Reverb

vanhagar

Senior member
Messages
227
I have three reverb pedals in mind, which one is better? Marshall reflector, Holly grail, and line6 verbzilla, any other pedals is this price range that I should check out?
 

NeilStryker

Senior member
Messages
266
Proguitarshop dot com has a  good video demonstration of the holy grail if you havent seen that...  unfortunately the verbzilla is out of stock, so no video for that one.  http://www.proguitarshop.com/product.php?ProductID=1067&CategoryID=19
 

taez555

Senior member
Messages
628
I just went through the whole looking for a good reverb pedal thing.  I've got an old 5150 head which doesn't have reverb, so finally decided to get one.

Anyway, I know it's probably way out of your price range, but I settled on a Dr. Scientist Reverberator and couldn't be happier.  Just daisy chained with my other pedals, it's whisper quiet, extremely transparent(with the effect at zero there's no difference between that and the bipassed sound), plus the reverbs just sound real and not digital in anyway.  Well worth the 2 month backordered wait and $250 price tag.

As for the pedals you mentioned, the only one I really liked was the Holy Grail, although I dug the Holy Grail Plus a bit more since it had more adjustability.

erik

 

Sixbender

Active member
Messages
67
Well, it's not a pedal, but the Rocktron Intellifex still has the best reverb for the buck, imo. They can be bought used for less than a lot of new pedals that can't touch the IFX. New, they were once close to 1G, in today's stompbox world, I've seen them go for under $100.
 

dbw

Senior member
Messages
4,531
taez555 said:
I just went through the whole looking for a good reverb pedal thing.  I've got an old 5150 head which doesn't have reverb, so finally decided to get one.

Anyway, I know it's probably way out of your price range, but I settled on a Dr. Scientist Reverberator and couldn't be happier.   Just daisy chained with my other pedals, it's whisper quiet, extremely transparent(with the effect at zero there's no difference between that and the bipassed sound), plus the reverbs just sound real and not digital in anyway.  Well worth the 2 month backordered wait and $250 price tag.

As for the pedals you mentioned, the only one I really liked was the Holy Grail, although I dug the Holy Grail Plus a bit more since it had more adjustability.

erik

Erik, I've been thinking about getting one of those!  I'm waiting for the US dollar to get stronger than the Canadian dollar, though.  :tard:
 

vanhagar

Senior member
Messages
227
Thanks guys! I'll check those out. Oh and dbw I believe the US dollar is now worth apprx $1.12 CAD. That's a good thing even though I live in Canada, The business I work for depends on a strong US dollar.
 

-CB-

Senior member
Messages
5,427
If you want reverb, just get reverb.

There is no and I mean NO comparison to a tube driven, three spring reverb with a long tank.  Better known as the Fender Reverb unit.

It is the final word in reverb.  Plus... with a bit of very minor switcheroo, you can turn it into an outrageous overdrive too.  Who needs a 12AX7 overdrive unit, when you can overdrive a 6V6?  Hmmmm?
 
K

kreig

Guest
Satriani uses 2 delays, each set at different ms. and he said somewhere, that it gives a reverb type sound. I don't remember the ms settings, sorry
 

Patrick from Davis

Senior member
Messages
2,197
=CB= said:
If you want reverb, just get reverb.

There is no and I mean NO comparison to a tube driven, three spring reverb with a long tank.  Better known as the Fender Reverb unit.

It is the final word in reverb.  Plus... with a bit of very minor switcheroo, you can turn it into an outrageous overdrive too.  Who needs a 12AX7 overdrive unit, when you can overdrive a 6V6?  Hmmmm?

Hey CB, do you have any where to go study up on how to properly build/add a reverb tank to an amp?  I have never had a source adequately explain the nuts and bolts of it.  I understand the general idea, but I'd like to add a nice reverb tank to the next amp I build.  The newer amps with their evil transistor switches and things confuse me...  Thanks
Patrick

 

-CB-

Senior member
Messages
5,427
Study the Fender schematics of the 60's.

The circuit is not too complex, but does require some space for two tubes and a transformer, as well as the associated parts on the board.

