Identifying MA856 diodes

Frequent question abouts LED and other types of diodes.
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Post by plush »

bobele3 wrote:That's how it's look:
914/4148 has pretty much the same characteristic
You won't hear the difference


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Post by mojah63 »

Kot diode graph vs 914 and kot sub ma856
Kot Diode Test.GIF

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Post by WattFx »


I thought I would share some things I have learned when searching far and wide for stocks of the rare MA856 diode as used in Analogman King of Tone. I feel it is important to share this information after being shocked at the dishonesty of several supposedly reputable companies. I hope this information is useful for anyone who is looking for those 'mojo' parts. Please excuse the rant!

I have come across reputable companies in the UK, USA and Spain falsely claiming to sell genuine MA856 diodes. They are actually selling you 1SS133 diodes with a large mark up. If you see MA856 diodes for sale then they are probably not genuine, regardless of the reputation of the company selling them.

The Analogman King of Tone uses original Panasonic NOS (New Old Stock) MA856 diodes. These are near impossible to find nowadays since the King of Tone became so sought after. Unfortunately there are quite a few online sellers falsely claiming to sell genuine MA856 diodes. I have come across several supposedly reputable sellers who are knowingly selling a different diode type and claiming it to be genuine MA856. Please do not be tricked by these dishonest businesses into paying a premium for diodes that are not the genuine article.

If you do a quick google search you will find the datasheet for the MA856 diode. They should be 2.2mm in length, 1.6mm in diameter and a single yellow stripe only. Taping should be a yellow band on one side and standard beige masking tape colour on the other. Any genuine Panasonic MA series diodes I have come across have also had a small blue/grey band on the cathode lead next to the body of the diode. Forward voltage measures slightly higher than the standard 1N4148/1N914, typically measuring around 10% higher as some have reported online. This is all based on thorough research I have conducted whilst searching far and wide to find genuine examples of the MA856 diode to build the King of Tone.

Do not be fooled by the 1SS133 diode, manufactured and discontinued by ROHM. These look similar to the MA856 as they also have a single yellow stripe, but are clearly different when comparing side by side. They also measure and behave different electronically, thus will not have the same sound as genuine MA856 diodes. You will find datasheets online that accurately describe the characteristics and dimensions. They are slightly longer and fatter than MA856, measuring 2.7mm long and 1.8mm in diameter. Forward voltage is near identical to the standard 1N4148 diode thus is not a match for the MA856. Taping is a blue band on one side and beige masking tape colour on the other. Supposedly reputable companies who are knowingly selling 1SS133 diodes can be found in the UK, Spain and USA. Please do not pay a premium for these diodes and do not believe the claims of these companies. If you have purchased these diodes from any of these dishonest companies and are unsure of their authenticity then please feel free to contact me and I should be able to give you further advice on how to check them.

The other diode being passed off as the MA856 is the MA858. These are, unlike the 1SS133, genuine Panasonic NOS diodes from the same series as the MA856. They differ in appearance as they have 2 yellow stripes rather than one. There are also blue and black stripe MA859 which measure near enough identical to MA858 in forward voltage. Dimensions and appearance are otherwise identical to the MA856. Forward voltage is a little higher than the MA856, as you will see in the datasheets. They are not genuine MA856, mojo versions of MA856, 'double yellow stripe' MA856, or any other name that sellers have given them. They are not MA856 at all. They are a different diode and should not be sold as MA856. They are, however, probably the closest substitute to the MA856 that are still available from some sellers today. If you are looking for the 'mojo' King of Tone parts then I would recommend seeking out a set of MA858 diodes rather than chasing the original MA856.

To save you some time and hassle - BQ Music, based in the Netherlands, are still selling genuine MA858/1S1588 diode sets for the King of Tone. They are straight up, not making any bogus claims and an absolutely fantastic company to deal with. They still have diode sets for the King of Tone available on Etsy. Please note am not affiliated with BQ music in any way; merely a happy customer of theirs.

Kind regards,

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Post by deltaeffects »

Thanks, very thorough PSA

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Post by modman »

I merged some threads on this issue. In summary still:
Dirk_Hendrik wrote: 27 Dec 2018, 08:52 The 2nd stripe is the mojo version of the MA856 diode. Especially for corksniffers. If I were Analogman I'd laugh my ass off seeing all cloners of his bluesbreaker clone go anal over a silicon signal diode. :blackeye
plush wrote: 16 Jan 2019, 12:12
bobele3 wrote:That's how it's look:
914/4148 has pretty much the same characteristic
You won't hear the difference
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