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Location: Utah | I'm wanting to build some of my own preamps and distortion boxes. Anyone have references to the tiny micro tubes and how to employ them?
Although I have no experience with designing tube circuits, my education and 10 yrs of professional experience is electrical engineering. I do have a basic understanding of tubes (and replaced many tubes in tv's and guitar amps in my youth). |
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Location: Florida Central Gulf Coast | You need to contact Vic (HumblePie aka Solid Top). I'll bet he has some ideas/info fer ya. |
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January 2006
Posts: 1128
Location: NW Washington State | If you Google "nuvistor", "nuvistor audio", "nuvistor preamp", you'll find info on those little guys. They are a little scarce but not as expensive as some of the more popular audio tubes. I've seen a Russian version that used to be available cheap.
You might also have fun experimenting with FETs. Their operation is analagous to a triode. Some people claim they sound like tubes, I dunno, could be another audiophool/musician superstition. This page has some neat looking circuits for FETS: http://www.runoffgroove.com/articles.html
-Steve W. |
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Posts: 4067
Location: Utah | numb, thanks.
I remember building some FET circuits back in the 70's and they definitely had a better sound than bipolar transistors. This time around the idea of going to tubes is enticing although more complicated. I had thought of using a couple of 12AX7 or similar tubes in one project. The micro tubes sound interesting but I have no idea if they will do what I want, which is allow being dialed in from clean to overdriven. |
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Posts: 2491
Location: Copenhagen Denmark | How could I ( nearly ) miss this thread ???
Originally posted by FlySig:
I'm wanting to build some of my own preamps and distortion boxes. Anyone have references to the tiny micro tubes and how to employ them?
Although I have no experience with designing tube circuits, my education and 10 yrs of professional experience is electrical engineering. I do have a basic understanding of tubes (and replaced many tubes in tv's and guitar amps in my youth). Iffy ;
You need to contact Vic (HumblePie aka Solid Top). I'll bet he has some ideas/info fer ya.
Numby ;
If you Google "nuvistor", "nuvistor audio", "nuvistor preamp", you'll find info on those little guys. They are a little scarce but not as expensive as some of the more popular audio tubes. I've seen a Russian version that used to be available cheap.
FlySig ( aka Jetlag -sufferor ) ;
I remember building some FET circuits back in the 70's and they definitely had a better sound than bipolar transistors. This time around the idea of going to tubes is enticing although more complicated. I had thought of using a couple of 12AX7 or similar tubes in one project. The micro tubes sound interesting but I have no idea if they will do what I want, which is allow being dialed in from clean to overdriven
`Kayyyy........
FlySig , I am not quite sure why ya want to get into this , do realize however , once ya start this game , ya will loose friends , alienate yer family , and will be stuck to people like us..
But to clarify ;
A Nuvistor is Not a Thermionic valve / Vacuum tube , allthough it works like one ( it `s a Voltage amplifier ) , there was something with it ( can n`t remember what ) , but , somehow " it did not catch on "..I even doubt ever employing one..
Micro -tubes ( MVT -technology ) is not commercially available yet..
The valves you refer too , are pre -amp. / control amp. valves ( low voltage / low -current type )..Typically known as " mini -watt "....ec 83 / single triode ..ecc 83 / double triode..( European designation ) , etc.
FET `s are okay , but I would say : Junction Field Effect Transistor ( J -FET ), to amplifiy Micro -currents..
BTW , the transistor that sounds like a Valve is a MOS-FET , employed in the Power -Stage.. equivalent to EL 84..EL 34..KT 66..etc. ( European designation )
Semi -conductor and Valves in Pre / Control stage sound alike , with valves having the advantage of being more Robust Electrically ( Higher resistance to Overload )
So , a J -FET to amplify Tiny Input ( micro volt / micro ampere ) , and then , a " Funny Circuit " for rumblin`/ tumblin` sounds , and a Vacuum Tube / Thermionic valve Booster ( Triode ofcourse ) , However , what is it that we´re dealin` with here .., I vaguely remember that ya`ve got some sort of string instrument , that " emulates " an Acoustic guitar , do ye` wish to make it sound like one ? , or , do ya intend to rival J.S.BACH , in getting Evicted from church ( Many times ) , like those , who collect speeding tickets ?
But...if ya want to be D I Y Big Time , than do realize , there are Three Component grades :
Consumer grade ( affordable , breaks down , ferget it )
Premium grade ( Good , and Costly )
Military grade ( the Best , Expensive !! )
I`m not quite sure I understand what ya intend to use it for , it can n`t be for REBEKKAHGOESSWIMMING , for them girls , with their sound , do n`t need any Electronic voodoo
If it is " fiddlin` " with instrumental sounds yer into , than it is Much Cheaper / Less of an Headache , to purchase a little electronic marvel like this
http://www.artproaudio.com/products.asp?id=58&cat=1&type=79
Vic
..and Welcome to the A / E boyz/ girlz Electron club..
Al : Chairman
Mr.Ovation : President
Iffy : Chief Whipp
Numby : Nuvi -man
Lt.Col. Calman : Restraining officer
Arthur : Celebrity -Xpert
Vic : Consultant ( a somebody , at last !! )
..and our latest addition..
FlySig : Proud Father :) |
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Posts: 1128
Location: NW Washington State | In my new position as Nuvi-man, I must once again insist that Nuvistors are tiny vacuum tubes. I've got a McIntosh receiver that uses a couple of Nuvistors in the FM front end. Not used much for audio, maybe the 6CW4/CV10579 would work.
I think that Nuvistor was an RCA trademark, perhaps they're also known by another generic name.
