Smothing DC-5 and an output master problem

[Gizmo77]

Well first of all, the latter. After buying my DC-5 second-hand I've discovered that the ouput master volume works in the range of "0.5 until 3" more less. The more volume I give... the same pressure I get. Maybe the power tubes? In that case why do they work and get "limited"?

On the other hand, while the clean channel sounds Ok I find the Lead channel "too lead" haha. I mean, don't know if they are the tubes age or what, but I can't get anything but distortion in Lead channel even at gain 1 or so in the second channel. I'd like a milder and warmer overdrive at first and then develop into a bigger distortion but without having to reach high gain settings (it's not my style). More less the "pulled channel" in the rhythm section.

BTW the power ones are STR 6L6 GC Grey which are supposed to be in the middle. . I've thought about buying spare tubes and even changing them as I don't know how old are the ones which came with it. But here (a region in the north of Spain) is a real madness to find Mesa Boogie or Groove Tubes (just one shop had a pair of Mesas and they were yellow and two sets of GTs one red and one blue, guess what he said "The color is just bullshit") and at least Sovtek (implying that taking it to a tech to choose a matched pair and that stuff will cost extra money).

I'm on the "round, warm" side of gain so please, if anyone could please tell me what selection would you make for this, I would really appreciate it.

Thanks all for any comment, suggestion and advice.

Mind my English, do my best, I'm Spanish

 

[edward]

Hi Gizmo,

You spanish is better than my english ...you're doing great!

First off, there is a modification for the output knob that will address this very problem. Check out the search function here. It is a very simple mod that involves cutting one resistor wire ...you don't even have to remove it; just cut it. I did it to my DC5 and it not only makes the knob MUCH more linear and easier to use, it also smooths out the tone when played at very low volumes. Definitely do this mod.

As to tubes, as far as I recall, the colors are meant to match the tubes in pairs or quads, and not intended to imply "tube harness" ...that's what I recall a Mesa Tech (at the factory) saying. If you want smoother tone, the Svetlana "Winged-C" are great power tubes IMHO.

If you want milder/warmer OD, then definitely try a 12AT7 in the PI position, and get a good pair of NOS 12AX7s for the V1 and V2. Or you can also try a 12AT7 in either/both of those spots and see if you like the tone/dynamics. BTW, lots has been said on this board lately about preamp tube choices ...you should look that up in the archives for this, as well.

One last thought, the Lead channel of the DC5 doesn't do mild breakup very well, IMHO. But I get a superb bluesy crunch from the Clean channel ...experiment with the gain. To "clean up" the tone, simply roll down the guitar's volume knob a bit, and it responds beautifully. Roll the vol back up to full and you get your mild crunch back ...very smooth and rich tones here. I personally feel the Lead channel is voiced better for real OD, from classic rock to metal the range is substantial, but OD nevertheless ...but that may just be me. Hope this helps

Edward

 

[tetsubin]

Like edward said, the lead channel is a real lead channel, although I find using the volume knob of the guitar works quite well in it. For a rounded tone I would disengage the graphic EQ.
But in the end the lead channel has a totally different character than the rhythm channel's high gain settings. I've just recently discovered unbelievable high gain tones in the rhythm channel with the pull boost activated.
As far as tubes go, I recommend using the Mesa 5881 STR-425 power tubes. They are not as harsh in the highs like the STR-430 6L6 are, and give a great full sound.
In the preamp you could try JJs for a little more warmth but don't expect too much of a change. Here's the tube layout: V1=input lead/rhythm; V2=lead; V3=lead/fx return; V4=rhythm; V5=reverb; V6=phase inverter.

Oh, and what are your settings in the channels? What speakers are you using?

 

[Gizmo77]

Thanks all...

Well I was expecting perhaps a smoother tone on the lead channel. Sound really great but would have liked to jump from pristine rhythm to warm overdrive without using a stomp box or rolling off the guitar knob.

So, finally the master volume is that way? What I'm saying is that it doesn't go more than 3'5. It's range is limited from 0'5 to that setting :S.

I have been searching about that mod but haven't find it (well, now it's 12:00 in Spain and I'm at work break, I first posted this at 0:00 so please understand I haven't been able to skimtoo much).

Thanks all again for your comments and suggestions .

 

[Ken j]

Gizmo77 , don't forget to use the clean channel's "pull for gain" to get you the blues crunch leading up to that of the lead channel. I think you will find this amp very versatle.

 

[edward]

Thanks all...

Well I was expecting perhaps a smoother tone on the lead channel. Sound really great but would have liked to jump from pristine rhythm to warm overdrive without using a stomp box or rolling off the guitar knob.

So, finally the master volume is that way? What I'm saying is that it doesn't go more than 3'5. It's range is limited from 0'5 to that setting :S.

I have been searching about that mod but haven't find it (well, now it's 12:00 in Spain and I'm at work break, I first posted this at 0:00 so please understand I haven't been able to skimtoo much).

Thanks all again for your comments and suggestions .

