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DIY Stompboxes => Building your own stompbox => Topic started by: Yazoo on August 15, 2024, 04:09:28 PM

Title: Diode in Rockman Guitar Compressor
Post by: Yazoo on August 15, 2024, 04:09:28 PM

(https://i.postimg.cc/LJnC9cH4/temp-Imageih4-JT8.avif) (https://postimg.cc/LJnC9cH4)


Another diode question. This is in a Rockman Guitar Compressor module. Any ideas what it might be? Unfortunately the text is obscured.
Title: Re: Diode in Rockman Guitar Compressor
Post by: GibsonGM on August 15, 2024, 04:26:17 PM
Quote from: Yazoo on August 15, 2024, 04:09:28 PM(https://i.postimg.cc/LJnC9cH4/temp-Imageih4-JT8.avif) (https://postimg.cc/LJnC9cH4)
 Unfortunately the text is obscured.


So is the picture...
Title: Re: Diode in Rockman Guitar Compressor
Post by: Yazoo on August 19, 2024, 07:12:45 PM
 :o
Title: Re: Diode in Rockman Guitar Compressor
Post by: ElectricDruid on August 19, 2024, 09:16:14 PM
In the Rockman X100 Rev.10 schematics, all the diodes in the preamp/compressor section are basic 1N914s - absolutely ordinary silicon signal diodes. 1N4148 is generally considered an identical part.

The one in the photo looks like the cheap silicon diodes I remember in Japanese gear from the 80's. whatever it is, I think it's highly unlikely to be special. On the contrary, I'm pretty certain it's extremely ordinary.
Title: Re: Diode in Rockman Guitar Compressor
Post by: Yazoo on September 19, 2024, 04:01:15 PM
I've managed to have a look at the real thing and it turns out to be a 4.7V Zener diode.
Title: Re: Diode in Rockman Guitar Compressor
Post by: ElectricDruid on September 19, 2024, 05:37:45 PM
Quote from: Yazoo on September 19, 2024, 04:01:15 PMI've managed to have a look at the real thing and it turns out to be a 4.7V Zener diode.
Well, that's not what I said, but it still fits under the general heading of "extremely ordinary"!

Which diode is this in the schematics exactly? I don't remember having seen a zener in there..
Title: Re: Diode in Rockman Guitar Compressor
Post by: Rob Strand on September 20, 2024, 12:41:53 AM
Quote from: Yazoo on September 19, 2024, 04:01:15 PMI've managed to have a look at the real thing and it turns out to be a 4.7V Zener diode.
From the package it's about a 500mW zener.

The choice of 500mW and 1W can make a difference in some circuits.  (There's even circuits which can care about the precise part as not all zeners are specified at the same test current.)


I found a pic of the PCB.

The diode you showed the picture of is D11.  I can see a number 1N5xxx
The diode just near it is D13 and I can see number yyy231
D11 and D13 look like different parts.

My guess would D13 is 1N5231,  which is a 5.1V 500mW (5.1V at 20mA test current).
If you can verified D11 is 4.7V then it likely to be 1N5230, which is a 4.7V 500mW zener (4.7V at 20mA test current).

I think Vivek posted some stuff on Rockman compressors a few years back, both here and on the fsb forum.
You might find some info or a schematic in those old posts.