[TomSix]

The operating points and quiescent plate currents for EL34 tubes in some popular amplifiers vary widely. The Ib for each tube is as follows:
Dynaco ST70 50ma
Marantz 7 50ma
Marantz 8 23ma
Triode Labs ST70 Upgrade 40ma
VTL [David Manly] 25-27ma
Manly published a book about his amplifiers in the 1980s [I have lost the book, but still have copies of some pages] where he states "Bias: Set conservatively at the factory to approx 25/27ma for EL34 and 30/35ma for 6550s. Current can be increased to double or triple those figures (moving nearer to Class A operation), but to no sonic benefit; and shortening tube life". [Bold text as written by Manley].
I run my EL34 at about 30 ma, and cannot discern much difference at higher current levels. Your results may vary.

I would say that operation entirely or mostly in class-A has significant ramifications for amplifier performance.

Device crossover distortion in push-pull class-A operation is entirely eliminated (though not magnetic zero-crossing hysteresis distortion, in the case of amplifiers utilizing output transformers).

Also, push-pull class-A amplifiers draw a very steady flow of current from the power supply, and so adverse power-supply modulation issues are substantially mitigated.

I would further contend that the determination of *no sonic benefit* via class-A operation of output device/s would have to be qualified further if one were attempting to make a generally applicable statement.

Sometimes it’s not a matter of excessive current through a device, but a problem of excessive peak voltage and/or excessive resting voltage at a given quiescent current which thereby exceeds rated tube/device dissipation limits.

Somewhat counterintuitively, class-A stages dissipate (convert to heat) the most power during resting (zero signal) conditions —not at maximum-rated (signal) output power as might be assumed.

So yeah, a relatively complex situation.

 

[StimpyWan]

Same here. I do hear (or imagine to hear) tiny differences between certain cables and interconnects, but not really anything pronounced enough to warrant paying an arm and a leg for them. There's obviously a huge jump in quality from something like an Amazon Basics interconnect to, say, a Snake Oil Taipan, but beyond that, the return on your investment curve drops off like crazy. At least from where I'm standing.

That said, there's one exception to that "rule": Speaker cables.
And that one totally snuck up on me, too.

About a year ago, I decided to replace the speaker cables I was using at the time because their connectors split to only about four inches apart, and only did so under a little bit of strain. With mono Aegirs and Vidars, that wasn't exactly ideal. Not strained enough to have me worried about the cable or the binding posts, but still enough to bother me.

The ones I was using were 12 AWG stranded "oxygen-free" copper, and I never really had any complaints about the sound I was getting.
I replaced them with cables of the same length, although about three times more expensive than the old ones were, and made of 14 AWG 6N OCC single crystal copper. Lots of mumbo jumbo that I don't care much about, and yes, also thinner conductors (14 vs. 12 AWG) than the ones they replaced. But they look really nice, so there's that. ;p

What I got from that change, and I don't use that figure of speech lightly here, almost literally blew me away. Having changed nothing else, the highs I got were noticeably clearer than they were ever before. But the biggest change was in the bass: It was always there with the old speaker cables, but now it gained a much fuller body. The bass didn't necessarily got any lower or louder, but it gained a metric Schiit-ton in definition. Before, an upright bass sounded like an upright bass alright, but now, it sounded like an upright bass that's standing right there in front of you inside the room.
Up to that unexpected "happy little accident", I didn't really believe that cables would (or even could) make such a huge difference. But since then, at least when it comes to speaker cables, I'm a believer.
(Although I will still vehemently refuse to believe that you get your money's worth when you spend more than, say, 200 bucks or so on a speaker cable. Beyond that, I really do believe that you're mostly just buying some proverbial snake oil.)

The other thing I've never had the chance to try myself, and would love to give a shot at some point, is to play around with a number of different power cables. I think that a higher-quality cable might actually make sense specifically for power amps, and I hear that you get some interesting results if you use a cable that has conductors that are both, stranded and solid core. The reason why I haven't tried anything in that regard yet is because the quality of the power that I get out of my wall is certifiably horrendous. I live at an apartment complex, and the way things are wired around here means that I am sharing my connection to the city's grid with 99 other units. I don't get any noticeable spikes when a neighbor starts vacuuming or their AC, fridge, or dryer starts up, or anything like that. I had it like that for the few years I lived in a 1920s-era high-rise in San Francisco, so it could definitely always be worse. But it's not exactly great, either. So before I play around with power cables to see if I can hear a difference, I'd like to make sure first that the power I feed into the system is as clean as possible to begin with, as that's pretty much guaranteed to make a much bigger difference than any power cable could ever provide.

