Synth Defects - Ticking Time Bombs

Discussions about anything analog, digital, MIDI, synth technology, techniques, theories and more.

Re: Synth Defects - Ticking Time Bombs

Postby rschnier » Mon Feb 23, 2015 7:04 pm

ARP Omni / Omni-2. Power supply throws voltage spikes when powered up, causing damage over time to the many tantalum (decoupling) capacitors connected across the power supply rails throughout the synth, eventually causing one or more to dead-short. Since the power supply rails are not fused, when the dead short happens it takes the power supply and other components down with it.
-- R.
rschnier
Supporting Member!
Supporting Member!
 
Posts: 219
Joined: Sun Jun 06, 2010 4:52 am
Location: USA

Re: Synth Defects - Ticking Time Bombs

Postby coastalscrub » Mon Feb 23, 2015 7:16 pm

fh991586 wrote:
coastalscrub wrote:- Roland Juno 106 / MKS-70 / HS-60 - the voice chips have an epoxy coating that eventually short the chips resulting in dead voices.


The MKS-70 is fine on this subject: you got it mixed with the MKS-7 & MKS-30, which share the save epoxy chip as the Juno 106.


Thanks for catching that. I edited the OP.

What about synths that use regular removable batteries, either for main power or for memory storage? Last month, I discovered that the batteries in one of my portable turntables were leaking heavily. I caught it in time but I can imagine someone putting a SH-101 or a TB-303 in a closet and not taking the batteries out and discovering the same thing. If you're lucky, the battery acid is contained in the battery compartment and just eats away at the contacts and springs. Which of these kind of synths are most at risk of real damage from a battery leak?
coastalscrub
Newbie
Newbie
 
Posts: 28
Joined: Sun Nov 02, 2014 5:25 pm

Re: Synth Defects - Ticking Time Bombs

Postby Swayze » Mon Feb 23, 2015 9:42 pm

I hear a lot about battery leakage in the Polysix. The Mono/Poly was part of the same family from Korg, but I have never heard of any issues, batteries or otherwise. Did Korg fix this problem on the Mono/Poly, just get lucky, or should I still be concerned? I better open 'er up today and have a look.

Edit: Just remembered that batteries are needed for patch storage, which the Mono/Poly doesn't have...what a relief.
Last edited by Swayze on Mon Feb 23, 2015 10:22 pm, edited 1 time in total.
User avatar
Swayze
Junior Member
Junior Member
 
Posts: 244
Joined: Mon Jul 01, 2013 1:49 am
Location: Carson City, NV
Gear: Mono/Poly, EX8000, JX3P, AX80, DX7IIFDE!, TG77, AN1x, Microbrute, Drumtraks

Re: Synth Defects - Ticking Time Bombs

Postby super_doraemon » Mon Feb 23, 2015 10:00 pm

The foam inside of the Realistic/Moog Concertmate MG-1 decays into a tar-like paste.
super_doraemon
Newbie
Newbie
 
Posts: 13
Joined: Thu Feb 27, 2014 12:58 am
Gear: Moog Little Phatty, Micromoog, Arp Odyssey, Roland Juno-106, Alpha Juno 1, Microbrute SE(orange), Rhodes Stage 73, Octatrack, Prophet 6
Band: Coral Bones, Pet Library

Re: Synth Defects - Ticking Time Bombs

Postby desmond » Mon Feb 23, 2015 10:02 pm

Earlier Wavestations and even the A/D Racks can have power supply issues - it seems that the original power supplies were somewhat under specced and can cause the rather lovely "click of death" - the WS randomly hangs and emits a repeated series of clicks to the audio output - I still have a recording of this ;)

The solution is usually to get a replacement power supply.

Also, another common one, not just for the Wavestation but for a lot of synths of that generation is of course fading backlights in displays - both my Wavestation and my CZ-1 have backlights that are so dim they barely shine in the dark.
User avatar
desmond
Active Member
Active Member
 
Posts: 614
Joined: Tue Oct 11, 2005 12:32 pm

Re: Synth Defects - Ticking Time Bombs

Postby tomorrowstops » Mon Feb 23, 2015 10:40 pm

super_doraemon wrote:The foam inside of the Realistic/Moog Concertmate MG-1 decays into a tar-like paste.


Moog Opus 3 does the same!
tomorrowstops
Supporting Member!
Supporting Member!
 
Posts: 1004
Joined: Mon Jan 25, 2010 2:55 pm
Location: Portland, ME

Re: Synth Defects - Ticking Time Bombs

Postby meatballfulton » Mon Feb 23, 2015 10:57 pm

The analog output stage FETs in the Alesis Ion and Micron go south regularly. Probably also true of the Akai Miniak.

The LED display of the Roland MC505 starts losing pixels over time.

The effects selector on the Korg EM-1 uses a detented pot rather than a physical switch, the part is no longer available if the original wears out.
I listened to Hatfield and the North at Rainbow. They were very wonderful and they made my heart a prisoner.
User avatar
meatballfulton
Moderator
Moderator
 
Posts: 5537
Joined: Wed Apr 13, 2005 9:29 pm
Gear: Live 9, Logic Pro X

Re: Synth Defects - Ticking Time Bombs

Postby ppg_wavecomputer » Tue Feb 24, 2015 1:01 am

rschnier wrote:ARP Omni / Omni-2. Power supply throws voltage spikes when powered up, causing damage over time to the many tantalum (decoupling) capacitors connected across the power supply rails throughout the synth, eventually causing one or more to dead-short. Since the power supply rails are not fused, when the dead short happens it takes the power supply and other components down with it.


Oh, right... thanks for reminding me why I sold my ARP Omni back in 1997.

