The Terrible Treble Trasher-feedback please!

[Noplasticrobots]

Well, I'm finally finished with my first design. Well, not really my design, it's really a modified Bazz Fuss. I call it the Terrible Treble Trasher. I would like some constructive criticism on it if you've got them time. I spent some time modding the tone control and came up with what I believe is a nice trashy, trebley sound. I'm not too good with the musical adjectives, but I'd describe it as sort of lo-fi and garage sounding. Because the tone pot it so large you get a nice sweep of tones. I don't really have a large assortment of components yet, so I used what I had.

I do ask for some help with the capacitor values though. C1 and C2 are ceramics, while C3 is a coated cap. I'm still not used to converting µf to pf to nf, but I tried my best and wrote them in on the schematic. I'll leave the written values from the capacitors below and if there's a mistake, just let me know so I can change the schematic. Thanks!

C1: 103-written on schematic as 0.01µf
C2: 151-written on schematic as 0.15nf
C3: 220J EM-written on scheamtic as 22nf

Hope you like it!

[Noplasticrobots]

By the way, if anyone knows of any free MP3 hosting website, please let me know so I can post a clip of this box. Thanks!

[Harry]

sounds intresting would breadboard it but i cant right now, anyway i'd be intrested in hearing clips, don't know any hosters though.

[Noplasticrobots]

I couldn't crank my amp earlier but just got the oppurtunity...this circuit is noisy when not playing. I thought it might be the 1M resistor so I replaced it with a 100k and it was still noisy. When I plugged directly into my Tascam the output was severly suppressed making a decent direct recording impossible. So I unplugged the Tascam wall wart and went back to the amp. While playing through the amp I plugged the Tascam wall wart into the same outlet as my amp and lots of noise was introduced to the signal.

Even though the circuit is still pretty noisy, I wonder what the hell is making my Tascam wart making everything so damn noisy?

[moosapotamus]

Do you have any different wallwarts you can try, or find an outlet that's on a different circuit... maybe?

...if anyone knows of any free MP3 hosting website...

Here you go... http://www.putfile.com/

Let's hear those clips!

Thanks
~ Charlie

[Noplasticrobots]

I do have one of those universal adapters that I could try...it did work for powering up an old Tascam 414MKII, so it should work for the digital 8 track. I do tend to get better recordings out in my shed, but it's so cold out there right now (well, for CA at least ) that it's not comfortable to sit out there and record. But I'll give it a shot if it's gonna make everything work better. Thanks for the tips and the link!

[MartyMart]

http://diz.faithweb.com/builders/caps.htm

Here's a capacitor chart for you

151 is 150pf
103 is a 0.01uf  ( 10n )
220 would seem like 0.22uf ( 220n ) ! or possible 22pf if it's tiny !
220n would be a quite chunky poly cap, and also quite big as a
silver mica 22 pf value .....

Marty.

[Noplasticrobots]

Well, my universal adapter won't work with my digital 8, so that's out of the question. I tried the amp/circuit at various locations throughout the house and still get a really bad buzzing hum. It's gotta be the circuit. Could all the noise be coming from the ceramic caps? I can't imagine they'd produce that much noise.
I was also reading about ground loop hum which got me wondering if something isn't grounded right in the circuit. I change the input resistor to 100k, besides that, everything in the above schematic is correct (except for the updated cap values), so if you see something that should be grounded, let me know. I'll be searching for bugs with a can of Raid in hand...

EDIT: I notice that the lower the value of the input resistor, the less hum I get. But I read that anything below 100 ohms leads the way to problems with impedance. Anyone have any info or opinions on this?

[Noplasticrobots]

A little update: I discovered that using a polarized 0.22µf cap at the output instead of the non polarized 0.22µf greatly reduces the hum. When I plugged into the tascam to record however, I still got more hum than was coming out of the amp. If anyone has time this weekend, try breadboarding this thing and see if you notice any peculuarities (did I just make that word up?)

The polarized cap has more distortion but reduces the hum.

The non polarized cap sounds more "spangly" but has less distortion. I prefer the non polarized cap myself, although there would be a drop in volume with a bypass installed (one more problem!) Ideally I'd like to mount a pot between the two to blend them or choose one or the other.

[Noplasticrobots]

After spending way too much time on this the last couple days, I think I've realized what I need to do. Because the capacitor at the output lets a lot of the high frequencies through I get a lot of excess noise. Changing cap values makes it lose the sound I like. So is there a way to keep the cap I like in the circuit, but send the higher frequencies to ground or something? It sounds impossible now that I actually see it in writing!

I've abandoned the tone control for now, and I'm just focusing on the core circuit.

So how about it? Anyway to keep the cap but still keep down high frequencies?

[MartyMart]

Try just a small cap, 1nf - 3n3 from signal to ground that will help
That's 0.001 to 0.003

Marty.