DOD 250,YJM308 COMPARISON

[parkhead]

guys, I'm enjoying fooling with the one I have

& and have instructed a buddy to buy two more NOS YJM pedals for me from the same place I got my first one

one stock

one old school grey exact

one with every trick in the book thrown at it ... lol

while factory spec is often best

I've been around this industry long enough to know exactly how these projects unfold, and to know that

the protypes the ARTIST got were fabulous & that the production units often have improvable compromises.

Often factory spec is best 95% of the time...

with this pedal I'll bet it was spec'ed with the dual 741 op amp and got switched at production to the one it ships with

some engineer or MBA argued sucessfully that fully clipped on a scope the waveform was the same & the $$ to be saved were

significant ...

Just look at the Marshall class 5 amps, some MBA argued that saving $$ by using a thin folded chassis with no boxing or

welds wouldn't be a problem ... net result a good product with a bad rattle

I've seen hundreds of examples

the last product that was tweaked for values 100% was Leo Fenders BF series of amps... even so we could list 5 or 6 tweaks

p

[stef]

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.

+1

[stef]

Funny thing is this. The FACTORY spec is most often the BEST spec. Leave the YJM alone.

The changes Steve and I have suggested are the ORIGINAL FACTORY specs, the best sounding late seventies "gray spec". Steve builds the best gray dod250 clones, improved with true bypass and signal light. If you are a fan of the recent YJM work and sound that's OK, but I like his early work, playing and tone. Having said that, the stock YJM308 is a good sounding treble booster for HB's.

[Steve Mavronis]

The changes Steve and I have suggested are the ORIGINAL FACTORY specs, the best sounding late seventies "gray spec". Steve builds the best gray dod250 clones, improved with true bypass and signal light. If you are a fan of the recent YJM work and sound that's OK, but I like his early work, playing and tone. Having said that, the stock YJM308 is a good sounding treble booster for HB's.

Thanks stef for the compliment. I wouldn't claim that I build the best gray 250 (and I'm not selling anything I make) since anyone can replicate that simple but 'holy grail' gray circuit and pretty it up any way they want for themselves. I do prefer the late 70's gray spec sound (actually 1979-1981) over the YJM308 that I also own one of. The 308 just seems to be more treble EQ'd than I prefer although it does sound better with my Yngwie Malmsteen signature strat more than with my standard strat. My 1979 version sounds the best overall, only if considering it's just a clone of what the original should sound like and nothing special other than build quality and looks on my end plus the true bypass and LED. I'm still tempted to mod my YJM308 to gray spec but something in me says keep it stock original. It might be worth $500 in another 30 years to a collector!

[Tone Slinger]

I guess I didnt look at that vid close enough (Jan. '85 in Japan). I used to use either a Voodoo Lab 'overdrive' (which is a real good 250 clone with an additional gain stage) or an old Distortion + at one point in my set up. I recall that I depleted my 9 volts within a couple of practices or gigs. It was funny. My bandmates would always show up with 9 volt batteries for me "Hey man, here ya go". They were tired of me messin with it. I do not like power supplies.

I also prefer older Malmsteen tone (my favorite tones of his are on 'Marching Out' and 'Trilogy'). He got a warmer type tone, that in the bridge position, seemed a tad closer to what a hb'er sounds like, as opposed to his brittle harshness of recent years.

[parkhead]

not a malmsteen guy so pardon the playing

I'm actually using my pedal as a clean boost after a tubescreamer, but I took the time to source three yjm308's
to do a comparison
conclusion RUN out and get a 1458 chip and a socket for that bad boy and plug it in

#1 dead stock as shipped right out of the box stock 4558 ? chip

#2 Dead stock but with socket for the chip and the 1458 dual op amp, no other changes

#3 Gray spec, .68mfd diode input cap and asymetical mismatched diodes

with the 1458 the distortion gets Chewey Thick, complex and woody
low strings growl the pedal is also louder

its more obvious and pronounced in person since the camera mic reduces bottom end and compreses everything to the same level

http://youtu.be/iEwg-DG3lbs" onclick="window.open(this.href);return false;

p

[Steve Mavronis]

Very nice set of videos and comparisions! I'm temped now to mod my stock YJM308 after all and do a better video demo of my DIY PCB gray spec 250 clone. The demo I got my wife's cousin to make was kinda crappy audio quality. For now listen to samples of Dean Cascione's (http://www.deancascione.com" onclick="window.open(this.href);return false;) new album Neoclassical Fire that he recorded the all the lead parts with using one of my clone pedals that I gave him or this video of him playing the pedal on the song Triskelion with the from the CD - http://www.youtube.com/watch?v=Mivy7vihICs" onclick="window.open(this.href);return false;

Plus I also have a 1980 Distortion+ still stock except I had to replace it's fried PCB with a custom replica that I made. I need to add true bypass to that next so I can use it with my 250 clone in combination better using one for lead and one for rythym although I love the gray 250 for both unless I want that classic Crazy Train sound with the Distortion +.