Basically.... what they do is steal a little signal from the preamp.  The signal goes through a fairly small coupling capacitor, to keep the lows out of the reverb signal.  The size of that capacitor is CRITICAL for good reverb tone, but... you can experiment with it after its all built and working.  The signal goes through both sides of a 12AT7, chosen for its current handling capacity.  The stand alone units use a 6V6 (the reissues do at least... originals used a... something similar, but a bit smaller, I forget the type).  The 12AT7 (or 6V6) are set up as drivers for the reverb tank itself.   The driver is a single ended audio amp, class A, and drives the tank through an output transformer that impedance matches the tube to ... 8ohms, just like a speaker.  Thats right, Fender tanks are 8 ohms on the input side.  The tank has a transducer that vibrates the springs, and a receiver that senses the vibrations.  This is essentially a mini speaker connected via spring to a mic element (worked out in detail so it functions properly of course).  The "mic output" of the tank is high impedance, so  it goes through half a 12AX7 for amplification back to preamp levels, then is mixed back into the signal chain.  After mixing, which eats some signal strength, its amplified one more time by the 2nd half of that 12AX7, and after that, the two channels of the amp are mixed and enter the driver.

Pretty much just copy and past the Fender circuit into your own, tweaking only needs to be done to the input coupling cap to the reverb circuit - typically .001uf or even 500pf, but you may find 250pf or even 125pf useful.  The TYPE of capacitor is also fairly critical, and I find that ceramic caps do the best, even though the "silver-mica" are better.  They're too good, and you get a harsh reverb with them (I've found).   The output at the mixing stage also needs to be tweaked, typically they use a large resistor and a very small bypass capacitor where the two signals are mixed.  The resistor is something like 3.3 to 10 MEGohms, while the bypass cap is in the order of 10pf to 47pf according to brightness tastes.   If you get the resistor too small, you get a LOT of gain in that channel, but the reverb quality suffers a whole lot.  Similarly, you can get some really ace reverb but the channel itself will suffer if you go too large on the resistor - and dont take the time to finely match the capacitor that is used to bleed the highs around the big resistor.

Simple no?
 

Patrick from Davis

Senior member
Messages
2,197
OK, so I have looked up the Super Reverb schematic (ab763) and everything you have mentioned is pretty much in place.  The 3.3M resistor and the 10 pF cap to couple the signals back together, a 7025 used to boost the signal into the phase inverter and so on...  But of course I have more questions.  If I do not know what the output of the power transformer that I am going to use is, how much trouble will I get into?  I was looking at several of the Hammond 370 power trannies and am kinda unsure about what I might need.  From the diagram, it is supposed to have...
B+  366V   
B+1 356V
B+2 346V
B+3 325V

The Super Reverb has higher voltages, 465 at B+, and 460 going to the Reverb tranny.  I am sure this will add a monkey wrench to the mix.  Adding to that, if it has to power a smaller output transformer after the 12AT7, I am unsure about figuring out what power requirements the reverb section will take.  Hmm.  I suppose I should tell you that the amp design is a franken amp (at least for the moment) that has two preamps loosely based on the Marshall JCM 800 and the Fender bassman preamps (Dirty and clean channels), going into a KT88 that goes into a single ended 20 watt output tranny.  Adding the "Surf" Reverb to this has been the icing on the cake dream.  A lot of other people have hammered out the details on both of the preamps, and the power amp sections of the schematic and layouts.  If I get the Hammond 370HX power tranny, it has 200 ma of power available power according to the specs. 

Hmm, the hamsters are getting tired.  Sorry VanHagar for taking over the thread with this, but I am quite curious about getting a kick ass reverb tank into a homebrew amp.  Thanks ahead of time for any help CB.  This might just turn into another thread.
Patrick

 

-CB-

Senior member
Messages
5,427
Hammond makes several 370's.  Some are 240-0-240 some are 275-0-275

The latter translates into 330vDC if you use a tube rectifier, and about 390vDC if you go solid state.

For a Super Reverb amp, a 373BX would be better.  Its 360-0-360,. yielding about 435vDC on a tube rectifier.

