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DrNomis_44
14-02-2017, 10:01 PM
Hi Everyone,

I couldn't think which forum section would be most appropriate place for me to start this thread, but the amplifiers section seemed the most appropriate cause we guitarists tend to use pedals with our amps anyway, I just had a bit of a win with regards to fixing my Ibanez TS-808 Tube Screamer pedal.

So what was wrong with it?, basically, it wasn't foot-switching reliably, sometimes it was a bit intermittent, other times it would simply refuse to foot-switch at all, sometimes it would stay bypassed, or un-bypassed, I decided to open it up and have a good look around on both sides of the circuit board using a magnifying glass to see if I could spot anything that might be causing the foot-switching to malfunction, this is a classic example of where you need to have a clear head while doing any troubleshooting, at the time I was doing the troubleshooting, I was feeling a bit tired so my mind wasn't as sharp as it could have been.

While looking at all the components on top of the circuit board with my magnifying glass, I noticed some whitish-looking substance underneath a small ceramic capacitor, one terminal of the capacitor was connected to a resistor that connected to one of the contacts of the foot-switch, the other terminal of the foot-switch was connected to circuit-ground, on a hunch I grabbed my digital multimeter, set it to the 20M resistance range, and measured the resistance of the capacitor, which should have measured close to infinity, it actually measured about 7.5 kilo ohms, that looked very suspicious to me, so I tried de-soldering the capacitor and then scraping away the whitish substance with a Stanley-knife blade, then I soldered the cap back into it's place on the circuit-board, result....that fixed the foot-switching malfunction completely and now the foot-switching reliably functioned as it was supposed to.

I'm going to take my Ibanez TS-808 pedal into uni tomorrow to give it a good test out with my Marshall amp along with my Boss BD-2 Blues Driver pedal (it had been playing-up too, but I believe I have also fixed it as well), will let you know how it goes.

stan
15-02-2017, 06:11 AM
good work Doc, nice when it's easier than expected

Andy40
15-02-2017, 11:38 AM
Nice work Doc. I still have all my pedals to fix.

DrNomis_44
15-02-2017, 04:05 PM
Update:

I just tried the TS-808 pedal out a few minutes ago, and it is playing up again, so I'm going to take it back home and have another look at it, it doesn't seem to be foot-switching properly, so maybe there's a faulty component somewhere.

DrNomis_44
12-03-2017, 01:14 PM
Update:

Apologies if this sounds a bit technical.

As far as I can determine, the circuitry on the TS-808's PCB that's responsible for turning on/off the two Fets (Field Effect Transistor) that do the footswitching, appears to be working okay, I verified this by using my signal-generator set to put out a square-wave at about 10Hz, when I applied the signal to one side of the two terminals of the mechanical footswitch, the indicator led blinked on and off, so, my conclusion is that either the mechanical footswitch has dirty intermittent contacts, or, something related to it is causing the pedal to footswitch intermittently.

Here's a schematic for the TS-808 that I found on the internet:

17991


In the schematic there are two resistors (a 62k and a 22k) connected in series going from V+ to circuit-ground, there's also another resistor (a 1M) connected to the junction between the 62k resistor and the 22k resistor, the 1M resistor is connected via a 22 Ohm resistor to one of the contacts on the mechanical footswitch, I think the cause of the intermittent footswitching has to be somewhere around this part of the circuitry.


Note: The two Fets in the schematic are the components marked 2SK30A.


The two 2SK30A Fets are being used as electronically controlled switches, and these route the input signal either straight-through to the output, or through the two Op-Amps (the two triangular shapes), when the mechanical footswitch is stomped-on, one of the 2SK30A Fets turns on and the other turns off.

DrNomis_44
26-03-2017, 10:27 PM
Update:

I was just doing some more work on my Ibanez TS808 pedal and I think I have finally cracked it this time round, in the schematic I posted, there is a small value capacitor (1000pf) going from one end of a 22 Ohm resistor to circuit ground, in my pedal it is a 10,000pF (10nF) ceramic capacitor, which appears to be the cause of the footswitching issue I've been experiencing, what I believe is going on with the capacitor is that it has gone leaky, but to detect it I had to set my digital multimeter to it's highest resistance range, I compared it with another known good 10nF cap (a yellow polypropylene type) and got very different results, so I tried using the yellow 10nF cap as a replacement, and now the pedal seems to reliably footswitching again like it's supposed to, I'll give it some soak-testing for some time just to be sure that I have finally fixed it for good now.

Simon Barden
26-03-2017, 11:26 PM
Is yours an original model or a re-issue? I've had mine since I bought it in 1980 and it's still working fine, though the pots are a bit scratchy and needs fairly regular doses of cleaner.
18385

DrNomis_44
26-03-2017, 11:47 PM
Is yours an original model or a re-issue? I've had mine since I bought it in 1980 and it's still working fine, though the pots are a bit scratchy and needs fairly regular doses of cleaner.
18385


Mine's actually a later re-issue, probably circa 2015 or so, I bought it last year from the Top End Sounds pro music shop, I have another pedal that needs some servicing work done on it to get it working again, it's my Boss Compressor/Sustainer, for some reason it doesn't seem to work at all, I'll need to find a schematic diagram for it and then do some tests on it.

