Line 6 Spider 112/210 debug, not the II, not the III, the first one

[scooperman]

Line 6 Spider, no output.  Found some downloadable schematics but only for the later versions.
Here is what I have done so far.  Questions at the end.

There is some similarity between the early Line 6 Spider circuit design and the later ones.  At the block diagram level its a lot like the Spider II 212. The actual schematic and layout of the mainboard is different, although the circuitry has similar circuit topology and identical components for a lot of it.  The preamp, codec, processor, DSP, memory, and front panel interface have enough similarity that the Spider II 212 literature is helpful for debugging.  The power amplifier section is a lot different, the Spider uses one LM4765 as a bridge driver, and the Spider II has two LM3886s, one for each speaker.

The Cirrus Logic CS4221 codec is used in both amps.  In the Spider 1, they ignored the Cirrus Logic recommended Butterworth output filter, just connected the left outputs to one half of the LM4765 and the right outputs to the other half.  The II does have additional filtering before the output amps.  The Spider II has an op amp buffer for the headphones, I think the Spider just taps off the LM4765 outputs.

Line 6 service bulletin 018 mentions this amp.  It states that C24 and C52 were not installed on production units.  If they were installed, then look for "smoke/burning around LM 4765 Power Amp IC U3".  It notes that if the unit has smoked, then U3 is probably dead.

So OK, my amp is dead, and the pcb does have C24 and C52 installed, so maybe my U3 is dead.  These caps look like ceramic 1206s, they are just bypass caps in parallel with a couple of 50V electrolytics from the Vcc/Vee rails to ground.  I figure they were probably not rated for this much voltage.  What the heck, I unsoldered the LM7465 and tossed it, and removed those caps.

I should be able to confirm that at least there is audio signal going to the power amp.  I traced out this part of the pcb. The CS4221 data sheet specifies a minimum of 10K resistive and a maximum of 100pf capacitive load on its analog outputs, so I was looking for something like that.  Instead I find the CS4221 outputs are AC coupled through 1uF caps to the LM7465 circuitry.   The LM7465 is arranged as a differential amp, with a 620K feedback resistor and a 620K resistor to ground from the noninverting input, and 10k input resistors to the coupling caps.  The AUDR- signal goes to C19, AUDR+ goes to C18,  AUDL- goes to C28, AUDL+ goes to C27.  With the LM7465 out of circuit, there is almost no loading, so I patched in a resistive test load across these differential outputs.  I attached probes to these nodes.  Ooops, maybe I should not have thrown out that LM7465 chip, because there is no audio showing up at these nodes, i.e. the 4221 was not sending any signal to the power amp section.

Back at the CS4221 , I checked the clocks.  Sampling frequency is the same as LRCK, the Left/right clock, it is 31.197kHz. SCLK measures 1.9966MHz, MCLK measures 11.979MHz.  So MCLK is 384Fs. Because there is a 47Kohm pulldown on the SDOUT pin, the 4221 wakes up in the clock master mode, it generates SCLK and LRCK from the MCLK input.  Also, it defaults to LRCK = MCLK/256, it has to later be programmed to change it to 384, so this indicates that the microprocessor was able to communicate with the 4221.  On the pcb, the ADC signal is the output from the 4221 DAC to the DSP chip ADC input, and the DAC signal is the DAC data from the DSP chip to the 4221's internal DAC.  The DAC signal from the DSP does show a small amount of activity suggesting that the DSP chip is trying to do something, you can see some changes in the serial data when wiggling various front panel knobs.  In particular, turning on the tremolo causes the MSB to shift back and forth.  The ADC signal never changes, you see a couple of bit transitions during the left data sample and a similar couple of bits during the right data sample.  Nothing affects this pattern, it does not respond to input signal level, or whether the input is plugged or unplugged.  The analog signals to the 4221 are fine, the clean signal is on pin 17 and the boosted signal is on pin 20.

A lot of circuit functionality can be tested using the built-in microprocessor.  I have done the reset, checked EPROM version, I have run through all the tests which can be done through the front panel without the additional Line 6 test fixture, everything tests OK.  However, without the test fixture, apparently I can not run any audio ADC or RAM tests.  The front panel tests only exercise the accessory TLC542 ADC which is used to measure the front panel pots and to detect whether the guitar or headphones are plugged in, it does not test the ADC and DAC in the codec nor the ones in the DSP chip, it does not test the DSP memory.  In these amps, signal level (volume) is controlled digitally within the 4221 codec. 

