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

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

Post by Maynardo » Mon Jun 11, 2012 7:58 pm

Nop I have tried those things, and I still think I need to either lose some lo mids or pump the hi mid area.

BTW for the people thinking about the "blanket removal" mod , I recorded this last night with my old iphone ( don't expect good sound quality) just to show how the amp became violin-like in the lead channel.

http://www.youtube.com/watch?v=zxc1Rkd39To

Greetings from Santiago, Chile!

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

Post by Monsta-Tone » Mon Jun 11, 2012 11:18 pm

:mrgreen: Glad you like the mod! :mrgreen:

As for the lower mids/upper mids thing, try experimenting with the tone stacks. There is a lot of room to move in these areas.
Elvis said.......
Amp techs do get shocked. :shock:

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

Post by Maynardo » Tue Jun 12, 2012 9:02 am

Yeah, most people just do the volume and fx loop mods, but I think your "blanket removal" mod is killer, and is the main reason why I keep bugging you for more ideas :lol:. Hopefully after watching the video more people will wanna try it.

In the "classic rock" department what I've settle for, is using the lead channel with the gain 1.5. I still wanna be able to use the the gain pot on the rhythm channel with muffling it.

When I use it clean-clean I usually crank the treble and presence pots, so a big pump in the high end won't really hurt, since I can allways back them off afterwards. Could you maybe suggest a starting point?.

I think the treble cap is 250pf, would it be a good idea to go 500pf? , the slope resistor is 150pf, how High would you go?


Cheers!

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

Post by Monsta-Tone » Tue Jun 12, 2012 10:39 am

The 1st slope resistor is 56k.
The 2nd one is 82k.
I would make the 1st one 82k and see what happens.

Some vintage Fender amps go as high as 150k, I don't think I would go above 100k.
For most of my amps, I go in the opposite direction and take them both down to 56k, or even 47k.


For the cap, you can go as high as 750pf and still not get too shrill sounding. I like the lead tone with a 1000pf cap across the stock cap, but it's too thin for my rhythm parts.
Remember, with the treble cap mod, you have to have the treble and mids above half way before you will even notice a difference.
Elvis said.......
Amp techs do get shocked. :shock:

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

Post by Maynardo » Sun Jul 01, 2012 6:12 pm

Hey I still haven't had the time to do any other mods. I wanted to ask you something since you know so much about these amps (I know I ask a lot of stuff).

The amp kinda of has a "spongy" feel to it when your playing in the lead channel, which is nice, I've played other amps with a really percusive feel. So I was wondering where is the spongyness coming from?... is it the fixed bias thing, just the brand of preamp tubes, the tannies?

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

Post by AshokanKid » Fri Jul 13, 2012 10:10 pm

Hey there;

This is truly wonderful stuff.
I just got a DC-5A that was modded by Voodoo Amps already, though I do not know what they did because it was before I took ownership (Volume mod at least).

Quite honestly, I have had several Mesa-Boogie Amps over the years and only kept them for days or even weeks before I sold them 'cause I could NEVER get a decent (Fender) clean sound out of them.

They always sound "boxy", mid-rangey, nasal and compressed to me compared to say, a Black Face Twin Reverb, Deluxe Reverb, Super Reverb or similar classic Fender.
My latest amp is a Hotrod Deluxe that, although it is PC board, ribbon cables and such, still has some nice Fender classic vibe and sound going on.

When I got the DC-5, I thought, well, OK, let's give yet another Boogie a try and see what it is capable of. Setting all the controls to their mid point, I plugged in with a Steinberger L-Series using EMGs and played for a bit.
ARRGH, there was that SAME Boogie compressed, boxey, mid-range squawk with NONE of the sparkle, bottom or brilliance that my Fender Hotrod Deluxe does so well.
I unplugged and prepared to sell yet another Boogie disappointment, and then, several days later, after doing some research on the forums, I was VERY confused and curious.

SO many people seemed to LOVE these little amps, that I figured that I would give it ONE more try. First, I dismantled the amp to inspect the innards and have a look about.
I was impressed with what I saw on the inside (good build quality) and even more confused that this thing would not get at least a little closer to Fender clean tones.

When I plugged it in next, I zeroed EVERY control first, and then began cracking the pots slowly from that zero point. WOW, was I surprised!
With the mid and bass on ZERO, and the presence and treble up above the mid-point, this amp actually sounded kind of glassy and clean in a Fender sort of way!

With a little more playing I dialed in quite a nice sound (clean) and then did the same with the OD channel, again, barely cracking the controls above zero.
Nice sustain at a realistic volume level. Hmmm, pretty good. Then I revisited the forums to find out more AND to see what other mods are available.

Now I am curious if anyone has one "definitive" repository hosting area for DC mods so that I do not have to go looking all through many forums to find them?
I can see that several people here have have done some serious homework and tech work on these amps and I am looking forward to some experimenting.

Thanks for this post and for the groundwork on these cool old amps~!
I am now a Mesa Boogie convert and looking forward to more and more...

AK

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

Post by Maynardo » Fri Jul 13, 2012 11:35 pm

Hey, so I got the 500 silver mica cap mod with a switch in the back of the amp, it get's it a tiny bit tighter in the low end, more mids, but good mids not honky mids and definetly a better string separation, highly recommend the mod, I really don't think my iphone can record something to notice the difference 'cause is subtle

Also I had a guy do me a "tight" switch based on what the egnater amps do, now that's a killer mod specially if you use low tunnings, he told me he didn't use the mods monsta suggested, he was using some caps at the first gain stage or maybe before, but it really does what my old egnater use to do with the switch.

https://www.youtube.com/watch?v=69UzI1AGcVw <- if you go to about 1:25 the Egnater explains the switch

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

Post by joe web » Fri Aug 24, 2012 2:35 pm

monsta-tone, i´m impressed!
i read both mod-threads and there are a lot of great ideas written down.

