DOD 250,YJM308 COMPARISON

[yngwie308]

Dude is using a Les Paul, so humbuckers, no single coils, but interesting comparison:
http://uk.youtube.com/watch?v=5WdgfOnrueU
http://uk.youtube.com/watch?v=u4iCrvhQo ... re=related
http://uk.youtube.com/watch?v=ECkRQvuwHSA&feature=user
http://uk.youtube.com/watch?v=uekZL52zNmc&feature=user
Cool
Hell, check 'em all out!!!
http://uk.youtube.com/profile_videos?p= ... ude&page=1
yngwie308

[45auto]

i can't hear the samples at work, will listen later at home. i wouldn't have used the y308 stock, got the analogman mojo just as you did. it has a semi-permanent spot on my fx board now.

[Tone Slinger]

The 250 original or reissue, sounds a bit warmer, with a slight bit more bass sag to it. The 308 is similar, but has a harsher more brittle aspect to it. Not as warm or bassy. Whats cool is experimenting with this circuit (essentially a MXR Distortion +) just by swapping out a few resistor/capacitor values along with different diodes, you can get varying cross pollinating shades of 250 or distortion +.

[parkhead]

apologies for digging up an old thread

last week on Vacation I sumbled on a NOS YJM308 at a small music store,

I bought it after a buddy raved about what a great trebel booster it made with certain amps we both own ....

I knew it sounded thin and crappy when I tried it ... the sales guy looked at me like I was buying the stores biggest dog

FWIW after a little internet research and about 30 minutes on the bench,

total 3 parts changes I am enjoying a fabulous overdrive device ...

this is probably the best full on 9 volt powered LIQIUD LEAD tone i've heard this side of a multi stage hi gain big $$ amp

here are the changes I made based on 70's spec units & suggested mxr tweaks

input grid pull down resistor (some people call it bias resistor) dod used 1 meg, 510k and 470 k (yjm is 470k)

I swapped this out to 1 meg

input capacitor: vintage spec is .01 yjm spec is .001 I split the value and used a .005 mallory 150

these two changes put the bottom end back in the unit

getting rid of the FIZZ and BUZZ:

the yjm has a 4.7 mfd cap between the IC and the clipping diodes, essentially the output cap
historic values here are 10mfd and 4.7mfd, while MXR and ross used 1mfd

I tried .68 mfd (the closest I had to 1mfd that fit )

interestingly this removed most of the nasty elements of the clipped tone without impairing the bottom end,

in fact this little change made the distortion tone magical & organic instead of boxy & solid state sounding

this makes sense because the diodes clip based on the signal swing hitting them, shelving out some of the bottom at this point

would move the trigger point of the diodes and shift the frequency of the distortion up 1 octave above the stock 4.7 mfd value

the result is better touch sensetivity, less blocking and mud in the distortion, and more musical lead harmonics

I'm dying to try asymetical diodes and tweaking the final .001 smoothing cap, but the unit is now so much fun I'll have to do

another pedal to tweak real soon

These tweaks work for the mxr distortion plus, ross distortion, dod yjm308 and od250 since they are all

improved clones of the Dan armstrong Blue Clipper

these are a fabulous steal for those who can solder and have the ears to dial in the proper sound

IMHO these are just like fuzz faces ... 99% of the production units sound just passable or bad

I've tried many VINTAGE MXR + units and never heard the full potential till now

like the fuzz face once you've played a great one it's a real eye opener

p

[spaceace76]

try out LED's for clippers. your post made me want to dig out my old D+ from wherever it's hiding, so thanks!

[parkhead]

http://youtu.be/LlyL7wO3RqU" onclick="window.open(this.href);return false;

p

[Tone Slinger]

Agreed, I'm gonna pull out my YJM and check this out.

Here's another thing about the YJM, it was DESIGNED to be used like how Yngwie uses one. I know it's an old unit (250) and that the D+ is even older, so Dan Armstrongs little 'plug in' was the earliest varient ?

Yngwie was CRANKING up his units (250) volume, to 'smooth' out the harsh quality of the gain, as well as to get at the bottom end. On original spec units, you get alot of 'flub' by doing this, so its not ideal. Plus, you have to have the unit on ALL the time, because by cranking up the volume knob on the unit, you have far surpassed the sound/volume of your amp when you turn the pedal off.

