My son managed to destroy my Plimsoul, I have now idea how he did it, but he actually burned a few components in it. I have repaired it so it is working now, but my problem is that he burned the IC, and the folks at Fulltone have grinded of the part number so I don’t know what IC they are using. I have tried a few standards but they have way to high gain for this pedal, I have tried JRC 4558, TL072.
Any idea what part to search for? I have installed a socket so I can easily swap.
//sven

Almost every circuit I have looked (if not all of them) have their opamps powered with 4.5v by a voltage divider.

Is there a problem by powering the opamp with 9v?
I mean, for higher thresholds feedback loop diodes (like an LED) it would be better to have 9v on the opamp right? To achieve more signal boost and then reaching the led clipping.

Am I right or this does not work?

Thanks in advance,
Frank

Excuse me if this is a stupid question, I've a lot to learn (esp using ICs & not simpler transistors & valves). But I was looking at using the lm13700 in place of the ca3080 (to build a Ross/dyna comp unsuprisingly).

I was curious though if you could use both op amps in the 13700 in parallel in place of the ca3080. I've some idea of the use and benefits of valves in parallel. I was just curious if anyone had tried using a lm13700 in parallel... it feels a bit wasteful to only employ half of it.

I find this page and I feel very intrested.

Came across a stash of old Reticon chips.

R5106, R5107, and R5108. These are 256, 512, and 1024-stage BBD devices respectively.

Looking for possible projects to utilize them in. Can someone point me in the right direction of some PCB layouts? Been looking but I have some up empty.

Known pedals to use these chips:

MXR micro chorus
MXR Micro flanger
DOD 575 Flanger

I know there are probably more! :applause:

I have some National Semi LM101AH and LF155H op-amps. Are these useful for any pedal designs? I would like to build a Rat....

So I am trying to invert a signal. No biggie. I am feeding the signal to pin 6 of a NJM2068. 5 to ground. 7 is output..check.

I matched the gain to the non-inverted signal, but on the scope, it doesn't look like my signal is inverted.

I'm using a digital scope and I wonder if it's not showing the invert by default?? Is that normal? I dont have a second probe to go between. :(

How else can I test polarity?

I am inverting the signal to send to a second amp in a 2 channel amplifier to bridge...

:scratch: :hmmm:

Made a simple inverting amp..but its not inverting....its part of an amplifier, so if the input is already inverted...would it not invert the signal?

So my bass amp I bought for $50.00 has a bunch of rca5532 and NJM2068's.

I am bored enough to swap them out..but am not sure which way to go really. do have some OPA2604's lying around, and can get 2134's and others...

So I guess I'll take a consensus(sp) :)

It is my experience that a Philips CD 4069 UBE Is a noisless and good sounding alternative to the 4049 variant in these circuits.and makes a great sounding fuzz too.

I've read that both increases headroom but most are from higher voltage supply. what really are the pros and cons between the two? which is better? thanks :thumbsup

What's the general consensus on NTE stuff? Particularly op-amps? It took me over an hour to figure out the reason my Barber Dirty Bomb clone didn't work was a faulty Texas Instruments TL071 (!). I picked up a NTE sub for it on the way to work this AM, but wonder if their stuff is bottom of the barrel, mid-level, or what the general perception is...

Hey just received 12pc of NE5532N Siemens.. I am:

1) trying to make sure they are real .....

2) Without experience with the chip want to know if it has more gain or more output than other duals? It sounds like it has more drive and high end sizzle

I just plugged it into the Rust driver I built vs. the jrc4558d and it was hotter for sure and had a sizzle to it...

Any opinions on 1 & 2 are greatly appreciated

I included a Picture of the tops again thanks in advance:

Hi,
I'm going to be building a headphone splitter with individual volume or gain controls. I'm splitting the signal 8 ways, so obviously, I'll need some amps. I'll be using TL072 dual opamps. Now, my question is this...what's the best way to control volume?

