Analogman - King of Tone  [traced]

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Postby The Rotagilla » 24 Oct 2007, 18:41

And this is a confirmed build?! Wow...thanks!
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Postby DougH » 24 Oct 2007, 18:41

I get a chuckle out of "strategically placed" carbon comp resistors in a 9v circuit.

Bowtweek schematics- a nonstop source of entertainment...
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Postby polarbearfx » 24 Oct 2007, 21:07

I have a tonepad version of the bb. I built this a while ago and its ok. What mods do I have to make to make it into just a single channel version of the kot?
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Postby DougH » 24 Oct 2007, 21:18

I guess you just look at one channel of the kot schematic and compare, then change the stuff on your circuit to match.

(???)
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Postby JHS » 25 Oct 2007, 15:10

IC in the KOT is a JRC4580D, ID-no. for the blue bands is 1S15800 and
the CC Rs look like carbon film types.

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Postby theyear2042 » 25 Oct 2007, 15:49

JHS wrote:IC in the KOT is a JRC4580D, ID-no. for the blue bands is 1S15800 and
the CC Rs look like carbon film types.

JHS


the one i traced had 4558d's in it. but they could have been changed as they are socketed. i did see on AM's site some time ago where he discusses using JRC4558d's in it.

ive have also seen pics of ones with 4580d's in it.

kt!
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Postby celadine » 26 Oct 2007, 06:35

:) Thanks, KT66!
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Postby Ghandi » 26 Oct 2007, 18:25

...thanks man!
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Postby Ghandi » 27 Oct 2007, 12:03

so...
I just tried the kot changes to my early bluesbreaker clone, which already had the cc's like the kot, the yellow band diodes, the treble pot and the jrc4580.

so the only change was the 100pF cap and the additional 10K resistor in the first op-amp loop.

this two changes make it 100% kot,
more drive more level and a bit more dynamics compared to the bb.
everybody who has an early bbI, do this change, its a keeper!
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Postby The Rotagilla » 27 Oct 2007, 16:27

I'm having difficulty finding some of the mentioned parts...

JRC4580D - found a NJM4580D or LM833
1N1588 - Cross-referenced to a NTE5174AK at $11 each! :shock:
MA856 - No longer in production?

This is killer work (thanks KT and everyone) but are we sure about these part numbers?
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Postby JHS » 27 Oct 2007, 17:23

As far as I know, 1N1588 and MA856 are no longer manufactured. I grapped my 1588 out of an old Japanese Radio from the seventies.

A few DIY-shops/suppliers in Japan sell them.

Compared to a 1N4148 the MA856 sound a bit fatter and more fuzzy.
IMHO a 1N4003 in series with a 1N914 is a good subs for 2 MA856 wired in series.

The blue band has a unique sound thats hard to get with other types.

Ghandi uses those diodes in some of his FX, maybe he can tell where he's got them from.

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Postby analogguru » 27 Oct 2007, 17:30

As far as I know, 1N1588 and ......


I think this is a typo and should correctly be written as 1 S 1588.....

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Postby The Rotagilla » 27 Oct 2007, 17:36

analogguru wrote:
As far as I know, 1N1588 and ......


I think this is a typo and should correctly be written as 1 S 1588.....

analogguru


1S1588 is discontinued.
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Postby theyear2042 » 28 Oct 2007, 04:17

it is supposed to be 1s1588 - you can use 1n4148's instead or you could try and track the 1s1588's in akihabara.

i updated the schem to reflect the typo on 1n1588 and original opamp spec.. sorry about that guys.

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Postby Ghandi » 28 Oct 2007, 16:17

JRC4580D = NJM4580D

I got my yellow and blue band diodes also from old "made in japan" electronics.

have a look inside old taiwan boss and ibanez stompboxes,
you can take some yellow band diodes out of the switching part of the wiring and replace them with standard silicon 1n4148's.
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Postby JHS » 28 Oct 2007, 19:41

Ghandi wrote: I got my yellow and blue band diodes also from old "made in japan" electronics.

That's what I did, too. You can find those yellow and blue band diodes on nearly every PCB used for cheap Japanese stuff during the '70th.

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Postby celadine » 29 Oct 2007, 00:42

The ma856 is also called ma2c856 - digikey has these for about 50 cents each. Smallbear has the 1s1588. Also, +1 on the diodes in older electronics. (make sure to ask permission before you rip open grandma's clock-radio...)
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Postby KHELSTROM » 29 Oct 2007, 17:00

When you build the two pedals in one box dose the battery feed into each pedals voltage divider for the 4.5v or do both sides run off a single shared voltage divider?
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Postby JHS » 29 Oct 2007, 21:08

I recommend the use of a single opamp to generate a buffered low impedance BIAS-supply.

The BIAS supply is not loaded down by the circuit and will work more stable than a std. supply w/o opamp.

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Postby Lovepedal Detective » 15 Nov 2007, 21:27

theyear2042 wrote:the way i drew the schem it didnt look like a mbb - when i looked at certain parts upside down and twisted around a bit - it started to look very familiar - im giving stomp boxes a rest for a while - ill prob just lurk around for a few months but thought i should share this one before i do as i dont have any quarms sharing a clone of a commercial pedal - take care and make sure you share it with your friends over at diystomp!

Image

Image

KT66!

edit: should have just listened to JHS in the first place.. ;)
edit2: updated the schematic dated 28-10-07


It appears that the clipping is switched isn't the usual landgraff style. You've got 4 diodes from pin s 6 to 7, and then 2 from pins 5 to 7. This would be a different sound than the usual switching diodes within the normal loop.

Not a straight rip off, but not really original either.

LPD
Last edited by Lovepedal Detective on 15 Nov 2007, 21:43, edited 1 time in total.
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