LM1458N Bass Balls Issue (Debug Info Included)

[pappasmurfsharem]

So I built the bassballs with the topopiccione layout.

Typical story. No Sweep.

I have two LM1458N 's or so they are called from tayda.

Was going to measure voltages and saw immediately that both Pin1 and Pin8 have 8.9V on it.

These aren't remotely connected on the board Checked for solder bridges yadda yadda.

Swapped with my other LM1458N same issue. So I pulled them and attached an clip to pin8 and ground to pin4 as is typical with Dual OPamps

And pin 1 still measures 8.9 volts I'm pretty sure that isn't supposed to happen. I assume my 1458s are fakes or blown?

If thats the case then I will be kind of happy since I built a DR a few months ago with the same problem.


EDIT: I may be mistaken My 4558s all measure the same when connected with flying leads.

Ill just put up another post with the DEBUG thread info when I get done with the overnight maintenance at work.

[Kipper4]

Did you do larrys layout?
I still have mine in the experiment box so if needs be I could check my voltages for you.
Here's the thread

http://www.diystompboxes.com/smfforum/index.php?topic=101858.0.l

Just so you know I got my chips from Tayda IIRC

[pappasmurfsharem]

1.What does it do, not do, and sound like?
   Passes sound in bypass.
   Engaged: mildly effected sound that changes sweep when the trimpots are adjusted.    
   Sensitivity pot has seemingly no effect on sound.
        When the FUZZ switch is engaged I get NO Sound

2.Name of the circuit =
   EHX Bass Balls

3.Source of the circuit (URL of schematic or project) =
   http://topopiccione.atspace.com/pjimages/EHBassBalls.sch.gif

4.Any modifications to the circuit?
   None

5.Any parts substitutions?
   N/A

6.Positive ground to negative ground conversion?
   Negative Ground

7.Voltage Source Reading? =>
   8.95V

Voltage at the circuit board end of the red battery lead =
   8.94V

Voltage at the circuit board end of the black battery lead =
   0v

Now, using the original schematic as a reference for which part is which (that is, which transistor is Q1, Q2, etc. and which IC is IC1, IC2, C1, and so on) measure and list the voltage on each pin of every transistor and IC. Just keep the black lead on ground, and touch the pointed end of the red probe to each one in turn. Report the voltages as follows:


IC1 (or U1) = LM1458N
P1 = 8.28V
P2 = 7.38V
P3 = 0V
P4 = 0V
P5 = 4.40V
P6 = 4.51V
P7 = 4.51V
P8 = 8.94V

IC1 = 4558
P1 = 4.48V
P2 = 4.48V
P3 = 4.47V
P4 = 0V
P5 = 4.47V
P6 = 4.48V
P7 = 4.44V
P8 = 8.94V

Q1
C = 8.94V
B = 7.83V
E = 7.19

Q2
C= 0V
B= 0.63V
E= 0V

Q3
C= 0V
B= 0.64V
E= 0V

D1
A (anode, the non-band end) = 8.28V
K (cathode, the banded end) = 7.84V

[GibsonGM]

Definitely something wrong around  U1!   That output (P1) should be nowhere near V+.    The link to the schematic doesn't work...can you post it from Photobucket or something?  I'm wondering what your VRef voltages are (assuming that you have a bias coming from somewhere).   Probably way off.   

Can you audio probe this bugger?  That may tell you pretty closely where the real trouble is happening.   Can't do much more than this with no schema, and didn't find it on my own in the 2 minutes I just searched for it...

[Mark Hammer]

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.

[nocentelli]

+1

I've bought a fair few of those LM1458 from Tayda, and they've all worked well - They sound particularly good in a Timmy.

[pinkjimiphoton]

try some different opamps. it doesn't HAVE to be 1458's in there, they are used cuz they can hit the power rails.

i've had the same damn problem with several attempts at this... i ended up giving up on it.

that said, i've used tayda 1458's, and they work great. BUT they seem to blow up pretty easy if there's an issue with a circuit...

