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Re: Dumbloid

PostPosted: 02 Apr 2014, 19:35
by bloomz
Nocentelli wrote:
GeSi wrote:looks real nice!
but most important... how does it sound ;)


Fastocker wrote: certainly not worthy of all the fuss IMO


So of course I've been watching this - and trying to stay out of it but curiosity got the better of me.

I noticed some changes you guy made to the circuit or the op amp or something else that's over my head.

Did it improve on it, compromise it, tone it down, turn it up, or what?

How does it sound is the $600 question. Because the original pedal was/IS worthy of all the fuss. Not sure $600 worth of fuss, but very happy being in for $300.

Can anyone post a clip? Even better a comparison clip.

Re: Dumbloid

PostPosted: 02 Apr 2014, 20:20
by IvIark
My layout didn't change the circuit. I added an additional layout that included a couple of diodes if that is what you would prefer over opamp clipping (which essentially makes it a TS808 with a couple of minor tweaked part values), but the main layout I did is as per the trace. Why are you finding it so hard to accept that not everyone may like this circuit as much as you do? The original, the Big Bloom and the layouts here will ALL have a certain amount of opamp clipping which isn't everyone's cup of tea, so some people may opt to use other opamps in an attempt to choose one that clips with their gear in a more pleasant way. I'm afraid the fact will remain that to some people it will sound shit.

Re: Dumbloid

PostPosted: 02 Apr 2014, 21:35
by alfieboy
Hi IVIark

I built you handy layout as a project with the right op amp and transistors and got a really gated fuzz effect. I then built a new one and got the same thing. Any ideas?

Thank you.

Re: Dumbloid

PostPosted: 02 Apr 2014, 21:51
by IvIark
Measure the DC voltages you're getting between all transistor and opamp pins and ground and post them here. That will give us a good clue if something looks amiss. Or you may just think opamp clipping is shit :)

Re: Dumbloid

PostPosted: 02 Apr 2014, 21:54
by alfieboy
:lol: Maybe.

It's strange, like an under biased fuzz face.

I'll measure the voltages and post them.

Re: Dumbloid

PostPosted: 02 Apr 2014, 22:00
by alfieboy
The transistor voltages I'm getting are =
Q1
C - 9.17v
B - 5.16v
E - 4.84v

Q2
C - 9.23v
B - 5.11v
E - 4.58v

Re: Dumbloid

PostPosted: 02 Apr 2014, 22:14
by mmolteratx
Well, update on PCB status. They came in today, but I accidentally ordered a previous revision that doesn't work. :slap: Will reorder in the next few days.

alfieboy wrote:The transistor voltages I'm getting are =
Q1
C - 9.17v
B - 5.16v
E - 4.84v

Q2
C - 9.23v
B - 5.11v
E - 4.58v


What about the op amp?

Re: Dumbloid

PostPosted: 02 Apr 2014, 22:24
by bloomz
IvIark wrote: Why are you finding it so hard to accept that not everyone may like this circuit as much as you do? I'm afraid the fact will remain that to some people it will sound shit.


What gives you that idea???

I'm asking to see if I'm missing something you guys discovered that I may not know.

I have no problem at all accepting there may be something better.

It was a sincere question.

Why are you trying to hard so put words into my mouth?

Re: Dumbloid

PostPosted: 02 Apr 2014, 22:26
by alfieboy
Op Amp
1- 5.08v
2- 0.55v
3- 5.57v
4 - 0v
5- 7.99v
6- 8.04v
7- 8.19v
9- 9.24v

Thanks.

Re: Dumbloid

PostPosted: 02 Apr 2014, 22:28
by IvIark
alfieboy wrote:The transistor voltages I'm getting are =
Q1
C - 9.17v
B - 5.16v
E - 4.84v

Q2
C - 9.23v
B - 5.11v
E - 4.58v


Base and emitter voltages all look high. Post the IC voltages

Re: Dumbloid

PostPosted: 02 Apr 2014, 22:39
by alfieboy
Posted above. They also seems high to me.

Re: Dumbloid

PostPosted: 02 Apr 2014, 22:45
by Fastocker
Just to clarify -- I first built IVIark's layout EXACTLY to Dumbloid spec including the correct opamp and pot values. Tried it out, then decided to try a few different opamps for fun . . . and I liked the MC33172N as johnk recommended -- it just sounded a bit more like a saturated amp to me (slightly less fuzzy decay). It's a very miniscule change but I could hear a slight difference and preferred it over the original chip. Again, a very minor change. The nice thing about a DIY project? No goop so I can try different components if I wish.