Now that I think I've finally got my TS-808 working properly, I'm going to do one mod to it, which is to swap out the stock red indicator led for a blue one, the red one is a bit too dim for my tastes, should be a fairly straightforward mod to do.


Here's a pic of my TS-808 pedal:

18386


I've tried it out a few times after working on it and it definitely does seem to be working a lot better than before....touchwood.


I'm going to wait till tomorrow morning and give it another test out, if it is still footswitching reliably when I test it out, then I'll know that it is well and truly fixed for sure, I want to make sure because I'm not entirely 100% convinced that it is fixed though, last time I thought I had fixed it, it proved me wrong, and the last thing I want is for it to go bad again right in the middle of a gig, or jam session.

I'm pretty keen on using it as a booster pedal with my Marshall amp, because of it's midrangey tone, apparently these TS series pedals tend to shine best when used as a booster pedal to kick an amp that's just breaking up into overdrive, this involves setting the Drive control to a low setting and then turning up the level/volume control.

I'm guessing that it would work pretty well with my Fender Super Twin amp, and my Gold Strat.

stan
27-03-2017, 02:11 AM
Nice detective work Doc, hopefully it all stays put now

Simon Barden
27-03-2017, 06:34 AM
The super twin at least has a gain + master volume control. If not, you'd be up around 200W before any amp drive was apparent, and the volume boost from a tube screamer would be truly frightening.

The tube screamers are supposed to work best with Fender style amps, which generally have a dip in the mids as their standard sound. Boosting with a mid-rich pedal is suppose to fill that gap and make a Fender sound a lot more meaty (especially with single coils). Marshals are a lot more mid-heavy in character to start with, so a TS makes the sound even more so, which doesn't always work so well (though if you've cut most of the mids on the EQ for a scooped sound, then it will fill those back in).

DrNomis_44
27-03-2017, 04:14 PM
I just gave my TS-808 pedal another test out a few minutes ago and it is still footswitching reliably, so, I'll call it well and truly fixed now.

Who would have thought that one little 10nF ceramic disc capacitor would cause all that trouble?...but there you have it folks, funny thing is that the capacitor looks perfectly normal to me, that explains why the cause of the footswitching issue was difficult to find, faulty components don't always look like they're faulty.


Here's a pic of the faulty cap which caused the unreliable footswitching issue:

18401


So how did I determine it was faulty?, I used my digital multimeter set to it's highest resistance range (2000k, or 2M) to measure the DC resistance of the cap, which in theory should be infinite, when I measured it I got a reading of about 1.8M, I compared that reading to the reading I got when I measured the DC resistance of the yellow cap (a known good one) that I used as a replacement, and got an infinite resistance reading, I then soldered-in the replacement cap.

In the schematic I posted, there's a 68k resistor going from +V,this resistor is connected in series with a 22k resistor which connects to circuit ground, using my digital multimeter, I measured the DC voltage at the point where the 68k resistor and the 22k resistor connect to each other (it measured 2.28V), there's also a 1M resistor connected to that point, and this connects to one of the contacts of the mechanical footswitch via a 22 Ohm resistor, I found that the DC voltage on the 22 Ohm resistor side of the 1M resistor was measuring about .5v to about .8 v when the footswitching was not working properly, now what's really interesting is that when I removed the faulty cap, the voltage at that point of the circuit read about 1.6v, so, my conclusion was that something about the faulty cap was reducing the voltage when the cap was in-circuit, I can now understand what was going on, the 1.8M DC resistance of the cap in series with the 1M resistor was forming what's called a "Voltage Divider" in electronics, normally the DC resistance of the cap should have measured infinite, but, it was actually measuring 1.8M, the 1M resistor is acting as a "Pull-Up" resistor for the mechanical footswitch, when you press down on the footswitch it causes the normally 1.6V on the 1M resistor to drop to 0V, this acts as a trigger-signal for the rest of the footswitching circuitry, because the normally 1.6V was being pulled-down to about .5v by the faulty cap, the rest of the footswitching circuit wasn't being triggered properly, and seemed to be stuck in one state, pressing down on the mechanical footswitch had no effect, as soon as I replaced the faulty cap with the new yellow cap, the voltage measured 1.6v again, and that restored the footswitching to normal operation.

Simon Barden
27-03-2017, 06:05 PM
Have a look at the old cap and see if it's got any voltage value on it. Caps can go short or partially short-circuit if their voltage rating is exceeded. They might have used a cap with too low a voltage rating. That cap is there to take any voltage spike, caused by the foot switch, to ground. DC is a lot worse at causing switching spikes than AC and they normally occur on break of circuit when you get a very brief arc as the current continues to flow until the air gap gets too large to sustain it. The switching spike can be many times greater than the switched circuit voltage, so unless the replacement cap has a decent voltage rating, it's likely to occur again over time.

DrNomis_44
27-03-2017, 06:52 PM
Have a look at the old cap and see if it's got any voltage value on it. Caps can go short or partially short-circuit if their voltage rating is exceeded. They might have used a cap with too low a voltage rating. That cap is there to take any voltage spike, caused by the foot switch, to ground. DC is a lot worse at causing switching spikes than AC and they normally occur on break of circuit when you get a very brief arc as the current continues to flow until the air gap gets too large to sustain it. The switching spike can be many times greater than the switched circuit voltage, so unless the replacement cap has a decent voltage rating, it's likely to occur again over time.


