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#1
So today I recieved a reverb tank for free from someone who didnt need it anymore. It was extremely dirty at first, but I gave her a face-lift:

Before:



After:




I guess I am going to have to build a reverb pedal with it . Anyone have any ideas for a reverb to build, other than that Stage Center Reverb from General Guitar Gadgets?

Kerry
#2
nice did you just sand it down to a shine?
Quote by rabidguitarist
I even tried dressing up as a fly myself, and throwing myself out of the window in the hope that they will follow me. But to no avail.

Quote by daytripper75
we have a Llama forum, and still no drum forum.
#4
Wow, you made it look real nice, wasnt expecting to look that nice and shiny
Ibanez AFS75/Fender Strat Plus > Fulltone Deja' Vibe > Keeley TS808 MOD+ > Fulltone OCD > VanAmps SoleMate > Metro JTM45
#5
gotta love the Metallica tabs under it


YOU ARE THE PEDAL MASTER


I'm sure you'll think of something.

good luck
#6
im pretty sure you have to put the reverb tank in/on your amp so the springs inside can pickup the vibration, and if you made it a stompbox, well trust me you dont want to step on, kick, drop, or otherwise disturb a reverb tank while its on, its kinda scary...big sound and not in a good way....maby you could add a footswitchable reverb tank to your setup though, it just has to be in/on your amp, make it tweed like the old fender reverb tanks people use with their vintage bassmans
#7
^-You dont quite understand what an Analog Reverb Pedal is. Its a pedal meaning it includes a bunch of other stuff rather than just this part. Its like the heart of a reverb pedal, but there much more going on. Its like, a wah has an inductor and wah pot and then other stuff. Same with this, but the reverb tank is the heart. You dont need an amp for this.
#8
I'm working on one of these.

I'm using an opamp to drive the reverb, and then a 12ax7 as a recovery unit.
I'd drive it with a tube if I could, but the impedance of a tube is too high, and so you'd lose a bunch of signal sending the signal into the tank. That's why old tube reverb amps need a transformer to match the impedance. That's why in newer amps they use opamps and not tubes, transformers cost around 15 bucks each, and an IC is like 15 cents in bulk.

Anyways, make sure your impedance feeding the tank is low. Most tanks are like 8-250 ohms on the input side. The output impedance doesn't matter, as long as it's big on the recieving end(signal isn't lost from low impedance to high impedance).
Measure the resistance of the input with your multimeter, but keep in mind DC resistance is different from impedance. That's why an 8 ohm speaker will read 6 ohms with a multimeter. Impedance changes with the AC signal.

Dunno if that helped at all. Btw, don't be too suprised if it sounds like ass, these tanks have alot of variation to them. It looks a bit small when compared to other tanks used guitar too.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#9
Thanks for that long read Pink. I will try to do a tube reverb unit to make a cool piece of equiptment. It is a bit small, but its pretty cool and I got if for free, so im gonna put it to use.
#10
^K, good luck with the tube stuff.

You need around one watt to drive it adequately btw. It's hard to get a decent amount of gain with one 12ax7 on the input. The original Fender standalone reverbs used a 6k6 tube(similar to a 6v6). It's a way bigger project though, you need a power transformer, and all sorts of crap.
Buy that time you'd probably want a new tank too...lol.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#12
Errrr....
A tube is really easy. I'll do it later(gotta go to school).
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#14
K well pretty much you'll need a 12 volt power supply to run this thing. The heaters of two 12ax7's should draw like 300mA, so I recommend a 500mA wall wart so you have some left over.

Tubes are like npn transistors. I assume you know how a transistor works.

Pin 1 on a 12ax7 is called the "plate". You hook this up to a positive voltage. It is comparable to the collector on a transistor.

Pin 2 is like the base, and it's called the "control grid."

And pin 3 is the "cathode" and it functions similarly to the emitter.

Simple enough eh?

Now a 12ax7 has two "triodes" within it. What does this mean? The 12ax7 has two independantly operating plates, two cathodes, and two grids. Each set of 3 is called a triode. It's essentially two tubes in one(or two transistors). This makes it very handy.

So to sum it up, here's the end result:
Triode #1:
1-Plate
2-Grid
3-Cathode
Triode #2:
6-Plate
7-Grid
8-Cathode

Now pins 4, 5, and 9 are dedicated to heating the tube up so the electrons can flow freely. The "12" in 12ax7 stands for the heater voltage(this is why it's handy to use a 12volt wall wart). Connect pins 4 and 5 to the positive, and then pins 9 to the negative(well polarity doesn't matter for the heaters, but you know what I mean).
If you're wondering why we tie pins 4+5 together, that's because the 12ax7 really has two heaters. Pins 4+5 are each one end of each heater, and the heaters have a common end on pin 9. Bridging pins 4 and 5 parallels the heaters, and so so each heater only sees 6 volts with a 12v wall wart(the heater is just a big fiery resistor, so the current is split between the two heaters."


