Nurse Quacky - New PCB and Build Report

[spudulike]

The Nurse Quacky is a build Ive wanted to complete for ages, but was wary because of the reports of difficulties with ICs etc. So I finally bit the bullet and dived in.

PCB Layout.




I cant take much credit for it - I wanted a 1590B fit but the perf & other pcb's didnt fit well. So I took the perf layout, futzed it around a bit and got it to fit. Pot values are at //www.home-wrecker.com - I left em off so you have to visit the site  :wink:

Build Report

Firstly I couldnt get the specified ICs, so I started with an LM1558 which is a tighter spec 1458 and swapped the ICs till I liked it.

LM1558 - Noisy background to the sweep. Quack sounds a bit stilted, and poor on bassier strings.
LM358 - As specified at home-wrecker. Much better than the 1558 but there's a "zing" to the decay of upper-register notes.
RC4558 - No quack at all.
TL072 - No quack at all.
TL062 - Fairly weak quack and the "q" (if thats right) is too wide.
LF353 - Rubbish. Absolute rubbish. Farts a lot.
OPA2134PA - Surprisingly poor. Not a lot of depth to the quack, poor sweep.
NE5532 - Bingo. Nice depth and width, responds well to picking dynamics and the start of the quack was better defined. Best of the lot, Its staying.

Next I tried some other trannies.

2N3904 - crap, utter crap. 3 different manufacturers, 5 of each, all rubbish. Lots of volume drop.
BC337 - Marginally better, but again lots of variance.
2N5088/9 - Lots of hiss, and a wierd warbling as the note died.
BC109C - See above.
BC549B - Winner. Compliments the NE5532 perfectly. No noise, depth and sweep improved. Tried 5, all consistent results.

I tried a few different LEDs - the only type that worked properly were bog-standard 3mm red, dont know about matching but using different "makes" was subtle. Best use 2 the same. Poor with 5mm, nearly dead with green and yellow.

Bottom Line
I tried all ICs with all trannies and the only combo that I (and another guitarist) liked was the NE5532 and BC549B for consistency and the best sound to my ears. This quack sounds close to a Mutron at times. Sound clips to follow if I can get this £$%$%^& software to work  :oops:

This is now a definite keeper and will be boxed up very soon. Trouble is I have to make 3 now, and one of them has to be for bass ...

[Mark Hammer]

Onlookers please note.  This is DIY at its finest.

Person takes an available design, comes up with his own PCB layout, POSTS it for others to use, and systematically works his way through a broad range of possible components to arrive at optimal choices.

Nice work.

For bass, swap the 4n7 filter caps for 10n or possible 12n-15n.
If a little more resonance makes the bass stick out a little better, increase the 470k feedback resistor in the filter stage for 560k or even 680k.  This will increase output level so you may want to tack an output level pot on the end.

[H4T]

Holy smokes, spudulike, you are my hero, haha. I am building the Nurse Quacky too, as my second pedal, and I was one day away from transferring a different PCB layout! Your layout looks a whole lot better, seems much more effecient than the one I had, so I will probably use it.

I can't tell you enough how much this helps me out, spud. Very glad to know exactly which combination will work well, and now I'm even more excited to build this, lol.

I bought the recommended LM358 IC from Small Bear, along with a 2N3904 transistor, and I will give them a shot and post my results here. If they don't turn out so well, I will go for what you recommended.

Again, thanks a ton for this, its a huge and totally unexpected help for me!

[petemoore]

Excellent rundown of ya'lls interesting NQ tests and results, did you have one player and one tweeker focusing on the NQ?
 Lots of differences in sweep speed and range when subsituting transistors in the NQ, I kind of liked for a while a high gain Q in the sweep Q socket, wierd and seriously wacky.
 I'll have to dig mine out now [no comparison so no pics :roll: ], and try some of the recommended actives, maybe a different LED or three.
 The circuit takes some tweeking and dialing for best quack setup, thank you for the excellent contribution !!

[spudulike]

Thanks for the comments (and praise from Mark Hammer - wow, Ive arrived  :oops: ).

I hope the report/opinions are helpful - Pete, there were 3 of us - one playing, one tweaking, one listening (and then swap around). If anyone wants to host the pcb layout feel free, no IP or copyright issues. But the credit goes to the guys at //www.runoffgroove.com and of course Mark H.

BTW the gear used was - Custom Fender Strat (ash/maple/Bareknuckle pups), LP Standard (stock), Heritage 335 (Barden pups), Vox AC30 TB, Fender Twin, Peavey Classic 50. Not all mine I hasten to add.

