Subminiatures

[analag]

Any ideas on the 5702WB and 5718 subs.

analag

 

[Gus]

Maybe a 6832

 

[Minion]

I don"t know about this exact model of Mini Tube But i am working on a preamp Project that uses the 6418 Sub Mini tubes which use a Much Lower Voltage and current than the 5702WB tubes....

here is the data sheet for the 5702WB tubes:

http://frank.yueksel.org/tubes/sheets/138/5/5702WB.pdf


If you need a Small Tube that uses a Much lower Voltage and Current then you should look at the 6418:

http://frank.yueksel.org/tubes/sheets/127/6/6418.pdf

It has a Plate voltage between 22v and 30V and a Fillament Voltage of 1.25v and only draws about 10mA current and they have a very pleasant warm tube sound but are Limited in Gain to about 8......


Cheers

 

[CJ]

be the first kid on the block with a min tube on board pre, in the guitar that is.
gain of 8 would be ideal.

beats a j201, me bet you.

 

[Minion]

[quote author="CJ"]be the first kid on the block with a min tube on board pre, in the guitar that is.
gain of 8 would be ideal.

beats a j201, me bet you.[/quote]

Yes that is very possible as they are "VERY" small , about the size of a Mid sized electrolytic Cap....

I know someone over at the "HomeRecording.com" forum who builds and sells Phantom Powered Tube Condensers useing these tubes and Panasonic WM61AY Capsules and he fits them inside a XLR Connector...
They are the same tubes used in the AT 3060 Tube condenser....

Since they are so small you can fit them in most solid state circuits which is why I wanted to try useing them.....

I don"t think they make them anymore and they seem fairly hard to find especially at a good price but I was lucky enough to get a few for about $2 each......



Cheers

 

[analag]

I got (12) 5702 for $6.00 and (24) 5718 for $6.00 and shipping was $1.50 for each set. How could I pass that up, even though I have no immediate use for them.

I'm taking a long break from DIYing so tube collecting is my new diversion. I see a couple of 6H30 in my future.

analag

 

[mikka]

I've been thinking about that mini tube pre for guitar, but I don't know much about those mini valves (other than Raytheon use them in military gear). Are any useful for audio still in production and likely to stay there?

I was thinking about using a rechargeable 9 volt battery if it was gonna be inside the guitar body, or putting it on a belt clip.

 

[Minion]

Well Most of these Tubes will not Run off of a 9v Battery as the lowest Voltage Ones I have seen were 15v and weren"t suitable for audio...

The ones I have (6418) are used in Portable audio amps and Recorders/Tape Machines ect and are suitable for audio but need a 22v to 30v Plate voltage and a 1.25v Filament, I suppose you could do a Starved plate design off of a 9v.....

The ones I have I don"t think are made anymore, actually I don"t think there are many Models that are made anymore...The ones I have were made in 1986....

If you take a Look on e-bay you can Find some Mini tubes on there....

Cheers

 

[mikka]

Thanks for that. I checked ebay.... yeah there are a few..... but I wanted to use something current. Maybe with the breakup of USSR there was less fear of EMF type attack.... so they went out of production.

More thinking needed........ :green:

 

[skipwave]

Just run three nine volts in series, and route out a larger cavity in your guitar body for all them batteries.

Seriously, I have a bass with EMG pickups that I run on 18V, just cuz its quieter that way.

 

[CJ]

hey, they make mini transformers, too!

maybe a hearing aid utc with a min tube would be cool, think of the saturation!

make a sub micro pig nose or something.

 

[mikka]

And build the whole lot into a cigarette packet!!!!!!!!!! A voltage doubler or trebler circuit should cover the volt problem...... I am such a dreamer.....

 

[tablebeast]

Hi guys I found a site that has these 6418 tubes for sale at $1.25 each! You have to buy 10 though and shipping is $10, but still its a good price. Here is the link http://www.piexx.com/index.php?main_page=product_info&products_id=33
I'm really liking the idea of building a circuit for inside the guitar or bass with this tube. Since there is a mic out there with this tube in it that fits into an XLR connector, why not fit one (or two) into a guitar? It sure would let you drive a preamp much like an active pickup setup. Anyone care to suggest a circuit? Also, couldn't you make a super-duper low watt guitar amp with these? I was thnking like an all tube headphone amp that runs on batteries. Where would one find one of these UTC mini transformers?

 

[Minion]

Well that is a Pretty Good deal ($1.25 each) which is pretty close to what I paid for mine (I paid $1.50 each but she gave me 5 extra and shipping was only $5) so I would grab them as I don"t think they are made anymore....

I did a Little search on the net when I first ordered my Tubes looking for some curcuit ideas useing these tubes and I couldn"t find hardly anything accept for 2 simple circuits which was enough to give me a good idea on how these were used...

this is what I found:

and

And looking at these circuits gave me the basic idea on how they would be used, You could probably do something simple with the first circuit and fit it in a Guitar pretty easilly and maybe lower the resistor values comeing off the supply rails going to the tube because you probably won"t have 36v and 5v (well maybe with two 9v and a voltage doubler and use a Zener Diode and a resistor to regulate the voltage for the 1.25v needed for the Filament..)

Well I hope it gives you some ideas....

Cheers

 

[analag]

The first schemo suffers from lack a grid leak resistance, the second schemo would be better served without that feedback scheme you have wrapped around it.

analag

 

[enthalpystudios]

ya know, i have an at3060, got a great deal on it when i was out for my first ldc.... i thought, tube, runs on phantom, great, sounds perfect.... i dont honestly know about it all the time. its really cool on some things, like heavy guitar sometimes. wish i could make it sound a lot better on vocals however. thought maybe it could use a real tube design.... or maybe a better tranny from cinemag or sumthin.

nice to know what that little thing in it is. its f-in small too dude... has little leads about 1/4wMetalFilm lead size leads. i should jack an ef86 in there and fee b+ through the body with a bnc or something equally ridiculous.

i'd mod it, i'm at that point with it i think.

anyway, carry on with the inside guitar idea, its good too.... tiny tube to an O-9 maybe? or is better response a better idea..... i have a crappy ibanez that i'd install an xlr male onto, could send the thing straight to a mic pre after its minitube->ouncer stage.

 

[analag]

 

[CJ]

thats cool!

I just found a telefunken DL 072 or somethin like that, new in da box.
these guys might be good in a tube mic, no?

 

[analag]

[quote author="CJ"]these guys might be good in a tube mic, no?[/quote]

I have a mic that uses a subminny, Gus uses them too. In fact we had a good conversation about them and other mic related stuff the other day.

analag

 

[peterc]

Enthalpy sez:

has little leads about 1/4wMetalFilm lead size leads

Even an AC 701 (U47) has thin leads to connect to, not solid pins like EF86/12AXx

I've not seen many subminature valves, but I think it is quite common on the small bottles

Peter