How good are the Sub Mini Tubes?

[aron]

I mean, do they sound markedly better than our transistors? I'm going to try them out, but so far I have not heard a tube based pedal that sounded amazingly different from our tried and true transistor circuits. Even the high voltage pedals have not impressed me that much.

How much voltage needs to be applied to these tubes for optimum performance? I need to hit the data sheets and check out the samples.
Thanks!

[svstee]

I don't know what it is, but my Pentaboost sounds so much better than any of the 5-10 transistor or IC boosters I have ever had on my board. It seems to have a little compression as well as great dynamic response. Even amps that don't "take" pedals well like my Peavy Windsor sound good with it.

I'm sure you are well acquainted with all the negatives (power/voltage, microphonics, heat, space, ect.). I personally think that they CAN sound better, but they don't always, and they can be a pain to work with sometimes.

My 0.02$.

[frequencycentral]

Aron, I'm obviously not the best person to answer your question (being the resident submini nut), but if you PM me your address I'll send you a small selection of subminis to try.

[aron]

Hmmm. I have used the 12V car radio tubes, hi-voltage tube pedals, starved tube pedals and I have not heard significantly different tones yet. I don't think I have heard the right combo yet. Almost everyone I know that has tried the hi-voltage and submini tube pedals, are still using solid state devices. Hmmm but it brings something to mind.....

[aron]

OK, done. Thanks.

Aron

[Ripthorn]

I am finishing a submini amp that knocks the socks off my solid state marshall (5210) in terms of tone.  It has probably the nicest distortion in my arsenal (over stompboxes, ss amps, modelled tones, etc.).

[kurtlives]

I love my little starved plate design preamps. They really impress me.

Give them a shot!

[solderman]

A different twist to the same question

Does sub minis sound different or bettercompared to there bigger normal form factor given the same conditions voltage vice and circuit etc.

I have only built with 12Ax7 and 12Au7 and EL90. Those are pretty small as well and can be used in a Hammond 1590B type of box.

//Solderman   

[Renegadrian]

Aron, the tube pedals you tried were DIY or commercials?!
I am a tube fanatic as you already know, still I built lots of transistor based circuits. Actually they're both good, still I am a little on the tube side. You know the tube adds a little magic in it...I tried a couple of submini circuits, like Rick's Pentaboost, which is decent at 9V but has a lot more headroom at 50V. Also the WEREWOLF, 6205 pentode. It works good at 50V.
And yeah, those circuits have a low parts count!!! And it's good to hear such pleasently tones out of those toys, isn't it?!

Maybe you still haven't tried the right tube circuit...but hey it's not a rule of thumb that tubes=better than trannies.
A.

[Ripthorn]

A different twist to the same question

Does sub minis sound different or bettercompared to there bigger normal form factor given the same conditions voltage vice and circuit etc.

I have only built with 12Ax7 and 12Au7 and EL90. Those are pretty small as well and can be used in a Hammond 1590B type of box.

//Solderman   

It's hard to match the same conditions, since most subminis have a max voltage of about 160V as opposed to 300V for "regular" tubes.  As far as sound, I can't speak to it, since I have used 6111 and 6021 but no 12au7 yet.

[solderman]

A different twist to the same question

Does sub minis sound different or bettercompared to there bigger normal form factor given the same conditions voltage vice and circuit etc.

I have only built with 12Ax7 and 12Au7 and EL90. Those are pretty small as well and can be used in a Hammond 1590B type of box.

//Solderman   

It's hard to match the same conditions, since most subminis have a max voltage of about 160V as opposed to 300V for "regular" tubes.  As far as sound, I can't speak to it, since I have used 6111 and 6021 but no 12au7 yet.

Well, lets say at starved or medium voltage (9-180V). Some of the ones I have built is the 12Au7 Rick H:s "Vibra Caster" at 24V and a design of my own with 12Ax7, based upon the preamp of the SOVTEK MIG 50 at 180V Both sounds good to my ears.