The 'stock' YJM spec takes all this into account. You HAVE to have this units volume knob up to at least 3 o clock, or it is very brittle and shrill. Set your amps volume to a point to where when the YJM is on (in Mamsteens case, ALL the time) it is where you want it, and viola, sounds REAL GOOD ! To me,, when the STOCK YJM is cranked (both knobs) you get the most BAD ASSED D+ type tone around. Has the fullness of the 250, but the tighter tracking of the D+. You have to set your amp to accomodate this though.

I took my YJM to 'analogman' spec, but found that it was better 'stock', so long as you use like Malmsteen does, ALL the way UP !

These NEW specs (thanks Parkhead !) sound like they may make the unit much more versatile as far as possibly NOT having to set the volume so high.

[stef]

YJM didn't crank the level (volume) on his dod250! His live settings are: Gain- maxed, Level - 9:00. I use the same settings and it's not harsh or brittle.

YJM 1984 pedalboard

[stef]

The best way to smooth out the 308 is to install an lm741cn IC and 10nF input cap (stock grey specs). That's all

[parkhead]

no doubt, I do not have the chip on hand otherwise it would be done already

It's a pretty cool pedal & keep in mind my tastes run more to the Billy G type tone and playing than Mr Malmsteen

I do however feel that there is a lot to be learned whenever you stumble upon an artist with an exceptional TONE


p

[Steve Mavronis]

The best way to smooth out the 308 is to install an lm741cn IC and 10nF input cap (stock grey specs). That's all

no doubt, I do not have the chip on hand otherwise it would be done already

Not quite. The LM741 chip has a different pinout than what's used (KA4558 dual op amp) on a stock YJM308 so that won't work without modifying the traces too or making an adapter socket. You could compromise and use a 1458 instead (which has the same pinout as the 4558) and it is a dual 741 anyway. Then just remove C2 (25pf cap that tames the 4558) and replace input cap C3 with a 0.01uF value to be late 70's gray spec. Skip doing step 2 in my illustration, that's not spec just someone else's suggestion. This older post of mine will help explain what to do if you so choose:

http://forum.metroamp.com/viewtopic.php ... 80#p334881" onclick="window.open(this.href);return false;

Steve

[parkhead]

ok Just installed the 1458 dual op amp (had to make a special shopping trip to get it )

left the 25pf fizzy cap

left the input .0033

output cap .68

added one germanium diode in series with the factory diodes

HOLY FREAKOUT this thing sounds amazing

there is no buzz fizz or rizz just big angry GROWL


CONCLUSION the op-amp is the KEY element

thanks guys

p

[stef]

The best way to smooth out the 308 is to install an lm741cn IC and 10nF input cap (stock grey specs). That's all

no doubt, I do not have the chip on hand otherwise it would be done already

Not quite. The LM741 chip has a different pinout than what's used (KA4558 dual op amp) on a stock YJM308 so that won't work without modifying the traces too or making an adapter socket.
Steve

I didn't say to just put a different IC there ! The word I used was "install"... Modding the 308 for an lm741cn is easy.. here's a nice tutorial
http://www.ultimate-guitar.com/forum/sh ... ?t=1235819" onclick="window.open(this.href);return false;

[Steve Mavronis]

Yeah, that Ultimate Guitar forum article is what I based my illustration on. Once you change to a 1458 or 741 chip (with PCB trace mods) you don't need the 25pF cap any more. The original gray 250 pedals didn't have one in the op amp feedback loop.

[Tone Slinger]

On the old footage of Malmsteens gear (like the Jan. '85 in Japan show) Malmsteen had the level up real high.

Funny thing is this. The FACTORY spec is most often the BEST spec. Leave the YJM alone. Set the amps volume a tad lower than where you want it,, and crank up both knobs of the YJM. THAT is where the sound lies. There is no fool proof way to get this pedal where it needs to be. Yngwie worked with these DOD dudes to get it where it needs to be.

Use it with both knobs at ,, at LEAST 2 or 3 o clock (preferably 4 or 5) and you see what it was designed to be. To put a MASTER volume on it would be the ticket.