Solid state valves revisited

Maxi

We are traditional folk I'd love some old school steam power to go shopping in with all that lovely brass and copper boiler / pipe work perhaps it could be powered by some fusion reactor instead of coal and a Motor Head logo on the bonnet

vasselmeyer

ThePrettyDamned said:

But none of this would be an issue if there was a solid state valve plug-in that captured the electronics within a valve (after all, it is just an electronic component).

Actually, there are. Jet City do solid state components they sell unter the brand name "Retrovalve" which are solid state, fully analogue replacements for valves. Look here http://www.jetcityamplification.com/#!retrovalves/ctjr

I'm going to get some of these next time I need new valves. You can see a demo from Jet City here:

http://youtu.be/7za6RsryEYU

AMT also do a similar product.

ThePrettyDamned

vasselmeyer;117640" said:

ThePrettyDamned said:But none of this would be an issue if there was a solid state valve plug-in that captured the electronics within a valve (after all, it is just an electronic component).





Actually, there are. Jet City do solid state components they sell unter the brand name "Retrovalve" which are solid state, fully analogue replacements for valves. Look here http://www.jetcityamplification.com/#!retrovalves/ctjr

I'm going to get some of these next time I need new valves. You can see a demo from Jet City here:



AMT also do a similar product.

That's what this thread is about - was just wondering if anyone had tried them to verify if they're any good or not.

Amt are also developing power valve ones... Which is even more interesting.

NervousJohn

ICBM;117382" said:

The interesting thing is that if you look on a scope, or even listen, to a valve distorting and a transistor distorting in isolation without the rest of what makes a valve amp different from a solid-state amp, it's quite hard to tell them apart.

They will look similar on an oscilloscope as single tone time domain measurements of distortion all look the same, because the interesting harmonics are so much smaller than the main tone you can't really see them. An alternative may be a couple of tones close together and look at the frequency spectrum to see differences. Although we're now into expensive test hardware that's beyond the scope of most workshops.

Can you spot the RF engineer?

ICBM

NervousJohn said:

They will look similar on an oscilloscope as single tone time domain measurements of distortion all look the same, because the interesting harmonics are so much smaller than the main tone you can't really see them. An alternative may be a couple of tones close together and look at the frequency spectrum to see differences. Although we're now into expensive test hardware that's beyond the scope of most workshops.

Can you spot the RF engineer?

Can I borrow some of your test gear?

That's definitely true. I certainly don't think they are identical, I just think that the differences are less night-and-day than most people who hear big differences between valve and solid-state *amps* think. The way the circuit is put together matters as much as the active components.

One of the real giveaways which is very hard to get right is what happens at the exact point of initial distortion, though - as yet, I've never heard a solid-state device of any kind that does it exactly the same as a valve amp. Fully clean or fully distorted is much harder to tell apart.

martinw

 

ThePrettyDamned said:

I suspect when I finally get me 6505 (many years from now...) I'll just revalve the lot with solid state valves and be done with it.......

Why would you do that? Sounds a bit dogmatic to me. What if it sounds as awesome as you hope with valves in?

ThePrettyDamned said:

Valves are expensive, poorer and poorer quality and bad for the environment.

Respectfully that's not true. Valves are currently cheaper than the solid state replacements, and I can't see SS replacements becoming cheaper even with increased volume.

As for the environment, that's not true either. OK, valves use a bit more energy, but that's so tiny on the scale of things it's not worth mentioning. I've said several times on this forum, and MR, that production of solid state electronics is an environmentally dirty business, as much as valves. I was in the semiconductor industry for 10 years, but do some research on the net if you don't believe me. Ok, there may be differences of magnitude here and there, but it's not like one's dirty and the other's clean. Both have pros and cons, and both can be (and probably aren't) controlled with good management.

The quality of today's valves in my experience is stable, and has been for years. Wherever you think that level is, and I think it's fine, it is at least not getting worse.

