How to raise the gain capabilities of the Ruby?

[JimRayden]

What resistors to swap in the preamp/poweramp to make it have as much gain as I could squeese from it without draining the battery in a second? I want my ruby to be more suitable for the sustainer.

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Jimbo

[JimRayden]

Come on, I bet most of you know how to raise the gain of the buffer...

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Jimbo

[smashinator]

Take a look at this article: http://www.runoffgroove.com/grace.html

[JimRayden]

If I build a Sparkle Boost in front of the Ruby, can I remove the input buffer?

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Jimbo

[TheBigMan]

Check the Fetzer-Ruby in the ROG FAQ.

[MrChameleon]

http://www.diystompboxes.com/sboxforum/viewtopic.php?t=27386&highlight=fetzer+ruby

http://www.national.com/pf/LM/LM386.html

[JimRayden]

Alright, "What to do when it doesn't work"

Sparkle boost - Q1

G - 0V
D - 0.5V
S - 4.48V (Nicely biased, aint it )

Ruby IC

1 - 0
2 - 0
3 - 0
4 - 0
5 - 7.46
6 - 8.09
7 - 3.4
8 - 0

Hope you can help me.

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Jimbo

[psw]

Sustainer stuff is getting past me....

As far as I can tell...the ruby buffer is obsolete in the sustainer application as the sparkle drive is a preamp and addresses the input impedance problem with the LM386 just as well...

I've successfully driven a rudimentary versions of the sustainer experiments using Ansil's "Sustainer Mod" circuit with just the 386 chip and an output capacitor....2 parts...

The problem is that the tone is completely sucked by the impedance mis match and it is more suseptable to oscillation...

Ehy oh why is there not a chip that's a low watt poweramp and preamp in one...even an op-amp which has internal biasing resistors, etc...is it really too much to ask...apparently yes...oh well.

Despite recent sustainer debate, my next preamp will use a 081 or similar single op-amp glued upside-down and wired "dead insect" style with identical resistors for bias and gain and wired directly to the poweramp board or even the poweramp chip itself...someones got to do something about this preamp/sustainer question without futzing around with multiple value resistors and trim pots...I realize I know little about electronics but really...wouldn't there be a market for a basic universal preamp/poweramp combo...if only for tranny radios or something...aghhhh... :roll:

...psw

[JimRayden]

lol, design your own damn sustainer chip. It might cost a bit but then you get the sustainer you want, PLUS, if the market likes your idea of this chip, you'll get rich and famous. Call it "The PSWIC".

Naah, I didn't think so either.

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Jimbo