That's a very valid point, the pedal itself only runs on +9V DC, and I'm guessing that the voltage-rating of those small disc ceramic caps is about 50V DC or so, as far as I can make out with my eyes alone, there is no marking on the cap indicating it's voltage rating, other than the three-digit marking indicating it's capacitance value, the replacement cap has a DC voltage rating of 100V DC so I think that it should be more than enough, now that you mention it, I was using a Switchmode Power Supply to power the pedal at one point before I noticed the footswitching issue, the Switchmode Power supply was designed to put out 18V DC at 2A, but, it was plugged into a small box that regulated the 18V DC down to +9V DC, and the pedal was getting regulated +9V DC.

It's possible that the ceramic dielectric of that ceramic cap may have gotten punctured by a spike coming from the Switchmode Power supply, but then again if that actually did happen then that would have taken-out all the other caps and the JRC4558D Op Amp IC too, I'm thinking that somehow the faulty cap might have suffered from moisture ingress, since the weather has been a bit humid and wet lately, and the moisture ingress is responsible for the 1.8M resistance reading I got, well it's about the best theory I can come up with so far, as a side note, I noticed that the cap seemed to be a bit temperature-sensitive too, desoldering it from the circuit board seemed to temporarily make it come good...how's that for a weird one?

Simon Barden
27-03-2017, 07:12 PM
You can get caps rated to just 2.5v or less. 100v should be enough though. The rating may be a code as it's a small cap. You can find the codes here: http://www.radio-electronics.com/info/data/capacitor/capacitor-markings.php

DrNomis_44
27-03-2017, 07:30 PM
You can get caps rated to just 2.5v or less. 100v should be enough though. The rating may be a code as it's a small cap. You can find the codes here: http://www.radio-electronics.com/info/data/capacitor/capacitor-markings.php


Cheers mate, I'll see if I can look up the voltage rating of the cap later on this week, maybe tomorrow after I buy a magnifier from Jaycar Electronics, been meaning to do that for a couple of weeks, will let you know about my findings.

I just remembered that I have a 20Mhz Dual Trace Oscilloscope that features a component tester function, I could use it to test the cap and see what results I get, just need to make up a set of test leads for it first though, might post some screenshots tomorrow when I get a chance to do so.

Simon Barden
27-03-2017, 08:54 PM
If it's got a capture facility, you could use the scope on the foot switching line to see if you do get occasional spikes and how big they are. Although having had a closer look at the schematic, I feel it fairly unlikely that they would be anything serious. Plus there are two other 1000pf capacitors connected to the flip-flop circuit that would see the same voltage spikes (if any) and should be affected in the same way (unless these had higher voltage ratings).

I'm more of a mind to think that it was just a single duff capacitor.

DrNomis_44
27-03-2017, 09:06 PM
If it's got a capture facility, you could use the scope on the foot switching line to see if you do get occasional spikes and how big they are. Although having had a closer look at the schematic, I feel it fairly unlikely that they would be anything serious. Plus there are two other 1000pf capacitors connected to the flip-flop circuit that would see the same voltage spikes (if any) and should be affected in the same way (unless these had higher voltage ratings).

I'm more of a mind to think that it was just a single duff capacitor.


I'm in the same frame of mind as you are about the duff cap, unfortunately my Oscilloscope doesn't have a capture facility, it's one of those old school analog CRT types I was able to buy before more expensive digital storage types became available, but, I really want to buy myself a new Digital Scope some time this year, Jaycar Electronics stock a 20Mhz Digital Scope that retails for something like Au$500.00 or so, they also stock a 100Mhz Digital Scope, but it's just over Au$1000.00.

One other thing I did was to replace the stock 100uF/16V Battery Bypass Cap with a new 330uF/16V one, it's not going to have any detrimental effects on the behavior of the TS-808 Circuit, it'll most likely improve the 9V supply rail filtering.

Simon Barden
27-03-2017, 09:22 PM
A 100MHz scope will tell you a lot more about the waveforms of short transients than a 20MHz scope will. Just a shame there's such a big price difference. You can get dual channel 100MHz (or even 200Mhz) scopes from China for nearer Au$750 (which I believe should make it duty-free for you) but I've got no idea how good they are.

DrNomis_44
27-03-2017, 09:31 PM
A 100MHz scope will tell you a lot more about the waveforms of short transients than a 20MHz scope will. Just a shame there's such a big price difference. You can get dual channel 100MHz (or even 200Mhz) scopes from China for nearer Au$750 (which I believe should make it duty-free for you) but I've got no idea how good they are.


It's definitely worth looking into though, I wonder if I could get a good 100Mhz Digital Scope on eBay for a good price, I'll have a look a bit later on tonight.

I may even be able to buy the 100Mhz Digital Scope from Jaycar if they will allow me to pay it off on layby, I'll ask them about it when I pay them a visit tomorrow.

