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 Forum index » Instruments and Equipment » Alesis Andromeda
Noisy voice problem
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Perfect Day



Joined: May 21, 2009
Posts: 53
Location: UK

PostPosted: Mon Mar 01, 2010 11:56 am    Post subject: Reply with quote  Mark this post and the followings unread

Yeh I have the problem with the sud osc to . If I turn the osc wave off and turn the subs volume down till I can only just hear it the volume changes on some of the voices . Its annoying because it changes the sound of the patch on certain voices . Im gonna contact Alesis and Ill let you know what they say . I talk to tech support quite a bit so Ill send Them an audio sample and a link to this forum page . Ill be sending mine in for servicing no doubt so Ill let you know how this turns out and also at what price . It may be another month though . Ill let you know
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pinealapoptosis



Joined: Nov 07, 2008
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PostPosted: Wed Mar 03, 2010 10:51 pm    Post subject: Reply with quote  Mark this post and the followings unread

Yea it is very annoying. The white noise sound I experience on voice 2 is even worse. I hope they sort it out for you and ill be waiting to hear about your experience with their service.

I cant decide how many of each voice chip I need to buy. For voice 2 I am gonna go ahead and replace the vco and vcf chips but on the other voices I dont know if the problem is within the vcf or vco chips. Sunny mentioned that the crunchy distorted sound we are experiencing is most likely a vcf chip problem. I just dont want to replace something that doesnt need replacing or miss something by replacing the wrong voice chip.

If you can dave, try and have the repair shop document or atleast verbally tell you what it is that they replaced and please pass the info onto to us.


I wonder if parts availability or future repair service is going to be affected if they actually did stop producing the andromeda...?

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Perfect Day



Joined: May 21, 2009
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PostPosted: Thu Mar 04, 2010 2:49 am    Post subject: Reply with quote  Mark this post and the followings unread

Ill get a full breakdown of the work done and the problem . I think they send this out on a service sheet when they return the synth to you . Im sure they did with my ion
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Perfect Day



Joined: May 21, 2009
Posts: 53
Location: UK

PostPosted: Mon Mar 08, 2010 12:05 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hello mate . Ive found out what is causing the distortion when the oscillator waves are off . Its the background tuning . I get the problem till I turn mine off . after about 10 seconds of doing so it disapears . You can leave temperature tune on . My voices are all still different volumes though and if I send a sign wave through to the amp bypassing the filters on some voices I have more harmonics ? Cant work that out at all .
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Perfect Day



Joined: May 21, 2009
Posts: 53
Location: UK

PostPosted: Mon Mar 08, 2010 12:31 pm    Post subject: Reply with quote  Mark this post and the followings unread

Ive run a voice cal after turning my background and temperature tune off and thats sorted out the extra harmonics I was hearing on some voices . and sorry my voices arent louder than each other it was the release trail merging into the newly played voice creating phase cancellation that was causing the volume to drop . knocking the release off remeded that . However it hasnt fixed the sub osc,s volume changing
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andyval8088



Joined: Nov 12, 2008
Posts: 29
Location: U.S.

PostPosted: Tue Mar 09, 2010 11:41 am    Post subject: Reply with quote  Mark this post and the followings unread

TSI shipped my A6 this morning. The tech I spoke with said the service log says they replaced a capacitor and the volume pot. I'll report back after I have given it a good checking. I'm really hoping this fixes it.....not feeling very optimistic at this point.
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pinealapoptosis



Joined: Nov 07, 2008
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PostPosted: Wed Mar 10, 2010 11:19 pm    Post subject: Reply with quote  Mark this post and the followings unread

dave, thanks a lot for the info and tests. I have not tried listening for the distortion with background tuning off, so thanks for the suggestion and I am happy it solved your problem. I will be trying this in the next day or two and see if my results are similar and I will post back with my results.

My voices dont seem to be different volumes but as you said it turned out to be the release settings. I was just having the inconsistent sub-osc volume problems along with the wave off distortion problem, of course.

I wonder what is causing the sub-osc level problems. dave, at what level does your sub-osc volumes start to level off and maintain a consistent volume over all voices?




andyval, I sure hope it solves your problem. Thanks for the update and I will be looking forward to hear if the problem is remedied. Can you also post the exact capacitor that was replaced?

