Does anybody know how I can find a replacement for these? I've looked around but can't seem to find anything. No datasheets or anything. Kinda lost, could really use a little help if anyone has any info on these. Thanks you in advance
First google hit: https://www.studioelectronics.biz/sunshop/index.php?l=product_detail&p=2091
As a 10.25kHz filter I suspect its for a reconstruction filter for 22.050kSPS DAC?
As a 10.25kHz filter I suspect its for a reconstruction filter for 22.050kSPS DAC?
interesting read.
Anti aliasing filter
very rare part, failure rate is known to be high
apparently caused by potting material.
9 pole low pass filter.
People have made, reproductions of the filter.
I cannot find recent supplier, all links are dead
I found a link from synth blog.
where guy was kinda lazy and made simple 2 pole filter
instead of 9 pole filter.
and even worse just lowered cutoff.
Murata Filter Low Cost
1 - ground
2 - audio IN
3 - ground
4 - V-
5 - ground
6 - audio OUT
7 - V +
Anti aliasing filter
very rare part, failure rate is known to be high
apparently caused by potting material.
9 pole low pass filter.
People have made, reproductions of the filter.
I cannot find recent supplier, all links are dead
I found a link from synth blog.
where guy was kinda lazy and made simple 2 pole filter
instead of 9 pole filter.
and even worse just lowered cutoff.
Murata Filter Low Cost
1 - ground
2 - audio IN
3 - ground
4 - V-
5 - ground
6 - audio OUT
7 - V +
In addition to Mark's comments and with a bit more sleuthing it appears to be a Active Low Pass Filter (9th Order) with a Fo 10.25KHz.
The bad news it also appears to be a custom Murata ERIE Hybrid IC, most likely to Lexicon specifications.
See attached pdf's for more info.
The bad news it also appears to be a custom Murata ERIE Hybrid IC, most likely to Lexicon specifications.
See attached pdf's for more info.
Filter was used by many manufactures.
AFL89WB
is the filter unit itself, the second number on the case is cutoff frequency.
this case 10250 is 10.25 khz
I found another were its used in CD players
But it was with 20000 suffix for 20 khz cutoff
Likely the Lexicon and various other synths or processors
would use lower cutoff value for slower/lower conversion rate.
This is picture from Radio Shack / Tandy CD-1000 CD player
likely made by Hitachi who also made DA-1000 CD player
this link was included in the previous blog links.
AFL89WB
is the filter unit itself, the second number on the case is cutoff frequency.
this case 10250 is 10.25 khz
I found another were its used in CD players
But it was with 20000 suffix for 20 khz cutoff
Likely the Lexicon and various other synths or processors
would use lower cutoff value for slower/lower conversion rate.
This is picture from Radio Shack / Tandy CD-1000 CD player
likely made by Hitachi who also made DA-1000 CD player
this link was included in the previous blog links.
Some 'potted' elements in synths can be recuperated as is if the potting material can dissolve left overnight in acetone.
If you replace it by a DIY solution like the above, then it's worthwhile to replace them on all channels. Try to keep the response as close as the original if at all possible.
If you replace it by a DIY solution like the above, then it's worthwhile to replace them on all channels. Try to keep the response as close as the original if at all possible.
Excellent! This is exactly the information I was hoping to find...thank you kindly for taking the time. This will surely help. Much appreciated!
I think this vendor used to offer filter replacements on ebay.
http://www.lenham.clara.co.uk/sound/lexicon224p1.html
http://www.lenham.clara.co.uk/sound/lexicon224p1.html
This ebay listing appears to be related to the above link
https://www.ebay.com/itm/333922903566?hash=item4dbf5b260e:g:ahwAAOSw6Gxe8JMa
https://www.ebay.com/itm/333922903566?hash=item4dbf5b260e:g:ahwAAOSw6Gxe8JMa
Northward Acoustics recently posted about this on instagram: https://www.instagram.com/p/CXEqVUptPWU/
He replaced the filters in a 480L. Not sure if they're the same as yours, but it looks like he had success with the Benden boards that Bill_P linked to above
He replaced the filters in a 480L. Not sure if they're the same as yours, but it looks like he had success with the Benden boards that Bill_P linked to above
9th order is getting too critical to make without trimming component values. Going for a compromise at maybe 6th order would allow repeatable results with 1% components available to amateurs.
This would need a slight reduction in 3 dB frequency, but not much.
If I can figure out the dimensions, especially pin 1 to pin 7, a PCB is easy to design