If you cascade the power supply, with each stage isolated from the other with a decent resistor...  run the four stages in classic setup.  That is, B+ for the plates, down a stage for the screen grids, down another stage for everything but the preamp first and second triodes, last stage for those triodes just mentioned.  The idea is not to achieve different voltages.  But, instead, to provide additional noise reduction through better ripple filtering, and to keep the various stages a bit isolated so they dont feed back into each other, which happens when you run lots off say... the last stage.  B+ self hum-cancels in the output transformer.  Down the chain... the screen grids do the same, as they're running back to back.  Next, things like vibrato, and reverb and the phase inverter are less prone to noise, as they're being fed fairly high level signals.  After that, the preamps need the most noise free part of the power supply, since they are taking very low level signals and amplifying them (and the noise).
 

Patrick from Davis

Senior member
Messages
2,197
I am not sure I want to move to the Hammond 373BX, I was looking into the 370 HX (275-0-275) because the amp was designed around those specs.  I am guessing it would be better to look around at the various reverb design to see if there was one designed for less voltage.  I will have to power 6 preamp tubes, one power amp tube, the reverb tank, and a relay switching setup, which is why I was pretty set on the 370HX.  Unless I am completely wrong and the amp design would not be too difficult to play with and get to run with the 373BX voltages.  Oh yeah, one other note it would be diode rectified at this point.  A tube rectifier is not in the design, and I am already biting off more than I should...
Patrick

 

-CB-

Senior member
Messages
5,427
Oh, I dont know the design you're using, and you mentioned Super Reverb... so I just made a suggestion.  By all means go with the transformer they suggest.

reverb tanks take no power, they're 100 percent passive
 

Patrick from Davis

Senior member
Messages
2,197
Well you may have inspired me to be overly ambitious again.  Please let me know if I am being a total maroon here.  Using the template of parts from the super reverb, it seems that you have your caps that let the highs into the 12AT7 that is a class A amp for the tank.  The transformer supplies the tube output with power, and the output is at 8 ohms impedance.  There are some resistors and electrolytics to run the 12AT7 properly.  There is a part of the diagram that shows the pedal attachment for the reverb, and some stuff in there that I am not the most familiar yet, but after that it goes in to the first half of the 7025 to boost the signal from the tank.  There is another electrolytic/resistor setup for this tube that both halfs of the tube are tied to.  Next the signal goes through the pot that will determine the level of reverb signal that gets mixed into the next stage where the 10 pF cap and 3.3M resistor are.  That then goes into the second half of the 7025 for a boost in signal strength and onto the power amp section of the amp.

If I were to try to modify this general setup to work in a different amp, I would be looking at figuring out which reverb unit (Accutronics type 9 looks nice,) the resistors on the tubes so that they are running happy, finding a tranny that would be appropriate to power the tank, and getting the coupling capacitors and mixing cap/resistor tuned for correct sound.  While this sounds like it is a bit intimidating, it also sounds like it might keep me occupied for another several months.  I suppose the big question I have is, am I taking on a challenge that is more trouble than it is worth?  Thanks for all of the help up to this point.  Reverb tanks have always been a mystery to this point, and this is starting to get fun.
Patrick

 

DocNrock

Senior member
Messages
4,295
=CB= said:
If you want reverb, just get reverb.

There is no and I mean NO comparison to a tube driven, three spring reverb with a long tank.  Better known as the Fender Reverb unit.

It is the final word in reverb.  Plus... with a bit of very minor switcheroo, you can turn it into an outrageous overdrive too.  Who needs a 12AX7 overdrive unit, when you can overdrive a 6V6?  Hmmmm?

I used to have a Fender Twin Reverb with one of those Ice Cube doohickies that went across the reverb in/out.  Not bad overdrive, IMHO.

My current amp has a spring reverb which sounds sweet, so no need for that effect.  :icon_biggrin:
 

Patrick from Davis

Senior member
Messages
2,197
Just a note, after reading a bit more, the type 9 tank requires a 10 ohm input.  If I get this to work, I might just hot glue treads and a turret to the reverb unit...
Patrick

 
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