3 spring 10 ohm reverb tank, in a 8 ohm

[bob p]

The nomenclature for the tanks can be confusing on several levels. Most people like to refer to the tanks as 2 spring and 3 spring tanks, while Fender refers to them as 4 and 6 spring tanks, because technically each spring unit is comprised of two springs. We shouldn't have any problems as long as we understand that when we say 2 spring we really mean 4 spring, and when we say 3 spring we really mean 6 spring.

Enzo makes a good point about tank length. It's important to know what size tank you're looking for. Some of the smaller amps like the PR would use the smaller type 8 tanks, but none of the larger amps use the smaller tanks. Big Fenders always used the Type 4 (2 spring) tanks. Some people will like to replace them wtih a type 9 (3 spring) tank for some added depth to the reverb.

The Deluxe Reverb used a big tank. Type 4. I think it's the smallest amp that uses the big tank. The current Fender part number and description for that tank are:

064063 REVERB UNIT 4 SPRING 4AB3C1B

If you want to go to the 3 spring tank, I think the one you want would be 9AB3C1B, provided it will fit in your chassis.

So the numbers would be:

Stock 4 spring: 4AB3C1B
Modded 6 spring: 9AB3C1B

[mikepukmel]

Thanks for the info and suggestions, as always.
I think the 3 spring long tank will fit, at least seems to have a few inches to spare at least. I have a 4 and 6 pound short handle sledge hammer in case it doesn't.
Also, thanks re short tanks not sounding very good. geez, the whole point here is to get a better sounding reverb!

Ill order a 9AB3C1B, accutronics.

[stokes]

If you havent ordered it yet,I would suggest these guys. Reverb Tanks I've put them in 3 different stand alone units and a Mesa Boogie combo,they sound much better than any other tanks I've tried over the years.

[mikepukmel]

If you havent ordered it yet,I would suggest these guys. Reverb Tanks I've put them in 3 different stand alone units and a Mesa Boogie combo,they sound much better than any other tanks I've tried over the years.

Thanks for the link Stokes, checking now!

[Gingertube]

On a London Power Standard build I did for a friend we auditioned quite a few reverb tanks (push Pull 12AT7 driver with output transformer).

The type 9 was definitely better than the shorter units or the 2 spring versions. The type 9 is the one with 3 springs which are really 6 springs as each of the 3 consists of 2 springs linked to make 1.

We tried Medium and Long delay options and preferred the long delay for our Classic Rock, Blues, Folk playing styles.

If you are a shreader however then a Medium Delay may suit better than the long delay.

Cheers,
Ian

[mikepukmel]

On a London Power Standard build I did for a friend we auditioned quite a few reverb tanks (push Pull 12AT7 driver with output transformer).

The type 9 was definitely better than the shorter units or the 2 spring versions. The type 9 is the one with 3 springs which are really 6 springs as each of the 3 consists of 2 springs linked to make 1.

We tried Medium and Long delay options and preferred the long delay for our Classic Rock, Blues, Folk playing styles.

If you are a shreader however then a Medium Delay may suit better than the long delay.

Cheers,
Ian

Thanks Ian, this is great info, sounds like the long s case, 3 (6) spring is the one for me. (Im no shredder, like bluesy rock type sounds).

[mikepukmel]

On a London Power Standard build I did for a friend we auditioned quite a few reverb tanks (push Pull 12AT7 driver with output transformer).

The type 9 was definitely better than the shorter units or the 2 spring versions. The type 9 is the one with 3 springs which are really 6 springs as each of the 3 consists of 2 springs linked to make 1.

We tried Medium and Long delay options and preferred the long delay for our Classic Rock, Blues, Folk playing styles.

If you are a shreader however then a Medium Delay may suit better than the long delay.

Cheers,
Ian

Thanks Ian, this is great info, sounds like the long s case, 3 (6) spring is the one for me. (Im no shredder, like bluesy rock type sounds).

[bob p]

When I think of lush reverb, Zep's cover of "I Can't Quit You Baby" comes to mind. I'm assuming that was studio reverb, not in-amp reverb. Anybody know?

