King Midas Drive (Keeley El Rey Dorado) - Update

I didn't want to "out" you hahah.
I did put an LED in D3 & it sounds similar in Gain & slightly less volume but compressed a bit more than Hi mode
Do you find it gets too much Gain & Bloom by 10 O'clock if 7.00 O'clock is minimum/Off on the Gain pot?
 
I did put an LED in D3 & it sounds similar in Gain & slightly less volume but compressed a bit more than Hi mode
Do you find it gets too much Gain & Bloom by 10 O'clock if 7.00 O'clock is minimum/Off on the Gain pot?
I find it bloomy at around 8:30. And that's with the tone control maxed. Matching it to a brighter guitar makes a difference. Doesn't sound very good on some of my guitars.
 
I find it bloomy at around 8:30. And that's with the tone control maxed. Matching it to a brighter guitar makes a difference. Doesn't sound very good on some of my guitars.
I'm using a Telecaster, forbid what it sounds like with a Les Paul!
 
I find it bloomy at around 8:30. And that's with the tone control maxed. Matching it to a brighter guitar makes a difference. Doesn't sound very good on some of my guitars.
The best sounds I'm getting is on the LED side of the clipper, gain around 11:30, vol around 9:30, tone at 3:30 on the bridge pickup of one of my P90 guitars. Pretty killer sound. This might be a "one trick pony" pedal but it sounds good with this combination.
 
The best sounds I'm getting is on the LED side of the clipper, gain around 11:30, vol around 9:30, tone at 3:30 on the bridge pickup of one of my P90 guitars. Pretty killer sound. This might be a "one trick pony" pedal but it sounds good with this combination.
The PedalPCB Unchained would have been a better option I just Found I think!?
It's being referred to as Brown Sounding which means Bridge Only One Trick Pony!!!
 
The PedalPCB Unchained would have been a better option I just Found I think!?
It's being referred to as Brown Sounding which means Bridge Only One Trick Pony!!!
Well EVH had a lot of tricks up his sleeve with that one bridge pickup!

I actually have a BSIAB2 on the bench I've been trying to get to for weeks now.
 
Well EVH had a lot of tricks up his sleeve with that one bridge pickup!

I actually have a BSIAB2 on the bench I've been trying to get to for weeks now.
Chuck suggested changing R6 - 4K7 to 10K so the Diodes are not getting over saturated.
I went and put a temporary B25K pot and it is a big improvement with a happy medium of around 12K.
As I have already built it , I will use a Trimmer in R6 set to 10 - 12K!
The Tone Control becomes more Responsive also!
It is Designed by Fault to work in the Bridge position as when in Neck position , the Bass Response takes over Big time.
This Helps to get to use the Neck pickup also!

Thanks Chuck D. Bones
 
Chuck suggested changing R6 - 4K7 to 10K so the Diodes are not getting over saturated.
I went and put a temporary B25K pot and it is a big improvement with a happy medium of around 12K.
As I have already built it , I will use a Trimmer in R6 set to 10 - 12K!
The Tone Control becomes more Responsive also!
It is Designed by Fault to work in the Bridge position as when in Neck position , the Bass Response takes over Big time.
This Helps to get to use the Neck pickup also!

Thanks Chuck D. Bones
Awesome, I have some of those multi-turn trimmers stand up that should I could probably pop in without too much danger of murdering the board. I'll give that a shot. R6 comes after the clipping circuit, so it's actually "throttling" the diode saturation?
 
Awesome, I have some of those multi-turn trimmers stand up that should I could probably pop in without too much danger of murdering the board. I'll give that a shot. R6 comes after the clipping circuit, so it's actually "throttling" the diode saturation?
After taking a Break & Revisiting, It works at 10K but it sacrifices the Volume (Headroom of the pedal), so you have to increase the Gain to get the Volume back????
I would settle for for around 7.5K, it's really a One Trick Pony that your other pedals can do without the Bloatiness, I'm not a BSIAB guy at all!
I'm not interested in the Unchained (Panama) either.
Pete Thorn did a brief demo & 90% is bridge pickup!
 
Last edited:
After taking a Break & Revisiting, It works at 10K but it sacrifices the Volume (Headroom of the pedal), so you have to increase the Gain to get the Volume back????
I would settle for for around 7.5K, it's really a One Trick Pony that your other pedals can do without the Bloatiness, I'm not a BSIAB guy at all!
Hmmm interesting, the pedal doesn't have a ton of volume or headroom to begin with.