I also disagree respectfully with ICBM; I think that the fundamental character of the way that a valve works is always going to be significantly different to a solid state amplification device. I've never heard a SS amp that transitions to overdrive in the way a valve does, or even adds harmonics when predominantly clean, despite having seen a lot of them, some of which were designed and built in the days when they were just putting a solid state device in a valve circuit, and many others besides. However there are new amplification devices around, or at least new applications for existing ones, and it may be that this can change...I'm open-minded!

Of course I'll be branded a 'valve-snob' for having voiced my opinion, but I will state again FWIW that I am open to non-valve amplification, and have owned and used them in the past, and would again. I just prefer valves as things stand at the moment.   This isn't some sort of pseudo-political crusade with me, it's just me relating my experience. And if you think I have some sort of commercial bias, well hardly. I'm sure that whatever happens, my tiny little enterprise will have enough to feed on to keep me going till retirement, and even if it doesn't I can always earn more at the new Aldi's they're opening up the road.

Of course a lot depends on how you use an amp; if you play either clean or heavily distorted, you may have less of an issue with SS. This point is often overlooked.

Going back to the OP, I notice that this question comes up now and again, but the answer is always the same...no-one's tried them. I happen to agree with those who think the development of SS replacement valves is a blind alley....I'd much rather see a fully integrated, ground-up design. Perhaps the AMT is that thing? I look forward to trying one.

Hope this isn't too controversial on this, the AntiTGP.

ThePrettyDamned

@martinw, you're not a valve snob and you're absolutely right on a lot of that, and the rest is just opinion based.

When I say valves are bad for the environment, it's not just the pure green effect immediately, but they're larger and use a lot of materials that go to waste when they blow. I guess it's six of one, half a dozen of the other. But solid state designs, if well designed, should very rarely waste any parts, whereas a valve amp will inevitably tire the valves, eventually, and need a replacement, as well as the usual capacitor replacements that occur (though not often).

And I do that 'clean, slightly dirty, heavy gain, lead' thing, which solid state does so well. If I was in a more traditional band, perhaps valves always will win.

You're right on the blind alley as well. I think the power valve replacements will be much more useful for many because they won't break (or shouldn't). Preamp valves last for ages anyway.

I still think, if the *do* preserve 99 percent of the tone of valves, they would be a better investment for many people who never want to worry about valves blowing. I don't think they'll replace valve products, but it would be nice if they could exist side by side. A lot of folks could have them as a backup set for a valve amp, too, guaranteeing a perfect set of valves at every gig that will never need to be replaced.

Misterg

ICBM said:

The interesting thing is that if you look on a scope, or even listen, to a valve distorting and a transistor distorting in isolation without the rest of what makes a valve amp different from a solid-state amp, it's quite hard to tell them apart.

I respectfully disagree. What happens when a typical transistor based gain stage distorts (hard clipping) is totally different to what happens when a typical valve (triode) based gain stage distorts (mainly compression). They look very different on a scope, and they sound very different. The design of the amplifer using these components obviously also has an effect, but it's the difference in behaviour when driven beyond the linear region (i.e. into distortion in the engineering sense) between valves and transistors that is at the root of the differences.

ThePrettyDamned said:

Another interesting concept would be a solid state design that accurately mimics the properties of, for example, old mullards. 

A Ukraian guy called Dimitri Danyuk has been working on this for ages. You can read about it here:

http://www.scribd.com/doc/65330169/Triode-Emulator-by-Dimitri-Danyuk

I think this spawned the 'Fetzer valve' replacement:

http://www.runoffgroove.com/fetzervalve.html

...which I suspect is the basis of the 'plug-in replacements'. With sufficient refinement, I'm sure that they will work just fine, but suspect that it's only a matter of time before everything gets replaced by an AxeFX type of modelling approach.

YMMV

ICBM

Misterg said:

I respectfully disagree. What happens when a typical transistor based gain stage distorts (hard clipping) is totally different to what happens when a typical valve (triode) based gain stage distorts (mainly compression).

