Solid State Tubes

admin · Post by **b0b** » 25 Apr 2013 10:58 pm

I wonder how these sound. 6L6 and 12AX7 solid state replacements.

http://eshop.amtelectronics.com/6l6-12a ... tubes.html

Daniel Policarpo · Post by **Daniel Policarpo** » 26 Apr 2013 2:03 am

This is very interesting bOb. I want to say somebody was trying to develop something similar in the US years ago, but nothing came of it.

Kelvin Monaghan · Post by **Kelvin Monaghan** » 26 Apr 2013 2:53 am

Thats an interesting concept. But why would you change a tube for solid state. I dont get it

Mike Bagwell · Post by **Mike Bagwell** » 26 Apr 2013 3:20 am

A similar device called a Fetron was available 40 years ago. Mesa Boogie used them for a while. This link has some good info.

http://www.philipstorr.id.au/radio/eleven/fetron.htm

Greg Cutshaw · Post by **Greg Cutshaw** » 26 Apr 2013 5:07 am

I was particulary amused by this commment from Сергей:

Интересно воткнуть в усилитель и послушать(у меня однотакт).Если будет музыка хорошо,а если просто звук,то для гитарных только и пойдет не замену вакуумных.И еще какая цена будет.Может за эти деньги лучше купить ведро 6П3С.

Greg

Greg Cutshaw · Post by **Greg Cutshaw** » 26 Apr 2013 5:12 am

OK, it's Russian... Google tranlsate:

It is interesting to plug into an amplifier and listen to (I odnotakt.) If the music is good, but if you just sound, and guitar only, and will not replace vakuumnyh.I budet.Mozhet yet what the price is better for the money to buy a bucket 6P3S.

Greg

admin · Post by **b0b** » 26 Apr 2013 6:55 am

If the sound is acceptable, the benefit is durability. Guitar amps take a lot of abuse. tubes<sup>*</sup> can break, and they deteriorate over time. I know people who replace their tubes every 2 or 3 years, claiming that they wear out like strings.

Like light bulbs, the filaments in tubes fail eventually. A solid state replacement wouldn't have that problem. You wouldn't need to carry spares in your pack-a-seat.

<sup>*</sup>We Americans call them tubes, but they are called valves in other countries.

Richard Sinkler · Post by **Richard Sinkler** » 26 Apr 2013 7:57 am

Plus, they look cool.

Bill A. Moore · Post by **Bill A. Moore** » 26 Apr 2013 8:37 am

They do look cool!
I think the manufacturers have come a long way with SS tube emulation already. Seems reasonable to put the package in a tube replacement format.

Alan Brookes · Post by **Alan Brookes** » 26 Apr 2013 8:59 am

Do they need to warm up like tubes do?

How does the cost compare with tubes ?

There are hundreds of different tubes out there, and some equipment has had to be discarded because the tubes have blown and replacements are not available. What sort of range will eventually become available?
Will it be limited to just 6L6 and 12AX7 ?

Dickie Whitley · Post by **Dickie Whitley** » 26 Apr 2013 10:21 am

Greg Cutshaw · Post by **Greg Cutshaw** » 26 Apr 2013 10:21 am

If it's going to emulate a tube, it had better glow when powered on!

Greg

Donny Hinson · Post by **Donny Hinson** » 26 Apr 2013 10:43 am

I honestly think that the difference between solid-state and tube amps is insignificant...until they're pushed into distortion. It's only then that tubes seem to have an advantage, but that is even coming to an end with modeling amps that can emulate tube distortion sounds. Look, I played tube amps for 25 years. I designed my own preamps and I modified amps for fun. But all that came to an end when the U.S.A. went out of the tube business. Foreign tubes just didn't have the quality and consistency, and very soon, NOS tubes became way overpriced. Of course, the old amps were easy to fix and modify, but that soon became less and less fun because the "heart" of the amp, the tubes, became more and more "iffy".

Sure, it's just an opinion, but it's an opinion that will soon be spreading. Tube amps are expensive to buy and maintain, and their advantages for normal pedal steel demands (clean power, headroom, and practicality) are mostly a myth, IMHO.

Iestyn Lewis · Post by **Iestyn Lewis** » 26 Apr 2013 11:41 am

Hear me out, I've got a great name for these. Let's call them "transistors."

Miguel Saldana · Post by **Miguel Saldana** » 26 Apr 2013 12:09 pm

Weber makes a rectifier tube replacement, that I imagine follows similar principles, since the early 2000s. Not much buzz or praise. Most I've read say they're not up to replacing real tubes.

And for an older attempt at replacing tubes:
http://www.philipstorr.id.au/radio/eleven/fetron.htm

Stephen Cowell · Post by **Stephen Cowell** » 26 Apr 2013 12:25 pm

b0b wrote:Like light bulbs, the filaments in tubes fail eventually. A solid state replacement wouldn't have that problem. You wouldn't need to carry spares in your pack-a-seat.