Here's the link for you. It was in another forum, not this one ...sorry about that.

http://www.thegearpage.net/board/showthread.php?t=229027&highlight=mesa+output+volume

As for reducing gain for what you want, I think your best bet is with AT7 preamp tubes in the PI, V1, and possibly in V2. ...heck maybe even try an AY7 (another 10% less gain than the AT7). Change one thing at a time, and see if you like the change. And while you're in there, replace your V5 reverb driver with an AT7 as well to improve the reverb tone.

The "pull boost" in the clean channel just has too much midrange and boost for my taste ...not a useful tone for me, anyway.

I agree, too, that this is a very tonally versatile amp. It is one of the few pieces of gear that I cannot think of ever parting with ...ever!

Edward

 

[Gizmo77]

Perhaps something really stupid, but:

The snip operation should be done on one side of the resistor? Remove it? Leave a wire linking both sides?


Thanks all .

 

[edward]

Makes no difference, really. Once the resistor is snipped on either side, it is out of the circuit. Snip one side and leave it in, if you like, then give her a listen to see if you like the mod ...I will bet you will.

Edward

 

[Calamity]

Jeeze. I've been meaning to do this ever since I got my DC-3. I've never messed with the guts of tube amps before so I was a little nervous before. I was bored today and have been following this thread for a couple days. I finally broke out the tools (screwdriver and scissors! Hah!) and did it. After I did it I forgot to plug the speaker in again (no idea how my transformer didn't blow, the mute function must have saved my ***; stupid me -- it's been a long day; got towed + ticket, blah blah).

_Anyway_, back on topic: It sounds like I lifted a blanket off my amp. The clean channel was decent before I did it (I found an awesome tone I've been in love with), but now it is even more awesome The lead channel was the main victim of the blanket syndrome. Now it definitely sounds way more open and way less muffled. Now to find an amazing lead tone (I fiddle with Ch. 2 way too much ).

By the way, I'm playing with my volumes at around 1.5-2, and it is astonishing how great this baby sounds. I wish you good luck with yours.

 

[Fxrs]

:evil: G@####it!! Now I'm gonna have to take my amp apart and do this!

 

[Calamity]

Just remove the 4 mounting screws on the top of your amp and the chassis will slide out. Be sure to deal with the wires, though. And if your metal bar is still on the back of the amp, take it off (obviously). Turn your amp off with your standby up and be sure to unplug it. It's not that difficult. Hell, if I could do it with scissors, you can do it.

 

[Fxrs]

Well,I did it! Scared the **** out of myself at 1st, when I got it back together and tried it, I had only the rhythm channel ! The led's lit up correctly, but no pots on my lead channel worked. Think it's just a footswitch problem as the plug on the end is somewhat bent.(this is a spare) I pulled it out and re-inserted, and now it seems to be functioning correctly. I still have to wait to test, this was all at a whisper as the wife and kids are sleeping. Can't wait to try it out at volume. Oh, I'm also running AT7's in V5 & V6.

 

[Hanslow]

I'm going to look at mine this week on my DC-3. Would it be better to desolder the resistor rather than snip it? Not opened mine up before so am having the same concerns as a lot that have gone before me :lol:

 

[Gizmo77]

Well, this afternoon I will make the mod in the "rehersal doom". I was doubting whether I had to leave both sides linked without resistor or not, as... I guess there would be some kind of use or need for this link and resistor.

May anybody guess why this resistor is set there? Because.. it seems that it has no use rather than losing versatility and, as some say, tone.

Thanks all...

Mind my English...

 

[Hanslow]

Well, I opened up my DC-3, found it's got a 1993 board in it (which dates it after when I was told it was made). Wasn't 100% sure on exactly which resistor to go for so have come for some friendly advice!

Took a couple of pics around the area and think I know which resistor is the infidel but could someone confirm before I bodge it?

Pic 1
Pic 2

The three purple wires are the ones from my master output pot, and I'm assuming the offending resistor is the one immediately to the right of the rightmost purple wire? There's also a veritcally mounted one there just back from the horizontal one next to the wire. I assume I leave that well alone?

Would I be safe to use a solder iron from the top, with a solder sucker to pull the solder out from round the resistor's right most leg (as you look at the pic) or would it be better to desolder from the bottom of the board, which will involve taking the whole board out? Would prefer to use a clean extraction rather than snipping it....

Cheers

Steve

 

[Hanslow]

Calamity, can you offer any advice on which resistor to snip ?

Cheers

Steve

 

[edward]

Hi Steve,

I can't see the resistor from your two pics. IIRC, the resistor is between the outer and center lugs of the output pot (if memory serves). If that's the resistor you see, snip or desolder just one end if that makes you feel safer. Put her back together and see how she sounds.

Edward

 

[Hanslow]

Braved it tonight

Desoldered the right leg of the resistor just right of the purple wires as you look at it on my pics. Pulled the resistor up and away, and wrapped in insulating tape.

Appears to have done the trick Output volume pot appears to have a lot more effect from 2 upwards and at lower volumes is a lot thicker in tone.

Thanks all for the info on here and the pointer to the other thread on the gear page. Going to post a response on there too as the guys were interested to know for sure which resistor it was

Thanks again!

Steve

 

[edward]

Hi Steve,

Yeah, saw you there on TGP. John P is amazing! Very knowledgable, and a superfriendly guy who digs music and "techie" stuff related to music. Glad you like the mod ...it really is an awesome difference!

Edward