STAGE CENTER REVERB (Parts List) Help

skotrocket · August 05, 2006, 10:22:05 AM

Hi,
I'm still fairly new to all of this but have been reading and reading...

I'm in the process of ordering parts for the STAGE CENTER REVERB (http://www.generalguitargadgets.com/index.php?option=content&task=view&id=124&Itemid=142)
and the "Materials List" isn't matching up with the "build instructions."

There is different resistors and caps on both of the pages. Which ones are correct?

I contacted the site/webmaster but no reply. I ALWAYS search before asking. Help would be greatly appreciated.

I just don't want to get the wrong parts.

THANKS!

petemoore · August 05, 2006, 05:40:04 PM

http://www.generalguitargadgets.com/diagrams/stage_center_reverb_sc.gif
I built from this schematic with these values on perfboard.
I used two batteries for v-/v+ PS.

ildar · August 05, 2006, 05:54:53 PM

Thanks to the OP for turning me on to my next "gotta build" project!

skotrocket · August 05, 2006, 08:32:26 PM

Thanks Pete! I'll use that as a checklist.

I appreciate it!

oldrocker · August 05, 2006, 09:03:36 PM

Don't you still have to hook it to a spring box for this circuit to work?

petemoore · August 06, 2006, 01:59:27 AM

Oh...yes you do !!!
Accutronics is where I got mine...chime in's for other sources?...works great and was like 25 bux.
And, you need to match the ohmage to the 386's output, and I forget what that is, at least you know this much, sorry I didn't mention...it's been a while, you mentioned caps and R's and I forgot about accessing the tank

I'll look and see what I can find out.

petemoore · August 06, 2006, 02:10:49 AM

Tank Input Impedance of 310 Ohms, [from BOM page at GGG]
http://ampwares.com/reverb_codes.html
Since the spring driver is essentially a 'speaker' and the TL074 [not 386, sorry] is driving it, you dont' want to exceed minimum ohmage added to the OA output, use something close to, but no less than 310ohms?
As I say, it's been a while, looks like I got myself in a quandry, I hope I haven't been more hindrance than help

disantlor · August 06, 2006, 09:56:32 AM

How does using a reverb pre amp compare to a reverb thats a part of the amp. Sound the same?

petemoore · August 06, 2006, 11:07:44 AM

How does using a reverb pre amp compare to a reverb thats a part of the amp. Sound the same?
"No, or "Just like Tubes"...lol.
Nice mech/spring reverb effect, not the 'ultimate Rev.' mine was built and finished for ~35$.
2x12'' Combo amps [cranked a little bit] have three drivers for the spring, 1 spring driver, and 2 'secondary shakers'...the speakers can 'secondary vibrate' the reverb springs a little bit...[IIUC] if the speakers vibrations are transferred through the spring's dampening suspension to the springs.
"What the input driver 'is', is heard through the mechanically vibrated springs, I'd imagine it's less than a big difference if tube or IC wiggles the springs via condenser...as long as it's sufficient...
If you're striving for 0% IC in the signal path...well the recovery amp's output is mixed directly to signal path, and so it follows that here, whatever differences IC to Tube comparisons 'do' could be better heard as differences in tone in the recovery amp.

skotrocket · August 06, 2006, 01:39:45 PM

As I wipe the drool and blank look off of my face...

Thanks for all of the info Pete. Yeah, I'm reading posts in several forums about this and hear all kinds of different ways to do it. Different caps, resistors, etc.

I got my tank from small bear, will get it Monday.

Thanks again! I'll keep reading.

jimbeaux · August 06, 2006, 02:01:18 PM

One modification is to leave out C2 (.01 cap from 'X' to Gnd.)
It adds more treble to the sound.

I used a spst switch to cut C2 in & out. (Like a normal / bright switch)

petemoore · August 06, 2006, 03:37:23 PM

C4 feeds the opamp to reverb tank input, and could be used to rolloff bass to the springs,
C6 between tank output and recovery amp is also a HP filter
If I were thinking of a new build in mod, a treble/bassier switch between two cap values for each c6 and c4, or sockets those positions and adjust values to taste.
Mine sounds great, I just wonder if I had say .01uf's in those positions...or even a switched .0068uf as C4 for a a 'sparlky' bass cut.
..Maybe I'm just over-complicating things.

skotrocket · August 06, 2006, 08:21:07 PM

All of these "tweaks" sound great! I especially like the idea of more treble.
I heard some complaining about the sound being to dark.
This is only my 2nd build so I'll try to keep it simple as I learn.

But I am a tone freak so I like all of the simple things that can change the sound, (i.e. removing or changing caps, resistors)

I'm aiming for a good surf tone. If it's not surfy enough, that's fine. Springs sound great anyway!

Thanks for the help fellas!

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STAGE CENTER REVERB (Parts List) Help

ildar