Search found 364 matches

by floris
19 May 2020, 17:37
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Ibanez BPL Bi-Stage Phaser and Ibanez PH10 Bi-Mode Phaser
Replies: 4
Views: 1462

Re: Ibanez BPL Bi-Stage Phaser and Ibanez PH10 Bi-Mode Phaser

The feedback pot takes the delayed signal from the output of the phase stages and routes a portion of that back into the input of the phase stages. The sound gets more resonance this way, making a more pronounced phasing signal. The difference between no feedback or max feedback should be quite audi...
by floris
09 Feb 2020, 13:56
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Amdek - CHK-100 ( Chorus ) [schematic]
Replies: 9
Views: 5669

Re: Amdek - CHK-100 ( Chorus ) [schematic]

A nice article with scans and schematic of the Amdek CHK-100 chorus can be found here:
https://www.muzines.co.uk/articles/amde ... s-kit/4433
by floris
24 Jan 2020, 15:32
Forum: Modern Stompbox Effects (1975 - ...)
Topic: MXR - M-108 Ten Band EQ new version [schematic]
Replies: 44
Views: 26260

Re: MXR - M-108 Ten Band EQ new version [schematic]

I ordered and received a replacement 20K W tapered slider pot from KeyMusic in Rotterdam in The Netherlands some time ago. It is part nr: MXR WMDU ECB046 20K REPLACEMENT SLIDER POT FOR MXR® EQ PEDALS It costed 7,50 euro + 5,- euro shipping. I replaced the faulty Gain slider pot in the MXR EQ and all...
by floris
24 Jan 2020, 15:29
Forum: Parts Sourcing & Trading
Topic: Slide potentiometer for black MXR Ten Band EQ
Replies: 5
Views: 2759

Re: Slide potentiometer for black MXR Ten Band EQ

I received the 20K W tapered slider pot from KeyMusic in Rotterdam The Netherlands some time ago. It is part nr: MXR WMDU ECB046 20K REPLACEMENT SLIDER POT FOR MXR® EQ PEDALS It costed 7,50 euro + 5,- euro shipping. I replaced the faulty Gain slider pot in the MXR EQ and all is working fine again! :-)
by floris
07 Jul 2019, 10:24
Forum: Boutique Stompboxes dissected...
Topic: TC Electronic - Spark Booster [traced]
Replies: 46
Views: 17799

Re: TC Electronic - Spark Booster [traced]

You have to check if the electrolytic capacitors can handle the higher voltages.
by floris
14 Jul 2018, 15:02
Forum: Boutique Stompboxes dissected...
Topic: TC Electronic - Spark Booster [traced]
Replies: 46
Views: 17799

Re: TC Electronic - Spark Booster [traced]

I have just repaired a Spark Booster, that did not power up, by replacing R46 1 Ohm, that is in series with the protection diode D9 (D7 in the schematics), with a jumper wire. R46 in this pedal was not 1 Ohm (anymore) but 730 kOhm! This resulted in not having +9V power on the PCB. After R46 was jump...
by floris
16 Jun 2018, 14:03
Forum: Pedal Debugging & Troubleshooting Support
Topic: Boss PH-3 LED always on and no effect
Replies: 6
Views: 313

Re: Boss PH-3 LED always on and no effect

Ah right...

I see a lot of digital pedals that have burned out 3,3V convertor chips.
Makes me wonder if a small universal replacement 3,3V power "helper" PCB would be handy, to repair these sorts of problems.
by floris
16 Jun 2018, 12:53
Forum: Pedal Debugging & Troubleshooting Support
Topic: Boss PH-3 LED always on and no effect
Replies: 6
Views: 313

Re: Boss PH-3 LED always on and no effect

The voltages at DC-DC regulator IC7 should be: +9V at pin 5 of IC7. +3.3V at pin 3 of IC7. IC7 is a S-8520E33MC DC-DC convertor chip that makes +3.3V out of the +9V power supply: https://www.digikey.com/products/en?lang=en&site=us&keywords=S-8520E33MC-BJST2U https://mouser.com/ProductDetail/628-8520...
by floris
31 Mar 2018, 17:40
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - DD3 Digital Delay [schematic]
Replies: 13
Views: 5969

Re: Boss - DD3 Digital Delay [schematic]

Seeing that MUTE (IC7 pin 59) is connected to the inputs of IC4d and IC4b via the Mode switch in Hold position, I can probably assume that MUTE is an output?
So why is MUTE always at 0V in my DD3 version A?
by floris
31 Mar 2018, 14:12
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - DD3 Digital Delay [schematic]
Replies: 13
Views: 5969

Re: Boss - DD3 Digital Delay [schematic]