[Mark Hammer]

You're half right.  Three of the 4opamps can be anything but the 4th the one used for the envelope follower does need to be a 1458 to get proper sweep, and the classic Bass Balls "fuzz".

[pinkjimiphoton]

the classic fuzz is TERRIBLE. 

i was obtuse... i shoulda said to see if it was workin', my bad!!

[jimilee]

I've built that one with no issues, so I can confirm the layout, did you check all the usual suspects, solder joints that should and should not  be touching?

[Mark Hammer]

the classic fuzz is TERRIBLE. 

i was obtuse... i shoulda said to see if it was workin', my bad!!

Oh believe me Sir James, I am definitely on that page with you, but some folks like it, and if they like it they should know what it takes to get it.

[pinkjimiphoton]

 

<shudder>

your mod to it is a huge improvement, mark, but still it's like... ya know... just cuz ya CAN do something, doesn't mean ya always should!!



makes me think of the "deluxe" big muff.... what a piece of poo. now they're going for 200+ broken. <shakes head>

[Mark Hammer]

When the word "vintage" gets mentioned, sometimes there is no accounting for taste.

[pinkjimiphoton]

hey mark, my name is jimi, and i'm a fuzzaholic...

[pappasmurfsharem]

Definitely something wrong around  U1!   That output (P1) should be nowhere near V+.    The link to the schematic doesn't work...can you post it from Photobucket or something?  I'm wondering what your VRef voltages are (assuming that you have a bias coming from somewhere).   Probably way off.  

Can you audio probe this bugger?  That may tell you pretty closely where the real trouble is happening.   Can't do much more than this with no schema, and didn't find it on my own in the 2 minutes I just searched for it...

I dont think it's a solder bridge because pulling the IC from the Socket Pin 1 reads 0V

I wouldn't even know where to begin to probe.

I suppose the output for the envelope follower? since with the switch engaged I lose all sound so it stands to reason that its not outputting?

Edit:

I'm getting No output on pin 1 of the 1458, I am getting signal on pin 2.

[deadastronaut]

i used a 358 in my breaded attempt....worked ok IIRC..

[pinkjimiphoton]

take the schematic, and work your way thru with the audio probe from the input of the circuit thru to each node. when suddenly it goes away, that's your problem.

did you use any standing components? if so, please re-flow the board in those areas...i find standing resistors sometimes move if soldering adjacent components and they lose some of their connection ability.
reflowing them while making sure there's a good physical connection sometimes fixes things when everything else fails. you may never know where the problem was if you reflow the whole board, but if it ends up working, who cares?

hang in there, you WILL get it!!

[pappasmurfsharem]

take the schematic, and work your way thru with the audio probe from the input of the circuit thru to each node. when suddenly it goes away, that's your problem.

did you use any standing components? if so, please re-flow the board in those areas...i find standing resistors sometimes move if soldering adjacent components and they lose some of their connection ability.
reflowing them while making sure there's a good physical connection sometimes fixes things when everything else fails. you may never know where the problem was if you reflow the whole board, but if it ends up working, who cares?

hang in there, you WILL get it!!

I probed a bit, Shouldn't I have output on Pin 1 of the 1458? Thats where it connects to the 4148.

I have signal on Pin 2 and subsequently the 220K that goes from pin 2 to pin 1, but there is no signal on pin1/opposite side of 220k.

Thats where the fuzz line connects to the filter section so Im fairly certain I have to have Signal there. I can't figure out why I do not. Its not pulled to ground because I can read dc voltage on it.

I had the genius idea to connect a test probe lead from a broke Multimeter and soldered it to my test box (DPDT switch for bypass with I/O jacks and  cut in half aligator clips for board in and board out 9v and gnd. I soldered the probe to the lug of the output alligator clip. So with the output aligator clip disconnected I can probe around with everything plugged in nice an neat.

[Mark Hammer]

i used a 358 in my breaded attempt....worked ok IIRC..

Yeah, they'll work, but the sweep on 1458s is better for some reason.

[pappasmurfsharem]

Bumpiddy bump bump bumpiddy bump bump