I've tested a handful of power conditioners, but they do jack-schiit for me, to be honest.
I have also looked into PS Audio's PowerPlants, but for what my gear can potentially draw I would need to get a single 20 or two 12s, but those are priced a tad steep for my taste.

I really wish Schiit would consider making power regenerators. At their core, they're essentially a sine wave generator strapped to the input of a beefy power amp. There's of course quite a bit more to the controlling end of things than just that, but it's not exactly rocket surgery, either. Nothing that Schiit hasn't done in some shape or form before.

I'm definitely not holding my breath, of course, but a boy can dream, right? ;p

When I worked at Nimbus Records, we had a manager that worked there, that was a serious audiophile. He even had a room mate that worked at a high end store. The manager had set up a couple of listening rooms, using Conrad Johnson tubed gear (PV-5, MV-45, & Motif) with Dahlquist DQ-20 speakers. I don't remember the interconnects, but the systems used Kimber Kable 8TC wire. Nice gear.

Well, imagine my surprise, when I showed up for work one day, and the system was gone! I quickly found out that a new manager didn't like the gear. Too complicated? He went with some cheap shelf system? The CJ gear and speakers were sent back to the Hi-Fi shop, to sell. The Kimber Kable had been trashed!!! So, I ran out back, found the dumpster, and saved the wire. The best speaker cable I've heard. Like you, everything was bigger and more open. Bass was awesome; much tighter, deeper, and more present. I was gob-smacked by the change...!

 

[tin-ear]

It'd be nice if maybe Freya didn't shut down the tubes quite so quickly. A minute or a little more would be my preference.

When the TV show Firefly (2002) was being broadcast, the directors would sometimes "fade to black" at the end of a scene, end of the episode, or whenever. They discovered that TV stations were using a device that, detecting "no signal", would cut to a commercial. This upset the Firefly people, because most of time when you faded to black/silence, you want a quite few seconds to follow. Not a screaming commercial. So, they worked out that they could fade to grey...
But yes, I would consider a home audio device that shuts itself off too quickly, to be defective. Or a device that turns on too slowly.

 

[barondla]

There was an audiophile fave back in the '90's (Audible Illusion Modulus 3A) that ate tubes about as fast as you could swap them. Juiced the tubes to the bleeding edge of their spec, and most tubes don't like that. IIRC Kevin Deal had a similar disclaimer on his site for that particular preamp back then.

I can't honestly say I've ever "worn out" a tube. Yes, I roll a lot, so many of them don't get a bunch of hours. But some do. The 300B's in my speaker amp are 20+ years old and likely have close to 10k hours on them. I still cannot perceive any sonic difference between them and a new (backup) pair that I swap in every now and then just to see. The used ones currently test at about 70% of NOS GM, but again I can't hear a difference at this point. I have a particular Foton 6N8S that I've used off and on for about 3 years now, and would guess it has 1500+ hours on it. It still tests very close to NOS GM. A year is not what I'd expect for the majority of tubes....probably more like 3 years (and more) for most. But a lot has to do with how many hours a day/week the tube is used, and even more importantly how it is run in the circuit as you noted. If run at its maximum parameters, then a year might be about right. If run conservatively, it should last much longer. Just my experience, which may or may not align with the experience of others.

You nailed it. That was the linestage I was talking about. It finally blew up and I replaced it with a Sonic Euphoria PLC transformer passive linestage. Nothing to go bad. Still works flawlessly, but I've moved to a tube linestage.
Thanks,
barondla

 

[EricDH]

When I worked at Nimbus Records, we had a manager that worked there, that was a serious audiophile. He even had a room mate that worked at a high end store. The manager had set up a couple of listening rooms, using Conrad Johnson tubed gear (PV-5, MV-45, & Motif) with Dahlquist DQ-20 speakers. I don't remember the interconnects, but the systems used Kimber Kable 8TC wire. Nice gear.

Well, imagine my surprise, when I showed up for work one day, and the system was gone! I quickly found out that a new manager didn't like the gear. Too complicated? He went with some cheap shelf system? The CJ gear and speakers were sent back to the Hi-Fi shop, to sell. The Kimber Kable had been trashed!!! So, I ran out back, found the dumpster, and saved the wire. The best speaker cable I've heard. Like you, everything was bigger and more open. Bass was awesome; much tighter, deeper, and more present. I was gob-smacked by the change...!

That new manager should have received 100 lashes at least.

 

[Paladin79]

For speakers I generally just use Canare 4S11 at 11AWG but I may well change that out when I go to my dream system. I may even braid my own. How difficult can it be?

