King of Tone

[jonnygreentrees]

I want to build a King of Tone (well half of it, the Prince of Tone). I know there are some obsolete diodes in it does anybody know what they can be swapped out for?

[Mark Hammer]

Nah, doesn't really matter all that much.  The KoT is essentially a modded Bluesbreaker.  A Bluesbreaker uses a quartet of 1N914s in the same position.  Will they sound a little different from MA856 and not absolutelyidentical to an actual KoT?  Yeah, probably; particularly given that diodes can have variation in forward voltage and any 4 diodes of the same type can result in a whole whack of different clipping thresholds.  But it's not like the difference between sticking a single op-amp into the 8-pin socket of a dual op-amp.  The key thing is the gain and tone-shaping of the first op-amp stage, which is where the biggest BB-vs-KoT differences lie.

Trust me, you'll be happy with 1N914s all round.  I've made a few, and they sound terrific.

[lars-musik]

There is already something to be found about the diodes in the King of Tone:

http://tagboardeffects.blogspot.de/2012/10/analogman-king-of-tone.html

Clipping diodes in General:
http://music.codydeschenes.com/?p=1615

Or here on the forum:

The MA856 are almost impossible to get. They were originally used for band switching in radio and tv tuners. I managed to get a couple of MA856 diodes, but not enough for a KoT.
Looking at data sheets for various other band switching diodes and comparing some basic Vf tests on a DMM diode setting, the BA278 and BA243 are very similar to the MA856 and have very similar specs on the datasheets. They should certainly sound more authentic than regular 1N914/1N4148's.

I bought for my KoTs a bulk of 500 pcs BA243 in an ebay auction and they sound superb - but I couldn't hear a difference to the 1N914 and the 1N4148 I used before. As Mark said. Do not worry too much about the diodes.

For the distortion diodes I used 1N4001s.

[MetalGuy]

Do you think Analogman tested dozens or hundreds of different diodes and decided that exactly those MA856s sounded best? I don't think so. Most probably the guy stumbled on those accidently and said to himself: "Hmmm, this is something they won't be able to copy...". And of course now he has all the reasons to claim that those diodes are the key for his KoT tone. So don't sweat it too much and let your years be the guide.

[GibsonGM]

I used LEDs (red and green) in my Bluesbreaker, and really liked the 'grit'.  Just something else you might try! 

[rullywowr]

In my rullywow queen of bone the suggested diodes are rumored to be 1S1588 and MA856.  The former are fairly easy to find.  The build doc has some info about this http://www.rullywow.com/product/queen-of-bone-dual-overdrive-bare-pcb/