 

[Boogdish]

I mean, do they sound markedly better than our transistors?

It's all in the eye (or ear in this case) of the beholder.  If you don't like the sound of tube pedals, then they aren't better.  If you do  like them, then they are.

I believe that guitar pedals were put on this planet so that we can have more fun.  Worrying about if a tube or a transistor sounds "better" isn't my idea of fun, but I'm sure some people enjoy fretting over those things.  I've been working on a couple of tube circuits recently and I enjoy working on those designs more than working on solid state designs.  I'm using tubes because it's more fun for me.  To each his (or her) own.

[aron]

> Aron, the tube pedals you tried were DIY or commercials?!

Both. I have made my own starved and 12V circuits. I have not made any hi-voltage tube pedals for myself but I have used them. I'm sure I have not used the right one that sounds markedly better than a good overdrive mated to a good tube amp.

>If you don't like the sound of tube pedals, then they aren't better

All the tube pedals I tried sound very different. For example:

EH English Muff'n sounds totally different than
Varidrive
Tube Driver
MiniBoogee
or my 12V pedals etc...

I too like the simplistic circuits of tubes. But FETs are close.

Are your circuits high-voltage or low?

[ninjaaron]

I tend to be of the opinion that tubes really come into their own when you are talking about power amp applications because they handle higher voltages and tend to have a more linear responce in that range. I find that FETs sound just about as good for small applications.

But, I'm kinda a n00b, so who cares?

[sean k]

I've got a bass preamp with 1 12AX7 which is straight out of one of Kevin O'connors book (of London Power) and I took it around to a bass player friend who has macs and pro tools etc. We plugged his Rick straight into the desk then put the preamp in there and the change of tone was noticable if not great. It was a clean boost and the distortion added was of the even harmonic type so it just sounded warmer and rounder.

I think that this is the most noticable use of tubes versus transistors. Clean. As soon as you push the tubes into weird places then the distortion becomes alike most circuits that bang the wave top down but when you use them to get clarity I think the difference is more marked even if it is quite subtle.

That said the tubes always come with the ripple of filaments... maybe someone could design a switching supply to push those babies into the above 20kHz region so it'd still be there... we just couldn't hear it!

[Ben N]

With subminis, it is often feasible to run the filaments off a battery, so no ripple, if that really bugs you.

[petemoore]