So basically, in a gain stage, you send the small current into the grid, which then modulates the higher current that you have hooked up to the cathode and plate so that it matches the waveform of the input, but with higher current.


Now as for making a simple gainstage...tubes are easy.

Hook a 100k from the plate into v+
Use a blocking capacitor to feed the input into the grid.
And then hook up the cathode to ground.
Attach the output to the plate through another blocking cap.


This isn't dangerous yet either...so feel free to mess around!
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#15
Quote by That_Pink_Queen
If you're wondering why we tie pins 4+5 together, that's because the 12ax7 really has two heaters. Pins 4+5 are each one end of each heater, and the heaters have a common end on pin 9. Bridging pins 4 and 5 parallels the heaters, and so so each heater only sees 6 volts with a 12v wall wart(the heater is just a big fiery resistor, so the current is split between the two heaters."

You mean each heater sees the 12 volts.
#16
Series...
12/2=6?

EDIT:


Man...that was some hardcore contradiction.

Oopsies.
The wiring I just gave you for the heaters is wrong...that's how you would wire if you had a 6.3 volt heater feed.
You want the heaters in series, so they should see 6 volts. I got the 6 volt part right in the first post, but for the other bit is off.

Just hook up v+ to pin 4 and the other to pin 5.

Good catch greenbox. Dunno what I was thinking at the time.

I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#17
Quote by That_Pink_Queen
K well pretty much you'll need a 12 volt power supply to run this thing. The heaters of two 12ax7's should draw like 300mA, so I recommend a 500mA wall wart so you have some left over.

Tubes are like npn transistors. I assume you know how a transistor works.

Pin 1 on a 12ax7 is called the "plate". You hook this up to a positive voltage. It is comparable to the collector on a transistor.

Pin 2 is like the base, and it's called the "control grid."

And pin 3 is the "cathode" and it functions similarly to the emitter.

Simple enough eh?

Now a 12ax7 has two "triodes" within it. What does this mean? The 12ax7 has two independantly operating plates, two cathodes, and two grids. Each set of 3 is called a triode. It's essentially two tubes in one(or two transistors). This makes it very handy.

So to sum it up, here's the end result:
Triode #1:
1-Plate
2-Grid
3-Cathode
Triode #2:
6-Plate
7-Grid
8-Cathode

Now pins 4, 5, and 9 are dedicated to heating the tube up so the electrons can flow freely. The "12" in 12ax7 stands for the heater voltage(this is why it's handy to use a 12volt wall wart). Connect pins 4 and 5 to the positive, and then pins 9 to the negative(well polarity doesn't matter for the heaters, but you know what I mean).
If you're wondering why we tie pins 4+5 together, that's because the 12ax7 really has two heaters. Pins 4+5 are each one end of each heater, and the heaters have a common end on pin 9. Bridging pins 4 and 5 parallels the heaters, and so so each heater only sees 6 volts with a 12v wall wart(the heater is just a big fiery resistor, so the current is split between the two heaters."


So basically, in a gain stage, you send the small current into the grid, which then modulates the higher current that you have hooked up to the cathode and plate so that it matches the waveform of the input, but with higher current.


Now as for making a simple gainstage...tubes are easy.

Hook a 100k from the plate into v+
Use a blocking capacitor to feed the input into the grid.
And then hook up the cathode to ground.
Attach the output to the plate through another blocking cap.

This isn't dangerous yet either...so feel free to mess around!

Quote by rabidguitarist
I even tried dressing up as a fly myself, and throwing myself out of the window in the hope that they will follow me. But to no avail.

Quote by daytripper75
we have a Llama forum, and still no drum forum.
#18
Just in case pink wasn't clear enough (for anyone wondering).

If you're using 6.3 VAC, then you wire one lead to pin 9, and then the other lead to pin 5 and 4 (connecting them together). Since it's 6.3 AC volts, it gives you a peak-peak voltage of 12.6 volts.

If you're using 12 VAC, then you want to wire 4 to one lead, 5 to the other lead, and ground pin 9. (Then they'd be wired in series, with the AC voltage (peak-peak 24 volts) halfed, to give you 12 volts on your heaters)
Last edited by greenbox at Sep 20, 2006,
#19
You wouldn't use pin 9 I don't believe.