Simon Barden
27-03-2017, 10:24 PM
It's all going to be about how many extra features they have, plus sampling rates. A lot of them seem to have very high sampling rates (1Ghz+) so that their anti-aliasing filter can have a gentle slope, so not ring and affect the higher frequency images.

DrNomis_44
27-03-2017, 10:28 PM
Some readers of this thread may be wondering why there's a capacitor going from the 1M resistor to circuit ground, there's a good reason for it being there which I'll explain, when you close the contacts of the mechanical footswitch, it doesn't just close it makes and breaks contact a few times before it finally closes, this behavior is called "Contact Bounce" in Electronics, it's not so much of a bad in Analog electronic circuitry, but in Digital circuitry it can cause havoc with the normal operation of a Digital circuit, the circuit that alternately turns the two 2SK30A Fets on and off in the TS-808 circuit is a Digital circuit called a Flip-Flop, you will notice that there are also two 1000pF caps connected to the junction of the 1M resistor and the cap going to circuit ground, these two 1000pF caps form the input of the Flip-Flop circuit, the cap going to ground is there to prevent false-triggering of the Flip-Flop circuit by the Contact-Bounce of the mechanical footswitch, if it was removed entirely, the Flip-Flop circuit would be triggered erratically this is because the Flip-Flop circuit interprets the noise-spikes generated by the Contact Bounce as a trigger signal because Digital circuits operate at fast speeds, putting the cap in it's place filters out the noise-spikes and gives the Flip-Flop circuit a clean trigger-signal.

DrNomis_44
28-03-2017, 12:13 PM
Just tested the pedal out a few minutes ago and it is still footswitching properly.....cool.

Simon Barden
28-03-2017, 06:20 PM
Good news, Doc.

I've got a couple of Pearl footpedals from 1983 that have stopped working. I decided to collect the whole set of them, so eventually tracked them all down on eBay. But they also did three double sized pedals (actually nearer 3x) in this short lived series that worked on 18v not 9v. They offer two versions of the same effect but normally with some extra features. For example, the Phaser has two speeds, and when you change speeds, it actually takes time to speed up or slow down, rather like a Leslie. Unfortunately my 18v adapter went missing and I didn't get to try them out until recently and two of them don't work at all. A shame, as they are nice pedals but being dual function, the circuit boards are crammed full of components so it's not easy to identify anything, even the circuit path.

Simon Barden
28-03-2017, 06:28 PM
Just looked the Pearl PH44 phaser up on line and they seem to be going for a lot of money now. I think I bought mine for £90/A$145 and I have seen some being sold for £400/$640!

The two non-working ones are the CE-22 chorus (an expanded Boss CE-1 format), and the AD-33 analogue delay.

DrNomis_44
28-03-2017, 06:35 PM
Good news, Doc.

I've got a couple of Pearl footpedals from 1983 that have stopped working. I decided to collect the whole set of them, so eventually tracked them all down on eBay. But they also did three double sized pedals (actually nearer 3x) in this short lived series that worked on 18v not 9v. They offer two versions of the same effect but normally with some extra features. For example, the Phaser has two speeds, and when you change speeds, it actually takes time to speed up or slow down, rather like a Leslie. Unfortunately my 18v adapter went missing and I didn't get to try them out until recently and two of them don't work at all. A shame, as they are nice pedals but being dual function, the circuit boards are crammed full of components so it's not easy to identify anything, even the circuit path.


If you've got a Digital Multimeter, try plugging in a guitar lead into the input with the bottom cover removed, and then check to see if the circuit board is getting any power, that's the first thing I'd do with those non-functional pedals, if no power is getting to the circuit boards, try checking if you're getting power on the solder lugs of the power socket, if you are, then it'll most likely be a break in the power wires going to the circuit boards, hope that helps.

Let me know how you go with them.

DrNomis_44
28-03-2017, 06:46 PM
Just looked the Pearl PH44 phaser up on line and they seem to be going for a lot of money now. I think I bought mine for £90/A$145 and I have seen some being sold for £400/$640!

The two non-working ones are the CE-22 chorus (an expanded Boss CE-1 format), and the AD-33 analogue delay.


I reckon that the CE-22 pedal, and the AD-33 are worth fixing, if you're lucky it may only be one minor component that's causing them to not work, I'm wondering if the AD-33 uses Bucket Brigade ICs, if so, and if any of them are faulty, it may be hard to find replacements, and a bit expensive if you can find them, some 70's era Analog Delay and Phaser/Flanger pedals used Bucket Brigade ICs, like the SAD1024 (Electro Harmonix Memory Man and Electric Mistress),the SAD1024 is getting harder to find, and very expensive too, heard some stories of people unknowingly buying fake/counterfeit ones on eBay.

Simon Barden
28-03-2017, 06:48 PM
I've done that bit, but everything was OK. On one I did find a bent over component that was shorting out on another track. Straightening that got the effect on/off light working but still no sound. Just can't find any schematics for these on-line, which would help considerably.

DrNomis_44
28-03-2017, 07:04 PM
I've done that bit, but everything was OK. On one I did find a bent over component that was shorting out on another track. Straightening that got the effect on/off light working but still no sound. Just can't find any schematics for these on-line, which would help considerably.


If both pedals use electronic footswitching like the TS-808, see if you get sound when the pedals are bypassed.