I intend to try confirming that the uP is attempting to change the signal level when the knobs are twisted.  If I rearrange everything in my shop, I could get this mess over to one of the digital workbenches where I could hook up a logic analyzer and do some more probing.  I have tried just looking at the serial communications between the uP and the 4221 with a scope, but I think it must be very asynchronous,  does not update the 4221 control register except when the front panel buttons are touched, and my scope can't catch it.  For now, all I can say is that it seems too quiet on those pins, I expected more activity than what I am seeing.

Now to the questions/requests.

a. Do you have or know where I can purchase any of the CS4221-KS parts?
b. Have you debugged and repaired one of these amps?  What would you look for next?
c. Do you have a Spider text fixture, or the schematic for a test fixture?

[EDWARDEFFECT1]

hey superman! a say that with pride.you know alot more than me on this subject.i am fixing a line 6 flextonel lll that plays perfectly then the volume drops off.hope it is an output transistor and nothing digital.the delay and reverb lights don't light anymore since i did the factory reset.i am also working on a johnson 50 watt mirage and i needed the same cs4221-ks chip as you .i went to this site  http://chips-now.com/ and had about a dozen places with this chip for sale.all you do is sign in with your information and request the number of chips you want i got 3 @ $5.00 each and $8.00 shipping.mouser and all the other american suppliers had nothing.my chips are on the way as we speak from hong kong. i used paypal and my credit card to buy them...hope this helps you. if you have any ideas on my flextone lll i have a post on this site......help!!!!!!!hope this helps you get your own cs4221-ks's...later.....ed!

[EDWARDEFFECT1]

forgot to tell you i just bought a hot air station and i removed my cs4221-ks chip from my johnson mirage.i bought a x-tronic4000 . it is the cats pajama's.works like a dream. check out one of my posts with a you tube video of a simular hot air station(the one with a plastic pump)......ed!!!!.............(what is the best way to remove and replace smd components)

[scooperman]

Ed,  thank you for posting.  I had seen your thread but did not have any information to contribute.  But since you helped me, I did some more searching for Flextone and I found a site which has some additional Line 6 information.  I see Flextone is mentioned in various service bulletins.  Try here:

http://www.schematicsforfree.com/archive/dir/Audio/Musical/PRODUCTS/LINE%206

Hope that helps.

I have had mixed results with the faraway chip resellers.  I would like to ask if you would update us on whether you do receive your chips as promised.  I set the Line 6 aside, I will probably not work on it again until next month.

scoop

[EDWARDEFFECT1]

how are the output chips in your amp? i just fixed my flextone lll by replacing them.my amp would play and after the output chips heated up the volume would drop off.it's common for them to go bad.plug into your amp with your guitar and run a cable from your effects send into another amp input if you get sound you have a problem in the output section, which is probably your output transistors.to find my bad cs4221-ks in my johnson mirage  i signal traced it with a mfj signal tracer injecter.it had signal coming into the chip,but nothing coming out the analog outputs.i paid about $80.00 for it it's small and runs on a 9 volt battery.it has 3 leads a signal out a ground and a signal in. i put a disassembled 1/4 inch phone plug in the input and hook the signal out to the tip the second terminal gets my ground lead, then i use the signal in lead for probing just like an oscilloscope.intead of a picture on my scope you get sound.you can here if an ic is amplifying the signal.also works good to find cold solder and testing transistors.i have fixed many amps with just this tester.works good for signal tracing guitar pedals also....ed...

[J M Fahey]

Signal tracers are great, they are "the poor man's scope".
Haven't used one for ages, but really they are very useful.
They can be made cigarette-pack size too !!
I'll build one and post here the schematic and PCB.

[scooperman]

a signal injecting probe is a good tool but not much use on the programmable digital components, I think you just got lucky Ed.  In this kind of circuit, you need to know if the chip did get all of its necessary signals, i.e., did it get programmed correctly?  If it did get told what to do, and then it doesn't work, then yes that chip is bad.  But I am not able to tell if its getting programmed correctly. 
In the Line6, injecting a standard analog signal, like a sine wave,  is about all you can do and that only gets you past the opamps in the pseudo-stereo preamp stage.  As soon as the CS4221 digitizes it, all you have are ones and zeros going to the DSP and then digital back from the DSP.  If that works, OK fine, you will then find some analog coming out of the CS4221 and going to the power amp stage.  I know about the power amp stuff, I saw it wasn't getting any input.  Maybe that is what died first, and maybe there was an electrical tsunami that zapped the CS4221 too, I have no way to tell. All I am able to tell is that there is activity (stuff happening) on the pins going to the CS4221 chip, I am not seeing anything like what I expect on the pins coming out of the chip.  So without anything more scientific, I am just guessing/hoping this its a dead chip. I am replacing the CS4221 and the power amp.

