Blackfire with Marshall TS low output into Tube amp

audioguy · February 09, 2006, 01:58:56 PM

I ahd originally posted this in a nother thread, but since its not really allong the lines of that topic, I started a new thread here is my problem-
I built a blackfire and added the Marshall TS and it sounds amazing... however...

I have to have the volume all the way up to get unity gain going into a tube amp. Going into a solid state amp it works just fine... Im going into a Fender Hot Rod Deluxe and with the amp volume on 3, I get nothing from the blackfire. At half I can hear the sound faintly. From 3/4 up, I was able to get a unity.

But like I said... with an SS amp it sounds MASSIVE.
Do I need to buffer it or something?

Thanks for your help!

audioguy · February 10, 2006, 09:24:27 AM

Anyone able to offer up ANY suggestion?

Thanks!

WGTP · February 10, 2006, 09:29:43 AM

Is the tone stack before or after the output pot? Did you use the 470K resistors to reduce the output?

audioguy · February 10, 2006, 10:24:37 AM

The tone stack is before the output pot.
Im not sure which 470k resistors youre refering to, but I dont believe I used them. I used the layout exactly as they are, no part subs for either.
Thanks for your help!

Paul Marossy · February 10, 2006, 12:44:27 PM

That's weird. My Blackfire even with the Marshall tone stack is very loud. Those 470K resistors at the output form a voltage divider. If you were to remove them (or 1/2 them), it would get a lot louder...

audioguy · February 10, 2006, 01:21:17 PM

Maybe I'll try 1/2ing those.

RDV · February 10, 2006, 01:34:43 PM

If using a MS TS I'd just remove the 470k.

YMMV

RDV

audioguy · February 10, 2006, 01:39:00 PM

Which 470k would you remove? R8 or R15?

WGTP · February 10, 2006, 01:39:44 PM

Both.

audioguy · February 10, 2006, 01:59:53 PM

Just leave em empty or put in a jumper of some sort?

Thanks again guys, I really appreciate it!

Paul Marossy · February 10, 2006, 06:08:13 PM

QuoteJust leave em empty or put in a jumper of some sort?

Remove the one to ground and use a jumper in place of the one that is in series with the output.

audioguy · February 10, 2006, 11:51:09 PM

I dont see a 470k at either location you're describing Paul. I'm using http://www.diystompboxes.com/analogalchemy/pedals/blackfire.gif I dont see either of the 2 you're describinging. I cant see one going to ground, nor running in series with the output... maybe Im misinterpreting it?

343 Salty Beans · February 11, 2006, 03:27:24 AM

Have you tried an audio probe? Identify what is killing the sound with it, and you'll have a lot more to go off of.

RDV · February 11, 2006, 07:03:18 AM

Uh, my advice was based on the old BF, I know nothing about the new one.

Sorry.

RDV

audioguy · February 11, 2006, 09:10:20 AM

RDV_ I appreciate the effort... maybe I'll try the old one and see if it cures my problem.

343- No I have not tried a probe. I dont know if a probe would find it... it sounds great through 3 SS amps, but not in my Hot Rod Deluxe... which sounds just fine with every other pedals I've built

Paul Marossy · February 11, 2006, 09:25:20 AM

QuoteI dont see a 470k at either location you're describing Paul.

Hmm... I wasn't aware that it has been changed. Apparently, it has been changed at some point. Mine is built per the original schematic. I have a PCB layout, but I dont think it prints to scale. Anyhow, you can see the pair of 470K resistors at the output. Check it out: http://www.diyguitarist.com/PDF_Files/Blackfire.pdf

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Blackfire with Marshall TS low output into Tube amp