DC Mods - Revisited...........Sort of.............

DC-2, 3, 5, 10
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Neptical
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Re: DC Mods - Revisited...........Sort of.............

Post by Neptical » Mon Feb 06, 2012 3:17 am

Needsmoregear: I followed you over here from the Mark Series forum. C'mon, you know you want that DC-10. :lol:

Monsta-Tone--c'mon brotha, you worshipped the DC-10! Tell this dude to stop playin' around and snag this amp! Ha Ha!!! :lol:
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needsmoregear12
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Re: DC Mods - Revisited...........Sort of.............

Post by needsmoregear12 » Mon Feb 06, 2012 7:11 am

Trust me i want it! Im just not in a situation where I can afford to buy it at the moment. But ive got a potential buyer for my 6505, and if he comes through with the deal, ill be ordering the DC10 right away =)

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Re: DC Mods - Revisited...........Sort of.............

Post by edward » Mon Feb 06, 2012 4:56 pm

Monsta-Tone wrote:...

Blanket Removal Mod:I always seem to forget to tell people about this one, but it makes a huge difference. It gets rid of a lot of the muddy tone and over all lack of dynamics compared to some of the Holy Grail amps.
1. Right after V6 (page 7 of drawing), there is a 75pf cap that ties pins 1 & 6 of V6 together.
Replace this cap with a 47pf Silver Mica cap.

2. Then, remove the 2 120pf caps across the 82K & 100K resistors that are located just to the Right of the 75pf cap.
These caps are placed here to eliminate oscillation and feedback.
I play a JS1000 (basswood body) and after this mod, I can get that perfect "Flying in a Blue Dream" feedback and sustain.
Well this one interests me the most. Hey Andy, could you elaborate on what you feel is "blanket removal"? As in "brighter" or more crisp highs? Or "more" highs? How does the midrange change, if at all?

As I "see it" from your description, changing the value of the caps at V6, the PI, is altering the shelf. So are you simply "moving" the frequency of what looks like a high-pass filter here, allowing more highs? Does changing the value of this cap affect the lows at all?

As for removing the two 120pF caps, or if I remove just one leg so I can experiment with the tone, is the result simply greater ability to feedback? Does this affect the tone at all?

Really looking forward to trying this mod out. I've done the OP volume one and really like that. Thanks for this whole post and sharing your experience with us all!!

Edward
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crguti
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Re: DC Mods - Revisited...........Sort of.............

Post by crguti » Tue Feb 07, 2012 10:38 am

Thanks Monsta for this thread. I have done the loop and volume mod and I consider they are 'a must' for DC-5/10 owners. I would like to experiment with your other mods as well although I'm quite happy with my amp how it's right now.
Cheers from Denmark.

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Re: DC Mods - Revisited...........Sort of.............

Post by biggness » Sun May 20, 2012 3:28 am

Hey Andy,

Thanks for posting this. :)

I never got back to you after you emailed me, and I did all the mods to my amp. Sounds great. I will post a video soon.

Thanks a bazirrion!

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Re: DC Mods - Revisited...........Sort of.............

Post by biggness » Sun May 20, 2012 3:30 am

http://www.youtube.com/watch?v=GsuSo0cB7BU

All amp... all awesome. Mesa Recto Traditional 4x12 with v30's.

Monsta-Tone
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Re: DC Mods - Revisited...........Sort of.............

Post by Monsta-Tone » Sun May 20, 2012 4:40 pm

:mrgreen: That is awesome!!!!
I was going to post a comment on YouTube, but I guess Google bought them and I needed to use my Google password or some such crap. Last thing I need is another freaking account somewhere in imagination land......


Anyway,
Glad you liked the mods!
Elvis said.......
Amp techs do get shocked. :shock:

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Re: DC Mods - Revisited...........Sort of.............

Post by Maynardo » Sun Jun 10, 2012 7:02 pm

Hi, I'm new to the forum. I have a DC-5A, firts of all I really wanna thank Monsta fot this thread, I had the "blanket removal" and the "volume" mods done and they're great specially the first one, all tho I think it should be renamed to "the uncompress rythm channel mod" .

I do have some questions for Monsta, I remember reading that after the fx loop mod you use the mix knob in there as a "negative feedback" pot. Could you elaborate on the tone capabilities of that, and how could it be done.

Also, for some reason this amp seems to LOVE emgs, or maybe I should say super tight bass pickups, is there a mod that would do something like a the tight switch on Egnater amps, I mean cut some of the bass in the first gain stage to get some of that "emg-love/super chugging" from the amp without having to use the EMGs?.

Greetings from Santiago, Chile
Last edited by Maynardo on Sun Jun 10, 2012 7:59 pm, edited 1 time in total.

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Re: DC Mods - Revisited...........Sort of.............

Post by Monsta-Tone » Sun Jun 10, 2012 7:36 pm

Right on, glad they worked for you!