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andyval8088



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PostPosted: Thu Mar 11, 2010 10:55 am    Post subject: Reply with quote  Mark this post and the followings unread

OK boys, here goes:

Repair Description
1 Replace C50
2. Replace volume pot
3. Full output check

Item Description
1. cap, ceramic
2. Pot 10KA dual 12mm
3. 1.5 Labor hours

Let ya know if it works or not in a few days.
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andyval8088



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PostPosted: Tue Mar 16, 2010 1:18 pm    Post subject: Reply with quote  Mark this post and the followings unread

I have not had any issues since I got it back. I think Im safe to say they finally fixed the problem! Only took them 3 times over 6 months...
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pinealapoptosis



Joined: Nov 07, 2008
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PostPosted: Wed Mar 17, 2010 1:35 am    Post subject: Reply with quote  Mark this post and the followings unread

great! I am very happy that they finally fixed it for you. 3rd times a charm haha.

This kinda gives me a little hope that if I sent my andromeda in to TSI they might actually fix it. But I still think buying some voice chips and having someone local do the surface mount work would be a safer option. I guess that is if the voice chips are actually the problem.

hmm

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Perfect Day



Joined: May 21, 2009
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PostPosted: Mon Apr 05, 2010 9:12 am    Post subject: Reply with quote  Mark this post and the followings unread

Hi apoptosis . I have my Andromeda in with a local engineer now although he hasnt been able to look at it yet . my subs changed volume on most voices I think also the osc 2 sub volume levels changed on different voices to that of osc 1 so with both mixed in the problem wasnt as noticabe . I have had a quick look through the service manual although at a glance I couldnt see anything about the sub osc problem in there .
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pinealapoptosis



Joined: Nov 07, 2008
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PostPosted: Mon Apr 12, 2010 1:52 am    Post subject: Reply with quote  Mark this post and the followings unread

I have read somewhere on the forum as well as mentioned in this thread, the resistor problem. Apparently on some units the ASIC board was mislabeled during silk screening. R74 and R73 are swapped so the wrong value resistor is installed in both.


The service manual states the problem as follows:

3.503 Voice 2 Fails Tuning or ASIC Test – Has Problem with Pre Filter Path
This is a very specific problem on the Analog ASIC PCB. R73 and R74 are swapped in the
silkscreen, so the wrong parts are stuffed on the board. We found this problem on both the
A6 sample and the separate Analog ASIC board sent by Yahorng.
Take a look at an Analog ASIC board, near R74 and R73. The "R74" silkscreen is on the left
resistor, while the "R73" silkscreen is on the right resistor. But, actually, the left resistor is
R73 and the right is R74.
So, the left resistor should be a 20K resistor. The right one should be a 0 ohm resistor. Look
around the other ASICs to see what it should look like.



I have toyed with the idea for awhile that this may be the reason why I have the loud "white noise" sound on voice 2 but I assumed that they would have solved this silkscreen issue before the late 2008 batch was produced. I am beginning to think otherwise. I bet they just use stocks of ASIC boards from previous batches that are left over. I doubt they re-manufacture ever single component for each new batch.

So I am beginning to think this may in fact be my problem since the problem stops when I turn AUDIN parameter OFF in the pre-filter mix section,as well as for a number of other reasons that really sound like the resistors are swapped.

I wish M.Peake would give this thread a read and comment.

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Perfect Day



Joined: May 21, 2009
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PostPosted: Mon Jun 28, 2010 12:28 pm    Post subject: Reply with quote  Mark this post and the followings unread

HI evrybody , Apoptosis , the engineer I have my A6 in with thinks that the sub osc levels are down to 3 of the osc ASICS . He thinks replacing them could solve the problem . Have you any experience of this ? Is it a simple procedure ? From what I can gather from skimming through the service manual , You just replace one then reboot maybe powering up with soft button 4 down . I dont think you have to re install the boot code or anything ?:S . If this is the case I will go ahead and get 1 osc chip replaced first and if that works follow on with the other 2 chips . Im panicing a bit about going ahead with the repair as this is the first A6 the engineer has worked on and running into more problems could be a nightmare as Alesis are offering no usefull tech support for the A6 at all . Its shocking ! What do you think I should do ?
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sunny pedaal