I've never had a tube filament fail... it's always they get gassy, or the cathode wears out (low emission)... or they get noisy/microphonic. One thing tubes *won't* do is get zapped... which is something transistors/IC's are very susceptible to. The filament does draw a lot of current... the hot-cold cycles are wear and tear on the tube.

If we get nano technology to come through for cathode chemistry the sky's the limit... they're already making micro-tubes with buckytube cathodes... diamond is another possibility, a great electron emitter. I'm just glad I can get decent new tubes, for a while there it was touch-and-go.

Len Amaral · Post by **Len Amaral** » 26 Apr 2013 6:41 pm

There is a SS replacement for a 5U4 tube that is supposed to eliminate the sag effect from the tube and get more headroom. If you replace preamp & power tubes with a ss tube replacement, wouldn't you basically have a ss amp? Unless the ss replacements emulate tube characteristics? Doesn't the FET technology do the same? It also seems FET has fallen by the wayside.

I just replaced a SS rectifier from a boutique amp with a 5U4 rectifier tube and it sounds much warmer IMO.

I just got a Fender Xcelsior 13 watt tube amp to leave at a friends house along with a guitar & lap steel. I hope the tubes hold up because this amp for jamming is a sweet sound.

admin · Post by **b0b** » 26 Apr 2013 7:33 pm

My Mesa/Boogie Maverick (prototype) has both rectifiers, with a switch. I don't like the tube rectifier for steel. The solid state diodes have more headroom. That's how it feels on the attack, anyway.

Ken Fox · Post by **Ken Fox** » 27 Apr 2013 4:07 am

Jim Evans first FET 500 HV was in fact his hybrid amp with high voltage FETs plugged into the tube sockets.

David Nugent · Post by **David Nugent** » 27 Apr 2013 9:36 am

Would appear to me that these would be ideal to carry as backup units for those of us who gig with tube amps. The risk of damage or breakage I assume would be greatly reduced thus making storage simpler.

Michael Hummel · Post by **Michael Hummel** » 27 Apr 2013 11:03 am

It is well known that 6-string guitarists (depending on genre, of course) like tube rectifiers because of the 'sag' or dip in B+ voltage that happens on the attack, especially with a big barre chord.

It makes perfect sense that steel players would prefer the solid-state rectifier that has much less 'sag' because it keeps that nice crisp attack that we all like. Again depending on style of steel being played.

(I normally am glued to the screen to wait and see what Cowell, Grafe, Sarno, et al will post on these subjects...but I'm getting braver

)

Mike

Stephen Cowell · Post by **Stephen Cowell** » 27 Apr 2013 4:14 pm

Michael Hummel wrote:It is well known that 6-string guitarists (depending on genre, of course) like tube rectifiers because of the 'sag' or dip in B+ voltage that happens on the attack, especially with a big barre chord.

Ah, but if your amp is true Class 'A' then it doesn't matter... the current never changes, so the rectifier doesn't affect the attack... any compression you're hearing from a Champ is saturation-based. One thing I've noticed... lower-voltage amps sound sweeter... the 80w Twin is just sweeter than the 100w one, for spanish electric. Opposite normally applies for steel... they like the silver-face. Note the popularity of Marshall amps... saturation/compression without tube recs.

It makes perfect sense that steel players would prefer the solid-state rectifier that has much less 'sag' because it keeps that nice crisp attack that we all like. Again depending on style of steel being played.

Even harmonics get in the way of polyphonic sound... they step on each other's toes. Steel players prefer cleaner amplification... hence the great preference for solid-state equipment, when 'normal' guitarists (jazz being an exception) prefer tubes' harmonic distortion, with and without tube rectifiers. Some tube rectifiers work almost like solid-state, like the GZ34... or the Fender amps that had *two* 5U4's in them.

Greg Cutshaw · Post by **Greg Cutshaw** » 27 Apr 2013 5:17 pm

Solid state tube =oxymoron.

Greg

Tim Marcus · Post by **Tim Marcus** » 28 Apr 2013 8:41 am

I think a lot of people mistake cathode bias sag for tube rectifier sag. The gz34 is like a rock - very efficient rectifier! I notice only a slight harmonic difference between that and silicon

These solid state devices are more expensive than new old stock tubes, and are untested over time - the ultimate test of electronic reliability

I'd skip em but then again I'm kind of a purist

admin · Post by **b0b** » 28 Apr 2013 6:05 pm

You can just solder a solid state bridge rectifier into a tube socket, or even wire up 4 diodes into an old tube socket. The components are dirt cheap.

But it's easier to just spend 10 bucks:
<center>
http://tubedepot.com/ssr.html

</center>