You could easily cut bass in the 1st gain stage. You may not get enough of a result from it though.
The Cathode Bypass capacitor on pin 8 of V1 is a 1 micro farad.
A .68 or .47 micro farad cap there would definitely remove some of the bass.

Another place that you can try (although this may not be a good place for a switch) is the tone stack resistor or Slope Resistor.
Your amp has 2 tone stacks. 1 is fixed and the last one is adjustable.
The Slope Resistor in the 1st one is 56k. You could easily change this for an 82k resistor. This will introduce more treble & upper mids and remove some of the bass.

Try those and see if you like them.

As for the NFB, basically if you remove the NFB or add more resistance in series with it so that the amp sees less NFB in the phase inverter, it will become much louder and will break up much faster.
You will also notice that it feels like the Presence knob is on 200!
Elvis said.......
Amp techs do get shocked. :shock:

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Re: DC Mods - Revisited...........Sort of.............

Post by Maynardo » Sun Jun 10, 2012 8:11 pm

Monsta-Tone wrote: Your amp has 2 tone stacks. 1 is fixed and the last one is adjustable.
The Slope Resistor in the 1st one is 56k. You could easily change this for an 82k resistor. This will introduce more treble & upper mids and remove some of the bass.
!
Ok I think that will be the next mod. Sorry about my ignorance but, Is this the same mod you mentioned here?
Monsta-Tone wrote:Lead Channel Mods

Tone Stack Mods:
Right after V3A is the Tone Stack. The DC lead channel has 2 tone stacks, but this is the one that is adjustable with the pots.
1. The stock Tone Stack resistor is 82K. Changing this resistor will change the overall frequency response of the Tone Stack.
Lower value = More Bass
Higher value = Less Bass
I like 56K or even 47K if the speaker is really bright.
This mod really depends on the speakers you are using. I use the C-90 in my DC-5 combo, so I like 56K the best. When I used Vintage 30's, I went down to 47K.
If the amp is too dark for you, then you can go as high as 100K, but you might try the next mod 1st.
Also, about the 500pf silver mica instead of the ceramic cap mod would that be a bad place for a switch?... I'm thinking it would be cool to have switch in the back of the amp to take it from vintage to modern tones.

Thanx in advance!

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Re: DC Mods - Revisited...........Sort of.............

Post by Monsta-Tone » Sun Jun 10, 2012 8:19 pm

Same mod, only this would be for the 1st tone stack instead of the 2nd one.

You can add a switch for the treble cap.
Remember though that this cap has high voltage on the input side, so the switch will pop unless you place a 10M ohm resistor across it.
I like to add 5-way mid sellector switches so that you can dial in just the right amount of sizzle.
The best way to do this is to place another capacitor in parallel with the existing capacitor.

You can go with these values and see which one you like the most:
250 pf
350 pf
500 pf
750 pf
1000 pf

When you add a capacitor in parallel, it will add to the value of the existing one.
You could easily try this in both tone stacks and see which one has more of an affect on your tone.

Be very careful though, like I said above, the Slope Resistor and the treble cap both have high voltage on them.
Drain the power supply caps and unplug the guitar every time before you reach in there.
It hurts bad if you mess up and forget!
Elvis said.......
Amp techs do get shocked. :shock:

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Re: DC Mods - Revisited...........Sort of.............

Post by Maynardo » Sun Jun 10, 2012 8:41 pm

oh I get it, so this mod would act before the adjustable tone stack instead of the first one you posted, killer!. This thread just keeps getting better!.

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Re: DC Mods - Revisited...........Sort of.............

Post by talltxguy » Sun Jun 10, 2012 9:08 pm

This was enjoyable reading. Thank you for that, Andy.

Now let's talk about the bias mod for the DC-3...I've read in other forums where folks have had problems. I just don't get it. It's not like it's simul-class... :?
YOUTUBE: mesafanintexas

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Re: DC Mods - Revisited...........Sort of.............

Post by Maynardo » Mon Jun 11, 2012 6:38 am

Hey, I thought of another question (sorry to bug you so much). This one is about the Rhythm channel, as you said you have the B version, so hopefully this question is shared with other A version users.

Personally I think I can get a VERY good clean-clean tone outta the rhythm channel. I mean with the gain knob in 1 or 2 and master cranked, but if I try to use it as a mid-gain channel to play something like I don't know, Pearl Jam, Led Zep or something in that ball park, it just doesn't cut it 'cause even tho you have more than enough gain for it once you start to use the gain knob the tone becomes really round and lo-mid oriented kinda like an old marshall with really crapped out tubes.

What would you recommend for me and the other A version users?.

Thanx!

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Re: DC Mods - Revisited...........Sort of.............

Post by Monsta-Tone » Mon Jun 11, 2012 9:50 am

Try using the same settings that you use for clean and then pulling the gain pot boost.
Then, try adjusting it to get those tones.

Or....

Try turning the master way down and cranking the gain.
In this way, you are using it like most people use the gain and master on their lead channels.
Elvis said.......
Amp techs do get shocked. :shock:

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