Diode clipping

[Reeltarded]

Any of you guys ever mod an amp with diode clipping? Anything special that you like?

I am thinking of adding some to an amp here, just looking for experiences.

[mat]

Any of you guys ever mod an amp with diode clipping? Anything special that you like?

I am thinking of adding some to an amp here, just looking for experiences.

Not mod but I built Marshall Silver Jubilee (2555) that has led clipping on the od-circuit. When I'm not in Dumble-mood I like the 2555 very much.

long noodling clip of the 2555: http://soundclick.com/share.cfm?id=8300020

[dynaman]

I tried it on a Super Lead(?). It was a very simple arrangement with only two diodes that I found in an old book written by Tom Mitchell. In my case, it resulted in distortion at the expense of noticeable signal loss. The 2555 has a more refined clipping circuit and I've only heard good things about that amp. Might be a neat effect to make switchable if you adapt it to another amp.

[Reeltarded]

I used to use a Randall that had a pair (seems 1n914.. odd.. my favorite Porsche..) to distort in a very nice way. With the diodes the amp really sings in the mids where I like it!

That amp was just a bit cleaner than the Marshall stuff without the diodes engaged. I am thinking they might be good to start with. I can't find a schematic for those amps. SH is crippled!

I would like to work it out on a gain knob for a switchable stage, so when out.. it's out.

[sliberty]

I removed the stock diode clipping stage from a Peavey once - does that count?

Diode clipping in a tube amp is not a good thing in my opinion. Make the tubes do what you want.

[Reeltarded]

The Randall thing was my favorite amp ever when that network was engaged. It made it's way into my lead rig as a driver, and my dirty rig because of the channel blending. Best distortion unit ever!

Seems like I could melt that into a Super Lead. I have nothing to compare too. Any other parts numbers that cause a pleasing effect? Seems like the 914s are at least a place to start. The Randall wasn't much different than a marginally distorted Marshall without them.

I'm excited.

Woo.

[Andy Le Blanc]

Many marshalls use a little network of 4 diodes of the same type and 1 electrolytic cap.
You can use damn near any diode to taste, the cap is around 4-5uf 63v
to block dc and introduce a phase shift, You rig it after the coupling cap
out put, to either ground or the cathode of the previous stage.
I think they ripped the notion from an old westbury distortion pedal.
There is a gain reduction, but less gain means more stability at high volume.
Its easy to add one stage to get the gain back, or think of the two stages it
take to make the cathode arrangement go, as one stage...

[Reeltarded]

Fantastic Andy! Thank you!

I wish Mouser was local! Damned Christmas is going to mess up shipping.. BET!

Merry Christmas, everyone!

[Andy Le Blanc]

You'll want to go over a pile of Marshall scheme, el34 world?, its implemented
in several models. Its so simple, nearly any kind of diode works, you should
be able to scrap up parts from rat sack (radio shack) or out of your bone pile
if you got one.

http://www.el34world.com/charts/Schematics1.php

[ChrisM]

Fantastic Andy! Thank you!

I wish Mouser was local! Damned Christmas is going to mess up shipping.. BET!

Merry Christmas, everyone!

Why do you need Mouser?
Worst comes to worst you can use RadioShack. They sell 1N914/1N4148, LEDs or all variety, 1N34a (Germanium), and of course 1N400x. All great diodes to experiment with clipping.

[Reeltarded]

I am starting with a '70 Super Trem that has some stuff to be undone.

I want to tuck this very late in the circuit, I was thinking of using half the trem tube for a final gain stage, incorporating the diodes in there, and using that stage mostly to makeup the loss, not so much as a normally added tube stage.

The simplest implementation of it so far is just strapping the pair from the wiper on a gain pot to the ground bus, so adding this on a 4th tube with a (switchable) gain control SEEMS like a good way, and I think my bone pile consists of at least one complete unused stage worth of parts.

(just no diodes... I opened everything I could find yesterday)

[Reeltarded]

Why do you need Mouser?
Worst comes to worst you can use RadioShack. They sell 1N914/1N4148, LEDs or all variety, 1N34a (Germanium), and of course 1N400x. All great diodes to experiment with clipping.

Not here. Between the three locations closeby, no joy. There is an assortment pack, but none of the numbers I have seen touted as the ones that make the good noise. I did buy a pack just to test on my Egnater 20.

They need to change the name of that place to Digital Mobile Radioshack. Crap!

[xtian]

There was an article in Wired about how Radio Shack stores come in two varieties: corporate clone store, and owner-influenced franchise. This explains why some RS stores have more interesting products.

Hopefully the rise of the DIY and Maker culture will mean more of the later variety.

One thing I miss about the Bay Area is awesome stores like Weird Stuff Warehouse and Frys.

[iknowjohnny]

Well, this thread prompted my curiosity because i owned a few marshall diode clippers including a jubilee and jcm switchers. And i liked those amps. But when i started making my own marshall in an attempt to make the ultimate marshall for ME at least, i had a chance to plug into a marshall 800 switcher and compare after not having owned or played one for years. And the tone sounded thin and crappy compared to my creation. I thought maybe it was just a bad one because i don't remember them sounding bad at all.

So today after reading this thread i had to try it. My amp sounded like that 800. Yep....if you make it all tube and do a good job of it, diodes aren't going to sound as good. I will say tho my jube sounded much better than the 800's, and even a 900 i had sounded very good. Those 2 had a different diode scheme tho. And next to my current creation they would probably also sound thin to some degree. I do however like the diode sound in some ways. And i could easily make it switchable. But the amp sounds much better w/o and i already have too many switches.

[Reeltarded]

Success! RS is different everywhere. 2 hours away and they have loads of all the numbers I was searching for. Rock.