Distortion + -vs- DS1 for Marshall-type sound?

[GibsonGM]

This is a little OT, but am I high here?  I've read a couple of posts about the Dist+ having a low output/gain, and you just mentioned driving it with a boost.   OTOH, the one I made and have all done increases my clean amp signal by like 6dB!! It's my #1 pedal, and I gig with it.  I really don't use it above about 50% level, with my amp set to about 3 (clean channel).    And, I used 914's for my clipping diodes....if I got any more gain out of that, it would be white noise!  This has more drive & saturation than a marshall stack, LOL.  Maybe I've got mojo here, something like a hot 741??   Or maybe the fact I'm driving the front end of a hot rod deluxe...

LED's have a higher forward voltage (their "turn on" level)....so, the output of the op amp gets to be higher before it gets clipped to ground, resulting in a louder signal. (A form of limiting, actually) However, this also makes the clipping not as "hard", resulting in more overdrive, less distortion sound as we're talking about it.  Experiment, some might like that.  Could add another diode like a 1n914 or ge after the LED...

If you don't have a meter to figure out LED polarity, use a VERY worn 9v batt, and QUICKLY touch the leads across it.  If it glows briefly, it's oriented to the battery poles. If not, it's backwards.  Be warned, do it too long and it will burn out.  You can put it in series with a 470 ohm resistor to do this, and it won't burn out even on a new 9v batt...

[billings]

6db is about right for a guitar plugged straight into the Dist+ circuit, which maxes out at around a 1.4V signal swing using your average silicon diode clippers.  People around here want to get closer to an 8 or 9V swing, though, which is like a 14 or 15db gain on a 0.3V guitar signal.  I'm not sure how common that desire is in the public at large.

[GibsonGM]

LMAO, Billings, ha ha!  Thanks for the reality check...I do like my amp, and hate to feed it much more than 3 or 4 volts on the input   

I know that when I'm soundchecked with Dist+ at 1/2 level, amp on 3-4 and ready to go, if I dime the Dist+ it's WAYYYY too loud and everyone starts throwing things at me....so, IMHO, it has PLENTY of gain - you could easily add a tone stack or whatever to it.  I've considered just using headphones from its output, LOL! (just joking).  I'm totally into the OA clipping plus diodes, too. 

[_tom_]

I think I'll buy myself a multimeter before modding then, seems like a useful tool to have in the kit.

Take it you can use it for checking the polarity of components? No idea how but I hope someone can tell me 

Learnt a lot in this thread so far, thanks 

[wampcat1]

Hmmm. Marshall type sound... They made a lot of amps over the years. Neither the ds1 nor d+ really sound like any of them, but properly modded they are both outstanding in their own way! I would classify the ds1 as the more "marshally" of the 2 however, but that's just a subjective opinion and cannnot be hard fact  since it's really comparing apples to grapes...
I can verify that the Thunderchief really does sound a whole lot like an old super lead! If I were to have named that pedal I would have called it the "Early Eddie" pedal, because it really nails the early VanHalen sound- to the point where I was totally amazed! With the perf layout it's an easy build, except fot the biasing part, but even that wasn't all THAT hard- just squirrely.
But, you MUST get a meter to bias it, although it need not be expensive. If you plan on making a hobby out of electronics you really ought to get one anyway!
I have heard good things about the Eighteen also, and there's an entirely different yet distinctly Marshall sound...

That's a good point.

Which Marshall? jcm800? jtm45? 18watt? They all sound different. IMO, I would follow what ROG has done (well, popularized more correctly) and build the marshall preamp of your choice using jfets. Will it sound identical? No, but close.

bw

[_tom_]

Which Marshall? jcm800? jtm45? 18watt? They all sound different. IMO, I would follow what ROG has done (well, popularized more correctly) and build the marshall preamp of your choice using jfets. Will it sound identical? No, but close.

bw

I guess JCM800, I love the classic rock/hard rock/metal tones which I mentioned in the first post and I'm guessing they are JCM800 or similar.

