School me on Diode Clipping

  • Thread starter Thread starter gtrlw
  • Start date Start date
diodes can be smooth, ratty, good or bad depending on what you want. It clips off the tops and bottoms of the signal and can be customized so to speak with resistance and caps. in the carvin bel air, its used the wrong way. The marshall jubille they started to get it right. In the peavey VTM its used correctly and in my opinion perfected by Jose Arrendondo. Making it switchable is the key. Have it or not.

most pedals use diodes. Cheap and effective.

my statements are based on the kind of tone i like. Some may think the dirt in the peavey VTM sucks ...... its subjective.
 
Thanks, Jerry. What is the alternative to diode clipping in a preamp?
 
nothing really, another tube gain stage and a 1 meg pot to hold it back and create buzzola.... some use a little op amp, also found in overdrive pedals to dirty things up a bit. The cool thing about diodes is that whether its a zner or an actual tube diode, they both sound very tubey when done right. its still a non digital device. analog. its not a bad thing .. only when used as a shortcut it gets raunchy.carvin el air carvin mts series etc ..
 
jerrydyer":3huo6p29 said:
nothing really, another tube gain stage and a 1 meg pot to hold it back and create buzzola.... some use a little op amp, also found in overdrive pedals to dirty things up a bit. The cool thing about diodes is that whether its a zner or an actual tube diode, they both sound very tubey when done right. its still a non digital device. analog. its not a bad thing .. only when used as a shortcut it gets raunchy.carvin el air carvin mts series etc ..
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Tubes are diodes.
 
di ode = two elements
tri ode = three elements plate cathode grid
 
my buddy richar uses an actul glass diode (tube diode 0 in a pedal he builds sounds killer. total squish effect compression.
 
Jerry pretty much said everything there is to say. Something I like to do is use LED's as clippers instead of silicon diodes because they have a much higher Vf than silicon or germanium. String a few diodes in series oriented the same way and you get double the headroom before clipping. Typically speaking, a single diode only clips one side of the signal, so you use diode clipper pairs placed in opposite orientation and you get both sides of your signal clipped. As Jerry said, diode clipping done in the right way can result in some very pleasing compression. Done wrong (like the Peavey Rockmaster preamp) and you get fuzziness and lack of dynamic range.
 
What are some amps that use diodes? The only ones I know of off the top of my head are some of the Marshall jcm900's and the jubilee, and Blackstar amps. I know I am missing a bunch. Anyone care to mention some?
 
mrkmas":1qij825q said:
What are some amps that use diodes? The only ones I know of off the top of my head are some of the Marshall jcm900's and the jubilee, and Blackstar amps. I know I am missing a bunch. Anyone care to mention some?
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marshall 2205/2210
 
Jerry - So a "Jose Mod" involves adding a clipping diode to the circuit to increase the gain? I find that so interesting as, for the most part, clipping diodes are frowned upon. But, the Jose Mod is the pinnacle of all things awesome and marshally. What makes the Jose Mod different in application from the carvin bel-air/mts clipping diode?
 
baron55":srs6nwz9 said:
Clipping diodes don't increase gain. They actually reduce it. What they actually do is increase distortion by clipping the signal as well as increasing compression. The compression reduces bandwidth giving you a fatter tone and more articulation. These two Changes give the perception of more gain. Guys that have amps with the switchable diodes will notice a volume drop (gain) when the diodes are switched in.
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Yeah, a pretty large volume drop...

Steve
 
When I take the clpping out of the circuit on my amp the volume jump is pretty big, enough that you go from tv volume to quiet jam levels.
 
Digital Jams":1g7id17n said:
When I take the clpping out of the circuit on my amp the volume jump is pretty big, enough that you go from tv volume to quiet jam levels.
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I noticed the same thing. :lol: :LOL:

A couple notches on the volume brings it back to where it was.
 
FET'S are also used similarly to diodes in amps/pedals. I think they sound more dynamic when used right
 
The Whale":1oml1oq9 said:
Jerry - So a "Jose Mod" involves adding a clipping diode to the circuit to increase the gain? I find that so interesting as, for the most part, clipping diodes are frowned upon. But, the Jose Mod is the pinnacle of all things awesome and marshally. What makes the Jose Mod different in application from the carvin bel-air/mts clipping diode?
Click to expand...

yeah..... the bel air did an old school trick called poor mans distortion. a couple 1n4007.....right before an input grid on like the second gain stage. yuck..

and yes certain tranistors or jfets make great diodes if you know enough about em to snip the correct leg. you can also miniimze the volume drop by sticking a resistor in there. 10k 12k I think I use on one of my choices for either more or less clip.
 
yep thats where I learned about the poor mans overdrive and all that. also a great section on using a triode as a diode. for some warm squish like compression
 
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