Not at all, you can easily get hard clipping from a single valve gain stage. I just went and checked since you had me doubting myself for a minute .

It's not a perfect square wave - the tops of the clipped waveform are slightly sloped - but it is most definitely hard clipping and not compression.

There is no reason for it not to be - all you're doing is making it produce a signal swing which goes outside the supply voltage limits, so it's a certainty that it will clip.

martinw

ThePrettyDamned said:

When I say valves are bad for the environment, it's not just the pure green effect immediately, but they're larger and use a lot of materials that go to waste when they blow. I guess it's six of one, half a dozen of the other. But solid state designs, if well designed, should very rarely waste any parts......

Fair point. I do throw away the odd blown Mosfet or whatever, and some caps here and there, but on the scale of it I bin a lot more valves.

However, I also send off to landfill quite a lot of entire amps and PCB assemblies that aren't worth repairing from SS amps, whereas valve amps tend to be repairable to a much greater degree. That's more a market positioning thing than SS versus Valve though, i.e. they're made cheap to sell cheap.

There're valve amps in that category too of course. I'm all for the amp makers making good quality SS amps that don't sound like valve amps (necessarily) but do their own thing, and are repairable. Sadly we live in a throwaway society.

monquixote

Absolutely. 

If they did a set of solid state valves that would essentially last for ever and sounded 90% as good as a fresh set of decent glass bottles I'd stick them in my gigging amp in a heartbeat. 

monquixote

It looks like the Retrovalves are designed by Roberts Audio Technologies and the patents they are covered by are listed here:

http://www.robertsaudiotech.com/dougroberts.php#Doug

Patents:

http://www.google.com/patents/US7286060

http://www.google.com/patents/US7408401

http://www.google.com/patents/US7482863

http://www.google.com/patents/US20080260183

Those of a geeky disposition can have a read up about how they work.

ThePrettyDamned

Wisdom for @martinw.  Didn't consider the implications of whole amps being discarded!  

monquixote

This video lets you do a blind test of sound difference. 

I actually picked out both of the retrovalves on clean sounds, but not on OD sounds. 

That's not to say they sounded worse, just different. 

Misterg

ICBM said:
Not at all, you can easily get hard clipping from a single valve gain stage. I just went and checked since you had me doubting myself for a minute .

You *can*, yes, but in a typical triode gain stage, you don't - not before an awful lot of compression first. Whereas with a transistor gain stage, all you can get is hard clipping.

Also, having the 'corners' rounded off matters too - If you see square corners on a clipped signal, all the harmonics will be present at comparable levels (odd and even), for rounded corners, odd harmonics dominate.

ThePrettyDamned

monquixote;118899" said:

This video lets you do a blind test of sound difference. 



I actually picked out both of the retrovalves on clean sounds, but not on OD sounds. That's not to say they sounded worse, just different. 

I got them all wrong - I thought 1 was the lower gain solid state thing.

This is a neat test that proves, if you replace one valve, it makes little (but noticeable) difference. I preferred, clean, the Amber one to all others.

Thing is, this just replaces one valve. I'd like to have a simple a/b/c/d - one all valve, one solid state pre and valve power, one solid state power, valve pre and lastly, all solid state. And for the results to not be announced for ages to get people really thinking.

dindude

@martinw I agree with everything you said in you post on the previous page.

I will also add that I'm an unashamed valve snob, what's the issue when you can buy a valve amp for next to no money these days, it's not a financial thing, it's preference. IMO, we seem to dance around this subject a lot with the net result that valves sound different to SS, and to these ears, the vast majority of the time, a LOT better than SS.

ICBM and the pretty damned have def marked themselves out as the SS fanboys of the site, but unfortunately I respectfully disagree that the answer to every amp question is Peavey

Back on topic, these solid state "valves" are interesting, but whilst valve supply is plentiful and relatively cheap, whilst the SS version are rare and pricey, they are somewhat pointless.

