Analogman KOT Mystery "H" IC

nimrodthebomber · Post by **nimrodthebomber** » 05 May 2020, 14:06

Out of curiosity I decided to strip off the "H" marking on my Analogman KOT 2012 version. Using a bottle of acetone nail polish. Hope this helps,

IC is nothing but 4580D (top marking is 4580D JRC B011B, bottom factory marking is "68h")

Enjoy! Still one of my favorite overdrive ever.

Hope everyone is safe and sound during this covid-19 pandemic.

Cigla tel. · Post by **Cigla tel.** » 05 May 2020, 18:51

Tnx for the info. Btw. that 4 clipping diodes "D8, D7, D11, D10", are not the rare ones 1S1588?!?
Can you read the inscription on them? They may just be ordinary 1n914 or even 1n4148?!?

nimrodthebomber · Post by **nimrodthebomber** » 06 May 2020, 07:48

Cigla tel. wrote:Tnx for the info. Btw. that 4 clipping diodes "D8, D7, D11, D10", are not the rare ones 1S1588?!?
Can you read the inscription on them? They may just be ordinary 1n914 or even 1n4148?!?

The four yellow diodes i believe are ma856 diodes. Yes markings on the other four are just 1N4148s

Cigla tel. · Post by **Cigla tel.** » 06 May 2020, 17:35

nimrodthebomber wrote:The four yellow diodes i believe are ma856 diodes. Yes markings on the other four are just 1N4148s

Thanks, I assumed those diodes were in question!

batteryacidtea · Post by **batteryacidtea** » 07 May 2020, 06:26

very ingenious indeed, hahahaha

oooscasianooo · Post by **oooscasianooo** » 07 May 2020, 17:07

Wow, not even a "DD"? Interesting...

You can raise the gain of a Bluesbreaker style pedal by:

Increasing Drive pot from 100k to 250k (or higher)
Increasing the 220k (R7 in the KOT) "gain resistor" for the 2nd half of dual opamp
Decreasing the 10k (R6 in KOT, his POT "turbo" mode lowers this to 1k I believe), but not much gain increase, maybe just a bit more saturation.

Can you confirm if the high gain side has any of these modifications?

nimrodthebomber · Post by **nimrodthebomber** » 01 Jun 2020, 04:41

oooscasianooo wrote: ↑07 May 2020, 17:07 Wow, not even a "DD"? Interesting...

You can raise the gain of a Bluesbreaker style pedal by:

Increasing Drive pot from 100k to 250k (or higher)
Increasing the 220k (R7 in the KOT) "gain resistor" for the 2nd half of dual opamp
Decreasing the 10k (R6 in KOT, his POT "turbo" mode lowers this to 1k I believe), but not much gain increase, maybe just a bit more saturation.

Can you confirm if the high gain side has any of these modifications?

Sure man. I'll try to ID the components. Resistors color coding and multimeter resistance as well. I'll do the same thing with all the components as well.

nimrodthebomber · Post by **nimrodthebomber** » 01 Jun 2020, 05:00

oooscasianooo wrote: ↑07 May 2020, 17:07 Wow, not even a "DD"? Interesting...

You can raise the gain of a Bluesbreaker style pedal by:

Increasing Drive pot from 100k to 250k (or higher)
Increasing the 220k (R7 in the KOT) "gain resistor" for the 2nd half of dual opamp
Decreasing the 10k (R6 in KOT, his POT "turbo" mode lowers this to 1k I believe), but not much gain increase, maybe just a bit more saturation.

Can you confirm if the high gain side has any of these modifications?

Check out the new pics as well. The orginal didnt really used a higher pot for the drive gain. For sure mods on the pcb board. I'll check it out soon on my kot.

Bolsyo · Post by **Bolsyo** » 04 Jun 2020, 14:49

@nimrodthebomber could you post some pictures of the resistors going into the drive pots? I believe it's R16 on the high-gain side, R17 on low-gain side. There was a gutshot in the Facebook group where this resistor has clearly been painted a red band (stock 1k) over a yellow band (100k) on the high gain side, would be interesting to see if it's the same in your pedal. Keep an eye out for any other resistor bands that look painted. Would also like to see the yellow feedback loop caps next to the ICs.

Nocentelli · Post by **Nocentelli** » 05 Jun 2020, 12:51

Bolsyo wrote: ↑04 Jun 2020, 14:49 this resistor has clearly been painted a red band (stock 1k) over a yellow band (100k) on the high gain side, would be interesting to see if it's the same in your pedal. Keep an eye out for any other resistor bands that look painted.

Sad

Whoismarykelly · Post by **Whoismarykelly** » 14 Jun 2020, 16:42

A long time ago someone on DIY stomps suggested repainting resistors to change apparent values as a diabolical way to throw off would-be cloners working from photos. Interesting to see analogman actually did it.

soulsonic · Post by **soulsonic** » 15 Jun 2020, 01:19

Whoismarykelly wrote: ↑14 Jun 2020, 16:42 A long time ago someone on DIY stomps suggested repainting resistors to change apparent values as a diabolical way to throw off would-be cloners working from photos. Interesting to see analogman actually did it.

It was done in the Lastgasp Super Oscillo Fuzz I traced a long time ago as well.

PRCUSTOMFX · Post by **PRCUSTOMFX** » 15 Jun 2020, 04:15

Good night, what will be this key between the two units?