Bipolar power...and hello!

[KiwiDoc]

hi all, firs time poster long time reader.
I'm based in New Zealand, really I have spent a lot of time on amps and guitars and just starting out with effects.
I'm building the Anderton stage centre reverb stand alone spring reverb unit.
It calls for bipolar -/+9v supply.
I see there is a lot on this topic on the web.
Specifically I wonder if I can use an lt1054 chip in place of max1044 in this schematic? Ie are the pins interchangeable?


As I understand the lt1054 will give more greater to,era de as far as current draw is concerned, which might be useful with the spring reverb.

If anyone has a better looking schematic/ layout for supplying 9v bipolar from a +9v DC supply then I'd be very appreciative.

Thanks guys,

[tubegeek]

I dunno, but here's what I'd do:

• look at the data sheet for the LT1054
http://cds.linear.com/docs/en/datasheet/1054lfh.pdf

• look at the data sheet for the MAX1044
http://datasheets.maximintegrated.com/en/ds/ICL7660-MAX1044.pdf

• see if the pinouts match.

[KiwiDoc]

Yes, it appears pin outs match. Thank you,
Will this schematic suit my purposes?
Also there is another schamtic that involves the sleeve and ring of a stereo jack in the build. I assume this is the input of the pedal.
What benefit is this??

[Beo]

Check out the roadrage and madbeans.com. The write up should tell you everything you'd like to know about the different chip options.

http://www.madbeanpedals.com/projects/index.html

[mth5044]

^ Came in there to recommend the roadrage ^

Read up about whether pins 1 and 8 can be jumpered or not when changing IC's in that madbean roadrage PDF. That last layout that you posted has pins 8 and 1 connected, so you wouldn't want to use that layout without modification.

Hard to tell what exactly is going on with the ring connection in the layout you posted without the schematic to look at.

[duck_arse]

nothing useful to add, except hello fom across the ditch, kiwi.

[antonis]

nothing useful to add...

You could add that Sleeve should be connected to GND...

(or maybe R.G. Keen had something else in his mind..  )

[duck_arse]

nothing useful to add...

You could add that Sleeve should be connected to GND...

(or maybe R.G. Keen had something else in his mind..  )

orrl right, I'll add that I can't see any posted images there might be in this thread. and sleeve etc.

[tubegeek]

Very common trick in the world of stompbox gizmos: using a Tip - Ring - Sleeve (TRS) input jack as a power switch.

Battery negative: goes to Ring of jack.
Ground: goes to Sleeve of jack.

Now:

Plug a Tip-Sleeve (TS) plug (found on the typical guitar cable) into the jack: the Sleeve of the TS plug will make contact with both the Ring and Sleeve contacts inside the TRS jack, connecting them together. Battery negative is thus connected to ground, and the device turns on. Remove the plug and it turns off, because then the battery only has one connection, at the positive end. No current flows, saving your battery power when you are not using the gizmo.

[mth5044]

So in the layout posted above, inserting a plug turns on the transistor and allows for 9V to flow into the bipolar power circuit? Makes sense I guess!

[antonis]

So in the layout posted above, inserting a plug turns on the transistor and allows for 9V to flow into the bipolar power circuit? Makes sense I guess!

Not exactly...

In the layout posted above, R1 & R2 form a voltage divider for Q1 base bias... Left side of R2 needs to have a GND connection (or at any other Voltage level lower than 9V..) for the divider to be effective...

Inserting the guitar cord plug short-circuits the Ring and Sleeve BUT if Sleeve isn't connected anywhere you can't make the circuit active...
(that's why I previously wrote that Sleeve HAS to be connected to GND..)

[duck_arse]

^ because its base is held to +V by the 1k resistor, the ring-connected 6k8 needs to be pulled to ground by shorting on a tip/sleeve plug, to turn on the PNP transistor, which then series-passes the +9V to the board, just as antonis told me I should say.

so the input sleeve MUST have a ground wire for the circuit to pass volts. a circuit diagram makes all this prattle so much easier.

[antonis]

the PNP transistor

So, you've guessed from the layout that Q1 is a PNP (E-B-C) BJT...

Any chance to be a NPN (C-B-E) type..?

[duck_arse]

I think it was shakespeare said "a 3906 is a 3906 is a 3906, and there's nothing quite as pretty as 2N3906 in the morning". those american transistors have funny pinouts, no?

[antonis]

I thought that Shakespeare said " a BC116 is a BC237 is a BC338 and there's nothing quite as pretty as BC547 in the morning " and disentangled from any pinout setting, yes?

[KiwiDoc]

nothing useful to add, except hello fom across the ditch, kiwi.

G'day!

[duck_arse]

well said, cobber. also, was it plato that said "I think that I shall never see a BC639 that hasn't had its legs twisted to fit".

is any of this useful, Kiwi?

[mth5044]

You guys are weird. 




Now get off my lawn.

[KiwiDoc]

Wow, great info!

So...I powered up the circuit for the first.
What I get is a fair bit of buzz, the guitar signal is amplified quite cleanly but the is little to no reverb added. When I tap the tank there is huge lush springy crashes etc but doesn't seem to be getting driven by the guitar signal. The bypass works fine.
Any thoughts ?
This is the layout
http://www.generalguitargadgets.com/pdf/ggg_sc_reverb_lo3.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

[duck_arse]

what? are we working on a circuit? I thought antonis and I were around for some philosophy and poetry on some guy's lawn.

your next two steps ....

http://www.diystompboxes.com/wiki/index.php?title=Debugging
http://www.diystompboxes.com/smfforum/index.php?topic=29816.0