Lovepedal - Dover Drive  [traced]

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Kennc_dk
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Post by Kennc_dk »

I have traced the 'Dover Drive' pedal from Lovepedal.

Seems like that hints from this forum were right: It's a blend of a fuzz face (dragon fuzz) and a zen drive.

Please let me know if you find mistakes or have observed differencies in component values from pedal to pedal.
Dover Drive Schematic Traced
Dover Drive Schematic Traced

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mirosol
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Post by mirosol »

Here's a stripboard layout... Currently unverified.
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Lovepedal-Dover-Drive.png
http://tagboardeffects.blogspot.com/
http://mirosol.kapsi.fi/
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zzztop
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Post by zzztop »

Thank you guys!
I wonder a cut under the D3 is needed.

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mirosol
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Post by mirosol »

Yup. That cut is missing from my original file. Sorry about that. Fixed the layout....
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Lovepedal-Dover-Drive.png
http://tagboardeffects.blogspot.com/
http://mirosol.kapsi.fi/
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AuditoryDriving
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Post by AuditoryDriving »

Thanks so much guys!!

Maybe the 81k/120k voltage divider should be replaced with a 200k trimpot? Are those fixed resistors in the original?

Thanks again!!!

Kennc_dk
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Post by Kennc_dk »

yes, the two resistors are discrete.
They are highlighted on the picture attached, they are at the back left.
The reason why I think* that they are 'tweaked at the factory' is because they are very precise values and completely different values from the rest.
*That divider ratio solution, using two unique resistors values is expensive, from a production point of view.

The two resistors are used to match the clipping point of the 'zen' overdrive with output amplitude of the 'fuzz face' ;-)
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Dover Drive - picture 1.png

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AuditoryDriving
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Post by AuditoryDriving »

Kennc_dk wrote:yes, the two resistors are discrete.
They are highlighted on the picture attached, they are at the back left.
The reason why I think* that they are 'tweaked at the factory' is because they are very precise values and completely different values from the rest.
*That divider ratio solution, using two unique resistors values is expensive, from a production point of view.

The two resistors are used to match the clipping point of the 'zen' overdrive with output amplitude of the 'fuzz face' ;-)

Makes sense!! Many thanks, Kennc_dk!!

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Post by bugg »

Got two PCB layouts worked up, getting ready to order a small batch. :thumbsup

On one I've substituted the 81.2K and 121K resistors with a series pair (75K + 6.2K, and 120K + 1K respectively) to make parts sourcing a bit easier.
On the other I've replaced them with a 25-turn trim pot, this should allow fine tuning.

Image

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mirosol
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Post by mirosol »

Couple slight errors on the previous stripboard layout. This should work.
Attachments
Lovepedal-Dover-Drive.png
http://tagboardeffects.blogspot.com/
http://mirosol.kapsi.fi/
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mirosol
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Post by mirosol »

Damn. Had the gain labels still in reverse. I seem to be slightly off my game... Anyway. One of our blog builders built this and apparently sounds very close to the original. So consider this verified.
(Also, if one of the mods would be so kind and remove the crap files from above - thanks!)
Attachments
Lovepedal-Dover-Drive.png
http://tagboardeffects.blogspot.com/
http://mirosol.kapsi.fi/
"No such thing as innocence" -Iron Chic

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Post by ivan H »

Ok, so I built one of these & it does work, but I have problems. With the gain set low it functions as it should, but turning the gain past say 8-30 or 9 results in it oscillating a little & crapping out. I have no solder whiskers bridging tracks & am pretty sure correct resistor values have been used throughout (I'll go over & check), so I'm thinking to maybe try adjusting the 120k/82k voltage divider. Would this maybe help?? I do have another couple of 2N3906's I could try in it. Any input appreciated. Cheers

artguitar
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Post by artguitar »

Anche io stesso problema però a guadagno ore 2. Lo risolto mettendo un trimmer da 50k al posto della resistenza 33k collegata ai transistor. Prova con questa regolazione. Ciao

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Post by ivan H »

Ok, my 2nd language skills are abysmal, no, non existent (& I'm computer illiterate so don't know how to get it translated), but I think I've got the gist of it, replace the 33k resistor at the collector/base junctions of the two transistors with a 50k trimmer to dial it in, at least, Im assuming you mean that 33k resistor, please correct me if Im wrong. Very much appreciated, thank you for the quick reply. Not sure on whether you have experienced the same or not, but thank you. Cheers

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Post by artguitar »

you just got it right

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Post by ivan H »

Thank you again. I'm off to get a trimpot now, I'm sure I'll have a resistor of suitable value once dialled in. It does sound good with the gain down low, I'm sure it'll be great when working properly. I used a Russian D9B detector diode for the germanium, measured a heap of all types I had (no 1N34A's) & used the one with the lowest measured drop. Again, you help is greatly appreciated, I'll let you know the outcome. Cheers

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Post by di-anno »

thanks for sharing, i have a doubt on 330 ohm resistor , with it the whole circuit runs at 6,7volt.. too low for me. Can you measure the voltage at pin 8 of the 5532 ic? about the voltage divider i see in posted photo the color codes grey-red-black-red-brown and brown-red-black-orange-brown that means 82k and 120k with 1% tolerance.

boukman
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Post by boukman »

Hi!
I have built it from one of Buggs` pcbs and it works ok but i have too much drive i think.
With the guitar volume on 10 its quite fuzzy losing definition on the bass strings.If i lower the volume it clears up.The trimmer doesn`t really lower the gain all that much.
The other thing is that with the volume of the guitar off it hums or motorboats.Someone said it is an impedance thing and putting a Klon buffer clears it.
What could i do?Do you think a 50k trimmer on the above mentioned 33k resistor on the 2n3906 could lower the gain a bit?
Thanks!!

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Post by ozzy666 »

ivan H wrote:Thank you again. I'm off to get a trimpot now, I'm sure I'll have a resistor of suitable value once dialled in. It does sound good with the gain down low, I'm sure it'll be great when working properly. I used a Russian D9B detector diode for the germanium, measured a heap of all types I had (no 1N34A's) & used the one with the lowest measured drop. Again, you help is greatly appreciated, I'll let you know the outcome. Cheers
I am experiencing the same issue. Did you get it solved yet? Thanks so much!

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Post by ozzy666 »

ozzy666 wrote:
ivan H wrote:Thank you again. I'm off to get a trimpot now, I'm sure I'll have a resistor of suitable value once dialled in. It does sound good with the gain down low, I'm sure it'll be great when working properly. I used a Russian D9B detector diode for the germanium, measured a heap of all types I had (no 1N34A's) & used the one with the lowest measured drop. Again, you help is greatly appreciated, I'll let you know the outcome. Cheers
I am experiencing the same issue. Did you get it solved yet? Thanks so much!
ok, I did that trick with replacing the 33k rezistor with 50k pot, but it had no effect at all. It still squeals when the gain pot is about half way up.
I also tried replace the Q1 and Q2 for 2n3906s with a different hfE. And it appears that when I use the hfE=211 for Q1 and hfE=360 for Q2, it start squealing only when the gain pot is about maxed.

Any help or advice will be greatly apreciated.

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Post by di-anno »

i built the pedal and i had same oscillations issue with gain maxed and/or guitar volume closed. To avoid this i put a 100 Ohm resistor in series at pin 3 of gain pot. So it never goes to zero. i also used hfeQ1<hfeQ2. With this mod I no longer have any noise. However,now, with guitar volume closed randomly the circuit picks up radio frequencies..

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