New DOD 250/308 Question! HELP !!!

[stand]

HELP !!!
I already started topic about DOD 250, and I almost ordered parts, but...

      I decided to see what DOD 250/308 owners say about this pedal, and I was very surprised to see that almost everybody said that this pedal doesn't give enough distortion. Most of them use it before other distortion pedal as signal booster, or with amp which already has included some kind of distortion. In general, people say that it just isn't "heavy" enough, though all of them said that otherwise sound is warm and pleasant, and suitable for some kinds of non-heavy rock. It seems that Yngwie's name is on this pedal  just there to improve selling, which is really unfair. On his website I saw that Yngwie really uses it, but it is just small part of effects-chain. I know, his sound is product of good guitar(s), effect devices and amps and probably is not so easy to achieve.
      But, it was not my intention. Of course, I was not so naive to believe that I can get DIY Malmsteen's sound for 10$ (or so), but when you put YJM's signature on some pedal then customer has right to expect sound that is at least similar to YJM's. And, if my ears are still in good working order, Yngwie's sound isn't so mild. It's heavy, isn't it? If I make it and if I end up with "The Shadows" tone, my son and me will be very disappointed (here goes an apology to all "The Shadows" fans).
      Please, let me know if those people are objective in their DOD reviews. I couldn't find any audio clip/presentation of this pedal on the net, is it possible to find some?
      Finally, I hope that Mark, Pete and other people who tried to help about this project can encourage me to make DOD250/308. Could I do some changes to make it more 'heavy'? If it's impossible, could anyone here give me some info which pedal I should make. It should give me enough distortion without any additional effect (our amp is multi-purpose device, it is not a classic guitar amp). And, this pedal shouldn't be too complicated (I think DOD250/308 isn't), since it will be my very first pedal project.
      Here is a simple question for Marin Lovric – since your friend has YJM 308, could you inform me about "bare" sound of his pedal. Is it 'heavy' enough?

[TheBigMan]

I've only played one briefly - I modded one with a Boss style DC jack and an LED and had a go of it.  With a strat I definitely thought it was more OD than distortion.  I would guess that Malmsteen uses it in front of an amp set with at least a little grit and then thumps it with the 308.

I'm sure you know that this pedal is 90% the same as the MXR Distortion+ used by Randy Rhoads, another heavy player.  However the old version of the Dist+ used germanium diodes, which clip harder than silicon and give more distortion, although less overall level.  It's a very simple mod to add a switch to choose between the standard clipping for use as a light distortion or overdrive, and germanium diodes for more aggressive sounds.

[Caferacernoc]

This is a very versatile circuit. It's all going to depend on the clipping diodes used. If you use germanium diodes I gaurantee a humbucker will drive it into fuzz land. LED's will be overdrive and silicone will be somewhere in the middle. I read your previous post and based on that my personal recommendation is to build the 308 stock with two changes. One, double the size of the output capacitor for a fuller sound. Two use germanium diodes assymetrically for a harmonically richer sound. One diode in one direction and two in the other. This is a easy circuit to mod, you can always change it around if you don't like it.

[Caferacernoc]

Let me add to my previous reply. Buy the eight pack of germanium diodes from this site. Then, you can fine tune the pedal to have just the right amount of output versus distortion for your taste. I recommend using more germanium diodes as opposed to switching to silicone because I think they sound better. I just modded a ross distortion pedal, similar circuit, the same way. It's all up to personal taste. the input and output caps control the bass. The cap to ground after the clipping diodes is your treble cut, and the diodes give the flavor of the distortion. Adjust to taste!

[Mark Hammer]

Most distortion pedals will achieve their "sound" in two ways: because of the distortion they produce themselves, and because of the distortion their high output produces in later parts of the signal chain (like the amp).  The 250/308/Distortion+ is designed to produce a reasonable amount of distortion on its own but also produce more distortion in the amplifier.

You still haven't played yours yet so it might surprise you in a good way.  If it still does not give YOU  enough distortion, you can do a few things.   One thing you can do is increase the 1meg resistance in the feedback loop of the op-amp (between output and '-' input) by either putting in a larger value (e.g., 1.5meg, 2.2meg) or putting another resistor in series with it (e.g, 470k, 680k, 1meg).  If that resistance is 1.5meg then the maximim gain will be 320 instead of 213.  That should get you a *little* more distortion.

The other thing to remember is that many of the opinions you run into on other forums are from people who have no understanding about how things work and can have unrealistic expectations or make unreasonable comparisons (e.g., hot pickups into pedal A going into an amp that overdrives easily vs weak pickups going into pedal B and an amp that stays clean until pushed to the extreme).

In many instances, pedals which are kown for extreme distortion actually have two or more clipping stages.  For example, the Big Muff storts the signal then reamplifies and distorts THAT.  If you wanted to get a very strong distortion, you could try making two of these and placing them in series.

[stand]

To TheBigMan:
I know that Distortion + is very similar to DOD 250, and I think that it uses Ge diodes assimetrically. Lots of people say that such approach gives reacher harmonics. Dist. + reviews are pretty similar to reviews of DOD250/308, which doesn't surprise me. Anyway, I'll try Ge diodes too, I'll see if they'll give me more distortion than Si.

