Testing issues mixer/amp

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fuzzyfuzz
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Testing issues mixer/amp

Post by fuzzyfuzz »

Hi,

This forum has been great, and along the way the reading has helped me resolve some issues, some of them out of scope of knowledge and some were just bad on my part. However, I am at the point where building a pedal on my breadboard is done, but now hen I test there are two totally different sounds. One is when I run the breadboard through my mixer (very fuzzy sounding) as expected, but then I connect to my amp and sounds more clean or clean with a little bit of distortion. Any thoughts on what i am missing? :wha?:

Fuzzy (only in mixer) :?:
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crochambeau
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Re: Testing issues mixer/amp

Post by crochambeau »

What sort of amplifier?
What sort of mixer?
What's the final output section of that fuzz circuit?
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Re: Testing issues mixer/amp

Post by fuzzyfuzz »

Presonus Studio Mixer 16.4.2 with no effects or eq, and Carvin 3VM amp head (clean channel) through 2x12 cab with celestion vintage 30 speakers. Excuse is not familiar with question of what final output section of fuzz circuit as for this one I am testing with a Gus Fuzz Face output to amp/mixer. Hope this answers your questions, let me know if anything else is needed to help resolve my issue.

Thanks!
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Re: Testing issues mixer/amp

Post by crochambeau »

I'm guessing the Presonus has a very high impedance differential mosfet input, whereas the Carvin is more of a middle impedance "classic" input with a 220K resistor doing grid leak duty:

http://carvinimages.com/schematics/v3m_blocked.pdf

Long story short: see if slapping a buffer in between your fuzz and the amp resolves your complaint.
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eatyourguitar
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Re: Testing issues mixer/amp

Post by eatyourguitar »

turn the volume down
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Re: Testing issues mixer/amp

Post by fuzzyfuzz »

crochambeau wrote:I'm guessing the Presonus has a very high impedance differential mosfet input, whereas the Carvin is more of a middle impedance "classic" input with a 220K resistor doing grid leak duty:

http://carvinimages.com/schematics/v3m_blocked.pdf

Long story short: see if slapping a buffer in between your fuzz and the amp resolves your complaint.
Thank you, I will try this.
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Re: Testing issues mixer/amp

Post by fuzzyfuzz »

eatyourguitar wrote:turn the volume down
Volume is down when testing, no need to disturb the neighbors until it's time to
disturb the neighbors! Want to wake them up with fuzz not
with just noise. :hello:
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Re: Testing issues mixer/amp

Post by eatyourguitar »

not the speakers, not the amp. turn down the volume of the output of the breadboard circuit. if you don't have a volume knob there then just turn down the trim control on the mixer. it might be labeled pre or gain on the mixer channel. you should really just add a volume control to the output of your breadboard so you can use it on everything. I hope you understand what I was trying to say now.
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Re: Testing issues mixer/amp

Post by fuzzyfuzz »

eatyourguitar wrote:not the speakers, not the amp. turn down the volume of the output of the breadboard circuit. if you don't have a volume knob there then just turn down the trim control on the mixer. it might be labeled pre or gain on the mixer channel. you should really just add a volume control to the output of your breadboard so you can use it on everything. I hope you understand what I was trying to say now.
Sorry my bad, reading too fast. Yes I do have volume on the output of the breadboard circuit and thought I had tested all those possibilities, however, I will test again and pull down volume on output and use only the amp volume. What was interesting is the tone when running through the mixer was great, had a creamy fuzz tone very cool sounding. With the amp, seems like too much headroom and not hitting that overdrive/fuzz level, I am just surprised and perplexed how and why the fuzz tone is elusive in the amp and there through the mixer? :idk:

Thank you for the reply 'eat', i appreciate the help and direction.

Fuzzy :animal:
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Re: Testing issues mixer/amp

Post by eatyourguitar »

The fuzz is happening in the mixer i think. You could build this into a pedal by adding an opamp and hitting it hard. Try that on the breadboard plugged into the amp
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Re: Testing issues mixer/amp

Post by crochambeau »

eatyourguitar wrote:The fuzz is happening in the mixer i think. You could build this into a pedal by adding an opamp and hitting it hard.
fuzzyfuzz wrote:a creamy fuzz tone
:idk: :snax:

Curious how this one will develop, I have yet to meet a modern mixer preamp which I would describe as creamy when pounding out the input. Maybe configure the opamp stage as having a variable gain, so when you roll back it'll amount to the aforementioned buffer between the circuit and amp and dialed up it will provide another source of grit. Best of both worlds.
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Re: Testing issues mixer/amp

Post by eatyourguitar »

look at the EQ section in a mixer. you can clip at the EQ without actually clipping in the pre. it is possible. regular opamp clipping at the pre is pretty boring but if your impedance is low enough and the capacitance high enough, you can get losses through the cable that will low pass and mid boost right before the clipping.
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Re: Testing issues mixer/amp

Post by fuzzyfuzz »

eatyourguitar wrote:look at the EQ section in a mixer. you can clip at the EQ without actually clipping in the pre. it is possible. regular opamp clipping at the pre is pretty boring but if your impedance is low enough and the capacitance high enough, you can get losses through the cable that will low pass and mid boost right before the clipping.
I think you are correct 'Eat', now if I can duplicate or close to that tone, be awesome. I was able to test hfe yesterday for the first time (new multimeter) and found that I had a 5088 in Q2 that was close to 700, not sure if this is part of the issue or not, but tested and ended up with Q1 3904 182 and Q2 206, and does sound better through the amp with a few eq adjustments. I just use what I have and build this into the enclosure and see what it sounds like instead of second guessing my ears each time I try more variations. I will take anymore suggestions that you guys come up with, and report back if I stumble across anything or when I have completed the pedal.

Thanks again!

May the Fuzz be with you. :yay:
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