Jump to content
Allex

Human Gear Animato

Recommended Posts

Does the 22u not look right? It's actually the only capacitor I am not so certain about.

 

That cap messes only with the bass response of the first stage. (a higher value would give more bass to stage1)

 

I was just not really "impressed" with the tonestack, most of it's range seems like a weakish treble cut on the plot. It is not really Muffish. Maybe i should change the view a bit.

Share this post


Link to post
Share on other sites

Le tired, but got a PCB

 

https://drive.google.com/file/d/0B7Lx-E88bAtES0pKbDRVWXpYTTQ/view?usp=sharing - Converted to PDF. Added PCB's based off existing.

*There appears to be a resistor code missing next to R25 on the PCB's. The non-defined resistor is R24.

* Also, There are 2 C20's on the PCB. The one coming from DA3 is C11, not C20

Edited by Crowella

Share this post


Link to post
Share on other sites
If you could simulate it, that would be absolutely fantastic!

 

I think an AC128 would slot in there but not sure what to pair it with. I'm in a situation where I can't figure out what to use in place of both of them because they don't exist here or they cost obscene amounts ($10 each!)

 

If there are any parts that are impossible/more expensive to get there, I can donate those if you want.

Share this post


Link to post
Share on other sites
Would putting in the clean blend be very complicated?

Not really, just need to find a suitable circuit to mash in with it. :LOL:

 

Absolutely incredible great work:D

Thank you :)

 

If there are any parts that are impossible/more expensive to get there, I can donate those if you want.

That would be awesome. It's mainly the NTE102/NTE103 pair that I can't get here. The C2240 transistors are going to be subbed with a BC549 because they are a pretty close match. The main part of the tone, whether people like it or not, is the caps and resistor layout. Next would be the NTE pair and the diodes. :)

Share this post


Link to post
Share on other sites

That would be awesome. It's mainly the NTE102/NTE103 pair that I can't get here. The C2240 transistors are going to be subbed with a BC549 because they are a pretty close match. The main part of the tone, whether people like it or not, is the caps and resistor layout. Next would be the NTE pair and the diodes. :)

 

I'm sure I can source a couple of pairs :ninja: Was there a specific HFE they had to be or anything? There are a fair few floating around, but most don't have the HFE listed.

Share this post


Link to post
Share on other sites

I couldn't get any hFE readings. I did not want to take them off the board because they'll most definitely leak more.

 

I'm going to try bread boarding the circuit with a 2N3904/2N3906 combination, maybe tomorrow because I have a gig to play/rehearse today. Yes, they're silicon and maybe a higher hFE but I think it'll provide a clearer answer, considering everything is getting squashed by the BMP stages too.

Share this post


Link to post
Share on other sites

Alright, so that switch... what does it do?

 

What I thought it did when I saw the transistor pairing. It's an unusual octave up effect. The switch changes how smooth the octave effect is and this is probably why the only chance you have of really hearing what the switch does is when the tone is on full and even then, it's difficult. The octave effect is always on.

 

Treble much?

Share this post


Link to post
Share on other sites

Share this post


Link to post
Share on other sites
Alright, so that switch... what does it do?

 

What I thought it did when I saw the transistor pairing. It's an unusual octave up effect. The switch changes how smooth the octave effect is and this is probably why the only chance you have of really hearing what the switch does is when the tone is on full and even then, it's difficult. The octave effect is always on.

 

Treble much?

 

Wait, what? Is it like one of those things that only dogs can hear? or is it just really subtle?

 

Sent a donation btw

Share this post


Link to post
Share on other sites

Thanks James and Matthijs :D

 

Started breadboarding it today in the 10 minutes I had awake before work (need coffee). I could only find electrolytic caps for some of the capacitors so I may need to change the schematic slightly. All of them have electrolytics in the boards but I couldn't tell if they were polar or not.

Share this post


Link to post
Share on other sites

Failed breadboard attempt. I'm going to try putting the much easier to confirm stages like the BMP stuff onto Veroboard and work from there tomorrow. Still not that certain on the first stage.