GAS is hitting me very hard yesterday as i tested a DC-5b, but there is one thing i was missing compared to my Roadster head:
the solo-level function.

is there any chance of having a switchable solo-level-function on a DC-5 amp?
let´s say i´ll do the FX-loop-mod and solder the cables to the send-jack, could i use the mix pot for adjusting the solo level?
and could i change the reverb-switch-jack to a TRS jack and make the reverb and the solo-level switchable?

would this be possible?
thanks for your advise on this.

and btw. did you found a solution for a switchable FX-loop already?
Joe´s Band: Risky Whisky; Morbid Sky

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

Post by Monsta-Tone » Tue Aug 28, 2012 10:02 am

I answered the Solo function question in your PM.
Didn't see the footswitchable loop question, sorry.

If multiple switching functions are needed, I use one of these: https://taweber.powweb.com/store/chansword.htm
I usually get the Optical one, and replace the LDR's with Vactec 5C1's.
You could try this for the footswitchable loop.
Their low power relay board is cool too.

You will most likely have to add a 10M resistor across the item that you are switching to avoid popping.


On a side note, if you're gassing for a DC, mine is up for sale.
Elvis said.......
Amp techs do get shocked. :shock:

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

Post by joe web » Tue Aug 28, 2012 12:31 pm

Monsta-Tone wrote:I answered the Solo function question in your PM.
Didn't see the footswitchable loop question, sorry.

If multiple switching functions are needed, I use one of these: https://taweber.powweb.com/store/chansword.htm
I usually get the Optical one, and replace the LDR's with Vactec 5C1's.
You could try this for the footswitchable loop.
Their low power relay board is cool too.

You will most likely have to add a 10M resistor across the item that you are switching to avoid popping.
thanks a lot for this helpful answer!

On a side note, if you're gassing for a DC, mine is up for sale.
thanks for the offer, but i guess you´re located in the US and i live in germany. so i would need a step-down trany and shipping would be very expensive i think.
Joe´s Band: Risky Whisky; Morbid Sky

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

Post by crguti » Mon Oct 22, 2012 8:35 am

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.
I've got a 47pf ceramic cap... is it relevant to know the voltage at which these caps works :?:

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

Post by Monsta-Tone » Mon Oct 22, 2012 10:32 am

You'll probably want to use 500v rated caps. Sorry, forgot to mention that.
Elvis said.......
Amp techs do get shocked. :shock:

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

Post by BlackBoxy » Sun Nov 25, 2012 4:57 am

Monsta-Tone wrote:I answered the Solo function question in your PM.
Didn't see the footswitchable loop question, sorry.

If multiple switching functions are needed, I use one of these: https://taweber.powweb.com/store/chansword.htm
I usually get the Optical one, and replace the LDR's with Vactec 5C1's.
You could try this for the footswitchable loop.
Their low power relay board is cool too.

You will most likely have to add a 10M resistor across the item that you are switching to avoid popping.


On a side note, if you're gassing for a DC, mine is up for sale.
Dc5's use Vactec VTL5C9, not really same photoresistor value part than 5C1


as other mods, i would put a .1 uf 715p cap to replace the terrible ceramic disk for a smoother and more usefull presence in the dc5.. follows the yellow cross wire near V6 #6 socket pin!

regards

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

Post by Monsta-Tone » Sun Nov 25, 2012 11:22 am

:lol: I was talking about the LDR's on the Weber "Optical Channel Switching Board" kit, not the LDR's in the amp....... :lol:
Elvis said.......
Amp techs do get shocked. :shock:

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

Post by BlackBoxy » Mon Nov 26, 2012 6:03 am

Monsta-Tone wrote::lol: I was talking about the LDR's on the Weber "Optical Channel Switching Board" kit, not the LDR's in the amp....... :lol:
:lol: :lol: :wink:
i still don't know what webber Optical Channel Switching Board would bring more , mesa dc5 switching matrix is already there with a 3v supply (no need of more PS), with its own muting (ldr) network, why adding a new gear to bypass this one? its not a old simplistic fender turet's or eyeslet's board, useless !
aswell Reverb chanel in the dc5 is swithched by relays RY2 RY3 drove by optocoupler 4n33, LDR's?
not really same voltage and current at this preamp stage, different impedance than inputs(there is word "Resistor" into LDR) , with alot of maths and redesign, maybe !

Dc5 is simple,

there is 3 relays NEC MR62 5UKSRY, 2 optocoupler 4n33, and 3 LDR VTL5c9,

switch drives two matrix, 20v and 5v, eathier lights off or on leds of LDR1 or LDR2 wich mute or open inputs of Ryth/Lead chan + the 4n33 leds lights up or off that drives RY2 RY3 dpdt (reverb input/output,Master and presence) on preamp stages to ryth/lead too, its a chain ..

LDR3 is alonne and switch EQ independently as Boost pull pot drives RY1 switching on or off preamp rythm chan (filter/resistor).

would be complex stuff to break this matrix by replacing 2 relays (reverb input RY2, Reverb output RY3) with two slower LDRs , good luck!

personnally i use a cheap 2 switchs Ftsw for channel ryth/lead and eq as i rewired front chan switch jack to the place of reverb one !
would be easy to drive eq with actual switching matrix, no need to add one another bypassing the existing one!

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