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PostPosted: Mon Jun 28, 2010 11:40 pm    Post subject: Reply with quote  Mark this post and the followings unread

good chance that may solve the problem.
soldering however needs good skill and practice.
it's up to the technician to decide if he has both
one tip , also look if all filterchips are oke, otherwise swap them too.
and don't replace too many, it's percisework, and when too many, swapping the whole board might be easier
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Perfect Day



Joined: May 21, 2009
Posts: 53
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PostPosted: Mon Jun 28, 2010 11:56 pm    Post subject: Reply with quote  Mark this post and the followings unread

HI Sunny , I thought the filter chips may sort out some of the osc signal bleeding through to the amp with osc waves off and filters bypassed , however this is very low and I feel I can work round it . Also it sounds like it could be an ampcal problem also, for some reason not all base levels are quite the same . I have set a patch up for the engineer to test the filter chips to though . The osc chips are £27 each here in the UK and then Ive gotta pay for the work , Ill ring Alesis later and find out how much the voice boards are .that way Ill still have spares I suppose Smile Thanks for the comment
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Perfect Day



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Location: UK

PostPosted: Wed Jun 30, 2010 10:29 am    Post subject: Reply with quote  Mark this post and the followings unread

Hi Everyone , right been over to speak to the egineer about proceeding with the osc ASIC chip repair , One of the problems I have is Alesis UK dont have any . Was told they had 100s a few days ago , Turns out they are ASIC filter chips . More useless information from Alesis/Numark ! Anyway another interesting thing they (Alesis uk) told me when asking if there where any ASIC boards available was that the ASIC boards arent being produced any more and that the Andromeda IS definately DISCONTINUED !Even though its still up on the Alesis product page . When I asked if They could get me the chips shipped from the U.S. The answer was no . I would have to speak to Alesis U.S. myself . Spoke to Alesis U.S. to ask if the chips could be shipped to the UK , Alesis U.S answer was that international parts orders arent being shipped and if Alesis UK dont have the parts neither would Alesis U.S. as they share the same parts . Also we are having trouble figureing out how to measure the information going in , coming out of the osc chips to the filter chips and even what buses to and between these chips are doing what . Absolute nightmare this is turning out to be , and Alesis/Numark are incompitant . Im not even recieving replies to emails . Its a complete joke .
Last edited by Perfect Day on Wed Jun 30, 2010 11:10 am; edited 1 time in total
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Perfect Day



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PostPosted: Wed Jun 30, 2010 10:58 am    Post subject: Reply with quote  Mark this post and the followings unread

Some more information I forgot to mention was we ran some more tests measuring the levels of the sub osc levels per voice and per oscillator 6 and 12 were the main offenders with the main osc volume set at a volume around 50 and the sub osc set around 3.6 , I cant remember the exact levels . another thing we noticed was that sub osc 2's output in relation to sub osc 1when set at the same volumes wasnt always consistant .They were both lots lower than the other voices on 6 and 12 but the level of sub oscillators on the same voice werent always the same sometimes quite diffent in level with each other . Sometimes on other voices not . When they were increased to around 10 the levels became more in range with each other , by a volume of 50 they were pretty much the same . All the main osc levels were fine per voice . even the pulse/square wave when set at a lower level in its osc page and in the pre filter mix . Its hard to determin whats the cause . the information being recieved by the dac's before the osc chips ,the dacs themselves . The osc chips or the filter chips . We dont know how to measure whats goin in out of the osc chips or the filter chips , Digital or analog as far as I can gather and Alesis either dont know , wont say or dont want to know . I think Im just gonna have to live with it . Finally Ive emailed Alesis U.S. to try and get confirmation about if the A6 is discontinued , But dont hold your breath
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HrastProgrammer



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PostPosted: Fri Jul 02, 2010 2:28 am    Post subject: Reply with quote  Mark this post and the followings unread

dave wrote:
Anyway another interesting thing they (Alesis uk) told me when asking if there where any ASIC boards available was that the ASIC boards arent being produced any more and that the Andromeda IS definately DISCONTINUED !Even though its still up on the Alesis product page . When I asked if They could get me the chips shipped from the U.S. The answer was no . I would have to speak to Alesis U.S. myself . Spoke to Alesis U.S. to ask if the chips could be shipped to the UK , Alesis U.S answer was that international parts orders arent being shipped and if Alesis UK dont have the parts neither would Alesis U.S. as they share the same parts.