Great job, I subscribed to your channel!

Steve

[Steve Mavronis]

Okay, you gave me a little DIY mod fever today. Needed a fast easy little project anyway.

Modded my DOD YJM308 Overdrive to late 70's gray specs. Removed stock KA4558 chip and replaced with socketed LM1458N (dual 741 op amp), removed C2, and replaced 0.001uF C3 with 0.01uF. Done in less than 30 minutes!



Finished off my DOD YJM308 Overdrive late 70's gray spec mod with original DOD style fluted knobs! Sounds freaking great now just like the gray DOD 250 clone (Neo-Classic 741 Overdrive) that I built from scratch last year.



I've been meaning to do this for some time. Only thing 'optional' I could add is true bypass 3PDT footswitch, LED, and Boss style power jack, and re-decal it to say YJM250.

[parkhead]

nice work there !!!

Funny thing is that I am not a monster Yngwie fan ...
the truly killer sounds on these are when the distorion is below noon and the level is past 12:00 and the pedal is LAST before your amps input ... freakishly great boosted tones are effortless

I can see why these did not sell well the KA4558 should have been designated KA KA 4558 & the average guy
would not dial the distortion back far enough to discover just how smooth and touch sensative these can be

of course with the wrong chip the liquid feel is not there

I've ordered two guitar gadgets kits so I can experiment with the circuit more, build them true bypass and have a light

just about every cap swap I've tried has produced valid tonal results there are a LOT of classic 70's tones in these

p

[Steve Mavronis]

This is interesting. Today after work I compared my gray 250 clone and the YJM308 mod to gray spec side by side. One thing I noticed was that at half way the level (volume) knob setting the YJM308 is louder. I found the reason why. My 250 clone uses a level pot value of A100K which is A for Audio Taper. The YJM308 uses a W100K for its Level pot. I've only seen A=Audio, B=Linear, and C=Reverse Audio log pots for sale online. I was trying to figure out what the W stood for. This is what I found:

If you look at this pot taper comparison graphic below you can see in the bottom left graph when the W taper is at 50% rotation it is at half the total volume range. In the top left graph the A taper has to be at roughly 75% rotation or so to have equal volume output.



Of course you can match their volumes by ear but now I know why.

[Steve Mavronis]

The other night I was Googl'ing and found an old 2004 write-up by Mike Spitzer, who used to work with Yngwie Malmsteen. He tells a more interesting and detailed story about modding the YJM308:

The YJM308 from DOD, like the 250 Reissue is a great Overdrive Pedal, but many people still prefer or wish they could get their hands on an old GRAY DOD 250. Most desire these over the yellows, re-issues and the newest YJM308 Yngwie version. However on EBAY the GRAY pedals go for as much as $300+ now. Of course the grey version is the one most often associated with Yngwie prior to the release of the 308. For my own personal use, I had a goal to both make a modern "Clone" and a "Mojo" exact clone of the GRAY pedal using the newest YJM308 as the basis. ANALOG MAN ...worked with me on this project and was so impressed, he plans to soon offer these mods to the public.

While the YJM308 was an excellent pedal, it used some modern opamps components and subsequent EQ tweaking to match the tone of the older 250 pedals as closely as possible while trying to reduce noise. Some people feel that while the YJM308 is excellent, it does not EXACTLY match the tone of the older grey pedals 100%. The consensus seems to be the 308 has less low end, slightly more treble, is a bit thinner and "feels" different response-wise. It sounds great, but is indeed slightly different. Many people love their 308 pedals, but would also still love to have a "grey" pedal in their collection for tonal variety. With these mods, components are physically removed and substituted to IDENTICALLY match the original specs of the grey DOD 250 pedals. No emulating here... the pedal is converted into a copy of a grey DOD... We used the original DOD factory schematics from the 1970s and three (3) grey DOD pedals for reference. Some of the modifications include:

Changing the stock 0.001uf input cap to 0.01uf improves low end and exactly matches original gray circuit design. Stock YJM308 has some low end roll off. A 25pf capaciter was added to the YJM308 circuit as an apparent "tweak" by DOD engineers to try and smooth the high end edginess of the 4558 chips to adjust them to sound like the older 741 circuits. The 4558 being an "improved low noise dual replacement for the old 741" has more hi-frequency response to be toned down. This small 25pf cap tweak is not needed with the change to a 1458 or 741 opamp, nor was it a part of the original grey circuit. A true purist will desire to clone the old Gray 250 by putting a single 741 opamp in this circuit and re-routing the pins in the existing dual opamp pin layout so it will work. This is not needed if the Dual 1458 Opamp from Texas Instruments is used since the MC1458 has IDENTICAL specs as both the original LM741CN and UA741CP, however a "mojo" mod will be available which is the ultimate in cloning the old grey pedals... it will put an old 741 single opamp into the slot. TI even admits in it's literature the MC1458 is actually just two UA741opamps on a single IC... thus all the specs like Max Voltage gain, slew rate, ramp, recovery, bias are identical to the old UA741. This is handy for use in this mod since the Dual 1458 and Dual 4558 share the same common 8 pin layout and make for an easy direct swap. Again a purist may desire the original 741 opamp installed instead of the 1458 (Dual 741) but we are unable to hear any difference since the 1458 is technically an authentic "Dual 741" opamp. The mod is a cleaner wiring job with the 1458 since the YJM308 board socket is soldered to use a dual chip and the old 741 was only a single ship. The "mojo" mod to a 741 chip requires some clipping, jumping and rerouting of pin assignments to make the 741 work in the dual 8 pin socket. By contrast as mentioned above, the 1458 is a direct swap. The overdrive circuit simply uses only 1/2 of the chip's dual 741 amps.

I compared this "Gray Mod" 308 to two (2) original Gray 250s I have - absolutely NO DIFFERENCE can be heard. Everything is the same... the better "tubey" feel and tone as compared to the slight transistory tone of the newer pedals. There is slightly more noise but heh.... everybody using these Overdrives with a maxxed out Marshall already know they need a Noise Suppressor pedal anyway. And of course the original vintage greys are a bit noisy!! The BOSS NS-2 is the suggested pedal for this purpose. The perfect tone match to the much-sought-after "magical" Gray makes sense. After these mods, you actually have a 99.99% authentic "new" GRAY DOD 250 with the identical cap and resistor values used in the old circuit, along with the "Dual 741" (1458) opamp with identical specs to the old 741 used in the originals.

Note: The new stock 4558 chips being used have several differences in terms of voltage gain, slew rates, etc as compared to the 741. So although it may be a new and quieter "replacement" that works great in many applications, you can hear a difference between a 741/1458 overdrive circuit design like a DOD 250, MXR+ and a 4558 design like the TS808/TS9, Guyatone OD-2, Nobels ODR-1. Keep your YJM308, it's great.... but if you have also wanted an old grey pedal in your arsenal but found the current $300+ EBAY prices a bit stiff, this mod now gives you that ability to own your own clone for less.

While I think the 741 and 1458 sound as identical as can be, the 4558 definitely does not. The 4558 in the YJM308 has more noticable treble present. The 1458 is a true 741 equivalent, with two in the same package.

[parkhead]

FWIW the Canadian Distributor is still sitting on a on a pile of these
and the have great pricing on them ...

go to your local dealer and have them make the call you will be pleasantly surprised,

of course you still have to source your own .01 cap and op amp

p

[CherokeeFury]

good thread...

could someone tell me about the dod 250"sound loft mod"

[Steve Mavronis]

FWIW the Canadian Distributor is still sitting on a on a pile of these
and the have great pricing on them ... go to your local dealer and have them make the call you will be pleasantly surprised

So what distributor would that be???

Here is a stompbox evolution comparision shot. These four pedals in my collection are like cousins directly related to each other, having the same basic circuit design. Left to right: 1980 MXR Distortion+ (DIY replica PCB repair), 1982 Ross R50 Distortion (replaced bad DC jack), 2006 DOD YJM308 Preamp Overdrive (gray spec mod), and my 2011 Neo-Classic 741 Overdrive clone (from scratch DIY) which is based on the 1979 gray DOD Overdrive Preamp 250.

[loud and dirty]

I didn't read every post on here, so forgive me if i say something that's been said...

If you use the DiMarzio pups that YJM uses the pedal doesn't really sound that bright when boosting an amp. The HS3 and YJM (HS4 now) don't have a ton of sparkle. i haven't tried the Duncans yet. The YJM308 can certainly stand some mods if you aren't using like YJM does, that's for sure. i haven't really felt the need to do anything to mine. Sometimes i pull the level down low and use it as an almost clean boost. It can really wake some strats up. i never cared for it with full size humbuckers unless they were real low output.

i do wish it wasn't so noisey though,

As far as YJM's settings... i have literally put my finger on YJM's pedal board.... He has several 308's and 250's on his board and all had the knobs in different places. The levels were super high on all of 'em though. The gain level was the main difference. He said for different "era's" of his tone. He also said some nights it just sounds better a certain way. The night i was looking, actually both times now, he also had a Tubescreamer.