Actually I just built another dirt pedal couple days ago that is even more problematic but in the other direction. Too bright and thin. But that's for another thread. I'll post a built report.
 
Update: Ok, second mod for today. I was chatting with @music6000 offline about this pedal too. Or maybe it was online? I'm forgetting hah.

Following @Chuck D. Bones's recommendation I also replaced R6 (4k7) with a 20k trimpot. I set it at 12k when I put it in and I think I'm going to leave it there.

There's definitely some improvement on the BAT46 side of the toggle, a bit more usable and less overly compressed. But the volume discrepancy is still pretty profound. But I can dial up some nice sounds on both sides of the clipping toggle now.
Best of all, I could do the mod without taking the board out, WOOT!

Very Marshally, I actually think it sounds way more like JCM800 territory than Plexi. The bass heaviness is still there but I think that's probably true of most MIAB's. The tone control is only a treble cut, it doesn't dial out the bass.

But it's definitely a worthwhile mod. Thanks @Chuck D. Bones and @music6000!

IMG_3475.JPG
 
Update: Ok, second mod for today. I was chatting with @music6000 offline about this pedal too. Or maybe it was online? I'm forgetting hah.

Following @Chuck D. Bones's recommendation I also replaced R6 (4k7) with a 20k trimpot. I set it at 12k when I put it in and I think I'm going to leave it there.

There's definitely some improvement on the BAT46 side of the toggle, a bit more usable and less overly compressed. But the volume discrepancy is still pretty profound. But I can dial up some nice sounds on both sides of the clipping toggle now.
Best of all, I could do the mod without taking the board out, WOOT!

Very Marshally, I actually think it sounds way more like JCM800 territory than Plexi. The bass heaviness is still there but I think that's probably true of most MIAB's. The tone control is only a treble cut, it doesn't dial out the bass.

But it's definitely a worthwhile mod. Thanks @Chuck D. Bones and @music6000!

View attachment 31862

I know this thread is a few months old but I wanted to comment as I'm currently experimenting with that circuit on the Protoboard (have the PCB on order but I like to lock in my "mods" before I commit)

As you may or may not know, the El Rey Dorado is a Carl Martin Plexitone clone (the small box version). I love the Plexitone circuit but it does have overbearing bass which was my motivation for building my own.
The Panama (Unchained) fixed this by adding a variable high pass filter at the beginning of the circuit (the Damping control), an overly complex solution when you can just swap a cap... IMHO

The Keeley version already does cut more bass than the Plexitone, with a 100n input cap instead of 220n. I feel that's not enough, but I still wouldn't bother with the Panama version unless for some reason you really want flexibility in tightness.
What you can do... just replace C3 with a 68nF or even 47nF. This will rolloff bass frequencies pre-distortion so that the distortion cleans up (makes it more JMP than JTM).

As for the change in volume when changing mode, there's nothing that can be done really, you're switching from diodes that clips at 2V to .2V. I don't find that switch useful (and may actually omit it and jumper the "High" position), to me the LEDs in there are integral part to the Plexitone sound, but maybe Mr Keeley wanted to ensure it wasn't a direct clone by adding something. Going from LEDs to BATs is such an insane jump, plain old Silicon would have made more sense, but I guess some people prefer the clipping nature of BATs.

If the plan is to be able to switch between both easily, then that's not gonna work, it totally changes the gain structure of the pedal. For this to work, one would have to use a DPDT switch and use it to kick in a higher R9 value in "Low" mode. Obviously this wouldn't work with the current PCB.

For the sake of discussion, another difference between the Keeley and original Carl Martin is the Keeley uses a smaller tone cap (39n vs 68n) with a higher value tone pot (B10 instead of B5). I've experimented with the value there and I do prefer the 39n. One other issue I had with the Plexitone is it was a bit lacking in mids through some amps, the smaller cap there moves the rolloff frequency upwards, letting more mids through. Using a larger value pot means it gets darker in the lower range, but in practice I prefer it because now it sounds great at noon while the Plexitone I had the tone always turned down (the Plexitone also uses smaller C2, C5 and C9 caps, at 25p instead of 120p... I changed C9 to 470pF!)

Another change is R3, where the Plexitone uses a 47R which increases the gain range ten-fold! The Plexitone has too much gain as it is (they even released a low gain variant, which sub the 1M pot for a 100k). The 470R sounds good IMHO!
 
Back
Top