[EDWARDEFFECT1]

i got analog signal into  both the left and right channels of the cs4221-ks ,but got no signal from the left and right analog outputs,so i have come to the same conclusion.that i have a bad chip.be it a sine wave or an audio signal it should pass signal.as you said the rest of the digital is another story.when i found no audio out i didn't worry about any of the digital part of the chip. i just concidered it dead in the water.....ed

[EDWARDEFFECT1]

hey scooperman.got my cs4221-ks chips today.i got 3. if you have a problem getting one let me know.i could send one to you if you are in the usa and in dire need of one.....will update the results of it's replacement in my other posting on the johnson mirage amp with no analog output form this chip....ed

[scooperman]

thank you Ed, that is a very kind offer.  I set the Line 6 repair aside for now, I have more junk...errrr....valuable equipment needing repairs.  So I am not in a hurry to purchase parts for the Line 6, I will wait to hear from you, if you have spares when you finish your repair.

[EDWARDEFFECT1]

will do....ed

[guitardog]

Hi gents...pardon me for jumping in, but I noticed you were chatting about an amp that I'm working on (Line 6 Spider - the first one, 112)....and I thought I'd bounce a question of of ya!  (Haven't found a schematic for it yet...)

The amp, as it stands, has an issue in that it won't get a clean tone....or I should say that it's very, very quiet in clean mode.  The distortion tones are there....I think there's something going on that may not be repairable (at least that's what the shop told me).

So I'd like to try something else with the amp...I'd like to just use the power output section of the amp, and provide it an input signal from my new POD floor pedal (HD500)...so I've opened it up and I see the LM4765 chip, and can tell that they are running it in Bridged Mode...(from doing a little DVM work).  What I'd like to do is to insert my POD signal so that I could use the amps Master Volume knob and LM4765 chip to provide the power amp output to the 112 speaker in the cab.   

I'm not able to tell where to insert the signal...I've traced the Master V pot and can see it come into the board, but I don't understand how that is working with the circuitry to be used as a master. 

Could I just inject the audio out of the POD to the inputs of the LM4765 (I think I'd need some kind of resistor between the insert point and the pin inputs 7 & 13, but not sure what value)....

Any thoughts on this would be great!  Thanks,
G~

[J M Fahey]

To save some work download the LM datasheet, hand draw the application schematic (it must be *very* close to what was used) and trace and draw the input lines to it.
Do they come straight from the Master Volume .... some power-in jacks ... from a frightening 400pin super-chip?
Some close clean sharp well illuminated pictures will help too.

[scooperman]

guitardog,  I apologize that I have not been monitoring this site for some time.  The Spider was removed from my workbench and sat in the corner, I worked on other things.  Yesterday Ed (Edwardeffect1) called to let me know that a CS4221 chip is on its way to me (Thanks Ed!) so I probably should get back to work on this amp.

I traced out a lot of the Spider pcb last year while attempting to debug this amp. The Spider component arrangement does bear a slight resemblance to the National LM4765 data sheet Figure 2, from the output pins of the chip to the speaker.  The input and feedback is a lot different.  

Crystal recommended that the CS4221 outputs go through a 2nd or 3rd order Butterworth.  Line6 didn't bother, they just AC coupled the CS4221 differential outputs to the inputs of the LM4765.  On the pcb there are a few places where they could populate caps to form various 1st order RC filters, like they could have made a lowpass in the LM4765 feedback path.  However, on my pcb all of these capacitors are not even populated, so the LM4765 is just a gain stage.  

If you can make a differential audio signal with similar signal levels to the Crystal chip, here is how you could connect it into their circuit:

AUDL- couples through C28, AUDL+ couples through C27.  AUDR- couples through C19, AUDR+  couples through C18.  You can follow the traces to see which capacitor pin is the in, which is out, then you can lift the inputs or cut the input traces and wire in your signals. The signal output from each cap heads over towards the LM4765, going through a 10K resistor on its way there.

If it would help, I drew the power amp section of the schematic.

[scooperman]

I installed the new CS4221 chip I got from Ed, and I now get analog signals all the way to the inputs of the power amp circuitry.  Hooray. The signal seems to respond to bass/middle/treble input knobs vs. input frequency, and amplitude follows the volume knobs as expected.   I have today ordered a new LM4765 chip and will report back when that is installed.  So far so good.