LM1458N Bass Balls Issue (Debug Info Included)

Started by pappasmurfsharem, September 19, 2013, 11:19:52 PM

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Mark Hammer

The first check that one always has to do is verify that there is an AC voltage going into the rectifier op-amp (the pin where R5 and C3 meet) when you strum, and a DC voltage being produced by it at the junction of D1 and R6.  You should see something around 50-60mv for the first (depending on pickups), and between 1 and 3V or so for the second.

If you get a thumbs up on the furnishing of a control signal by the rectifier/follower portion of the circuit, then the next thing to do is verify that the filters work.  Set the switch to the non-fuzz setting, set the sensitivity to nil, and play with the trimpots to verify that each of the filters respond appropriately.

If the envelope follower portion responds properly, and the filters behave as expected, then that point to one or more of the transistors as possibly being either dead (not likely) or having the wrong pinouts (more likely).

That isd the general strategy to pursue when troubleshooting anything with a sidechain: separate it into the part that detects signal, the part that gets controlled by the sidechain, and the path that directs the control signal to the portion being controlled.  Failure in any one segment means no effect, but you need to narow it down to what segment.

pappasmurfsharem

Quote from: Mark Hammer on September 23, 2013, 12:20:40 PM
The first check that one always has to do is verify that there is an AC voltage going into the rectifier op-amp (the pin where R5 and C3 meet) when you strum, and a DC voltage being produced by it at the junction of D1 and R6.  You should see something around 50-60mv for the first (depending on pickups), and between 1 and 3V or so for the second.

If you get a thumbs up on the furnishing of a control signal by the rectifier/follower portion of the circuit, then the next thing to do is verify that the filters work.  Set the switch to the non-fuzz setting, set the sensitivity to nil, and play with the trimpots to verify that each of the filters respond appropriately.

If the envelope follower portion responds properly, and the filters behave as expected, then that point to one or more of the transistors as possibly being either dead (not likely) or having the wrong pinouts (more likely).

That isd the general strategy to pursue when troubleshooting anything with a sidechain: separate it into the part that detects signal, the part that gets controlled by the sidechain, and the path that directs the control signal to the portion being controlled.  Failure in any one segment means no effect, but you need to narow it down to what segment.

I am getting AC signal that spikes when strumming at the junctiong of C3 and R5- granted its around 100mV but it "idles" at 50ish mV which could just be my crappy DMM.

I am getting 7 volts DC at the junction of R6 and D1.

This goes back to me getting over 8Vs on pin1 of the 1458 I stated earlier. THere is no solder bridge because pulling the 1458 and measuring the pin sockets reads 0V

Assume a bad 1458?
"I want to build a delay, but I don't have the time."

pappasmurfsharem

#22
Appears I have bad luck all 4 of my 1458s from tayda are bad. reading the same 8v on pin one

Tried a 5532 and Im getting sweep now so thats great. the distortion is ridiculously gated. though when enabled.

Mark is that a function of a 5532 or is there something else to look at?

Here is a sound cloud clip. I recorded through the iPhone jam up app since I don't have my recording equipment at the house.
https://soundcloud.com/nicholas-schaffrin/bass-balls-test

"I want to build a delay, but I don't have the time."

LaceSensor

Quote from: Mark Hammer on September 20, 2013, 08:52:47 AM
You can dispel any concerns about the chips being "fakes".  I've bought and used them before, with full success.

You know, there is a reason why criminals don't go around counterfeiting pennies.

4x tayda 1458s do not envelope in a meatball build of mine... go figure!

pappasmurfsharem

Quote from: LaceSensor on September 28, 2013, 03:04:53 PM
Quote from: Mark Hammer on September 20, 2013, 08:52:47 AM
You can dispel any concerns about the chips being "fakes".  I've bought and used them before, with full success.

You know, there is a reason why criminals don't go around counterfeiting pennies.

4x tayda 1458s do not envelope in a meatball build of mine... go figure!

Did you have the LM1458Ns too? They also have LM1458 or the HA17458? Mine were the N ones
"I want to build a delay, but I don't have the time."

LaceSensor

1458 is a 1458
Is kinda like tl072p or cp or whatever.
The codes are relating to characteristics that don't matter to pedal builds.

pappasmurfsharem

Quote from: LaceSensor on September 29, 2013, 04:58:32 AM
1458 is a 1458
Is kinda like tl072p or cp or whatever.
The codes are relating to characteristics that don't matter to pedal builds.

Not if the 1458Ns are from a different manufacturer and/or factory seconds.
"I want to build a delay, but I don't have the time."

pappasmurfsharem

Not saying that's the case here. Im just curious if the 1458Ns have worked for people from tayda
"I want to build a delay, but I don't have the time."

pappasmurfsharem

#28
Bump

Thanks to the info from Mark I saw that I was not getting any change in DC voltage after D1. Since I was out of 1458's I tried the 5532 as per the above post.

I now get sweep that sounds alright. Already ordered 4 more 1458's from tayda (fingers crossed that they work)

The Fuzz is kind of gated though. I'm a very heavy handed bassist (grew up playing rush tunes) and I have to really push myself to get my jazz bass to get any "reasonable fuzz"
Here is a soundcloud clip with guitar. Which actually works the fuzz better than my Jazz Bass does.
https://soundcloud.com/nicholas-schaffrin/bass-balls-test

Mark H. the 5532 shouldn't be the cause of the lack of fuzz should it?
"I want to build a delay, but I don't have the time."

Mark Hammer

In fact, the "fuzz" in the Bassballs is just the sound a 1458 makes when pushed a little too hard.  Since it HAS to be pushed in order to get enough gain for the envelope follower, it was a freebie just waiting to be exploited, so that's what EHX did.

pappasmurfsharem

Quote from: Mark Hammer on September 30, 2013, 07:29:38 PM
In fact, the "fuzz" in the Bassballs is just the sound a 1458 makes when pushed a little too hard.  Since it HAS to be pushed in order to get enough gain for the envelope follower, it was a freebie just waiting to be exploited, so that's what EHX did.

But what about the gating I'm experiencing?
"I want to build a delay, but I don't have the time."

Mark Hammer


pappasmurfsharem

Quote from: Mark Hammer on September 30, 2013, 09:06:19 PM
That I can't help you with.

Ahh righto

Thanks for the help thus far.

I'll see what happens when the new 1458s come in
"I want to build a delay, but I don't have the time."

pappasmurfsharem

Bought 4 more 1458N s from tayda. They are also bad. Switching between the 5532 continues to sweep so I can firmly say stay away from the 1458n from tayda. Haven't tried their 1458 non-N yet but the N ones appear to be duds. I bought the original ones over a year ago and these ones last week
"I want to build a delay, but I don't have the time."