  "Can you send me a brochure? I would love to see one''.
  I mean, do they sound markedly better than our transistors?
  I'll have to get some to verify my theories as stated below.
  I'm going to try them out, but so far I have not heard a tube based pedal that sounded amazingly different from our tried and true transistor circuits.
I think it'd be possible to hide a tube in my signal path and have me think there's only transistor up to the point of the input tube on the amp.
Even the high voltage pedals have not impressed me that much.
  I'm not sure high voltage or low voltage is the 'ticket', but it's all about the 'spillover', when one tube magnifies and the other one magnifies again, the other one gets distortions in the view, and the 'wiggle' between them may cause a slight 'wake'. Speaking of 'wiggle' tubes seem to do remarkably well when vibrated very forcefully at various frequencies, mostly in the guitar freq. range.
  Except for application of very forceful vibrating, transistors seem perfectly able to paint fine pictures, as good and better [almost exactly like tubes in this sense], I'd describe the difference as something like a bevel-chisel tip Sharpie and a chisel-tip sharpie...both apply color, both make wide or ~sharp lines, either one can be used to produce very attractive or extremely ugly artwork, some people can even tell the difference [sometimes, but they know when they're not certain] between bevel-tip and chisel tip.
  ...''as good and better'' used in a context where wide application possibilities is taken into account. [tubes and transistors are as good and better than each other].
  Whoever designed Sub-Mini's faced ''a tall wall with a small vaulting pole'' [shorten the wall, Clyde], and most of the designs for output were limited to small wattage. When I listened to my Sedan DeVille's radio, it sounded super-fine, very detailed reproduction, it was frequently the source of comment from DeVille passengers who were very complimentary.
  That brings me to the OT...
  By the time I have an OT and Power Supply, the thought of putting in say a Jfet occurs, but then then, because the power supply is already present and answering for tubes, preamps become tubes.
  Having side by sided Jfet and 12a_7's though as initial preamp devices, I would have to say it's sort of like choosing the bevel or chisel Sharpie when I need to draw, either draws fine pictures with a steady hand.
  I have an 18watt with a stage-pull switch, replacing the tube stage with an earlier Jfet stage...ok...different, but not a lab type test [since the order is re-arranged]...but who cares, either way is a coin flip type decision for me.
  I like having the preamp tube in the amp be HV, since I'm not desiring these tubes to distort, oh however contrare to pre-amp distortion endeavors.
  I tried distorting preamp tubes, but prefer the Speaker/OT/output tube/PS interactions, the reactive, weighted loads seem to be where the sweetest and most easy to find juice is for me.
  How much voltage needs to be applied to these tubes for optimum performance?
  Just a little bit over the max rating, or a whole lot under.
  For ultimate performance, highest voltage they can stand.
  I need to hit the data sheets and check out the samples.
  The LV stuff...you've tried, I've tried...there's a ceiling that is pretty easy to get to the level where the input puts pressure on it, boost the input or drop the supply voltage...
  The HV stuff..clean preamp and almost too small power section, simple, very effective.
  Then we enter the Dual Recto type designs, which might just be a really good thing to try with LV tubes, pay particular attention to layout/noise...
  Some desire the DR's ''heavy machinery on lawn chair'' type of crunch, I think it'd be kind neat and expensive to try 1:1's through preamp in place of some staging caps.
  All that requires a whole buncha workin' with HV's and big, expensive parts, and all the 'long preamps' I've tried...the dern 9v pedals ran 'em off the block.
  Not to say 12ax7's can't distort nice, personal tastes after trying numerous approaches to make a 12a_7 distort heavily and 'nicely' have fallen short of the efforts invested. The last Glass-Dirt pedal I built is de-commissioned, part of that was the idea of tube in pedal..the 'drum roll on coffee can' when anything touched the pedalboard. It required 'x' amount of input to do it's trick, I believe this is the case because without the reactive load, there's a point at which onset of distortion occurs, finding the 'sweet spot' which allows you to play 'under, on, and over' that line is where the ''play this thing for hours'' vibe seems to occur.
  I've been using 9 and 12v supplies for chip/transistor operations, very simple, 'clean-ish' preamp [Blackface = 12a_7], and various wattage outputs [<2watts - >20watts].
  Most all of my distortion is made with transistors and output tubes.

[DougH]

I don't know what it is, but my Pentaboost sounds so much better than any of the 5-10 transistor or IC boosters I have ever had on my board. It seems to have a little compression as well as great dynamic response. Even amps that don't "take" pedals well like my Peavy Windsor sound good with it.

I would agree that I think pentodes have a little more to offer in tube pedals than triodes. There's something really nice about the dynamics/compression of my pentode driver that I still enjoy. There is a uniqueness to it that I don't find in SS stuff. Probably has to do with the screen circuit and the way it compresses. Probably should go back and experiment with low voltage pentode pedal circuits some more.

[petemoore]

  I learned from, and have little to add to what Doug said, and may feel inclined to experiment further at some point.
  The closest thing I've tried which may be similar [passive loading], would be an attenuated tube amp, not purely non-reactive, but that can be a very nice sound.

[panterica]

My 2 cents:

Considering how relatively young these submini pedal designs are, I believe they have much more potential for quality sound than their transistor counterparts. The only reason I say that is because of what Doug Hammond and others mentioned before; their compression and dynamics are naturally different. I prefer tubes for their more impressive bass response. Of course preference in tone is all opinion anyway..

I can't lie. I'm a tube-head. Tubes are magic.