Spin Semiconductor

Hi Y'all


I have a cool one for you.
I have a wonderful tube guitar amp that I love
that has factory integrated FV-1 doing just reverb .... badly haha

I wont call any names, as it would be in bad taste
but this is a large amplifier company with a secondary line of korean pcb based amps

I will enclose pics soon

the fv-1 has pin 13 pulled to ground, and it has no eprom
so just to change 8 factory programs ... what is the simplest approach?
switches and pots, or a rotary encoder, or rotary switch?
can i use conventional amp toggle switches to input program change?

the data sheet shows one with 3 switches and 3 pots.
.. will that work without the 24lc32a eeprom ?
that would be ideal.

I saw a post that showed pulling specific pins to +3.3v or gnd, would select a specific preset. any refrence on that hiding around?

I also build some cool acoustic preamp buffers of my own
.... and a fv-1 could be a great component if this interfacing all works out.

many thanks

Willie

looks like I can lift r91 - r96 and wire in 3 pots to p0 p1 p2
and 3 switches to s0 s1 s2

Archangel wrote: the fv-1 has pin 13 pulled to ground, and it has no eprom
so just to change 8 factory programs ... what is the simplest approach?
switches and pots, or a rotary encoder, or rotary switch?
can i use conventional amp toggle switches to input program change?

The best solution is which ever you feel is best, any of them will work. Simpley depends on what parts you have/how much space to add parts/how much you want to spend on switches/etc.

Archangel wrote: the data sheet shows one with 3 switches and 3 pots.
.. will that work without the 24lc32a eeprom ?
that would be ideal.

Yes it will, switches and pots are program dependent.

Archangel wrote: I saw a post that showed pulling specific pins to +3.3v or gnd, would select a specific preset. any refrence on that hiding around?

In the datasheet.

Thanks!

I wired up 3 push/pull dpdt pots
they are 250k though ...and not giving any adjustment, even at the far end of its travel

I will need to parallel a resistor with the pots elements
and bring the impedance down to 50k

am I reading the data sheet right in that the pots
wiper swings between ground and +3.3v

the switching is working great though!

Archangel wrote:Thanks!
am I reading the data sheet right in that the pots
wiper swings between ground and +3.3v

Yes, one end of POT to gnd, other to 3.3 and wiper to pin.

Frank thanks for taking the time with a silly guitar amp question. As it turns out the custom program set from the manufacturer was not too useful .... Pitch shifted tremolo for example.

However ... I build reference quality acoustic preamp buffer line drivers. I use gold plated black solder masked beautiful boards and a BB opa2134 . I am designing a new one that uses a ssm2166 for parallel compression and to have effects would be great

The scrm boards are pretty cool
I will talk to you more about those soon

And I have a pretty cool tube amp for a development platform now haha

Hey, that's a cool idea, to find devices that use the FV-1 and put whatever program you like in them!

I noticed there's a dual-ipod mixer out there from Radio shack that uses the FV-1.... That could a fun platform, too