Lovepedal - Dover Drive  [traced]

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Re: Lovepedal - Dover Drive

Postby ivan H » 01 Oct 2017, 01:14

That's great if one is looking to change the original effect into a high gain distortion (I already have high gain distortions), however I put this together because I wanted the original effect for some Reverend Billy G type tones which it can do quite well. A search on transistor gains for silicon fuzz face type circuits led me to info that the first transistor gain is best somewhere around 65% ~ 85% of the second transistor. Actual gains aren't so important (allegedly) so long as this ratio is kept. Apparently this gives the best interaction between the guitar & effect, allowing cleanup with the guitar's volume control, touch sensitivity etc. Also mentioned experimenting with input/output cap values along with the transistors to get tonal response desired. Cheers
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Re: Lovepedal - Dover Drive

Postby Manfred » 01 Oct 2017, 09:22

A search on transistor gains for silicon fuzz face type circuits led me to info that the first transistor gain is best somewhere around 65% ~ 85% of the second transistor.

I am interrest in this theme too and going to work on it.
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Re: Lovepedal - Dover Drive

Postby di-anno » 02 Oct 2017, 21:23

Manfred wrote:Thanks, sounds good!
I further step could be to hook in the blend circuity of the Lovepedal Silicon Fuzzmaster.
http://tagboardeffects.blogspot.de/2012/06/lovepedal-silicon-fuzzmaster.html



Thanks for reply, it's fairly clear that bassy/clarity of this pedal strongly depends on its input impedance and probably in your link there is the best solution to manipulate it. However I found in buffered version a better sound than the original (..for my ears and for my rig..) so i experienced in that way introducing a dual gang pot in buffer to control clarity/bass and volume pot responce. i still have some noise problem but promises good.

dov_buf_1.jpeg



I think that in front of fuzz face type pedal it would be very useful something like this:
http://www.stompbox.de/buffer_english.html

cheers
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Re: Lovepedal - Dover Drive

Postby ivan H » 03 Oct 2017, 06:52

Manfred wrote:
A search on transistor gains for silicon fuzz face type circuits led me to info that the first transistor gain is best somewhere around 65% ~ 85% of the second transistor.

I am interrest in this theme too and going to work on it.

Cool, I'd be interested in your results. I'll do the same when time allows. Cheers
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Re: Lovepedal - Dover Drive

Postby ivan H » 31 Oct 2017, 10:55

Ok, I know its been a while, been pretty busy but I have spent a little time tweaking. Went back to 209 hfe for Q1 & 271 hfe for Q2 (Q1 @ 77% of Q2). This gives the best performance & interaction with the guitar, just bass heavy. So, I lowered the value of the FF output cap by half to 0.047uf which did the trick. Still have the resistor in series with the gain pot at the moment. Cheers
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Re: Lovepedal - Dover Drive

Postby Kennc_dk » 05 Nov 2017, 09:32

I have measured key bias nodes on the Dover Drive that i traced the schematic from:
Battery measured to 9.43 volts.
On the IC :
pin 1,2,5,6 and 7 = 3.04 Volt
Pin 3 = 2.88 Volt ( hmm, I’ll recheck this one)
Pin 8 = 6.17 Volt
Pin 4 = 0 Volt
On PNPs :
Q1: 6.17 V, 5.89V and 4.85 V
Q2: 2.07 V, 4.85V and 5.49 V
I’ll measure HFE on both of them very soon.
Note to PNPs: gain is set to 1’oclock. Internal trimmer is Stock, as on the schematic.
Last edited by Kennc_dk on 05 Nov 2017, 09:57, edited 1 time in total.

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di-anno (05 Nov 2017, 20:53), Manfred (05 Nov 2017, 09:35)
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Re: Lovepedal - Dover Drive

Postby Kennc_dk » 05 Nov 2017, 09:55

Yes, the pedal i quite bassy, so i have added an external switchable low-cut a’ka ‘The fuzz face Eric Johnson mod’ on the output of the Dover drive. Adding the low-cut between fuzz stage and OD stage causes nasty biasshifts.
I use the low-cut mainly on solos that are not to take too much Sound space in the band. In a trio constellation i almost never use the low cut.
Yes, due to the High gain of this pedal and the PNPs (AM detectors!) at the input, the pedal i prone to Pick up radio signals, mobile phones ect.
Despite bassy’ness and radio moskow, I LOVE MY DOVER DRIVE PEDAL!
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Re: Lovepedal - Dover Drive

Postby ivan H » 06 Nov 2017, 10:36

Thanks heaps for the voltages Kennc_dc, I'll check through mine against them. I did a quick google search but haven't found anything on the Eric Johnson low cut mod yet, I'd be interested to know about. I'll look a bit further. I did look at the the axis fuzz mods, might try a couple of. Cheers
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Re: Lovepedal - Dover Drive

Postby Kennc_dk » 12 Nov 2017, 18:06

ivan H wrote: I did a quick google search but haven't found anything on the Eric Johnson low cut mod yet, I'd be interested to know about. I'll look a bit further. I did look at the the axis fuzz mods, might try a couple of. Cheers


on this www: https://www.electrosmash.com/fuzz-face its stated that:
"Eric Johnson seems to prefer a 100KΩ level resistor over the stock 500KΩ. Using a smaller resistor, the filter will cut more lows out (fc=160Hz) which will result in a brighter sound."
This makes sense regarding Erics solos, so I added the 160Hz LF/bass cut on the output of the Dover drive as I described previously. if your solo is to ride on the top of a crowed band, this preferably selectable -mod/option makes sense, both for the fuzz faces and the dover drive ;-)
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Re: Lovepedal - Dover Drive

Postby ivan H » 13 Nov 2017, 10:04

Kennc_dk wrote:
ivan H wrote: I did a quick google search but haven't found anything on the Eric Johnson low cut mod yet, I'd be interested to know about. I'll look a bit further. I did look at the the axis fuzz mods, might try a couple of. Cheers


on this www: https://www.electrosmash.com/fuzz-face its stated that:
"Eric Johnson seems to prefer a 100KΩ level resistor over the stock 500KΩ. Using a smaller resistor, the filter will cut more lows out (fc=160Hz) which will result in a brighter sound."
This makes sense regarding Erics solos, so I added the 160Hz LF/bass cut on the output of the Dover drive as I described previously. if your solo is to ride on the top of a crowed band, this preferably selectable -mod/option makes sense, both for the fuzz faces and the dover drive ;-)


This is exactly why I am experimenting to brighten it up. In a 3 piece setting it might do ok as is, but trying to use for leads in a 4 piece, well, you already know. Thanks heaps for the tip, greatly appreciated. Cheers
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