Rat mod

[StephenGiles]

I found this over in Effektgerate
http://www.kotipolttoinen.com/sisalto/kitara/rat_mod/index.php
Stephen

[Bernardduur]

I've done this mod; it sounds really good (better than before)

I also changed the diodes from silicium to LED's and none; I can hear no difference between none and LED's and a lot of difference between the LED's and the silicium diodes.

[Steben]

I've done this mod; it sounds really good (better than before)

I also changed the diodes from silicium to LED's and none; I can hear no difference between none and LED's and a lot of difference between the LED's and the silicium diodes.

Bedoel je met "none" dat je enkel de opamp laat oversturen? Hoe klinkt dat dan?

[Khas Evets]

Bedoel je met "none" dat je enkel de opamp laat oversturen? Hoe klinkt dat dan?

My Dutch isn't what it used to be, but here's a translation for the rest of us.

"Do you mean that with "none" you only have opamp saturation/overdrive? How does that sound?"

[Steben]

Bedoel je met "none" dat je enkel de opamp laat oversturen? Hoe klinkt dat dan?

My Dutch isn't what it used to be, but here's a translation for the rest of us.

"Do you mean that with "none" you only have opamp saturation/overdrive? How does that sound?"

Well what a test where you get A+++, my friend. 

[Khas Evets]

dank

[Bernardduur]

As I said, when I don't connect any clipping diodes at that point (I have a DPDT switch with a middle position; in the middle position there is no conenction. At the right are the original 4148's, on the left 2 red LED's) I can hear no difference between the LED position and the "none" position. I've tested it at different settings and at all points (only when I turn up the distortion to the max I hear some faint difference) I hear no difference.

I thought it was normal. Need to mod it more when I have some time.

Oh, and power to the Dutch (speaking countries)

[Khas Evets]

Do the LED's light up when you play? If they do, it means that they are clipping, but not very much. They should light up since the turbo rat uses LED's.

Another thing you might consider is hard wiring the LED's so that they're always connected. You could then use the former LED pole for another combination. As long as the forward voltage is less than the LED, they will clip first. Maybe try an asymetrical combination or SI plus GE in each direction.

[Bernardduur]

Yes, they light up. I am pretty happy with the sound. I just wondered why I did not hear any difference between the none and LED section (and if it was normal).

[Steben]

It's possible that a distorted bass note is not that different whether driven by diodes, transistors or opamps. There are less high overtones than with guitars. Perhaps the Si or LED trick can be explained by the difference in clipping voltage, giving Si more distortion at the same opamp gain. However, the opamp should clip at even higher voltages than the LED, as long as the battery isn't to low.

[Bernardduur]

Also checked with guitar

Ah well, I like the sound. Any more mods to preform on a rat?

[pjl]

Nice to see that you have found my stuff helpfull!

Best regards,
Pekka (@kotipolttoinen.com)