Swayze wrote:I hear a lot about battery leakage in the Polysix. The Mono/Poly was part of the same family from Korg, but I have never heard of any issues, batteries or otherwise. Did Korg fix this problem on the Mono/Poly, just get lucky, or should I still be concerned? I better open 'er up today and have a look.

Edit: Just remembered that batteries are needed for patch storage, which the Mono/Poly doesn't have...what a relief.


Glad you found out the answer for yourself.

Stephen
"Like the light from distant stars, Stephen Parsick's music has existed for some time, but is only now reaching us on Earth." -- Chuck van Zyl / Star´s End

https://ramp1.bandcamp.com/

https://stephenparsick.bandcamp.com/
User avatar
ppg_wavecomputer
Senior Member
Senior Member
 
Posts: 962
Joined: Wed Feb 06, 2013 3:37 pm
Location: teutoburg forest, eastern westphalia, germany
Gear: more keys than hands (and feet)
Band: ['ramp]

Re: Synth Defects - Ticking Time Bombs

Postby coastalscrub » Tue Feb 24, 2015 1:22 am

Some minor defects:

Roland JX-8P - the aftertouch stops working when the metal strip inside gets oxidized

Oberheim Matrix-1000 (black units only?) - humming power supply transformer

Aren't there some synths that have humming or buzzing backlit displays?
coastalscrub
Newbie
Newbie
 
Posts: 28
Joined: Sun Nov 02, 2014 5:25 pm

Re: Synth Defects - Ticking Time Bombs

Postby max badwan » Tue Feb 24, 2015 1:40 am

coastalscrub wrote:Aren't there some synths that have humming or buzzing backlit displays?


Korg M/T series
Roland D70/MV30
Kawai K5000

That's just in my arsenal.
max badwan
Active Member
Active Member
 
Posts: 295
Joined: Tue Aug 06, 2013 1:34 am
Location: Sydney, Australia
Real name: Max
Gear: T1, XV 5080, Fantom XR, Varios, Cubase 4

Re: Synth Defects - Ticking Time Bombs

Postby Percivale » Tue Feb 24, 2015 3:40 am

Lots of Roland TR-626s have this "burnt" LCD.

Image
User avatar
Percivale
Junior Member
Junior Member
 
Posts: 226
Joined: Mon Sep 09, 2013 1:56 am
Location: SG Synthesizers Group
Gear: Blofeld, Juno-106, AN1X, MB-6582/SEQ V4, etc

Re: Synth Defects - Ticking Time Bombs

Postby mmp » Tue Feb 24, 2015 4:08 am

Rhodes Chroma: backup battery leakage & bad power supply design. Road case foam rot ruins exterior finish.
Michael McInnis Productions
www.mm-pro.com
User avatar
mmp
Junior Member
Junior Member
 
Posts: 110
Joined: Thu Sep 13, 2007 11:59 am
Location: Portland, Maine USA
Real name: Michael McInnis
Gear: VS VL-1 Varios VoyagerRME MinimoogD CS60 SY-2 Kronos M3X MW1 2600 PS3100 DV-800 Z1 Chroma XT Blofeld k5K PolyMoog Avatar MS20 PE-1000 P6 OB6 m4000d
Band: Iberquez

Re: Synth Defects - Ticking Time Bombs

Postby baz99 » Tue Feb 24, 2015 6:30 am

coastalscrub wrote:Oberheim Matrix-1000 (black units only?) - humming power supply transformer


Nope, white units are just as likely to be affected. They use the exact same transformer after all.

Fortunately the hum is actually only a physical vibration caused by the transformer, it does not propagate to the audio signal path.
baz99
Newbie
Newbie
 
Posts: 86
Joined: Sun May 25, 2014 9:19 am
Location: Europe

Re: Synth Defects - Ticking Time Bombs

Postby Europanaut » Tue Feb 24, 2015 8:58 am

rschnier wrote:ARP Omni / Omni-2. Power supply throws voltage spikes when powered up, causing damage over time to the many tantalum (decoupling) capacitors connected across the power supply rails throughout the synth, eventually causing one or more to dead-short. Since the power supply rails are not fused, when the dead short happens it takes the power supply and other components down with it.


And the official Arp "fix" ensures that the 18v spike stays on, so your synth fries immediately. I just had my Omni's psu upgraded. Nice and safe now. (I also had the filter mod done, and it really sounds good.)
Europanaut
Newbie
Newbie
 
Posts: 46
Joined: Wed Jul 18, 2012 6:38 am

Re: Synth Defects - Ticking Time Bombs

Postby ppg_wavecomputer » Tue Feb 24, 2015 2:24 pm

max badwan wrote:
coastalscrub wrote:Aren't there some synths that have humming or buzzing backlit displays?


Korg M/T series
Roland D70/MV30
Kawai K5000

That's just in my arsenal.


Korg Wavestation (EX) -- high-pitched whine from the display.

The WS keyboard reportedly might become sticky due to deteriorating component parts -- haven't experienced this myself but I've seen two or three examples with that issue (early DX-7 models seem to suffer from the same disease)

Stephen
"Like the light from distant stars, Stephen Parsick's music has existed for some time, but is only now reaching us on Earth." -- Chuck van Zyl / Star´s End

https://ramp1.bandcamp.com/

https://stephenparsick.bandcamp.com/
User avatar
ppg_wavecomputer
Senior Member
Senior Member
 
Posts: 962
Joined: Wed Feb 06, 2013 3:37 pm
Location: teutoburg forest, eastern westphalia, germany
Gear: more keys than hands (and feet)
Band: ['ramp]

PreviousNext

Return to General Synthesizers

Who is online

Users browsing this forum: Bing [Bot], Google Adsense [Bot] and 23 guests