Yes, unfortunately, Andromeda spare parts are getting more and more hard to find. I know this because I bought a lot of spare parts for my two A6 during the last few months. I had to wait 2-3 months for some of them, like Front Left Panel PCB, and I was able to get them just because my local synth dealer has a business in USA, so he could acquire them directly from Alesis USA ...

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Perfect Day



Joined: May 21, 2009
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Location: UK

PostPosted: Sat Jul 03, 2010 12:56 am    Post subject: Reply with quote  Mark this post and the followings unread

Im considering getting rid of my A6 now , just because of the lack of support and the lack of parts / people who can actualy fix them . Could turn out to be very costly Sad . As far as the sub osc problem goes all I can say is Ive no Idea what is actually causing the problem ? Shame . It can be worked around . Just cant realy use the sub osc at low levels on poly patches . I Did put a post up to see if any other users had the same problem but it only has the one reply . I do know of 2 other people who have the same problem but as far as everyone else is concerned , I dont know if they do or they dont . If everybodys does it it could be the software ? Who knows . Ah well I tried ! My A6 is coming back home today
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sunny pedaal



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PostPosted: Sat Jul 03, 2010 3:47 am    Post subject: Reply with quote  Mark this post and the followings unread

no sub osc problem here. think it's due to bad osc chip, just a guess
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Perfect Day



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PostPosted: Sat Jul 03, 2010 5:58 am    Post subject: Reply with quote  Mark this post and the followings unread

Cheers Sunny at least I know that theyre not all the same then , Gotta say though , Ive just got it back and fired it up after 3 months away . Sounds great . Now I dont want to get rid of it again Smile . Ill try and get a patch up sometime for other users to try , See if I get any feedback . Would still like to find out how many others have the problem
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HrastProgrammer



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PostPosted: Sat Jul 03, 2010 9:04 am    Post subject: Reply with quote  Mark this post and the followings unread

No sub osc problem here, as well ...
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Perfect Day



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PostPosted: Sat Jul 03, 2010 11:36 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks for the reply , just to make sure , everybody is setting the voices to rotation , and not lowest when testing the sub osc volumes ? Thanks again , Hrast programmer just listening some of your music now Smile Very nice
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HrastProgrammer



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PostPosted: Sat Jul 03, 2010 10:51 pm    Post subject: Reply with quote  Mark this post and the followings unread

Perfect Day wrote:
Thanks for the reply , just to make sure , everybody is setting the voices to rotation , and not lowest when testing the sub osc volumes ? Thanks again , Hrast programmer just listening some of your music now Smile Very nice


Thanks! It can be better but I am still learning Wink

I didn't test sub oscs so thoroughly, I must admit, but I didn't notice such anomalies during the regular work with any of my two Andromedas (and I own them for quite some time). Of course, there are some subtle (read: cannot be noticed by ear, or are hard to notice, but can be measured) differences between voices (volume, tuning, filter, etc.), but that's the reason for having a real analog synth. Because of this, I am using rotary mode very often, so those subtle differences can be used in a musical way ...

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Perfect Day



Joined: May 21, 2009
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PostPosted: Sun Jul 04, 2010 1:14 am    Post subject: Reply with quote  Mark this post and the followings unread

yeh , I have noticeable differnces with my oscillators to , I love the little nuances They have , The main oscillators are completely fine sounding , so are the subs , its just at low levels , they arent all the same volumes . Its around 3.6 that its most noticable , when the sub volume is 10 its very hard to distinguish . Also the bleeding I have from the oscillators is noticable in osc 1 at voices 1 and 5
osc 2 at voices 1 5 9 13 , Its also slightly more noticable with the signal routed through the filters when filter bypass is pressed it becomes slightly quieter , Im sure I have read or have seen on one of the shematics that these voices are controled from one of the 4 dacs ? I havent time to look just yet but I will be going through the service manual again
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