Then I realized I didn't like the TONE or VOLUME pots -- with the switch on ROCK, the tone got very bright after 9:00 on the dial and the 'sweet spot' (for me, at least) was very small. That's typical of linear pot here -- I didn't like it and prefer the more gradual sweep of an audio pot . . . it's just easier to adjust. Same for the volume -- with the 100K pot it goes into boost after about 9:00 on my rig -- I prefer a more gradual volume increase. Neither of these 'mods' change the sound, they only allow for better adjustability.

I'll stand by my 'not worth the fuss' comment. It's a nice circuit, I get the whole Dumble thing, it sounds pretty good . . . but it's not worth the $300 to me, let alone $600. And if anyone bought one of the $999 double versions on eBay, I'd have to ask . . . . how high was the tree you fell out of? Did it hurt landing on your head? And I trust my own ears, too -- been playing since 1970, gone through tons of gear, yada yada.

But I also realize that I'm looking at this from the perspective of a DIY guy -- it's much easier for me to experiement with circuits and such than someone who doesn't know which end is the business end of a soldering iron. As such, I don't get real excited about ODs or fuzz pedals or whathaveyou and can be a bit jaded at times . . . but if you're happy with your purchase, no need to keep coming back and reiterating -- we fuckin' get it aleady. :)

(Don't feel bad, I pretty much had the same reaction when I built a Jan Ray . . . )

Re: Dumbloid

PostPosted: 02 Apr 2014, 23:05
by IvIark
alfieboy wrote:Op Amp
1- 5.08v
2- 0.55v
3- 5.57v
4 - 0v
5- 7.99v
6- 8.04v
7- 8.19v
9- 9.24v

Thanks.


Yes the only ones that look as expected are 4 and 8 :D
But starting at the beginning the one that really stands out is pin 2 which is far too low. Check your soldering of all components on that row and the IC pins themselves. Reflow the solder if any of the joints look suspect.

My only reservation here is that you've built this twice with the same results which could point to a faulty batch, or mislabelled components maybe? Double check everything, look for shorts, make sure cuts are clean, check soldering and values. If you don't spot anything post a front and back pic of your build so we can see if anything stands out

Re: Dumbloid

PostPosted: 02 Apr 2014, 23:06
by bloomz
Thank you Fastocker - your post made sense to me a bit. Quite a bit actually.

As for soldering irons - you hold it by the hot end correct?

Re: Dumbloid

PostPosted: 02 Apr 2014, 23:07
by rocklander
bloomz wrote:Why are you trying to hard so put words into my mouth?

I think you mean "Why are you trying so hard to put words into my mouth"





/irony

Re: Dumbloid

PostPosted: 02 Apr 2014, 23:50
by Fastocker
bloomz wrote:As for soldering irons - you hold it by the hot end correct?


Yes, that's correct . . .

Re: Dumbloid

PostPosted: 03 Apr 2014, 00:20
by bloomz
rocklander wrote:
bloomz wrote:Why are you trying to hard so put words into my mouth?

I think you mean "Why are you trying so hard to put words into my mouth"

/irony


ahhh, the grammar police strike again - color me corrected

Re: Dumbloid

PostPosted: 03 Apr 2014, 00:22
by sinner
bloomz wrote:
rocklander wrote:
bloomz wrote:Why are you trying to hard so put words into my mouth?

I think you mean "Why are you trying so hard to put words into my mouth"

/irony


ahhh, the grammar police strike again - color me corrected



Go home Gypsy

Re: Dumbloid

PostPosted: 03 Apr 2014, 00:55
by rocklander
bloomz wrote:
rocklander wrote:
bloomz wrote:Why are you trying to hard so put words into my mouth?

I think you mean "Why are you trying so hard to put words into my mouth"

/irony


ahhh, the grammar police strike again - colour me corrected

fix'd :hug:

Re: Dumbloid

PostPosted: 03 Apr 2014, 01:44
by guitarpkr76
mmolteratx wrote:Well, update on PCB status. They came in today, but I accidentally ordered a previous revision that doesn't work. :slap: Will reorder in the next few days.



That stinks, man. I don't mind paying a little extra when you get the new ones to help offset the cost of the bad boards.