KT77 Mod Question/Idea/Punshishment

Trout · 31st May 2006, 11:26 PM

OK, Now I know I am a sucker for punishment. When I did this amp layout, I made sure to allow chassis space for expansion into some internal effects options.

I have a schematic of a mod for a classic distortion effect. Initally I will just use a Push in Push out switch, Later I will wire in a footswitch activated relay.

My principal question is basically, The insertion point for the effect.
I would rather it effect only 1 channel, to allow A/B switching.
I have 1 channel set slightly hotter than the other, But this is "supposed to be" a more distorted growl effect.

Opinions??

Effect Added to Schematic

Trout · 1st June 2006, 03:04 AM

OOOPS, I think I spliced it in at the wrong point, I need to edit the drawing.

Eh, tomorrow

Trout · 1st June 2006, 03:12 PM

OK, I think I have this mod located properly, I guess the best bet is to wire it in and give it a go.

Corrected insert
Trout

poobah · 1st June 2006, 03:38 PM

Gene,

Your mod is deriving its plate supply from the grid of V2... no power there.

Do you have the original schematic for just the "mod" part of the circuit... or can you link to something?

It doesn't look like your taking the output the mod correctly either.

Trout · 1st June 2006, 10:16 PM

AHHhhhhh Yes, I think I see it, I missed the 100K resistor that connects the supply in there.

Remember the old Seymour Duncan convertable 100W?
It was way ahead of its time in many aspects, Just poorly implemented.( reliability related )

I own one of those units,Got it ages ago from my brother( the wrecking ball)

Anyway, I restored it, modded it out and fixed a few issues it was known for. Wrapped it in plastic and stored it away.

The unit had a unique modular preamp that used any combo of 3 modules, with 15 different modules to choose from.

There is a great documentation on the web at DIYguitarist.com

I found all the layouts and schematics I needed over the years and thought I would try a splice in type thing with the amp I am currently using.

Seemed easy enough, The modules are fairly simple, I have even made a few from scratch. But I liked the classic distortion module enough to try and re-use it.

My women has our FTP space stuffed with her ebay glass for the next couple days, So I will need to wait before I upload the rest of the info/drawings.

I get 15 megs she gets 35?? lol, Its time for a talk.

trout

poobah · 1st June 2006, 10:24 PM

Cool,

I can see the circuit is a clipper... give you some fuzz.

I don't get the output though...

You will need a cap to couple the output of the mod into the grid of V2.

I'll be around...

Good luck with the boss... isn't she the girl that scores cool stuff for you at estate sales?

31st May 2006, 11:26 PM	#1
Trout diyAudio Member Join Date: Nov 2004 Location: Midwest Madman	KT77 Mod Question/Idea/Punshishment OK, Now I know I am a sucker for punishment. When I did this amp layout, I made sure to allow chassis space for expansion into some internal effects options. I have a schematic of a mod for a classic distortion effect. Initally I will just use a Push in Push out switch, Later I will wire in a footswitch activated relay. My principal question is basically, The insertion point for the effect. I would rather it effect only 1 channel, to allow A/B switching. I have 1 channel set slightly hotter than the other, But this is "supposed to be" a more distorted growl effect. Opinions?? Effect Added to Schematic

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1st June 2006, 03:04 AM	#2
Trout diyAudio Member Join Date: Nov 2004 Location: Midwest Madman	OOOPS, I think I spliced it in at the wrong point, I need to edit the drawing. Eh, tomorrow

1st June 2006, 03:12 PM	#3
Trout diyAudio Member Join Date: Nov 2004 Location: Midwest Madman	OK, I think I have this mod located properly, I guess the best bet is to wire it in and give it a go. Corrected insert Trout

1st June 2006, 03:38 PM	#4
poobah diyAudio Member Join Date: Nov 2005	Gene, Your mod is deriving its plate supply from the grid of V2... no power there. Do you have the original schematic for just the "mod" part of the circuit... or can you link to something? It doesn't look like your taking the output the mod correctly either.

1st June 2006, 10:16 PM	#5
Trout diyAudio Member Join Date: Nov 2004 Location: Midwest Madman	AHHhhhhh Yes, I think I see it, I missed the 100K resistor that connects the supply in there. Remember the old Seymour Duncan convertable 100W? It was way ahead of its time in many aspects, Just poorly implemented.( reliability related ) I own one of those units,Got it ages ago from my brother( the wrecking ball) Anyway, I restored it, modded it out and fixed a few issues it was known for. Wrapped it in plastic and stored it away. The unit had a unique modular preamp that used any combo of 3 modules, with 15 different modules to choose from. There is a great documentation on the web at DIYguitarist.com I found all the layouts and schematics I needed over the years and thought I would try a splice in type thing with the amp I am currently using. Seemed easy enough, The modules are fairly simple, I have even made a few from scratch. But I liked the classic distortion module enough to try and re-use it. My women has our FTP space stuffed with her ebay glass for the next couple days, So I will need to wait before I upload the rest of the info/drawings. I get 15 megs she gets 35?? lol, Its time for a talk. trout

1st June 2006, 10:24 PM	#6
poobah diyAudio Member Join Date: Nov 2005	Cool, I can see the circuit is a clipper... give you some fuzz. I don't get the output though... You will need a cap to couple the output of the mod into the grid of V2. I'll be around... Good luck with the boss... isn't she the girl that scores cool stuff for you at estate sales?

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