 

[433521]

I like silver plated copper for one of my IEMs better than 100% copper. Feel free to use that single datum to guide your entire audio life.

I have a silver plated oxygen-starved copper headphone cable around here somewhere. I got it on sale. It's really pretty and feels nice to use.

For your survey.

 

[macdonjh]

Same here. I do hear (or imagine to hear) tiny differences between certain cables and interconnects, but not really anything pronounced enough to warrant paying an arm and a leg for them. There's obviously a huge jump in quality from something like an Amazon Basics interconnect to, say, a Snake Oil Taipan, but beyond that, the return on your investment curve drops off like crazy. At least from where I'm standing.

That said, there's one exception to that "rule": Speaker cables.
And that one totally snuck up on me, too.

About a year ago, I decided to replace the speaker cables I was using at the time because their connectors split to only about four inches apart, and only did so under a little bit of strain. With mono Aegirs and Vidars, that wasn't exactly ideal. Not strained enough to have me worried about the cable or the binding posts, but still enough to bother me.

The ones I was using were 12 AWG stranded "oxygen-free" copper, and I never really had any complaints about the sound I was getting.
I replaced them with cables of the same length, although about three times more expensive than the old ones were, and made of 14 AWG 6N OCC single crystal copper. Lots of mumbo jumbo that I don't care much about, and yes, also thinner conductors (14 vs. 12 AWG) than the ones they replaced. But they look really nice, so there's that. ;p

What I got from that change, and I don't use that figure of speech lightly here, almost literally blew me away. Having changed nothing else, the highs I got were noticeably clearer than they were ever before. But the biggest change was in the bass: It was always there with the old speaker cables, but now it gained a much fuller body. The bass didn't necessarily got any lower or louder, but it gained a metric Schiit-ton in definition. Before, an upright bass sounded like an upright bass alright, but now, it sounded like an upright bass that's standing right there in front of you inside the room.
Up to that unexpected "happy little accident", I didn't really believe that cables would (or even could) make such a huge difference. But since then, at least when it comes to speaker cables, I'm a believer.
(Although I will still vehemently refuse to believe that you get your money's worth when you spend more than, say, 200 bucks or so on a speaker cable. Beyond that, I really do believe that you're mostly just buying some proverbial snake oil.)

The other thing I've never had the chance to try myself, and would love to give a shot at some point, is to play around with a number of different power cables. I think that a higher-quality cable might actually make sense specifically for power amps, and I hear that you get some interesting results if you use a cable that has conductors that are both, stranded and solid core. The reason why I haven't tried anything in that regard yet is because the quality of the power that I get out of my wall is certifiably horrendous. I live at an apartment complex, and the way things are wired around here means that I am sharing my connection to the city's grid with 99 other units. I don't get any noticeable spikes when a neighbor starts vacuuming or their AC, fridge, or dryer starts up, or anything like that. I had it like that for the few years I lived in a 1920s-era high-rise in San Francisco, so it could definitely always be worse. But it's not exactly great, either. So before I play around with power cables to see if I can hear a difference, I'd like to make sure first that the power I feed into the system is as clean as possible to begin with, as that's pretty much guaranteed to make a much bigger difference than any power cable could ever provide.

I've tested a handful of power conditioners, but they do jack-schiit for me, to be honest.
I have also looked into PS Audio's PowerPlants, but for what my gear can potentially draw I would need to get a single 20 or two 12s, but those are priced a tad steep for my taste.

I really wish Schiit would consider making power regenerators. At their core, they're essentially a sine wave generator strapped to the input of a beefy power amp. There's of course quite a bit more to the controlling end of things than just that, but it's not exactly rocket surgery, either. Nothing that Schiit hasn't done in some shape or form before.

I'm definitely not holding my breath, of course, but a boy can dream, right? ;p

I was part of the Yulong DA-1 tour recently. It was shipoed with an add on outboard power supply. It made a big enough difference I would consider buying one even though I consider it expensive. Not snake oil to me.

I looked at Paul McGowen's pricing and decided at this time I won't. Maybe when I have a room with better acoustics and the time to listen critically.

After mt tine on the Yulong tour I sent a product request type email to Schiit Central. A generic power regenerator would be great, but perhaps expensive. Maybe a super-whammy, really clean DC power supply? Maybe that amounts to the same thing, does clean DC require clean AC (or batteries)?

I've thought about that, too. I don't use my gear 24/7, so I could build a simpke battery power supply with onboard charger...

There was an audiophile fave back in the '90's (Audible Illusion Modulus 3A) that ate tubes about as fast as you could swap them. Juiced the tubes to the bleeding edge of their spec, and most tubes don't like that. IIRC Kevin Deal had a similar disclaimer on his site for that particular preamp back then.