Simon Barden
28-03-2017, 07:10 PM
I will. It was over a year ago that I last looked at them, and can't remember any more than the above and whether I got anything at all in bypass.

dave.king1
28-03-2017, 07:24 PM
There are schematics sites that may help, I have it bookmarked on my PC which is now off I'll post the links up in the morning.

May have already seen the site but will post anyway

Simon Barden
28-03-2017, 07:42 PM
They normally come up quickly on the images section of a Google search, but I've had no luck so far. However this particular rage of pedals were only made for a couple of years around 82/83, so they are relatively rare and the schematics may never have been made available. I bought an Octaver pedal at the time, it was far better than the Boss one). But I expect they failed to compete with Boss, or their corporate philosophy changed and decided they weren't going to do guitar FX any more, so stopped making them.

But thanks for the offer Dave, and I'll have a look through the sites when you get the links up.

dave.king1
29-03-2017, 09:08 AM
Sorry I'm late back to the party with this, we are minding grandchild No.8 today and I've been on poppy duty :)

I can't remember who referred me to these, I was looking for an old Electronics Today magizine circuit for a guitar box called an attack delay unit. No one could help with that but included in these links is the Boss Slow Gear ( Boss SG-1 ) which is/was the same thing it fades onto the note so you can get a nice violin effect and the one I built back around 1970 gave a beautiful creamy overdrive on bypass so I probably stuffed something in the build.

Here's a bunch of schematics and kits
http://www.generalguitargadgets.com/how-to-build-it/technical-help/schematics/

And another site with just kits and stuff
https://www.pedalempire.com.au/collections/byoc-pedals

dave.king1
29-03-2017, 09:10 AM
A quick google found this

https://www.google.com.au/search?q=pearl+ph-44+schematic&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwibzOnlw_rSAhWCabwKHXtDB38QsAQIGA&biw=1440&bih=791

And then this

http://s853.photobucket.com/user/bernardduur/media/Schematics/PearlPH44-Audio.jpg.html

DrNomis_44
29-03-2017, 02:13 PM
Cheers for the schematics links dave.king1, those will definitely be useful, I seem to remember that ETI Attack/Release circuit, well it does sound familiar to me anyway.

dave.king1
29-03-2017, 02:35 PM
The circuit diagram link I posted up doesn't include the tone stage, but it is there I'll post the link later

DrNomis_44
29-03-2017, 02:57 PM
The circuit diagram link I posted up doesn't include the tone stage, but it is there I'll post the link later


Cheers mate.

dave.king1
29-03-2017, 03:32 PM
Power cct
http://s853.photobucket.com/user/bernardduur/media/Schematics/PearlPH44-Power.jpg.html

Pretty sure this is the tone stage
http://i853.photobucket.com/albums/ab93/bernardduur/Schematics/PearlPH44-Phase.jpg

Probably easier to go here and pick the bones out of it
https://www.google.com.au/search?q=pearl+ph-44+schematic&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwibzOnlw_rSAhWCabwKHXtDB38QsAQIGA&biw=1440&bih=791#imgrc=_

Simon Barden
29-03-2017, 04:31 PM
Fortunately Dave, my PH-44 works well. Unfortunately it's the CE-22 Chorus and the AD-33 delay that I need the diagrams for and which I couldn't find. I can find something for the Pearl single pedal delay, but not the dual one. Couldn't see anything in those links you put up either.

DrNomis_44
29-03-2017, 04:56 PM
Fortunately Dave, my PH-44 works well. Unfortunately it's the CE-22 Chorus and the AD-33 delay that I need the diagrams for and which I couldn't find. I can find something for the Pearl single pedal delay, but not the dual one. Couldn't see anything in those links you put up either.


It may be that you might be able to use the schematic for the single delay to service the dual delay pedal, often you'll find that manufacturers will cut manufacturing costs by just using existing circuits and doing minor mods on them to create new pedal designs, there should be enough similarities between the single and dual delay to enable you to get some idea where the cause of the non-functioning pedal may be, that's something you could try if you can't find a schematic anywhere.

Simon Barden
29-03-2017, 05:00 PM
Possibly, though the higher supply voltage (18V vs 9V) means that the power regulation chips will certainly be different and power rails will probably be higher voltages to increase the headroom (maybe converted to +9V, 0V and -9V rails).

dave.king1
29-03-2017, 05:04 PM
No worries Simon, I'll go digging again tomorrow

dave.king1
30-03-2017, 02:06 PM
Here ya go Simon

Pearl CE-22 & AD-33 Lots of Schematic images and pics, I'll leave it to you to sort the chaff from the straw

CE-22
https://www.google.com.au/search?q=pearl+ce-22+schematic&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjogfytx_3SAhULs1QKHcsXCrkQ_AUIBigB&biw=1440&bih=791#imgrc=_

AD-33
https://www.google.com.au/search?q=pearl+ce-22+schematic&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjogfytx_3SAhULs1QKHcsXCrkQ_AUIBigB&biw=1440&bih=791#tbm=isch&q=pearl+ad33+schematic&*

Simon Barden
30-03-2017, 06:40 PM
Unfortunately Dave, no joy. Looked at the CE-22 first. Schematics aplenty, but most were for the Pearl CH-02 chorus, the rest for Boss choruses and others for non-specific chorus designs. But no CE-22 schematic. likewise for the AD-33. If you put quotes around "Pearl CE-22" it cuts out a lot of unwanted stuff (especially pictures of oysters), but no schematics. But thank you for trying.

dave.king1
31-03-2017, 05:02 AM
No worries Simon, gave it a shot.

