SOLVED Rodent problem

[Idroj]

Hi! And this is the 3rd and for now, last faulty pedal I build. A RAT that, now that I remember, I got from Tayda, pcb included. I built it, and similar to the Blue Breaker, I was able to enjoy it for a few seconds and then nothing.. I took it out of the enclosure, used this system that this youtube explained to narrow down if the problem is in the pcb board or the wiring, and it only worked for a moment, sounded amazing, but just for those few seconds. Now that I fixed 2 pedals this week with your all your help, and learning lots of things, I guess that a good place to start would be a good cleaning, right? I'll also have to try to unplug some pads and re-wire the 3PDT switch board...

Should I reflow anything else or just start the IPA toothbrush cleaning and put it all back together?

If I get to fix this one, after having fixed the other 2, this will be a HUGE VICTORY! Thanks everyone for taking the time to help out!

 

[Chas Grant]

Everyone's a bit different. Personally, I set it to 325. Tip goes on the board for about 3 seconds and I'm good. Anything over 400 is too much.

Is that Celsius, and what type of solder are you using. I believe lead free solder requires a higher temp. I use tin/lead and shoot for 460 to 470 F

 

[Idroj]

Futurelec has the 301N

Didn't even notice.. thought I had a 308N in Futurelec's cart. I need to slow down and pay more attention! ?

 

[BuddytheReow]

Is that Celsius, and what type of solder are you using. I believe lead free solder requires a higher temp. I use tin/lead and shoot for 460 to 470 F

Celsius, sorry about that

 

[Idroj]

Yes you can. I looked at board and thought it was a TL072, its actually a TL071! An OP07 or a LM308N will go right in. With the OP07 or TL071 C3 30pF cap is not needed. With a LM308N it is. Since you included it any IC will work. Even an OP07 might sound better than a TL071.
I've found the LM308N at a few different places, they come and go as they get them. So you have to find them when you can. You can also use a LM301N which is in stock here https://www.futurlec.com/Linear/LM301ANpr.shtml. The big difference is the slew rate of the op amps. The 308/301 are set by the 30pF cap at .5V/uS the TL series has a slew rate of 13V/uS.

Yesterday, while organizing parts from Tayda, I saw that for some strange reason I have a spare OP07 and a TL072.. I've just started building pedals and already have parts I didn't even know I had! ? I guess I'll try these two first and then buy just the LM308N. It would be cool to be able to install all three and have a toggle switch to change chips! ?

 

[Chas Grant]

The TL072 won't work. I thought that was what the Tayda board had on it and they had parked the one of the channels. But definitely try the OP07. It should be a direct swap. I have had some issues with the TL series chips in high gain circuits. Not sure if it was a bad chip or what, I just swapped them with a different type of chip.

 

[Idroj]

I will do that! With your experience, how would you describe the improvement you get going from TL071 to OP07 and the one I will get going from OP07 to LM308N when I get it? Thanks

 

[Idroj]

I swapped the TL071 for an OP07. Hmm? I'm not sure I necessarily like it better.. It does sound bigger and rounder but there is something about the TL071 that I like, it has more clarity and top end.. edgier.. I'll order the 308 and see what happens.. Now that I'm swapping IC opamps and disconnecting cables in between I wonder if I could leave everything connected and powered on while I switch chips.. can I? Also, it would be cool to have 3 opamps connected and a selector switch... each sound could work for different applications.. is there such a thing? An IC selector switch?

 

[Chas Grant]

You are one of the few who like the TL071 over the OP07. That’s the great thing about building your own pedals though, you can tweak and modify them for your taste not the generic sound of a pre-manufactured pedal. Me personally, I like my sound like I like my women, with a full round bottom!?

 

[Idroj]

?You are one of the few who like the TL071 over the OP07. That’s the great thing about building your own pedals though, you can tweak and modify them for your taste not the generic sound of a pre-manufactured pedal. Me personally, I like my sound like I like my women, with a full round bottom!?

? You're 100% right! This is the fun of it! When I listen to the tones, I'm imagining how will they sit in one of my productions/mixes.. And that RAT with TL071 feels like it would "cut" more.. the other ones could "muddy" a little bit more.. but I see how you can like the OP07 too.. it's a bigger, rounder, creamier sound! I have now the 308N on the way and soon we can talk about that one! ?

 

[Chas Grant]

? You're 100% right! This is the fun of it! When I listen to the tones, I'm imagining how will they sit in one of my productions/mixes.. And that RAT with TL071 feels like it would "cut" more.. the other ones could "muddy" a little bit more.. but I see how you can like the OP07 too.. it's a bigger, rounder, creamier sound! I have now the 308N on the way and soon we can talk about that one! ?

The distortion of the 308N is why people like it. There is something about it, but you can’t really explain it. I side by sided one with a 308 and one with a OP07 and there was definitely a difference.

