Seeing Eye Mod: 3 tiny questions.

[bobbletrox]

I'd like to try my hand at doing the Keeley Seeing Eye mod using the utterly brilliant schem that Phillip posted about a month ago.  But I just wanted to ask a few questions before I hack into my DS-1...

1)  Metal Film Caps:  I know Robert Keeley uses metal film caps, but would Metallized Polyester Greencaps still be an improvement?  It's just that they're easier to find  :oops:

2) The 1UF NP Caps:  Are these non-polarized electrolytics, or would 1UF greencaps be ok?

3) The 5mm LED  If I use a 3mm LED (to avoid drilling the box), I can leave R35 as the original 3k9, right?

I'm still a tad confused as to how to add the cap across the clipping diodes too...but I'll tackle that problem when I get to it.

Thanks if anyone can help!

[Ansil]

I'd like to try my hand at doing the Keeley Seeing Eye mod using the utterly brilliant schem that Phillip posted about a month ago.  But I just wanted to ask a few questions before I hack into my DS-1...

1)  Metal Film Caps:  I know Robert Keeley uses metal film caps, but would Metallized Polyester Greencaps still be an improvement?  It's just that they're easier to find  :oops:

2) The 1UF NP Caps:  Are these non-polarized electrolytics, or would 1UF greencaps be ok?

3) The 5mm LED  If I use a 3mm LED (to avoid drilling the box), I can leave R35 as the original 3k9, right?

I'm still a tad confused as to how to add the cap across the clipping diodes too...but I'll tackle that problem when I get to it.

Thanks if anyone can help!

1..  sure why not anything is usually better than the original

2 yes non polarized and 1uf caps should be fine

3. yes.

[bobbletrox]

2 yes non polarized and 1uf caps should be fine

Oh, so either NPs or Greencaps are fine?  Too easy!  Thanks again Ansil -you seem to have all the answers  :wink:

The great thing about this mod is that it comes to a total of about a $1.50

[Ansil]

I TRY..  

its all a matter of options

[Bucksears]

Just my $.02

I have two DS-1's and did the SEM  on one and the Ultra on the other. The SEM turned out great. For both, I used the .1uF and 1uF film caps from Digi-Key (they look like the ones in Robert's pics), and metal film caps from them as well.
The Ultra, if I can get the tone control working right, is VERY close to hitting the mark with Steve Vai's sound: very tight distortion, lots of it and more bass. The tone ctrl on mine is rolling off the treble AND volume (about 65-75% cut) as the knob goes CLOCK-wise. I e-mailed Robert and he had some suggestions (UN-believable great guy!!)
The SEM sounds really REALLY good, but the Ultra was what I had hoped it would be.  Both are keepers.

[Bucksears]

Oh, and I didn't try the whole drilling/new LED thing to be able to see the 'Seeing Eye'. I liked the sound, too lazy to change the look.

[phillip]

When I modified my DS-1 I did a combination of the SEM and the Ultra.  I changed all the resistors and capacitors as per the Ultra mod, but with the clipping diodes section, I only went as far as the SEM...with the red LED in the clipping section inside the box instead of outside like Keeley does it.  I also changed C4, the 250pF ceramic capacitor between the base and collector of Q2, with a 470pF Silver Mica like he did in one of Steve Vai's DS-1s (not a part of the regular Ultra mods).  For the on/off LED I used a  3mm white super bright red indicator.  Great sounding mods!

Phillip

[Ansil]

When I modified my DS-1 I did a combination of the SEM and the Ultra.  
Phillip

thats what i did on my site.   tooo.  

[Axmanjr]

I gotta look for these components!

[Peter Snowberg]

#1: Metallized polyester = metalized film. I really like Xicon "greencaps" too. Other film types beyond polyester (mylar) include polystyrene, polycarbonate (lexan), and poly tetra fluoro ethylene (teflon).

#2: I prefer films to electrolytics as a general rule.

#3: I don't think the LED size really matters. The chemistry is the same. Just a guess.

Take care,
-Peter

[bobbletrox]

My local compontent shop, Jaycar, has "High Quality Metallised/Polypropylene" non-polar capacitors and their description says they're ideal for "high quality crossovers and have excellent audiofrequency characteristics".  They're rated at 250vdc so they're about 1" x 0.5" axials -but I've been itching to try them because they're Fluroecent Yellow!  They'd be too big for a DS-1 mod, but could I use them instead of aluminum electrolytics for input and output caps in other circuits?

I'm ashamed to admit that I like to use components simply because they look cool  :oops:

[Peter Snowberg]

My local compontent shop, Jaycar, has "High Quality Metallised/Polypropylene" .....  could I use them instead of polarized electrolytics for input and output caps in other circuits?

Poly-anything caps are really good stuff. Go for it!

The holy grail would probably be copper foil and polystyrene, or aluminum foil and polystyrene.

Poly want a cracker?


Check out all the cool cap options here: http://www.angela.com/

Take care,
-Peter

[bobbletrox]

Great!  Thanks Peter.

...and that site is like a candy store.   :shock:

[modmod]

i am just trying to order panasonic v-series metal stack film caps, are u guys using 100v or 50v version ? thanks

[Ed G.]

50v is more than enough.

[phillip]

I used the 50V V-Series on all of my Boss mods.  The great thing is that those very high quality stacked metal film Panasonics are cheaper for each capacitor than the standard polyester film "greenies" that I used to get from Mouser.  The down side is that you have to order at least 10 of each value, but 0.1uF capacitors get used up really fast!

Phillip