MXR - M-108 Ten Band EQ new version

floris · Post by **floris** » 12 Dec 2017, 19:13

Dunlop has the sliders on their website (but you can't buy them directly from Dunlop):

https://www.jimdunlop.com/product/ecb04 ... 07226-8.do

Dunlop refered me to AB Music (algambenelux.be) but they also don't deliver directly to an end customer.
They refer me to an "MXR dealer" or repair service like Kebe.nl.

So what happens is that I need to order it from Kebe repair centre (in Eindhoven The Netherlands), who need to order the slider from AB Music (Antwerp Belgium), who will in turn have to order it from MXR/Dunlop (U.S.A.) who have ordered it from some distributor (perhaps U.S.A) which had ordered it from a manufacturer (probably Asia).
So the slider will go through 5 different locations, has been in 3 continents and 5 countries, and will be priced upwards 4 times (everybody want to earn some money, right?) ...

How tiresome... and a waste of energy... Why isn't there a more direct route for getting a specific simple slider? Is this still the 1980-ies or something?
(Sorry for the rant... currently a bit frustrated...)

floris · Post by **floris** » 13 Jan 2018, 16:44

Slider search is continued here: https://www.freestompboxes.org/viewtopic ... 17&t=28737

I ordered a replacement slider from Key Music in Rotterdam The Netherlands for 7,50 euro and 5,- euro shipping.
"MXR WMDU ECB046 x 1 (EUR 7,50)"

Ashura · Post by **Ashura** » 12 Oct 2018, 17:24

x-tn wrote:There is a 'newer' version called M108S.
It says "...it's been upgraded with noise-reduction circuitry, true bypass switching, a lightweight aluminum housing, brighter LEDs, and a second output."
https://www.jimdunlop.com/product/m108s ... 09564-9.do

Would anyone have the schematic and PCB photos of this new version?

hemisfeer · Post by **hemisfeer** » 17 Jul 2019, 21:22

Hey everyone! First of all a big thank you to Apollo Music Service for doing the hard work of tracing this circuit. I just received an M-108 for repair. It had gotten wet and dried out, and sat for a few years. My issue is SP1 and SP2 stay dimly lit when in bypass. And the LED in SP3 is intermittent. I reflowed the solder for the CLR's and it didn't seem to make a difference. I also sprayed the sliders with Deoxit and allowed them to dry for a day.
I read in a previous post that someone just rearranged a few of the SP's and the problem was fixed. I was thinking of just removing the two trouble pots and clean the leads and reinsert them. Any insight would be helpful. Thanks.

floris · Post by **floris** » 24 Jan 2020, 15:32

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 is working fine again!

Henz · Post by **Henz** » 24 Feb 2022, 03:33

Greetings! I have been searching for an answer. Please help . I have that black mxr 10 band m- 108 pcb rev e. I need two caps .cap 9 for the 4k (3.3n) and cap 18 for 250Hz (680n) . the schematic is here but doesn't show the voltages. Can someone please tell me what they are so I can order them? Thank you for your time, James L.

Fender3D · Post by **Fender3D** » 24 Feb 2022, 12:08

anything above 16V will do

Henz · Post by **Henz** » 14 Mar 2022, 16:44

I'm a bit confused. After viewing another schematic here, is the 4 k cap a 3.3n or a 33n? Thanx everyone! Jim

floris · Post by **floris** » 14 Mar 2022, 17:48

The schematic that I have shows 2 capacitors for the 4kHz band:
C9 3n3 (inside the opamp feedback loop)
C10 33n (connected to 4kHz slider)

Henz · Post by **Henz** » 14 Mar 2022, 18:16

Ty. I'm 99.9% sure the pcb board says cap 9. Go with what the board says? 3.3n? As mentioned above, order them above 16v? Thanks brother. Jim

floris · Post by **floris** » 14 Mar 2022, 18:27

C9 should be 3,3nF (3n3). The DC power voltage is 18V so the caps should be rated for at least 18V.

Henz · Post by **Henz** » 16 Mar 2022, 06:00

Ty. For verification, is cap 18 ( 250 Hz) a 680n? Same voltage? Thank you for your time, Jim

floris · Post by **floris** » 21 Mar 2022, 17:02

> "is cap 18 ( 250 Hz) a 680n? Same voltage? "
Yes and yes

Henz · Post by **Henz** » 01 Apr 2022, 17:17

Ok, just got back with tech support from MXR/ Dunlop. Said cap 9 is 3,300pF and cap 18 is .68mf. I've searched just about everywhere. Man, can anyone point me where I can purchase these elusive lil components? Thanks Brothers and Sisters! Blessings! Jim

floris · Post by **floris** » 04 Apr 2022, 16:00

>Said cap 9 is 3,300pF and cap 18 is .68mf
Yes as said, C9 is 3,3nF and C18 680nF. These are regular values that can be found in all the regular places (like AliExpress, Mouser, etc).

Henz · Post by **Henz** » 04 Apr 2022, 16:10

Ty for the reply. I've tried those places brother. Here is what I'm typing in a search field. 3.3 nF 18 vdc SMD cap. That applies for the 680 as well. Am i typing in correct info? The lowest voltage is 50. On the 3.3 and I can't find 680nf or .68uf. Will the 50 volt fit between the two solder pads? Thanks for your time! jim

floris · Post by **floris** » 04 Apr 2022, 16:22

I would search for "680nF smd". Then make sure that the voltage rating is at least 18V. Then look for the correct size: SMD components have a package size type like "0805 (2012 metric)" or "0603 (1608 metric)". I don't know which package size is used in this pedal. See also:
https://www.electronics-notes.com/artic ... ckages.php

Henz · Post by **Henz** » 05 Apr 2022, 15:33

( sigh) I just got back from Dunlop tech support about the sizes and voltages of these two caps. Here's what info he gave me: Hi James,

I've included the values for these components below.

C9: 3300PF 16V SMT0805COG
C18: .68MF 16V PEN FLM 3216 . Can you help me ? On the .68 , is 3216 the size?

floris · Post by **floris** » 05 Apr 2022, 15:42

I googled "16V PEN FLM 3216" and one of the first hits was:
https://www.digikey.com/en/products/det ... BA/3066281
That states "Film Capacitor 16V 25V Polyester, Polyethylene Naphthalate (PEN), Metallized - Stacked 1206 (3216 Metric)".
So I think C18 is from the 1206 (3216 Metric) package series.

And C9 is from the 0805 package series.

Henz · Post by **Henz** » 05 Apr 2022, 16:13

Ty! Im 99.9% certain I found the 3.3 on mouser. The .68 is a bit difficult. Thanks for the link! Let me go there, you are very helpful! Ty! James

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