[petemoore]

Everytime I strike one then the other string [to get low and high freq output from the guitar for tweeking 'feedback' I can hear], on the hung guitar, I wish I had a notebanger or autonotebanger to do that.
 To properly tweek and test a circuit, the guitar must be played through it many different ways, this often means hanging the guitar on me while I bend to do the tweeking.
 I end up taking the box upstairs to the studio room with the big amp in it, testing the pedal while dialing knobs, then returning it to the 'lab' amp where the bench is in the basement for further refinements.
 This works, but two or three sets of opinions and viewpoints would be cool.

[Paul Perry (Frostwave)]

To properly tweek and test a circuit, the guitar must be played through it many different ways, this often means hanging the guitar on me while I bend to do the tweeking.

There's an easier way, if you make a CD of test twangs!

[Gabriel Simoes]

I Think I'm facing the same problem with my bassballs clone .... so maybe I should give a shot with ne5532 ..... thanks for all this info !

[formerMember1]

yeah nice job

why did you use some carbon film and some metal film resistors?
benefit to this?  I think you probably just happen to have those values and used whatever compostion they were, right?

[spudulike]

I think you probably just happen to have those values and used whatever compostion they were, right?

Yup  :wink:

Just etched the pcbs for the new ones and ordered all metal film for them.
Also rejigged the pcb to include a resonance trimpot as per Mark's suggstion.

[markr04]

Thanks, spud. You rule, btw.

[spudulike]

One (final ?) addition to the build report.

I got some LM358's from an extremely generous forum member (thanks Leon ) and tried them last night. I'll keep the NE5532 thanks  :wink:

[Mark Hammer]

How useful did you find the addition of the resonance/gain adjustment?

[bancika]

Hi,
I'm making Nursie according to your layour and I'd like to try IC and tranny you suggested. In local store thay have BC549 without B, is that the same tranny?
Tnx

[spudulike]

The letters indicate gain/hfe groups (A=low, B=medium C=high). AFAIK the absence of a letter means it hasnt been tested for hfe range. Should be ok.

I would try a bunch of different transistors as it really dows have a big say in how the cct sounds.

[bancika]

I just got it and it's C (not mentioned in catalogue), will it make much difference? should I use that one or wait to order from another e-shop?
Tnx

[reeko81]

Need some help...i've followed this pcb board to build my nurse quack, now i've put on a Lm358 an a Bc459...
I've noticed a strange thing about my nurse quack...first of all, i 've noticed that if i roll on sensitivity and roll off range the filter interact as the sensitivity is closed and notes doesn't sweep...
Second thing...if i use for a long time the effect with a weak sensitivity and poor range (so i have to hit hard strings to get a sweep) after a while the pedal stops to sweep, so i try increasing sensitivity and range but the pedal seems to be paralized, he doesn't sweep anyway...then he produces after hitting hard strings a strong whistle...i'm afraid i'll become deaf!
Then the pedal begin to sweep normally...!!!
But as i said before...is it normal that range and sensitivity interact in this way?
In other filter i've tried, when sensitivity is rolled on, you haven't to pay attention to the range control, cause filter is on its maximum bypass....Am i wrong?
Following this pcb project i've wired the other Sensitivity and Range lug that aren't mentioned in the project to ground holes.
Am i wrong too?

http://www.elixant.com/~stompbox/smfforum/index.php?topic=35760.msg305763

this is the link to this NURSE QUACKY project...
please help mE!!!

[Mugshot]

bumping this old thread for subscription 

first post in the thread said TL072 makes no quack. i breadboarded one last night and man, it does quack!

@bryan,

i see you used a 100K pot for the Sensitivity control, but there is a 47K fixed resistor from lug 3 of the SEns pot to ground. im wondring, what gives? why not just use a 50K pot (or something near 31K) and omit the 47K altogether? is it because of the sweep? from what i understand the 47K resistor lowers the total pot resistance since it appears the outer lugs of the 100K Sens control is bridged.

[Alkerion]

Hi !

Thanks a lot for such a nice contribution to this pedal mods.

I've swapped the original TL022CP on my block version (around '78) by NE5532AP, that's working great, nice sound.

Issues raised when I changed the 2SC1849 transistors by BC549CTA... :-(

Q1: OK
Q2: OK
Q3: NOT OK
Q4:OK

When I replace Q3 the pad isn't working well at all.
I loose effect on position 1, it's really noisy on position 2, etc.... crap sound.
Once replaced by stock transistor everything went back to normal.

Any explanation ?


Globally the sound effect is nice, a little bit noisy on position 2 and 4, but OK.

I've just the feeling that I lost a bit on speed.

Many thanks in advance for support

Best regards

[Agung Kurniawan]

Thanks for the information. I have breadboarding this one many times and never get them working. Im using TL072.
Have you try with LM833?