 

[Idroj]

The distortion of the 308N is why people like it. There is something about it, but you can’t really explain it. I side by sided one with a 308 and one with a OP07 and there was definitely a difference.

I was about to check out on Jameco but for two 308N, they want to charge me 13.90, + 4.34 shipping + 6.10 Min. Order fee.. = $24.34! ? Any better ideas? eBay is full of them.. but that thought again.. are they real?

Would you trust any of these?

10pcs LM308N Operational Amplifier LM308 LM308AN DIP-8 IC | eBay

Find many great new & used options and get the best deals for 10pcs LM308N Operational Amplifier LM308 LM308AN DIP-8 IC at the best online prices at eBay! Free shipping for many products!

www.ebay.com

LM308N Precision Operational Amplifier, Vs=20v, Io=0.2nA, Is=0.3mA, Pm=500mW, | eBay

The LM308N is a high-performance operational amplifier (op-amp) integrated circuit that provides exceptional accuracy and stability in a wide range of applications. With its advanced design and precise specifications, this versatile chip is an essential component in a wide range of electronic...

www.ebay.com

LM308N Linear Precison Op Amp, USA seller, Fast Shipping! | eBay

(1) LM308N Op Amp IC - 8 Pin DIP.

www.ebay.com

 

[Idroj]

I was about to check out on Jameco but for two 308N, they want to charge me 13.90, + 4.34 shipping + 6.10 Min. Order fee.. = $24.34! ? Any better ideas? eBay is full of them.. but that thought again.. are they real?

Would you trust any of these?

10pcs LM308N Operational Amplifier LM308 LM308AN DIP-8 IC | eBay

Find many great new & used options and get the best deals for 10pcs LM308N Operational Amplifier LM308 LM308AN DIP-8 IC at the best online prices at eBay! Free shipping for many products!

www.ebay.com

LM308N Precision Operational Amplifier, Vs=20v, Io=0.2nA, Is=0.3mA, Pm=500mW, | eBay

The LM308N is a high-performance operational amplifier (op-amp) integrated circuit that provides exceptional accuracy and stability in a wide range of applications. With its advanced design and precise specifications, this versatile chip is an essential component in a wide range of electronic...

www.ebay.com

LM308N Linear Precison Op Amp, USA seller, Fast Shipping! | eBay

(1) LM308N Op Amp IC - 8 Pin DIP.

www.ebay.com

Found a better option ?:

LM308N

DIP8 Single op amp used in the ProCo RAT. For data sheet click Here

buildyourownclone.com

 

[Chas Grant]

BYOC is legit!!

 

[Idroj]

BYOC is legit!!

Alright I'll go with that! Thanks!!

By the way, what do you think about this? :


Noise level optimization is something that I'm definitely interested in for all my pedals.. But only if it doesn't cost me quality.. I guess pedals are noisy and you just have to be ok with it lol..

 

[Idroj]

What is the best "affordable" power supply for pedals? I bought a d'addario 9v adapter and it whistles like crazy with most of my pedals.. sometimes I prefer batteries... is there a DIY option?

 

[Chas Grant]

What is the best "affordable" power supply for pedals? I bought a d'addario 9v adapter and it whistles like crazy with most of my pedals.. sometimes I prefer batteries... is there a DIY option?

I’m not the person to ask about that. My house is over 100 years old, and the “grid I’m on is a the same age! Noise is something I’m used to. I try to use quality caps and also add a 100nF cap to the power stage. When ever I go jam somewhere with decent power I am surprised at how quiet the pedals are. I tried many power supplies to quiet the noise at home but no luck. What I did notice is any of the isolated power supplies where somewhat quieter, but no major difference in them.

 

[Idroj]

Same here.. not 100 but 50 years old with same grid!
I'll do some research.. ?

 

[PJS]

I have a cheap Caline power supply with about 8 or 9 outputs. I have never heard any artifacts and I have had it on the oscilloscope and it is dead straight DC within the frequency limits of the scope (up to 500 kHz).

 

[perfboarder]

The distortion of the 308N is why people like it. There is something about it, but you can’t really explain it. I side by sided one with a 308 and one with a OP07 and there was definitely a difference.

Yes, but not night and day difference for me.

@Idroj Can you point us the minor mod? Sound interesting, never try before.

 

[Idroj]

Yes, but not night and day difference for me.

@Idroj Can you point us the minor mod? Sound interesting, never try before.

Unfortunately, I don't know how to do this mod... Or any other mod yet.. ? I read that info on a comment in another forum while researching LM308s, maybe you can contact the owner of that comment. It is comment #15 in this thread by someone named Jack:

Rat's Lm308n Vs. Lm308an

So I just got a big box vintage RI Rat in the mail today (many thanks to Josh here at TGP for that!) and the pedal sounds amazing. I've always thought of the pedal as a high gain distortion but I could almost get some of John Mayer's tones with the distortion set pretty low. Sounded like a...

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