There's a couple over in the UK who run a business repairing H||H amplifiers that I've had some dealings with, given their interest in odd stuff they could be worth asking because people with interesting hobbies/ businesses tend to network.

I'll post a link back here when the PC is on

Simon Barden
31-03-2017, 05:31 AM
My mate Ivan once had a company that use to make HH amps on contract for them!

dave.king1
31-03-2017, 06:38 AM
I've still got the H||H IC-100S that I purchased new around 1975, had to hunt down a schematic and some filter caps and that's how I found these guys and have found them easy and pleasant to deal with, despite what the website may suggest

http://www.majelectronic.co.uk/

The HH is incredibly loud, guaranteed minimum 100W RMS into 4 ohms and through a Marshall quad box it sounded massive. Now runs through an 8 ohm 4x10 Eminence loaded box ( had a brain fade when I purchased the speakers :D )

DrNomis_44
11-04-2017, 02:01 PM
I've still got the H||H IC-100S that I purchased new around 1975, had to hunt down a schematic and some filter caps and that's how I found these guys and have found them easy and pleasant to deal with, despite what the website may suggest

http://www.majelectronic.co.uk/

The HH is incredibly loud, guaranteed minimum 100W RMS into 4 ohms and through a Marshall quad box it sounded massive. Now runs through an 8 ohm 4x10 Eminence loaded box ( had a brain fade when I purchased the speakers :D )


Didn't Marc Bolan from T Rex use one of those in his stage rig at some point in his career?, I think I remember playing through one some years ago, they're actually pretty cool sounding solid state amps, I think they were one of the first amps to use the then new LM741 Op Amp ICs.

Kick
23-04-2017, 03:46 PM
This topic triggered me since I also have an Original TS-808 which I bought in 1980. I also found this page: http://www.analogman.com/tshist.htm

Could be of any help?

DrNomis_44
23-04-2017, 04:04 PM
Cheers for posting that link Kick, will definitely be helpful.


There's also this website too, lots of info:

https://www.tonehome.de/ibanez/9-series/pt9-phaser/

Simon Barden
23-04-2017, 04:46 PM
I had a PT-909 phaser as well (narrow box, 3-control, round footswitch version). It was OK, but not as good sounding to me as a friend's MXR Phase 90. I bought it before I got the TS-808, which is probably why I bought the TS-808 (being another Ibanez pedal) rather than any other drive pedal. I got rid of it a long time ago for peanuts.

DrNomis_44
06-05-2017, 12:04 AM
I had another hiccup with my TS-808 pedal earlier tonight, I plugged my guitar in expecting the pedal to work fine and it made a really strange squealing noise which eventually went away, and then it stopped footswitching properly, the indicator Led refused to light up when the pedal did footswitch, and then the sound got very distorted as if the battery was dying, I tried plugging in my Carson 9V plugpack in the DC in socket on the TS-808 pedal and the pedal worked perfectly, so, I got my multimeter and used it to test the battery, it read about 9.2V, I tried a second good 9V battery just to be sure with same results, so I had a look at the 9V battery connector and...as it turned out the cause of the malfunction was simply a broken red wire in the 9V battery clip itself, so I carefully desoldered the battery clip wires and then replaced the battery clip with a new one, that fixed the pedal completely so it worked properly with a 9V battery.

Andy40
07-05-2017, 03:51 AM
That would have taken me hours to work that out doc...

Kick
07-05-2017, 04:02 AM
Nice example of deducted research. Good job!

DrNomis_44
10-05-2017, 03:18 PM
Update:


Seems like I'm still not out of the woods with my TS-808 pedal, the pedal seems to function fine when my Carson 9V DC Plugpack adaptor is plugged into it, but when I try to run it off it's internal 9V battery it doesn't seem to be working properly, I've tested the 9V battery and it is fine, so I'm thinking that it's either the replacement battery clip, or a bad contact in the DC in socket, so, I'm going to have to do some more detective work with my multimeter this afternoon.


A lot of the times with these pedals there's a couple of contacts in the DC in socket that disconnect the battery when a plugpack adaptor is plugged into it, when the plugpack is disconnected from the pedal, the two contacts short-together and connect the 9V battery up to the circuit-board in the pedal, if these contacts are dirty then the contacts won't properly short together, I might have a replacement socket that I can use in amongst my bits and pieces.


Update:

After a quick bit of detective work with my multimeter, I think I have found the cause of the problem, it appears that the two contacts in the DC in socket that connect the + terminal of the 9V battery to the power in on the circuit board, aren't making proper contact like they're supposed to, checking the continuity of the contacts with my multimeter set to continuity test produces no beeping sound from my multimeter, thus indicating that that there's no continuity between the two contacts when there should be, because of this the circuit board isn't getting power from the 9V battery when it's supposed to, the reason why the pedal powers up with my Carson 9V DC plugpack adaptor is that the plugpack adaptor is bypassing the battery when it's plugged in, so, replacing the DC in socket should fix the problem once and for all.