It's getting late, forgive me if I'm mad...but if you were using a center tapped transformer with AC heaters things are a bit different.
On an amp style transformer you have -6.3 ac volts and +6.3 ac volt leads, with a center tap. The center tap could be run to pin 9, but it shouldn't be grounded.

We're using a wall wart...no center tap, and 12volts dc.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#20
I messed with this some more.

I just hooked up two 386 opamps for the driver and recovery...it worked fairly well.
http://www.ciphersbyritter.com/NOISE/SPEC386.HTM
That's a real basic showing of how you wire the opamp. You want to use a cap with a variable resistor in parallel for the variable gain option.

The biggest issue for me was the EQing of the circuit.
It was lacking in treble, I'm guessing because I didn't buffer the opamp input, or the impedance from the driver to the tank was mismatched. The 386 had plenty of power for the input application, but I think you could probably use something better. For the input you can just use a buffer like the GGG buffer, but the impdance leading to the tank is much harder to control. I suggest hooking up one of those 386 setups just to test the tank. Just one of those little amps leading into the the tank, and one coming out.

I've looked at tons of amp schematics just from when I was learning about tubes, and they all use a TL072 opamp it seems.

The tubes should have plenty of gain for recovering the circuit.
We just need a driver. I suggest we be lazy bastards and snatch one out of an amp.

Or you could do something nuts and try and drive it with some push/pull 12ax7's...but IMO that's taking the project too far.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#21
you'd ground pin 9 with a 12 VAC, and if it were center tapped, you'd simply not connect the center to anything and leave it isolated.
#22
You'd leave pin 9 disconnected...
+12 to pin 4, ground pin 5.

Pin 9 isn't connected.

I'm positive.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#24
I'm using 9
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I'm a retired Supermod off to the greener pastures of the real world.
#27
oh, you're right
you only ground pin 9 if you're using 12 DC. That would be my mistake, I wasn't paying attention. with AC, you'd just connect one lead to 4 and the other to 5
Last edited by greenbox at Sep 20, 2006,
#28
^We're using DC...you leave pin 9 undone.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#29
if your'e using a 12vdc, you'd connect the positive lead to 4, the negative lead to 5, and you'd ground pin 9. That should give you ~12 volts on your heaters. Unless you're grounding your negative lead, which is (of course) a different story.
Last edited by greenbox at Sep 20, 2006,
#30
The neg is grounded!
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#31
Ok, here is some pictures of the inside of the Tank, and the tubes I got. I only have pictures of 1 of the 2 tubes.

Inside the Tank:



Sovtek Fender 12AX7 Vacuum Tube:

#32
ahh, vacuum tubes, magic little tone bottles....looks pretty good, you better post sound clips when its done...or im gonna be pissed
#33
Ok, finished perfing the first section of this pedal (I am basicially doing little sections to make it a little more easy to follow). This is the Input Buffer/Boost section which is essentially a JFET buffer and an Op Amp boost. Heres some pictures:


#34
No one likes responding to me...

Anyway...So I just tested out the Transistor Input Buffer and Op Amp Boost section of the pedal. It works great. Its gonna sound amazing once the tubes are added! Then I hooked up the reverb tank after the Input Buffer and Booster. It boosted it pretty nice. The tank definately works correctly. The reverb is way to strong right now though because theres no Mix pot, or Dwell pot, or anything besides the First Section's Gain pot. So far so good on this design. I will make a box layout in a second to show how the box with be layed out.
#35
That looks really awesome, bet it'll sound great.
Amp:
Fender Blues Jr (GH1230 Celestion Speaker)
Pedals
Barber DD
Wilson WH-10 Clone
Ibanez WH10 V2

Pitchblack Tuner
Boss DD-3
Guitars: 06' Custom Fender Strat Lindy Fralin Blues Specials, Callaham Tremolo
09' Olympic White Stratocaster
#36
box layout! now!

looking good dude, what are the tubes for? i dont know much baout reverbs really, espeicially real ones
#37
^-Thanks. I will have to do the box layout a bit later today.

The tubes really arent needed. Its just that, would you rather have a solid state overdrive with the transistors and diodes creating an overdrive tone, or tubes creating the real overdrive?! But its basically just to add drive to the reverb tank so you can hear it and its not just quiet. Thats why I have a boost type thing in the front, because the reverb tank needs to be driven or it has no volume.
#39
No huge capacitors, and no transformers. Its not an amp head, its just a preamp "style" reverb unit. When I say preamp "style" it has Tone Stack, Gain, Master Volume, and Reverb.
#40
ah right, as i said, tubes confuse the hell outta me, i love 'em to bits, but give me good old SS gear for a build at the moment any day
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