They are the electric car of the amp world, maybe we will come to rely on them in time, but you would have to be an early-adopting fool to put your money this way right now, hence why no one has tried them.

My god, hard day at work and a bit of booze has made me rather blunt, sorry

ICBM

dindude said:

I will also add that I'm an unashamed valve snob, what's the issue when you can buy a valve amp for next to no money these days, it's not a financial thing, it's preference. IMO, we seem to dance around this subject a lot with the net result that valves sound different to SS, and to these ears, the vast majority of the time, a LOT better than SS.

ICBM and the pretty damned have def marked themselves out as the SS fanboys of the site, but unfortunately I respectfully disagree that the answer to every amp question is Peavey

I'm not really a solid-state fanboy - I admit I do like many solid-state amps, although not as much as my favourite valve amps - and I do really feel that they're much better than most people are willing to admit (perhaps because they've never really tried to sit down and get good sounds out of something they perceive as inferior before they start) but where I really part company is over cheap valve amps. The majority really sound worse to me than many solid-state amps. That includes some valve amps made by Peavey in relation to their solid-state ones .

I really feel that a lot of these cheap valve amps only sell because they're valve - to me, they don't have many of the characteristics of good valve amps, whereas a decent solid-state amp often can do.

Regardless of what I said about it being harder to tell the difference between the two components than you might think outside the complete amp, I do also agree with martinw and others about that edge-of-breakup problem - solid-state hasn't ever quite got that right. I hear it mostly as a slightly 'separated' effect where the distortion seems to ride on top of, and separate from, the larger clean sound. Some valve amps do it too, but all solid-state ones I've ever heard do - it's something I always hear, even though for most of the sounds I use it doesn't bother me.

Where I am a solid-state fanboy is that I actively prefer a lot of outright solid-state distortion and fuzz sounds to valve overdrive. It's different, but in a good way.

ThePrettyDamned

Dunno about fanboy - I like a good sounding amp, regardless of how it gets there, and how people define 'good' varies.  Can't afford a 6505 or a 5150, so the next best thing is either a cheap, poorly made valve amp that may sound poor at lower volume and may not even fit in my room for practice, or a modelling amp which, asides from the Blackstar ID range, have not hit the spot with me for my style, or an analogue solid state amp, of which there are at least 2 that fit the bill. 

But when I do get a valve amp, and I will because currently, solid state amps *don't* sound as good, I'd rather it not crap out on me at a gig, which is really why I'm interested in these replacements.  Power amp valve replacements have not yet been released, and these are the ones I'd most be interested in as 12ax7s seem to last for a long time anyway, whereas power valves can blow at a gig. These solid state replacements could end the need to take a backup amp (which will almost certainly be a solid state or modeller amp anyway.  On the other hand, they might take a great sounding valve amp and make it sound dead, lifeless and generally naff.  I hope they don't, though.

It also prevents the (probably unlikely, admittedly) possibility of a valve going taking out more of the circuit, leading to a costly repair (or, on a cheaper valve amp, a write off).  No idea if that sort of stuff actually happens to be honest, but I've heard horror stories.

ICBM

ThePrettyDamned said:

It also prevents the (probably unlikely, admittedly) possibility of a valve going taking out more of the circuit, leading to a costly repair (or, on a cheaper valve amp, a write off).  No idea if that sort of stuff actually happens to be honest, but I've heard horror stories.

Sadly it does, and more often than you might think - not so much the write-off bit (it would have to be a very cheap amp and a very expensive repair), but a lot of amps suffer damage as a result of failed valves… usually due to bad design or poorly specified parts. A really well-designed, well-made valve amp should never fail in any way other than blown valves and fuses. There are a few which that applies to, at least in my experience (not that I've seen every dead amp there is) but they're generally at the very expensive end of the range - and even some very expensive ones are not immune, if they're poorly designed… there was a Custom Shop Fender I had a few weeks back which did extensive damage to itself all for the lack of an HT fuse.