IC7 pins 23 EFSW, 25 FETSW and 26 HOLD, seem to work as they should. The LED also works as it should. But I'm having difficulty with interpreting the states of pins 59 MUTE, 63 TIME4, 65 TIME6. They work with the Mode of the pedal. The Mode knob connects: - MUTE with TIME4 in 50ms Mode. - MUTE with ...
by floris
31 Mar 2018, 10:57
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - DD3 Digital Delay [schematic]
Replies: 13
Views: 5969

Re: Boss - DD3 Digital Delay [schematic]

Thanks for the tip Dirk.
I have repaired a few DD3s by replacing the bad 10uF caps. In those cases I could always measure that some coupling capacitor did not pass the signal. This seems not to be the case with this one.
by floris
30 Mar 2018, 22:20
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - DD3 Digital Delay [schematic]
Replies: 13
Views: 5969

Re: Boss - DD3 Digital Delay [schematic]

Thanks again for thinking about this with me. Much appreciated. :thumbsup
I will try your suggestions and see where that takes me.
Learning something new every day! :-)
by floris
28 Mar 2018, 21:21
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - DD3 Digital Delay [schematic]
Replies: 13
Views: 5969

Re: Boss DD3 [schematic]

You should be able to measure (if you have a scope) the voltage on C033 or better on Q006 source and see your delayed audio as a waveform. If nothing there, try 8b output - this will be jumping around but at least you should see it change when there's audio coming in. If that's all dead check the b...
by floris
14 Mar 2018, 18:06
Forum: Boutique Stompboxes dissected...
Topic: Keeley - 30ms Double Tracker
Replies: 6
Views: 2296

Re: Keeley - 30ms Double Tracker

Some picts with IC1 TL074 quad opamp removed: 2018-03-14 16.34.24 - Copy.jpg 2018-03-14 16.34.39.jpg Opamp B has minus input and output connected together so it is a buffer. Opamp C has a resistor between input and output and works as an amplifier or mixer. Opamp D is not used. In my pedal, the sign...
by floris
09 Mar 2018, 13:41
Forum: Boutique Stompboxes dissected...
Topic: Keeley - 30ms Double Tracker
Replies: 6
Views: 2296

Re: Keeley - 30ms Double Tracker

Boba7 wrote:Is the 3pdt latching or momentary?
It is a latching switch.
by floris
07 Mar 2018, 23:06
Forum: Boutique Stompboxes dissected...
Topic: Keeley - 30ms Double Tracker
Replies: 6
Views: 2296

Re: Keeley - 30ms Double Tracker

Boba7 wrote:A relay AND a 3pdt?
Yes I also found that interesting. Seems overkill.

Also the PCB mentions a "trails" function next to the 2 DIP switches and at the bottom of the PCB.
But this is not implemented as far as I can see.
by floris
06 Mar 2018, 18:41
Forum: Boutique Stompboxes dissected...
Topic: Keeley - 30ms Double Tracker
Replies: 6
Views: 2296

Keeley - 30ms Double Tracker

Keeley 30ms Double Tracker gutshots. Spin Semiconductor FV-1 for audio delay / detune / reverb: http://www.spinsemi.com/products.html 24LC32A 8pin DIP EEPROM that holds the program for the FV-1 chip. TL074 for the audio path, probably buffers and such to interface with the FV-1 chip. TQ2-9V "single ...
by floris
16 Feb 2018, 10:21
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - DD3 Digital Delay [schematic]
Replies: 13
Views: 5969

Re: Boss DD3 [schematic]

Thanks for the detailed explanation, it confirms what I was thinking and makes it all very clear.
Yes I have a scope, so I'll probe some more to see what is failing. Currently I suspect the Sample & Hold circuit IC3b 4066.
by floris
13 Feb 2018, 17:16
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Boss - DD3 Digital Delay [schematic]
Replies: 13
Views: 5969

Re: Boss DD3 [schematic]

A question about the Boss DD3-A: DD-3A_SERVICE_NOTES.pdf http://www.freestompboxes.org/download/file.php?id=27741 Mine has only clean signal but no delay signal. I see that the AD conversion is done by a "Successive approximation ADC" with the micro-controller IC7, the resistor ladder RA1, Sample&Ho...
by floris
06 Feb 2018, 19:02
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Ibanez BPL Bi-Stage Phaser and Ibanez PH10 Bi-Mode Phaser
Replies: 4
Views: 1462

Re: Ibanez BPL Bi-Stage Phaser and Ibanez PH10 Bi-Mode Phase

After adjusting the Width trim-pot, VR4 1k Ohm, I found that the maximum range of the Width could be a bit larger so that the Phaser can "move" from more low to more high. For this I changed R66 82k Ohm resistor, that is in series with the Width pot, on the potentiometer PCB that holds the LFO, into...