[Mick Bailey]

The circuit has a lot to do with how good a reverb sounds and many amp-based reverbs don't have enough control - just an output level that determines how much reverb gets mixed in with the dry signal, and even that has a preset maximum. Very often any additional post-manufacture dwell control mod is just a level control on the input that can go from zero up to the existing pre-set level set by the circuit topology and really does nothing to enhance the reverb. Kind of like a control to give you much less than you started with. I like to be able to drive the tank really hard with the dwell at maximum and I've spent endless hours looking at scope traces to get a better drive circuit. For me, a tank really comes to life with a much higher drive level than amp manufacturers provide. In addition, I like to be able to shift from 100% dry to 100% wet and anything in between.

There are other considerations, too; the frequency band that is chosen to drive the tank, the high-pass filtering on the output to reduce feedback and rumble, plus any resonant capacitance that the output coil 'sees' in parallel to itself.

For my money the same tank in a standalone reverb (say, a 6G15) will always sound a lot better than in an amp, because in general the amp is always compromised in how much circuitry is given over to the reverb section.

It comes down to personal listening preference and how much the reverb needs to be there just as a support, or an effect in its own right. I sometimes like to push my reverb to get the same sound from guitar as the (keyboard) reverb in the theme to 'Get Carter'.

[mikepukmel]

When I think of lush reverb, Zep's cover of "I Can't Quit You Baby" comes to mind. I'm assuming that was studio reverb, not in-amp reverb. Anybody know?

I dont' know what they used on that recording, but back in the late 80's, I went to the Institute of Audio Research in the village in Manhattan
a kind of trade school for people to learn enough to get their foot in the door at one of the big recording studios (that have since all gone bust).
Anyway, we saw the reverb systems they had in one studio, it was a huge HUGE metal plate hanging in the basement of the building where the studio was
located. This was one of the commercial units, weighted like 600 pounds: emt 140 plate reverb - Bing images

[mikepukmel]

I dont' know what they used on that recording, but back in the late 80's, I went to the Institute of Audio Research in the village in Manhattan
a kind of trade school for people to learn enough to get their foot in the door at one of the big recording studios (that have since all gone bust).
Anyway, we saw the reverb systems they had in one studio, it was a huge HUGE metal plate hanging in the basement of the building where the studio was
located. This was one of the commercial units, weighted like 600 pounds: emt 140 plate reverb - Bing images

It was more something like this, looked to be custom made.
Reverb Steel Plate Reverb - DannyChesnut.com

[Enzo]

There were/are spring reverbs, plate reverbs, and back in the day actual echo chambers were used. That is to say a large hard walled room with a speaker and a mic. I have noted certain recordings where they used a stairwell in a building for reverb. In fact in college, we used the stairwell in my six-floor dormitory for jamming guitar and harp because the reverb sounded so good.

[mikepukmel]

Help with resistor size discrepancy: Deluxe AB763 layout vs schematic

Hi All,
Trying not to create a new thread for every little thing.

Regarding reverb on a Deluxe AB763, I reviewed several schematics and layouts for this amp, and there is a discrepancy Im not sure what to do about.

In the reverb circuit, on the schematic, e.g.

http://www.thevintagesound.com/ffg/s...b763_schem.gif

there is a 3.3MEG resistor with a parallel 10pf capacitor, that ties to the grid of 1/2 a 7025.



On the layout,

http://www.thevintagesound.com/ffg/s...763_layout.gif

this resistor is 4.7MEG.


This is a fair difference, and I can't find any references to why the difference. Can anyone suggest which one should be used, and possibly why Fender changed it? Im assuming its not a type'o.

Thanks,
MP

[Enzo]

Believe the schematic. Look over several hundred other Fender reverb amps and see the 3meg resistors in them all.

[J M Fahey]

Agree and add: even IF it were a 4M7 resistor there (maybe one day they run out of 3M3 and by sheer chance that particular chassis was used by another draftsman for the layout) , itīs not such a big deal.

Thar resistor is part of an attenuator so the strong previous preamp section does not swamp the far weaker reverb return signal.
The attenuator ends up being said 3M3 in series with 220k.

So if preamp is putting out, say, 3V RMS, you'll get some 200mV *preamp dry signal* at the mixing point.
I BET reverb recovery signal there is about that.

And if you use 4M7 instead?
Well, then youīll get some 150mV RMS there ... as I said no BIG deal since in any case that mixed (dry + reverb) signal gets reamplified by the extra triode added in that channel.

So maybe you get same volume out with volume pot set to 6 instead of set to 5?
Guess not many will even notice that.

That said, for consistency itīs always advisable to build things "by the book", specially in a high production Factory setting such as Fender.