose the question again, why bother with hifi?

Absolutely spot on Andy!

Because I had a penchant for impromptu night time concerts where I would nick mums Gibbo, and an amp, and do one of my impressions of Tony Iomi, Dad built me a little practice amp that I was allowed to run after dark.

The thing is actually a transistor circuit with a choke loaded, sliding bias, class A output stage, (it's powered by a PJ996 6Volt battery), think 60's car radio.

Due to the design of the output its always in a state of soft clipping, and has a fairly asymmetric "barn roof" amplitude distortion, it has technically got a dreadful specification but has a very distinctive sound, great for guitar. Probably its THD is through the roof of said barn!

One day a few months ago I was messing around with a radio circuit and using the little practice amp as an output for it, a piece of harpsichord music came on the radio as I switched on and I don't think I've ever heard such good rendition, (The Stranglers, Golden Brown ironically. RIP, David Paul Greenfield ).

So yes. I'm with Andy, ultimately if it sounds good, it is good!

Maybe a few like minded people who are prepared to ignore specifications, could start a new movement in audio, based solely on listening pleasure.

Thanks,
Amie.

[Mark Hennessy]

Already done, I'm afraid.

There's no shortage of valve amplifiers with terrible specifications and absolutely massive price tags. And to go with these low-powered amplifiers, there's no shortage of high-efficiency loudspeakers that also have terrible specifications and absolutely massive price tags. Some people seem to like them; I find them to be universally horrible. But then, knowing what real instruments and voices sound like is a large part of my job.

For obvious reasons it didn't happen this year, but normally I go to the Munich hi-end hi-fi show each year. This show is pretty much the largest event in the hi-fi calender, and virtually all manufacturers are there. I make a point of visiting as many of these "wacky" systems as possible, hoping that one day I'll see what all the fuss is about, but to be honest, it's just a form of torture.

As I say, in the recording studio or on the stage, throw in as much of your preferred distortion as you like - it's part of the creative process. If you want to do that to an existing recording in the privacy of your own home, that's your choice, but it isn't what the artist intended. Knowing a fair bit about how recordings are made, I prefer to listen as accurately as possible, mostly out of respect to all those concerned in its the creation.

What some might not realise is just how much the hi-fi industry plays on insecurity to sell products. It's all about the next upgrade, be it new kit or new accessories like interconnects or damping pebbles or pylons for your speaker cables (I'm not kidding!). It doesn't matter what your system is, recordings quality varies. But there is something you can spend your money on to improve matters - that is what these people believe; that is the myth that is propagated by the hi-fi press, internet "experts", dealers and manufacturers. The result is a constant life of insecurity and (hopefully) spending. The whole thing is seriously quite worrying - like any hobby, there are those that take all this to extremes, and it's simply staggering to look at how much they spend on it. Their choice, but there's got to be better uses for that money.

The answer is simple: to accept that not all recordings are perfect, and to enjoy them for what they are - after all, they would have been produced with a target demographic (and hence assumptions about replay equipment and surroundings), which is why Nirvana will never sound good, whatever the system - but that doesn't matter if you love the music.

A good hi-fi should add nothing to a recording - it should just deliver what is present. A "wacky" setup using valve amplifiers and horn loudspeakers will add lots of colour and excitement, and that will work well with certain recordings (but make others worse, unfortunately). But you can't change the nature of the added colour and excitement without changing the equipment. It's like having a particular filter permanently enabled on your camera, with no option to choose another or turn it off.

Once you know that your system is very accurate, you know that any problems with the sound is nothing to do with your gear and everything to do with the recording. That's very liberating - it removes all the worry and allows you to just concentrate on the music. And when you play a really well produced recording, it will sound amazing. That doesn't happen with the "wacky" system - all recordings send to sound pretty similar as they've had the same "filter" applied. A good hi-fi allows you to listen right into the production techniques in a really forensic way - such details are obscured by systems with large amounts of distortion. Worse, it's possible to mistake some sorts of distortion for added detail!

In short, I use solid-state amplification and monitor-class loudspeakers, and mostly listen to CD. It's not what everyone wants, but having heard an extremely wide range of systems, I've heard nothing to tempt me away...

[Doodlebug]

I was always been satisfied with my home built Williamson amp. :-)