Simon Barden
10-05-2017, 04:37 PM
You could always try squirting some contact cleaner into the 9v socket, then push the adapter in and out a few times to see if that clears any dirty or corroded contacts.

Also worth double-checking that you didn't connect the new battery clip wires the wrong way round.

DrNomis_44
10-05-2017, 04:42 PM
You could always try squirting some contact cleaner into the 9v socket, then push the adapter in and out a few times to see if that clears any dirty or corroded contacts.

Also worth double-checking that you didn't connect the new battery clip wires the wrong way round.


Cheers mate, I guess I could have tried cleaning the contacts, but it's easy enough just to replace the original DC in socket altogether cause I've found a replacement for it that I know is a good one, when I soldered in the new battery clip, I triple-checked that I got the polarity correct.

Simon Barden
10-05-2017, 04:45 PM
Glad you triple-checked at the time. It's always worth asking the question, just in case.

Just a thought, but why isn't 'triple' spelt with 3 'p's. ;)

DrNomis_44
10-05-2017, 04:56 PM
Glad you triple-checked at the time. It's always worth asking the question, just in case.

Just a thought, but why isn't 'triple' spelt with 3 'p's. ;)


Yep, as the saying goes "Measure twice, cut once", and I agree, it's always good to triple-check things to make sure they are 100% correct, because human beings aren't infallible, we make mistakes, and it's usually when we have lapses in concentration that mistakes are more likely to occur.

I think the reason why "Triple" isn't spelt with three 'p's is probably due to one of those quirks of the English language, the really interesting thing is, the English language is actually a mixture of other languages which goes back to ancient times.


I'm just in the process of searching for some suitable wire to wire-up the new DC in socket to the circuit board, I really want to find a piece of 3-way ribbon cable rather than use three separate pieces of wire, just to keep things neat.

Update:

I just found exactly what I was after, all I need to do now is un-solder the old DC in socket and replace it with the new one and then it should be good to go.

I'll post some pics so you can see what the old socket and the new socket look like and the piece of 3-way ribbon wire I used to fit the new socket to the circuit board....stay tuned.


Here we go:


19260


The small socket on the left hand side of the pic is the original DC in socket, the one on the right hand side is the new one, next to the new one is the piece of 3-way ribbon wire I'm going to use to connect it to the circuit board, the reason for that is that the new socket is a bit wider than the original, so I need to turn it 90 degrees in order to get it to fit, this necessitates connecting the three terminals to the circuit board via three pieces of wire, the good news is that the new socket will fit in the hole in the pedal's casing, and it will be held securely in place via a thin nut.


Before going any further, I thought it would be prudent to check that the two switched-contacts in the new DC in socket were indeed good, so I used my multimeter set to continuity test to test for continuity between the two contacts, fortunately they tested good.


And then out of curiosity, I picked up the old DC in socket and had a look at it,.....and now I know, as it turns out, one of the terminals on the old DC in socket is a bit loose (it happens to be one of the switched contacts that disconnects the battery when the adaptor is plugged in), I'm guessing that heat from soldering probably caused it to come lose.


So there you have it folks....the root-cause of all the trouble.

Simon Barden
10-05-2017, 05:24 PM
...adjusts dial...

DrNomis_44
10-05-2017, 06:04 PM
And here's a pic of the modified new DC in socket:

19266


All I need to do now is solder the tinned ends of each of the three wires to their respective solder pads, and then mount the new DC socket in it's mounting hole in the pedal's casing, and then the repair job is done.


Update:

Just tested it out prior to putting the pedal back together again, and the pedal seems to be working properly again with it's 9V battery powering it, so...I'm calling it fixed.


And as you can see from the pic, the repair is un-noticeable:

19267

stan
10-05-2017, 06:48 PM
Nice fix Doc, must be good to have it back in action

DrNomis_44
10-05-2017, 07:18 PM
Nice fix Doc, must be good to have it back in action


For sure, knowing that all your musical gear is working like it's supposed to, makes things a lot easier, and stress-free, plus it enables you to focus on making music, I'm sure you'd agree mate.


My TS-808 pedal is sounding good with both my LP Studio and my Gold Strat, and it also plays nicely with my new Boss RE20 pedal as well, I'm getting some pretty cool Blues sounds at the moment.

DrNomis_44
21-02-2018, 08:43 PM
Update:


Recently I had been experiencing a weird issue with my TS-808 pedal, everything seemed to be okay when the TS-808 pedal was bypassed, but, when I engaged it I noticed that the output level was a bit low and would gradually get a bit louder, so I decided to have a look inside it to see if I could figure out what was going on, and it was while I was looking inside the pedal that I accidentally found the cause of the issue, I found a loose wire that had obviously broken away from the circuit board, the wire went to the middle solder lug on the output-level control pot, I examined the component side of the circuit board to see where the wire came from and found an empty hole next to some other wires, so I flipped the circuit board over, located the solder pad, used some solderwick to desolder the pad, a small piece of wire came away from the solder pad, next I stripped the end of the loose wire, tinned it and then soldered it to the circuit board, when I gave my TS-808 pedal a test out after putting it all back together I found that it was now working again as it was supposed to, with good output level, what's more, it no longer behaved like it did before, so I'm considering it fixed for the time being.