I can't honestly say I've ever "worn out" a tube. Yes, I roll a lot, so many of them don't get a bunch of hours. But some do. The 300B's in my speaker amp are 20+ years old and likely have close to 10k hours on them. I still cannot perceive any sonic difference between them and a new (backup) pair that I swap in every now and then just to see. The used ones currently test at about 70% of NOS GM, but again I can't hear a difference at this point. I have a particular Foton 6N8S that I've used off and on for about 3 years now, and would guess it has 1500+ hours on it. It still tests very close to NOS GM. A year is not what I'd expect for the majority of tubes....probably more like 3 years (and more) for most. But a lot has to do with how many hours a day/week the tube is used, and even more importantly how it is run in the circuit as you noted. If run at its maximum parameters, then a year might be about right. If run conservatively, it should last much longer. Just my experience, which may or may not align with the experience of others.

To paraphrase Hawkeye Pierce: your tubes are fine, your ears are worn out.

 

[45longcolt]

I've tested a handful of power conditioners, but they do jack-schiit for me, to be honest.
I have also looked into PS Audio's PowerPlants, but for what my gear can potentially draw I would need to get a single 20 or two 12s, but those are priced a tad steep for my taste.

Installing a PS Audio regenerator was equivalent to a speaker upgrade for my system. YMMV.

Oh, and when swapping wires, don't forget to clean everything, deoxit, etc. Can make a difference that might surprise.

 

[33na3rd]

When I worked at Nimbus Records, we had a manager that worked there, that was a serious audiophile. He even had a room mate that worked at a high end store. The manager had set up a couple of listening rooms, using Conrad Johnson tubed gear (PV-5, MV-45, & Motif) with Dahlquist DQ-20 speakers. I don't remember the interconnects, but the systems used Kimber Kable 8TC wire. Nice gear.

Well, imagine my surprise, when I showed up for work one day, and the system was gone! I quickly found out that a new manager didn't like the gear. Too complicated? He went with some cheap shelf system? The CJ gear and speakers were sent back to the Hi-Fi shop, to sell. The Kimber Kable had been trashed!!! So, I ran out back, found the dumpster, and saved the wire. The best speaker cable I've heard. Like you, everything was bigger and more open. Bass was awesome; much tighter, deeper, and more present. I was gob-smacked by the change...!

I like Kimber's design philosophy - good copper, good connectors, and minimum dielectric. I am slowly changing all of my speaker cables and IC's, except phono, over to Kimber. I haven't been disappointed yet.

 

[artur9]

This is what happens when parts become uncertain--you either do a lot of what-ifing, or you take the chance that you simply won't be building something for a good long while. Me, I'd rather build something. I suspect most of the people who work for us would rather build something as well.

I work in software and the most frustrating thing, to me, is someone who spends minutes/hours what-ifing when making a change and running the tests literally takes 30s.
I don't have magic smoke to consider, thank goodness.

 

[artur9]

I'll say it up front, that my idea is just wrong!
My idea is, faced with indecision of getting silver vs black, is to get... one of each.
Wrong!

You'll always be able to tell which is the L and which is the R amps if you do.

 

[wout31]

All that fun talk about speaker cables.
Take of the rear panel of your speakers and look inside.
You're spending money outside to connect the cheapest piss poor cabling, connectors and bad soldering inside.
Hilarious.
Yes cables can sound different because of different impedance, conductance and capacitance. Brand and price has nothing to with it. You have to find a match with your gear regardless of price. Base your choice on looks is just as valid if that is important to you.

 

[Plautus001]

All that fun talk about speaker cables.
Take of the rear panel of your speakers and look inside.
You're spending money outside to connect the cheapest piss poor cabling, connectors and bad soldering inside.
Hilarious.
Yes cables can sound different because of different impedance, conductance and capacitance. Brand and price has nothing to with it. You have to find a match with your gear regardless of price. Base your choice on looks is just as valid if that is important to you.

In my experience strand count makes a difference, especially for bass. A high strand count 16 AWG seems to have more bass than a low strand count 12 AWG.

When I used to bi amp and/or bi wire I used weaved IXOS 16 high strand for mid/high and stand copper high strand count 12 AWG for bass.

 

[Ableza]

A high strand count 16 AWG can carry more current than a low strand count 12 AWG.

I'm sorry but this is technically incorrect. Higher strand count = more flexibility, but ampacity is determined by the temperature rise in the wire as current increases, with solid-core wire having the highest ampacity for any given size.