Subdecay - Liquid Sunshine  [traced]

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Brian M
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Post by Brian M »

here is the new link http://www.subdecay.com/images/schemlsv2.gif

Thanks to just1more for emailing me the file, and saving me a bit of time.

Perhaps one of the mods could edit the original post people do not have to dig through the thread to find it.

Brian

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Post by Greg »

Brian M wrote:here is the new link http://www.subdecay.com/images/schemlsv2.gif

Thanks to just1more for emailing me the file, and saving me a bit of time.

Perhaps one of the mods could edit the original post people do not have to dig through the thread to find it.

Brian
Done...

Thanks Brian.
culturejam wrote: We are equal opportunity exposure artists.

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Post by Siriustar »

Say, Brian, any chance at being one of those few select peeps you send those prototypes to? :lol:

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Post by kbibs »

Brian,
Thanks for posting the schematic! that was very generous.

All,
I had a question on the output low pass filter and output impedance. The output resistor of 100k combined with the 0.0022uf cap gives a low pass break frequency of 723 Hz which seems very low. It also means that the min output impedance would be 100k (right?) which seems high to me. Is this correct? I'm thinking of building this as it sounds very good but I was just surprised at this value of output resistance.

Thanks,
Ken

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Post by Brian M »

kbibs wrote:Brian,
Thanks for posting the schematic! that was very generous.

All,
I had a question on the output low pass filter and output impedance. The output resistor of 100k combined with the 0.0022uf cap gives a low pass break frequency of 723 Hz which seems very low. It also means that the min output impedance would be 100k (right?) which seems high to me. Is this correct? I'm thinking of building this as it sounds very good but I was just surprised at this value of output resistance.

Thanks,
Ken
I don't have all the math in front of me right now, but the output LPF value you have looks right.

If you look at the whole schematic most of the boost is to the mid range and high end.

the .01 cap and 100k drive pot form a HPF ~ 150hz or so. The low end is not getting a full boost. On the first gain stage (2nd fet) the .22uf cap boosts higher frequencies. To be honest I really have never known how to calculate this correctly, since the the impedance to that cap is going to vary as the signal swings through it's range. So I have always used a hack that seems to be accurate enough. (ignoring the pot, and just assuming this knob is turned all the way up) I basically take the parallel resistance of the drain and source resistors, and the cap value and do the math as any other passive filter. (trim pots usually bias around 20 to 25K) I know this is not completely accurate, but for cascaded gain stages like this i usually trust my ear more than a specific frequency goal. I dont recall the exact value but i think it is also around 150hz, though it may be a bit lower.

So yes, the HPF on the output is set fairly low, but the higher frequencies receive much more of a boost than the low end. The LPF kind of smooths everything out. It's probably even lower than you calculated because of the output impedance of the 3rd gain stage.

The output impedance of the pedal is relatively high. I have tried using a buffer on the end of the circuit, but it doesn't sound as good to me. I tried using a smaller pot, smaller resistor, and larger caps to get close to the LPF and HPF on the output, but it sounds pretty nasty. I suppose the LPF cap could be loading down the last gain stage to an extent with the lower impedance values.

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Post by kbibs »

Thanks for the reply! ... I'm looking forward to this one.

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Post by azrael »

Does anyone still have this schematic? I just heard about this pedal called the Buster Jangle that was rather rare, using the Liquid Sunshine and Super Chili Picoso designs. So I was wondering how it good it sounds...and I have the minibooster part for the Chili Picoso, but no Sunshine.
Any help? :)

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Post by Mich P »

here it is :
Mich P.
SUBDECAY Liquid Sunshine.gif
SUBDECAY Liquid Sunshine.gif (10.1 KiB) Viewed 4411 times

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Post by Brian M »

azrael wrote:Does anyone still have this schematic? I just heard about this pedal called the Buster Jangle that was rather rare, using the Liquid Sunshine and Super Chili Picoso designs. So I was wondering how it good it sounds...and I have the minibooster part for the Chili Picoso, but no Sunshine.
Any help? :)

That's very strange. I have received a few calls and emails over the last couple weeks about the buster jangle. It was a joint venture between subdecay and catalinbread. There were 23 made (one of which I own)
In the end Nic and I decided to kill it, because the logistics of splitting the work was more costly than it was worth.

Before a couple weeks ago no one had asked us about that pedal for a couple years. Someone called yesterday asking us to build them one. I told them they'd probably be better off to find an SCP and LS second hand and that would be way cheaper than it would be for us to make a one off. It's also not really a subdecay pedal. it's a subdecay/catalinbread pedal, so I wouldn't feel right trying to do one on our own.

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Post by azrael »

Haha, someone on another forum recently got...#19, ithink it was? Anyway, he adores it, and there have been a couple of people who were quite tank with the clips of it. I wouldn't be surprised if one of them was your mystery caller. :)

The demo Burgerman666 does is quite nice, you and Nick made something pretty sweet here. :D

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Post by RnFR »

probably due to the TGP hype machine. which is first in the chain?
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Post by Brian M »

RnFR wrote:probably due to the TGP hype machine. which is first in the chain?
I haven't seen much on TGP about it. Apparently someone found one and posted on Jemsite. I just read that thread. Semi-entertaining.

it's boost>overdrive.

