fender blender

9 volts · August 06, 2007, 05:49:53 AM

Just a quite note to ask if this one is supposed to compress when it is all flat out.....Mine seems to get more distorted but also get quieter. I had a similar experience with the ampeg scrambler and am wondering if this is a normal characteristic of this type of pedal. Thanks

Toney · August 06, 2007, 07:16:01 AM

Which layout did you build?

9 volts · August 06, 2007, 08:00:36 AM

I built the version at fuzz central. It's the power chords that compress rather than single notes. Maybe these are better for single lines....

9 volts · August 06, 2007, 08:13:12 AM

I'm using 2n5089 tansistors. Could these be too powerful (hfe 450 - 1800)?

Toney · August 06, 2007, 08:21:18 AM

Well, the original used 2n3391 and 2n3391As...
the second may be a low noise version (may be = not sure!) anyway the Hfes are shown as 250-500.
2n5089s may be as high as 900 so yeah, I'd socket and see!
Try something lower gain.

niopren · August 08, 2007, 03:25:51 PM

i use the 2N5551...

sound really good...

Zero the hero · August 08, 2007, 04:00:13 PM

I used my layout and 5x 2SC1740 as transistor.
Their hFE figure were around 380-400, and it didn't suffer of what you describe.
Diodes were OA95.
I chose those components because... well, it was what I had at home...

Unfortunately I gave it away and I miss it very much! I think I'll build another one, one day... this pedal was reallly nasty!

9 volts · August 08, 2007, 06:58:36 PM

I've since replaced most of the transistors with 2n3391 and done a voltage check on each one they all have the .6 volt swing. I note that some of the resistors (eg 150k reads only 120k) when in the circuit (maybe 3). I'm using 1n34a diodes. The new transistors didn't change to behaviour. Thanks for the replies.

sonic_tooth · August 08, 2007, 07:04:34 PM

FWIW I built a FB clone off of one of the GEO layouts and it does the same thing. I just figured it was the nature of the pedal. I have other fuzzes that do the same thing. It always bothered me that the clean signal was not boosted with the distorted one.... it kinda made the blending aspect of the pedal a lot less useful.

9 volts · August 09, 2007, 12:09:30 AM

Ok......my blend pot does control the the octave and the signal on both sides is distorted (good thing). I've rechecked my voltages and on transistor 4 I have
e .35 v
b .75 v
c 2.4 v
When I disconnect the input wire I get the following voltage on the same transistor
e .5 v
b 1.10 v
c 2.40 v
.........
Finally the capacitor before it has a voltage reading of 5.8v on the pos and .96 on the neg. The rest have zero on the neg.....could this be leaking?
I'll keep checking.
ps with the audio probe there is a major signal drop on this transistor but by the end of the circuit its loud

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