I'm getting confused... am I in the OFC, or the vintage radio/audio forum?
-Steve W. |
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Posts: 2491
Location: Copenhagen Denmark | Numby ;
Let us recap(itulate )...Vacuum tubes are devices that consist of an Anode /grid(s) / Cathode , contained in a glass envelope which is vacuumized , I.E No Air ...
The Nuvistor is contained within a Mu -metal housing , and allthough sealed , it is not vacuumized , if memory serves me well , than it`s range was rather limited..
Both are Voltage amplification devices..I.E it works/operates like a vacuum tube..
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I'm getting confused... am I in the OFC, or the vintage radio/audio forum?
-Steve W.
---------------------------------------------
Let us Recap. again ,..
Most Ovation guitars are Acoustic / Electric devices , many ( if not most ) sound best when driving a sound -reinforcement system , witness the testimoney of many cherished members on the topic of Deep v.s Mid v.s Shallow bowl ,built -in pre -amp , graph.eq. , and soforth..
Allthough , many of said cherished members could n`t care 2 hoots , wether the Amps. driven , are made with Valves , Semi -conductors , or cardboard folded into a Cone , their curiosity Does get aroused when shelling out hard earned cash , And..many can actually hear those differences , this threadstarter testifies to it..
I would say , this being an Ovation forum , mentioning the Differences of the Electronics driven by aforementioned A/E devices , ( Ovation / Adamas ) , would be a Duty , indeed , an Honor , for those who can help out , when U and I are standing there with a Git. that just will not " do it " , we would like to be helped out ASAP, Yesterday even ..
We `ve only scratched the tip of the Iceberg , next could be choice of Cable , and , ahaa...the Loudspeaker..
Look , this is a serious Git. House , Nothing is too Much , Complicated or above our X -pertise...
Too bad that most of us are Flat-broke...
Vic
..where can I obtain an ADamas , I`ve got a dollar and 53 cents... :) |
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Location: Florida Central Gulf Coast | FlySig ,
Look at what ya started... 
Vic is on a roll now... 
Let me add that if I had any questions on an amp project, Vic is da man to go to!  |
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Posts: 1071
Location: Carle Place, NY | I built a very nice distortion box, called Shreadmeister, from a kit from this company: Officially Licensed Circuits .
I highly recommend OLC. The owner, Mark, really stands behind his kits. I had some trouble getting the box to work. I send it to Mark and he corrected the problem. The kits cost almost as much as a brand-name stomp-box, but the engineering is superior, and you have the satisfaction of knowing that you built it your self. After building this kit, I now have the confidence to tackle most electronics soldering jobs. |
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Posts: 1128
Location: NW Washington State | You might also take a look at the PAIA stack-in-a-box kit: http://www.paia.com/proddetail.asp?prod=9210K
Vic, you're the one who made me Nuvi-man- I didn't want the job but now must do my best :) . So look at the Wikipedia article about nuvistors: http://en.wikipedia.org/wiki/Nuvistor and the 6CW4 data sheet: http://www.nj7p.org/Tube4.php?tube=6CW4
-Steve W. |
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Posts: 5881
Location: Colorado Rocky Mountains | VCRs became obsolete before I learned how to program the clock. On a good day, I usually can figure out how to change batteries in most pedals. |
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Location: Upper Left USA | I bow in reverence to you consumate Electonical Geeks. Love the products, can't fathom the theory...
Pure Freak'n Magic (PFM)
Sweet skills... |
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Posts: 4067
Location: Utah | Originally posted by HumblePie aka Solid Top:
However , what is it that we´re dealin` with here .., I vaguely remember that ya`ve got some sort of string instrument , that " emulates " an Acoustic guitar , do ye` wish to make it sound like one ? , or , do ya intend to rival J.S.BACH , in getting Evicted from church ( Many times ) , like those , who collect speeding tickets ?
I`m not quite sure I understand what ya intend to use it for , it can n`t be for REBEKKAHGOESSWIMMING , for them girls , with their sound , do n`t need any Electronic voodoo
If it is " fiddlin` " with instrumental sounds yer into , than it is Much Cheaper / Less of an Headache , to purchase a little electronic marvel like this
http://www.artproaudio.com/products.asp?id=58&cat=1&type=79
Vic
The goal is to make my own stomp box with two functions. First, a basic preamp that can be dialed from clean to distorted. The ART tube preamp does just that, and does a fine job. But it isn't a stomp box. Second feature would be a simple gain boost.
The idea is to have true bypass. The first stage would be the preamp/distortion section that would simply be dialed in. Stomp on, stomp bypass. The second stage would be simple boost. Stomp boost, stomp bypass. That way I can dial in my sound for a particular song using the preamp/distortion side. When it comes time for a solo, just stomp on the boost switch to get an additional boost of a few dB. Then after the solo, bypass the boost and go back to the lower volume.
The ART Tube actually has exactly what I want, but it isn't in a stomp configuration. There is a little switch on the front that selects +6dB or +20dB of gain. Presumably that switch just changes a resistor value. If I could make that switch a durable stomp switch, and put a potentiometer on the faceplate to adjust the amount of boost, it would be just right. (But I don't need all the other stuff like phantom power and phase inverting).
The girls of Rebekkahgoesswimming don't need technological gizmos. They're talented. Me, on the other hand, I need all the electronic assistance possible! |
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Posts: 1128
Location: NW Washington State | Here's a project that uses a 12AX7 with low plate voltage: http://solorb.com/elect/musiccirc/firebottle/ |
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Building a micro tube preamp