Marcel
21-02-2018, 09:05 PM
Damn those random capacitive couplings.... such a nuisance...

DrNomis_44
21-02-2018, 09:28 PM
Damn those random capacitive couplings.... such a nuisance...


Actually, the wire had broken off just inside the hole in the circuit board and was causing a high-resistance path for the output signal on the wiper of the output level pot, hence the reason why the output level gradually increased when the pedal was engaged, but since the wire was still in the hole, it looked perfectly normal to me, I only discovered it by accident when I somehow disturbed it enough so that it fell out of the hole in the circuit board.

This is a case where a happy accident saved me a lot of fault-finding time, and it turned out to be a relatively easy fix.


Note: If you have a look at the circuit diagram of the TS-808 that I posted, the wire that broke off the circuit board is represented by the line that goes from the wiper connection (the little arrow) of 100k Log level control, to the source of one of the footswitching Fets, when the TS-808 is bypassed, that Fet is turned off and the other Fet is turned on, allowing the signal from the input buffer to flow to the output buffer, hence the reason why the issue only occurred when the pedal was engaged.

The Signal from the wiper of the output level pot was getting to the output buffer, but, because of the high-resistance caused by the break in the wire, the output level was lower that it normally would have been.


Note 2: I almost forgot to mention that I used my 20Mhz Analog Dual Trace Oscilloscope to monitor the output level at the output jack on the side of the pedal, definitely a handy piece of test-equipment to have on hand.


My Dick Smith Electronics Q-1804 20Mhz Dual Trace Oscilloscope:

24937


With the help of my dad, I ordered it from Dick Smith Electronics in 1998, making it about 20 years old by now, still seems to be going strong.

Marcel
22-02-2018, 05:30 AM
You've got the newer version.. Mine is a '86 vintage 20MHz Kenwood from the same retail chain. It works but the gain and timebase controls are in dire need of replacement due to use and so are very touchy... Much more a 'just turn it on and then set and forget' device nowadays...

Been looking at a modern replacement via Ebay that will cost near half what I paid way back then for my old and tired Kenwood...

https://www.ebay.com.au/sch/i.html?_from=R40&_sacat=0&_nkw=DSO5102P&rt=nc&LH_PrefLoc=1&_trksid=p2045573.m1684

DrNomis_44
22-02-2018, 09:47 AM
You've got the newer version.. Mine is a '86 vintage 20MHz Kenwood from the same retail chain. It works but the gain and timebase controls are in dire need of replacement due to use and so are very touchy... Much more a 'just turn it on and then set and forget' device nowadays...

Been looking at a modern replacement via Ebay that will cost near half what I paid way back then for my old and tired Kenwood...

https://www.ebay.com.au/sch/i.html?_from=R40&_sacat=0&_nkw=DSO5102P&rt=nc&LH_PrefLoc=1&_trksid=p2045573.m1684


My DSE Q-1804 cost around Au$700.00 when my dad and I bought it brand new, one thing I'll have to do one day is replace the trimpot (I'm guessing that's what it is) for the trace rotation cause it's getting increasingly hard to adjust.


Been seriously thinking of getting myself a good Digital Scope for a long time, I found that Jaycar Electronics stock a couple of good ones, a 20Mhz one and a 100Mhz one, the 100Mhz one is the more expensive of the two.

Simon Barden
22-02-2018, 05:04 PM
That trimpot may just need a squirt of contact cleaner, rather than replacement. Worth trying that first.

DrNomis_44
22-02-2018, 05:10 PM
That trimpot may just need a squirt of contact cleaner, rather than replacement. Worth trying that first.


It's not so much that, it's one of those miniature blue plastic PCB -mounted trimpots that has a white plastic centre where the adjustment screwdriver goes, basically over the years I've had the Scope the white plastic screwdriver adjustment centre for the trimpot got a bit worn so that the trimpot has gotten hard to adjust, but yes I could try giving it a spray with contact cleaner.

Simon Barden
22-02-2018, 05:27 PM
Ah, I see. Well, if you can get to it - replace it!

DrNomis_44
22-02-2018, 05:40 PM
Ah, I see. Well, if you can get to it - replace it!


For sure, I think I should be able to get a replacement for it from Jaycar Electronics with not too much trouble, might be a good idea to see if I can find a service manual for the Scope on the internet, as it is, the Scope is still quite useable as a piece of test equipment.

Simon Barden
22-02-2018, 06:06 PM
Mine is a '86 vintage 20MHz Kenwood
That would mix up cake in no time! ;)

DrNomis_44
22-02-2018, 06:13 PM
Hahahaha....

DrNomis_44
22-02-2018, 06:26 PM
My Scope has a couple of useful functions built into it, it can be operated in X/Y mode which is useful for checking phase, and it also features a component tester function.

Marcel
22-02-2018, 08:22 PM
That would mix up cake in no time! ;)

Yep! Also lets me talk on Chicken band radio, and chills my beer.... and somewhere there is a function to make home movies... ;) ;) ;)