Tonepad Ross Phaser pot question

[Toney]

I have seen a few ideas flosting around with this.
Tonepad lists two 500KC (reverse audio), but others have been mentioned.

What have people used that works nicely with a decent and usable sweep for the Rate and Regen?

Here's a  linky to the schem http://www.tonepad.com/getFile.asp?id=99

[anchovie]

I used two 470K linears as they were easiest for me to get. Works fine for me, but I'm not that fussy. 

[Toney]

How's the pot sweep?
Is it weirdly bunched up or anything?
Those reverse log pots are hard to find locally.

[Thomeeque]

I have seen a few ideas flosting around with this.
Tonepad lists two 500KC (reverse audio), but others have been mentioned.

What have people used that works nicely with a decent and usable sweep for the Rate and Regen?

Here's a  linky to the schem http://www.tonepad.com/getFile.asp?id=99

For speed pots I simply use logarithmic (audio) pot with reversed wiring and function (imo much better, than to use linear pot here).

For regen I would try linear (or maybe both, linear and audio with reversed wiring as well to feel the difference)..

[anchovie]

How's the pot sweep?
Is it weirdly bunched up or anything?
Those reverse log pots are hard to find locally.

To be honest, I wouldn't know as this is the first phaser I have ever owned! I haven't found it difficult to dial in sounds that I like.

[Toney]

Well I have had a good hunt around and I have a couple of 100KCs so I guess I'll give them a go.

[Mark Hammer]

Although a C-taper is ideal, you might want to consider using a 3-position on-off-on toggle in conjunction with a 100k pot in its place.  Depending upon the range of speeds that is of most interest to you, using a toggle to supplement the pot resistance with an additional resistance may well be the fastest way to achieve optimum "dialability" for the speeds that interest you most.  I suppose the other option is to go with a 500kC pot and use a SPST toggle to "zoom in" on the faster range by adding a parallel resistor.  So, if you straddled a 500k pot with an 68k resistor, the effective max resistance would be around 60k, which would spread out the first 60k of overall adjustment (over and above the 4k7 default resistance) over the entire rotation of the pot, and allow for greater selectivity among fast speeds, where syncing modulation rate to the song becomes more important.

[Thomeeque]

Although a C-taper is ideal, you might want to consider using a 3-position on-off-on toggle in conjunction with a 100k pot in its place.  Depending upon the range of speeds that is of most interest to you, using a toggle to supplement the pot resistance with an additional resistance may well be the fastest way to achieve optimum "dialability" for the speeds that interest you most.  I suppose the other option is to go with a 500kC pot and use a SPST toggle to "zoom in" on the faster range by adding a parallel resistor.  So, if you straddled a 500k pot with an 68k resistor, the effective max resistance would be around 60k, which would spread out the first 60k of overall adjustment (over and above the 4k7 default resistance) over the entire rotation of the pot, and allow for greater selectivity among fast speeds, where syncing modulation rate to the song becomes more important.

Maybe he could try to lower LFO's 4k7 resistor to 1k and enlarge 3.3uF cap to 15uF to get to the (almost) same range with 100kC? Would LFO stand this change?

[Mark Hammer]

My suggestion is not so much to get more range, but rather to be able to zero in on the portion of the overall available range that is of most interest.  The current arrangement, even with the ideal pot still confines the medium-to-fast range of speeds (say, 1hz-5hz) to less than half the rate pot's rotation.  The ideal is to have that range spread out over the full rotation when faster speeds are of most interest, and revert back to the normal distribution of speeds to select from when longer sweeps are of most interest.

[Toney]

Nice suggestions.
I will give the parallel switch a go if the 100KC doesn't cut it, although I am loath to cut another hole in the enclosure at this point (mega tight build space-wise).
I tried making my own 500KC from a linear but the results seemed a little "off". I never seem to get the predicted results when I do this!!

[Toney]

Ok, well soldered a 47k across lugs 3 and 2 of a 500k linear.

Seems to work very well for controlling the rate