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Post by fuzzg0d »

This is my first post here after lurking for a while. I thought I'd resurrect this thread briefly.

I just built a liquid sunshine (version 2) with 2N5458s and it's great. A nice mix between a booster and an overdrive. It doesn't produce a lot of overdrive itself, so if it's running into a very clean amp it basically a booster. I think it sounds best into an amp that already has some preamp drive going. Does a good 'Keef' sound then :). It's quiet too.

I breadboarded it before building it point-to-point, and I used 100k trimmers on the breadboard to bias the jfets. I noticed that with the 2N5458s, it doesn't seem to be particularly sensitive to the bias. Once the bias resistance got above a minimal level, it worked and the amount of drive, the volume and the tone didn't change noticeably after that point when turning up the trimmers. In the final version, I replaced both of the trimmers with 47k resistors.

I also used external switches for the bass and treble cut/boost options that are internal on the original. I think they're really useful to have on the outside of the pedal and they're all voiced nicely.

I wondered if anyone has tried the new 'version 3' Liquid Sunshine or knows anything about the changes to the circuit that give it more gain. The YouTube demo sounds great. Anyone got one yet?

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Post by sonicmojo »

fuzzg0d wrote:I replaced both of the trimmers with 47k
I had some spare 2n5457s laying around so I breadboarded the circuit also. Funny, but without seeing your post first I ended on the same 47k values in those spots. What drain voltages were you at? Mine were both around 5.5.

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Post by fuzzg0d »

sonicmojo wrote:
fuzzg0d wrote:I replaced both of the trimmers with 47k
I had some spare 2n5457s laying around so I breadboarded the circuit also. Funny, but without seeing your post first I ended on the same 47k values in those spots. What drain voltages were you at? Mine were both around 5.5.
I didn't measure them, sorry! Just experimented by ear with some different settings on the trimmers and 47k seemed to be solidly within the range that worked for both of them. I wonder whether the original jfets (MPF102) were just more finicky than 5457/5458s.

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Post by sonicmojo »

No problem, ears are best! I had about six 2n5457s to choose from and I will say that they all seem to be slightly different voltages when swapped. I haven't done too much with tuning FETs but this was a good exercise. Now to scrap the breadboard and try something else.....

My thanks goes to Brian M from Subdecay willing to share his knowledge. This thread made me want to pursue learning about FET tuning.

I have a little mid-70s Silverface Champ that I once modded to a Tweed and then put it back. This circuit makes it sound like before when I had modded it to the Tweed which had higher gain and broke up earlier. It also sounds really good through my '68 Twin Reverb which coincidentally is the same amp from the older LS video on the Subdecay website, perhaps they have the drip edge Blackface version like I do. I may try to record a clip before I undo the breadboard but I realize now that I need to first build an effect loop box so I can easily A/B the breadboard.

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Post by Quietus »

hi sonicmojo, may i ask where can one acquire those wires,the ones with the black "thingy" at each end? i've been looking for them for quite some time already. do they have specific names for me to go to my local hardware shop to ask/make an enquiry? sorry, noob here. i tried describing to the shop people that i'm looking for a wire with a black "thingy" at each end, but it seems like they haven't got a clue of what i'm looking for and only direct me to the normal wires. i'm stumped. :oops: is it a diy thing? if so, how is it done? thanks in advance.

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Post by coldcraft »

Quietus wrote:hi sonicmojo, may i ask where can one acquire those wires,the ones with the black "thingy" at each end? i've been looking for them for quite some time already. do they have specific names for me to go to my local hardware shop to ask/make an enquiry? sorry, noob here. i tried describing to the shop people that i'm looking for a wire with a black "thingy" at each end, but it seems like they haven't got a clue of what i'm looking for and only direct me to the normal wires. i'm stumped. :oops: is it a diy thing? if so, how is it done? thanks in advance.

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Brian M
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Post by Brian M »

fuzzg0d wrote: I wondered if anyone has tried the new 'version 3' Liquid Sunshine or knows anything about the changes to the circuit that give it more gain. The YouTube demo sounds great. Anyone got one yet?
The new version is quite different. Still jfet based, but it has three gain stages. They are biased differently. One of the gain stages is also used to implement a faux active tone control.
It is still fairly simple and the new one does not require trimmers. I'm sure some will say "ah-ha... mu-amp." Not on this one. a single jfet for each stage, and a fourth to buffer the output.

The MKiii uses J201's. Since most through hole jfets have been discontinued I decided we needed to convert everything to a single component until we can convert everything to SMT. The J201 works well as an amplifier and a switch, so it was the logical choice. There's also still a lot of them out there. :D

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Post by roseblood11 »

schematic would be interesting!

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