 

EDIT: Few things fixed. Many things learned. Should work now.

https://drive.google.com/file/d/0B7Lx-E88bAtEblBSMU5GQUplOEE/view?usp=sharing

 

EDIT 2: Attempted again. Failed breadboard. I'm thinking human error this time. The veroboard idea is looking good. Might have to grab the veroboard parts tomorrow.

Edited by Crowella

Share this post


Link to post
Share on other sites

So the revision 1.08 is what I would say the circuit is, despite not having built it yet, I can't see there being any more errors or issues. I'm setting up a sim of the circuit using some software at uni (LTspice) right now. No idea how long that will take to get running for the whole thing.

 

Basically, I am guessing a little with the first stage, but it seems to be a germanium Sziklai paired Dallas Rangemaster circuit for treble boosting connected to a tweaked Big Muff Pi with an emitter follower/output buffer similar to a Tubescreamer's buffers.

 

The distortion pot sets the "sustain" for the BMP and simultaneously the volume for the Rangemaster type circuit. This is why you get no output when the dist is down and absolutely insane amounts of gain when it's turned up. Only pedal I've owned that can feedback so easily. It'd be quite interesting to see someone split up both circuits with two different pots so you can adjust them individually.

 

I suck at putting circuits on a breadboard apparently but I'd prefer to be using the boards here at uni rather than my really tiny one at home which when you're putting more than five connections into a node, can really make life difficult.

Share this post


Link to post
Share on other sites

So it's basically a treble booster going into a buffered Big Muff? That's quite surprising!

You know the octave effect on it? Is it up or down?

Share this post


Link to post
Share on other sites

Octave up. It kind of just adds a small amount of octave to the signal, nothing too menacing.

 

Just tested the switch. 10dB level drop when engaged. Did DPTP want to confirm that with the new first stage? It could well be the case, just might not be noticeable once you've pushed it through a BMP.

 

Second stage ("sustain"/BMP) acts as a low pass filter so now it's starting to look a bit more friendly. With the switch it boosts around 160Hz to about 12KHz with a peak around 14dB at 1KHz, when the dist pot is at 10k/90k, so 90%

 

EDIT: Using a Tone Stack Calculator, you have a very "boring" tone control setup. It boosts the treble quite a bit in that but overall with the caps selected in the BMP itself, it really doesn't do too much. What I had done in LTspice matches what DPTP got.

 

Basically, what happens is the front of the circuit absolutely nerfs the bass of the BMP otherwise you'd end up with a BMP that's effectively a treble cut. This way, it makes it more of a band pass circuit. The capacitors in the BMP are chosen to let as much bass through as possible. This balancing act kind of works pretty well but you still end up with a more treble based circuit. Intriguing.

 

Also, may have the tone wired the wrong way in the schematic.

 

EDIT: The tone controls the "Q" of the pedal. It goes from 600Hz when off and goes through to about 1kHz when all the way up. Frequencies after 5KHz are reduced when the tone is off, when the tone is on, frequencies after 10KHz are cut off, so you end up with those airy frequencies with tone. There isn't much addition to the bass between amounts.

 

ANOTHER EDIT: I put some of the frequency plots in the imgur folder, trying both a standard NPN transistor (no octave feedback in that mode I would assume) and the pairing.

Edited by Crowella

Share this post


Link to post
Share on other sites

In my sims it seemed like the switch only lowered the input impedance but did nothing else.

(in my eyes the switch parallels R16 with R17 and R18 with R19 in both cases halving the original resistance)

Share this post


Link to post
Share on other sites
I fixed the transistors up since your sim if you wanted to try again?

 

I just tried the new (ver 1.08) input stage and it doesn't work according to LTSpice.

 

Is this the right circuit for stage 1?

new1.thumb.jpg.4c92174e94911e60c97ea0a71c120a30.jpg

Share this post


Link to post
Share on other sites

Hmm, strange. I got it working right away. Strange circuit but the potentiometer does what it says on the tin.

 

(aware the pulldown resistor value is wrong)

 

http://i.imgur.com/9FDAuzH.png

 

Playing with the switch does virtually nothing to the shape of the 1KHz signal.

Edited by Crowella

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...