How would I go about building the Marshall preamp of my choice exactly?! Sounds good to me. Will have a search and see what I can find

[wampcat1]

Which Marshall? jcm800? jtm45? 18watt? They all sound different. IMO, I would follow what ROG has done (well, popularized more correctly) and build the marshall preamp of your choice using jfets. Will it sound identical? No, but close.

bw

I guess JCM800, I love the classic rock/hard rock/metal tones which I mentioned in the first post and I'm guessing they are JCM800 or similar.

How would I go about building the Marshall preamp of my choice exactly?! Sounds good to me. Will have a search and see what I can find

I can't remember who actually did the schem, but I would search for jcm800 jfet or something like that - there is a design already available...

bw

[wampcat1]

Just found it for you.

http://www.erikhansen.net/diy/schematics/misc/jcm800.png

and


http://www.erikhansen.net/diy/schematics/misc/JCM800emulatorParts.jpg

have fun!

bw

[_tom_]

aha cheers.. looks complicated haha

I have no idea how to read those diagrams at the minute. Never was good at electronics diagrams 

Is there somewhere I can get a pcb type thing for this? The 2nd diagram is easier to follow for me as it shows it all laid out, but I have no idea how to attach some parts such as the 100k trims and the Q parts 

[Gilles C]

Just to start off, I'm new here and new to modding pedals, so hello 

Basically, I'm on a quest to find a Marshall-flavoured overdrive/distortion box that I can run onto the clean/slighty breaking up clean channel of my Fender hot rod deluxe, and have heard that the Dist + and DS1 are kinda similar.
....Cheers for any help

....
I use a HRDx myself, with a Les Paul.   I know what you mean about the drive channel for some uses ;o)  My sound is a Dist+ into the clean channel, which is easy, and could be modded to have tone controls to drop the mids and get that fat but crisp brown sound.  I easily get old Mountain, BOC, Molly Hatchett, GNR sounds, which is pretty close to what you seem to like.  I cannot get that using the yellow/red channels on that amp!   Maybe borrow a dist. pedal and try the clean channel to get an idea of where you want to go.
....   

Haaa... HRDx users. Using one myself, at least I can relate to the sound.

I also would like to have a Marshally sound sometimes, so I feel a bit more concerned about this thread ...

I don't remember seing that last circuit of a JCM800 emulator. It looks interesting. I"ll put it on my list and I'll keep an eye on the thread for a while...

Gilles

[_tom_]

Hmmm just rediscovered the BYOC pedals, now unsure what to do 

At the minute I use my Keeley Rat for a med-gain rock tone and its pretty nice, but not really cutting/gainy enough for leads or hard rock/metal.. Not sure whether to just get the Dist + and use that as a standalone distortion, or get a BYOC Tri-Boost and use that infront of the Rat for higher gain stuff.. gah!

[RollingElbow]

Woops! I am 80% finished on my thunderchief.. I had built an amp already so i just figured i'd follow the layout stock and build the thing on a small peice of perf board.. well for one, its been a real pain in the a$$ and a few times i have had to double check against the schem because i have wired things the wrong way, second, i am "between" multimeters meaning the good one i borrowed had to be given back. The one i am getting hasn't landed on my lap yet. this means that last week i pretty much free handed it based on the schem.  ::)So i am guessing this thing prob won't work and i should prob build on breadboard first but I got greedy. In any event, this whole biasing for JFETS thing has caught my attention a little late.. where is that explained? ( the how to do it and what you are looking for) I can understand biasing for diff tubes but when I was on the ROG site I didn't see any mention of this biasing. Can someone point me in the right direction?

As for the DS-1, i thought the Keeley was a tad too compressed after listening to it. Monte Allum does wicked pedal mods but that DS-1 didn't really catch my attention as much as the BD-2 and SD-1 mods. The one I really liked was the classic mod by indyguitarist. That sounds really thick.. you could back off the gain a bit and boost it and it might be killer. My tube amp didn't turn out the best but clean or slightly dirty, its really proved useful for my overdrive pedals. Definitely nice to run these pedals through even the cheapest of tube amps.