reducing the signal to the PI on a 2204

Marshall Amp Discussion

Moderators: pompeiisneaks, Colossal

User avatar
Curranproducer
Posts: 285
Joined: Sun Oct 16, 2011 4:58 pm
Location: Akron, Ohio

reducing the signal to the PI on a 2204

Post by Curranproducer »

IF I wanted to be able to make more of the MV on my 2204 clone usable, could I add a resistor between the 22n off of the MV wiper and the PI. would this "choke down" or reduce the signal hitting the PI so I would have to turn up the MV beyond 9 O'clock to get the same volume level I have at that 9 O'Clock? AND how much would this affect or "ruin" the signal?
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
User avatar
martin manning
Posts: 13081
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: reducing the signal to the PI on a 2204

Post by martin manning »

No, but if you put a resistor (say 470k) between the treble wiper and the CW terminal of the MV pot it will have that effect. Of course you will be limiting the maximum signal into the PI that way.
User avatar
Curranproducer
Posts: 285
Joined: Sun Oct 16, 2011 4:58 pm
Location: Akron, Ohio

Re: reducing the signal to the PI on a 2204

Post by Curranproducer »

OK, that seems like the move to try then. Even if I loose a few DB of volume because of that WHO cares. the amp is so loud right now it is un-real. even in a 40-60 foot stage I got the sound guys telling me anything over 10 O'Clock is wayyyyyyyyyyyyyyyyyyyy to much.
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
JD0x0
Posts: 550
Joined: Tue Oct 09, 2007 2:19 am

Re: reducing the signal to the PI on a 2204

Post by JD0x0 »

I try not to use the taper of the pot as a gauge. If above '10:00' is 'too much' then dont run it that high. My Hiwatt rarely gets past 9:00 if the preamp gain is high. But if I'm running the preamp volume low, the master is much less sensitive, and sounds better opened up more.

Seems like you're giving up signal just to have a potentially slightly smoother taper on the volume. If you think the tradeoff is worth it, it wouldn't hurt to try. Personally, I'd just keep the master set lower, if it's too loud or invest/build an attenuator, if opening up the master volume more, with less volume, is the goal.
It's true i've lost my marbles and i cant remember where i put them
User avatar
Littlewyan
Posts: 1911
Joined: Thu Sep 12, 2013 6:50 pm
Location: UK

Re: reducing the signal to the PI on a 2204

Post by Littlewyan »

I think with these amps they start clipping the power amp pretty early on. Hence why the MV isn't that usable as.....a MV. Get an attenuator. Even if it just knocks 6dB off, it'll help a lot.
User avatar
Curranproducer
Posts: 285
Joined: Sun Oct 16, 2011 4:58 pm
Location: Akron, Ohio

Re: reducing the signal to the PI on a 2204

Post by Curranproducer »

no no guys. I am looking to make the amp quieter.............. it is a 50 watt home brew that I cannot even get the MV over 9O'clock. I would like to get the amp so I can use a bit more of the MV swing on the amp. that is all. I want high noon to be my 9 o'clock.
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
User avatar
Curranproducer
Posts: 285
Joined: Sun Oct 16, 2011 4:58 pm
Location: Akron, Ohio

Re: reducing the signal to the PI on a 2204

Post by Curranproducer »

Hell I am even fine with changing out the MV POT if that helps
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
User avatar
Littlewyan
Posts: 1911
Joined: Thu Sep 12, 2013 6:50 pm
Location: UK

Re: reducing the signal to the PI on a 2204

Post by Littlewyan »

Ok hang on. Do you want to be able to push the power amp into distortion by turning the MV up?
User avatar
Curranproducer
Posts: 285
Joined: Sun Oct 16, 2011 4:58 pm
Location: Akron, Ohio

Re: reducing the signal to the PI on a 2204

Post by Curranproducer »

no, I got TONS of distortion. I just want to be able to move the MV above 9 O'Clock with out killing low flying birds. I would like to make the 9'Oclock volume(which is smashingly loud) my 12 noon MV setting.
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
User avatar
Littlewyan
Posts: 1911
Joined: Thu Sep 12, 2013 6:50 pm
Location: UK

Re: reducing the signal to the PI on a 2204

Post by Littlewyan »

Just try putting a 250K resistor in parallel with the MV pot.
User avatar
Curranproducer
Posts: 285
Joined: Sun Oct 16, 2011 4:58 pm
Location: Akron, Ohio

Re: reducing the signal to the PI on a 2204

Post by Curranproducer »

so going from the CCW lug(#1) to the wiper lug(#2) to the 22nf coupling cap?
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
User avatar
Littlewyan
Posts: 1911
Joined: Thu Sep 12, 2013 6:50 pm
Location: UK

Re: reducing the signal to the PI on a 2204

Post by Littlewyan »

From the X in the drawing to ground
You do not have the required permissions to view the files attached to this post.
User avatar
Curranproducer
Posts: 285
Joined: Sun Oct 16, 2011 4:58 pm
Location: Akron, Ohio

Re: reducing the signal to the PI on a 2204

Post by Curranproducer »

here is my schematic with all of the mods and stuff I have done to it so far. adding a selectable NFB between 47K/100K/150K, and a resonance control on the back of the amp
You do not have the required permissions to view the files attached to this post.
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
User avatar
Littlewyan
Posts: 1911
Joined: Thu Sep 12, 2013 6:50 pm
Location: UK

Re: reducing the signal to the PI on a 2204

Post by Littlewyan »

Ok before you do my mod lets clarify a few things.

So in there you've got a switchable solo boost. Is that solo boost pot between the master volume pot and ground?
User avatar
xtian
Posts: 6990
Joined: Mon Apr 19, 2010 8:15 pm
Location: NorCal
Contact:

Re: reducing the signal to the PI on a 2204

Post by xtian »

I have another solution for you. Remove the knob from the MV. Turn the pot to the place where the amp sounds like you want when the MV is at noon. Now put the knob back on...with indicator pointing at noon. Done.
I build and repair tube amps. http://amps.monkeymatic.com
Post Reply