Tommy muddy?

B

bn40

New member
Just finished my Timmy/Tommy with an LM1458N, and after a little troubleshooting it's up and running fine. However, I expected that with the gain down and the tone cut controls turned down it would be essentially a clean or slightly dirty boost with flat eq, and as I turn the gain up, I have the option of then removing or retaining as much bass and treble from the original signal as I want. Instead, even with G+B+T on 0, and volume set for unity, it sounds noticeably muffled at the top--kind of a wet blanket effect. This is ok at higher gains, but not when I need some sparkle to come through. Any suggestions for where the trouble might be, or how to remedy? TIA, Ben
 
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Really it is based on your preference. I can't really say if the LM1458 will sound better than the 4559, because everyone is not the same.

Here is a good thread on the different Opamps you can use in this circuit:

Favorite op amp in your Timmy?

I was in a tweaking mood this past weekend, and decided to swap the stock 4559 chip in my Timmy. I've had this new Timmy for about a month now, and found the stock sound to have alot of bite. I had a few op amps lying around, a JRC4558D, an RC4558P & an NE5532. The differences are subtle, but...
www.thegearpage.net

And yes you can try a TL072.

Ultimately it is what sounds best to you. I would try the TL072 and see if it changes the tone to your liking. What is muddy to you may be magic to someone else.

Now if it is still too muddy after trying different Opamps there may be a problem elsewhere. But I would start there.
 
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Honestly, I'm a little skeptical that choice of opamp would have this effect, which sounds almost like a turned down tone control on a guitar, but I'll give it a shot.
 
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Changing op-amps can affect the sound in some pedals, probably more in pedals using diodes for distortion since you are usually tweaking the relative gain in the circuit when you do.
 
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I swapped out the 4558 (sorry, I misnamed it above) for a TL072, and I definitely like it better, and the muffled quality is much reduced, especially when running after a buffer. But it is still not exactly neutral at the clean boost setting, rather a bit middy. But it sounds great with the gain up.
 
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make sure you keep the bass and tone knobs wide open (ccw) if you want a more full range boost. also try keeping the toggle in the middle position for the least compression.
 
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After playing with it a bit I'm a lot happier. The tone controls are pretty interactive; rolling back the bass actually takes the blanket off the treble, gives a nice clear sound at a variety of gain levels. Well done PaulC and Bugg.
 
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