1) Use dual gang pot to control signal upstream of the opamp
2) Use single gang pot to control the gain of the opamp
3) Use dual gang pot to control the output into my jacks

I assume option 1 would be bad because it would also affect the...

I've got a bunch of oddball op-amps (at least to me) ones I haven't seen in pedals. It would be nice to have some sort of list of what op-amps are good for effects building and what their characteristics are. We know the common ones like 4558, 1458, 741...

Here are some I don't have experience with:
KF353
KA358
CA3260
TL064
LM386

Maybe some of the Elder Statesmen here could share their expertise?

TT

Hey guys,
I don't often have as much to contribute as most of you in the way of electronics knowledge, but I remembered that I had made this clip of 14 different opamps tested my two Timmy pedals back a few years ago. I hope it may help someone in choosing opamps for a build. Some of the included chips, JRC4559, JRC4558, RC4558, Eternity mystery chip, LM1458, TL072, Burr Brown, and a bunch more.

Have you guys noticed how with certaing biasing the 741 acts like there is very tiny hearable delay between the signal and your actual playing? I mean eg. in DOD 250 grey where the biasing is 22k+22k+470k, you can clearly hear how the 741 reacts kind of lazy to your playing, especially when you shred really fast. It feels like sound from your amp with the dod 250 drags behind your fingers...but it's sometimes really hard to notice. But I like the way 741 reacts with this biasing.

Does this...

Hi guys!

I ve the some problem of most of you, i ve a mxr flanger clone with a bad sad1024 probably. I ve decided after many years to' resuscitate it...i ve bought a mn3007 and i build a daughterboard following the layout founded here..

I ve seen the new Schematic to fill mn3007, but im not surehow to' link daughterboard to' mxr pcb...someone could explain it a little more simplified..?

Thank you in advance!

Another queztion: i ve not found cd4013 & cd4049( buffer for retrofit) but only...

FACT: The go-to devices for +/-9 volts from a 9 volt supply and +18 volts from a 9 volt supply in stompboxes are MAX1044, TC1044, LT1054 etc...........

The humble 555 appears capable of performing both these roles.

Here's the voltage doubler link:

.....and here's the negative voltage link:

The text is in Dutch, so you'll need to use Goggle's translation feature, but the schematics are in the international language of electronics.

Both the linked circuits run at around 20kHz, if whining...

I'm curious about the effective input impedance of various op-amps, in various circuits.

Consider, as an example a TL072 vs. an LM833, -the LM833 has better specs overall. -The selling point for the TL072 (in a guitar stompbox..) is the bi-FET input's ultra-high input impedance,
-but, configured as a non-inverting amplifier, won't the LM833 have very high input impedance also?

Is an LM833 a good choice for a guitar level input?
- such as in a buffer-less screamer type circuit?
Or, will it...

I read about and I think it's an interesting option, saving space and some money, but my knowledge is not enough to understand wich pin is equivalent between both IC's.

Anybody alredy do it or, at least, can help me??
Tanks in advance!!

Datasheets down here

Hi,
I'm thinking about making a headphone amp that takes a balanced input. Essentially, it's for an in-ear monitor. My question is, can I just put the a balanced signal from an XLR straight into the a headphone OpAmp or do I need to ReAmp the signal first and make it unbalanced?

Thanks!

hello everybody..

i saw a diy guyatone fl3 in diystompbox site., when i saw the schematic it has a MN3207 and MN3102..

I wonder if i could use a MN3007 and MN3101..is this possible?

any opinions? thank you..

I understand that the CMOS version of the 555 timer is lower current and thus pops less. Is there ever a need to use the bipolar version? I am buying a batch and would get just one type if there is a preference or both if there is value in having both on hand.

everybody...good day

what is the normal delay range of this pedal?..and what is the maximum range of this pedal if modded?
According to tonepad it can achieve a 580 ms delay..so in 44k sdram memory of pt2399 it can achieve a 580 ms delay?
is this right?..
So if it has only 20k sdram memory it will achieve only 500 ms delay??

anybody knows this?..this is just my view.

thank you..