One of my filters disappeared

Tips and techniques for Minimoog Analog Synthesizers
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tommyecho
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One of my filters disappeared

Post by tommyecho » Thu Jul 04, 2013 1:20 am

Hey Guys,

Got a bit of a problem that popped up with my XL. Suddenly, many of my patches, including the "Init Parameters" preset, are lacking the dual filter. On these patch presets, there is now only one filter, and the spacing knob has no effect. I toggled through the presets and found some patches that do still have the dual filter, and on these the spacing knob works as expected. Seems like a firmware issue maybe? Any ideas?

Sorry I haven't been contributing to the forums for a while. Things have been busy lately! Been enjoying reading along though: )
THE GOLDEN MINIMOOG VOYAGER #31

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RL
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Re: One of my filters disappeared

Post by RL » Thu Jul 04, 2013 10:18 am

Hi,
please check filter poles 1-4 of filter A and B. I'm pretty sure one or more are dead.
BTW the filter is a real hardware filter not software :wink:

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thealien666
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Re: One of my filters disappeared

Post by thealien666 » Thu Jul 04, 2013 12:54 pm

Some of the patches that still work might have the filter mode set to highpass/lowpass, and the high pass might still work while the second low pass is probably defective, as Rudi suspects.

Anyhow, I would contact Moog Music ASAP about it.
Moog Minimoog D (1975)
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tommyecho
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Re: One of my filters disappeared

Post by tommyecho » Thu Jul 04, 2013 1:10 pm

Hey thanks for the help!

I actually just checked the poles right before discovering your reply. sure enough, the 4 pole filter on filter B is broken. 1 to 3 poles works fine, and the all the poles work on filter A. The 4 pole filter is dead on filter B though.

I'm bummed that this is a holiday, and Moog is closed. I'm hoping they open back up tomorrow. I hope that this is a fixable problem. . . Switched On, here in austin, has repair guys, and I am out of warranty. Do you think it would be a good idea to just take it to them? I'll wait to get a response from Perry, but shipping the XL is not something I am thrilled to do.

tom
THE GOLDEN MINIMOOG VOYAGER #31

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thealien666
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Re: One of my filters disappeared

Post by thealien666 » Thu Jul 04, 2013 1:35 pm

Moog Music will most probably suggest you bring it to a certified/authorized Moog repair center. Let's hope Switched On is one of them... Good luck and keep us posted.
Moog Minimoog D (1975)
DSI OB6
DSI Prophet REV2
Oberheim Matrix-6
Ensoniq SQ-80
Korg DW8000
Behringer DeepMind 12
Alesis Ion

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RL
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Re: One of my filters disappeared

Post by RL » Thu Jul 04, 2013 1:59 pm

tommyecho wrote:I hope that this is a fixable problem. . .
Sure! The tech should replace U51 (4052) by a HEF4052 then it must work :D

Have fun and a Happy Holiday,
Rudi

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thealien666
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Re: One of my filters disappeared

Post by thealien666 » Thu Jul 04, 2013 2:55 pm

I wonder why there is such a relatively high rate of failure of this analog multiplexer in voyagers ? Noisy power rails ?
Moog Minimoog D (1975)
DSI OB6
DSI Prophet REV2
Oberheim Matrix-6
Ensoniq SQ-80
Korg DW8000
Behringer DeepMind 12
Alesis Ion

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RL
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Re: One of my filters disappeared

Post by RL » Thu Jul 04, 2013 3:16 pm

thealien666 wrote:I wonder why there is such a relatively high rate of failure of this analog multiplexer in voyagers ? Noisy power rails ?
You should ask Texas Instruments :mrgreen:

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tommyecho
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Re: One of my filters disappeared

Post by tommyecho » Fri Jul 05, 2013 3:10 pm

RL wrote:
tommyecho wrote:I hope that this is a fixable problem. . .
Sure! The tech should replace U51 (4052) by a HEF4052 then it must work :D

Have fun and a Happy Holiday,
Rudi

Thanks, Rudi. Switched on is not an authorized moog repair center, though they have lots of experience fixing moog stuff (I know they've restored a few polymoogs very nicely). So, if I tell them to do this replacement, it should be fine, right? I'm out of warranty, so if I can get it done here, I definitely will. Still waiting to hear back from Perry. I think he's out for the weekend.

Thanks!!

tom
THE GOLDEN MINIMOOG VOYAGER #31

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RL
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Re: One of my filters disappeared

Post by RL » Fri Jul 05, 2013 3:29 pm

Hi Tom,
tommyecho wrote:So, if I tell them to do this replacement, it should be fine, right?
Yes, I'm sure for 100%.
Have fun,
Rudi

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weemac
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Re: One of my filters disappeared

Post by weemac » Thu Oct 24, 2013 6:55 pm

I had this fault on a new Voyager Select on the day I got it. I hope it does not take too much trouble to fix it...

Eden.

d s murray
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Re: One of my filters disappeared

Post by d s murray » Tue Feb 04, 2014 2:43 pm

Hi Guys

I have the EXACT same problem with my Voyager RME - the filter B 4-pole has ceased to function.

Naturally it's out of warranty so I'll have to pay good money to correct what's clearly a design fault with this component.

Rudi, anyone, can you tell me if it's the same part number which needs replacing in a Voyager RME, and what would be a fair price for the repair in the UK?

Dave
RL wrote:
tommyecho wrote:I hope that this is a fixable problem. . .
Sure! The tech should replace U51 (4052) by a HEF4052 then it must work :D

Have fun and a Happy Holiday,
Rudi

clusterflux81
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Re: One of my filters disappeared

Post by clusterflux81 » Thu May 15, 2014 5:10 am

Hi do you fixed? i'm having similar problem, channel right output is dead, even with headphones, and if i switch filter in hipass lowpass doesn't sound, filterspacing doesn't work as well...i haven't checked filter poles yet... Which ic's do you substitute?

d s murray
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Re: One of my filters disappeared

Post by d s murray » Thu May 15, 2014 3:38 pm

Hi there

As far as I know, Rudi's reply was based on our basic diagnostics - that is, we were able to narrow it down to a specific faulty IC because our filters were not functioning in 4-pole mode on the left or right in dual lowpass mode. So I think you will have to try changing the filter pole settings if you want to locate the nasty chip.

If you have the same problem then the good news is that the replacement IC is really affordable.

Hope that helps

Dave

PaulPalladino
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Re: One of my filters disappeared

Post by PaulPalladino » Sat Oct 17, 2015 4:00 pm

Hi all,

I am experiencing the same problem. Both of my filters work from 1 to 3 poles, however, once in 4 pole mode both left and right signal is extremely attenuated and noisy. I am sure that I can handle replacing an IC chip, did the above advice fix the issue? I would consider sending my XL to NC, however, I have contacted Moog service twice and have been totally ignored.

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