To Caferacernoc:
Thanks for your advices – I'll certainly tweak not just diodes and these two caps, but also this cap next to gain pot (as Mark H. proposed) and ICs, too. It will be something like a small pedal lab    Unfortunatelly, I cannot order diodes from this site because we here still have problem to buy things over the net (this forum really is not place for such sad stories). At our el.parts supplier's shop they have only one kind of Ge diodes (1N914), and they don't order it anymore because almost nobody needs any of those. I hope that 1N914 can do the job...

To Mark Hammer:
You scored again, man... I understand what you are trying to explain about ways to produce distortion, and I know that it is usually produced by both pedal and amp.
Once again you gave me some useful advices. It won't be problem at all to change that 1M resistor into any higher value. How high can I go with these values before I burn something? Do you think that with increased resistance in the feedback loop I can get enough distortion?
I also know that guitar itself is very important part of effect chain, and that good and strong pickups can produce great distortion quite easily. Here is just one example – long time ago (1982) some kid asked us to try his new Ibanez guitar on our band's Marshall amp. At that time our guitar player had original Fender Stratocaster and was so proud of it. We looked at boy's guitar as it is just another Jap's crap (then almost all guitars from Asia were considered as very bad). We moved banana jack from Strat to Ibanez and immediately we heard horrible feedback. Boy played just one chord and we heard such a roaring sound so we couldn't believe this guitar can produce such a good distortion. We played it and understood that this guitar has very good pickups. Our guitarist was not very happy, but somehow he cheered up himself by saying "Japs probably included some kind of active electronics inside, it'll never sound as good as Strat". What I am trying to say with this story is – the best pedal will sound bad with "lazzy" pickups.
Few hours ago I examined a huge list of reviews of MXR Dist. +... All those who hated it said that this pedal is too mild, that distortion is so weak... On the other hand, people who liked it play mostly blues or other "softer" kinds of rock. Those who succeed to get powerful sound from this pedal said that they use it before some other distortion/fuzz pedal. Hmmm...
When I started previous topic (about DOD250) I forgot to include a very important detail (shame on me!) – our amp doesn't have 'overdrive' or "gain" channel. Actually, we use Yamaha mixer and power amp (slave) to play my synths and my son's Strat-clone through it). So, we need pedal that will give us enough distortion without any additional effects caused by amp or anything else. Now when you know what we need, do you think that I should start some other project, or maybe I can get enough distortion by switching to Ge diodes and by increasing value of 1M resistor as you proposed?

[lovric]

he hehe, nice and thorough man! you have a knack for starting a discussion...

distortion with diodes comes down to how much diodes limit or clip. that depends on on how many volts diodes let through them.
Ge passes around 0.3V
SI -----------------0.7V

If they are connected to ground, the more they pass - more they clip the signal.
The opposite happens when they are in the feedback loop of an op-amp. The more they pass - larger is negative feedback - so, less clipping.

It is *extremly* hard to add anything new to what guys already said in this topic.

308 distorts the signal by itself AND it can overdrive the amp on top of that.

Dogovoricu se sa ortakom pa cu da ti posaljem privatnu poruku sa telefonom da se nadjemo i da probas...

marin

[stand]

To Marin:
I understood what you explained... Thanks!
Go to your Yu e-mail address, I've sent short note to you... 

[burnt fingers]

I don't know how much distortion you are looking for but I played hard rock with mine for a long time.  It's not boss metal zone, mesa rectifier distortion but it is certainly more than enough gain for me.  Check out http://www.kilback.net/homebrewtweaks/pedals/pedals.htm
He's got some sound samlpes of a Dist+ he made.  The Dist+ and the DOD 250/308 are very similar.  I'd say this sound clip will give you a good idea of what it can do.  If nothing else, socket everything and try it.  Iit doesn't hod up to your ears you can swap out things to your hearts content.  Thats what many of us do before we commit to a circuit.

Scott

[stand]

To burnt fingers:
Thanks, man! That's what I needed. This man used Daphne Strat and Traynor YGM-3 (2 x EL84 amp with 12" speaker), though I am not quite sure if this amp has included some kind of overdrive. These sound-samples are quite satisfying for me – I don't expect anything else but "healthy" distortion, and these samples proved that Distortion + gives such kind of sound. From other people's review I saw that most of them complained about too weak distortion of both Dist. + and DOD 250, but now I understand that they probably expected "metal zone"-like sound. And, if their pickups are weak then they probably need something else, or some kind of additional overdrive.
I'll probably go for DOD 308 clone project, but I'll definetelly raise resistance in the feedback loop and I'll do all the other tweaks which Mark and other friendly people mentioned in my previous topic. And, since diodes are not expensive, I have idea to include a simple multy-way selector which will give me opportunity to choose between Si/Ge/Si+Ge diodes in both simmetrical and assimetrical position. It will complicate schematic a little but this is not commercial project so I don't worry about it.

[burnt fingers]

Right on. get that soldering iron burning.  Once you've done one, its like a roller coster.  Wahooooooey.

Good luck with your build and let us know how it turned ot.

Scott