*best* LDR for Mutron III / Neutron circuit

oldfatbubba · Post by **oldfatbubba** » 15 Apr 2010, 13:52

Hey, man.

This is my first post to this forum. Howdy....

Can I get any input on what *the best* LDR is for the Mutron III / Neuton circuit? DIY is fine.

I used H11F3 opto-FET isolator for ease of implementation but, even after several hours of fiddling with the current scaling resistor, it only sounds so-so. I think the slope of their response curve of is too steep for this circuit.

Thanks,
Bubba

mictester · Post by **mictester** » 15 Apr 2010, 14:00

oldfatbubba wrote:Hey, man. This is my first post to this forum. Howdy....

Can I get any input on what *the best* LDR is for the Mutron III / Neuton circuit? DIY is fine.

I used H11F3 opto-FET isolator for ease of implementation but, even after several hours of fiddling with the current scaling resistor, it only sounds so-so. I think the slope of their response curve of is too steep for this circuit.

Thanks,
Bubba

Where did you get your H11F3s? I need some myself. The LDRs I used in my Mutron-alike were cheap 1M ones form Futurlec.

oldfatbubba · Post by **oldfatbubba** » 15 Apr 2010, 15:08

mictester wrote: Where did you get your H11F3s? I need some myself. The LDRs I used in my Mutron-alike were cheap 1M ones form Futurlec.

Hi, mictester. They're in-stock at Small Bear Electronics...
http://www.smallbearelec.com/Detail.bok?no=702

mictester · Post by **mictester** » 15 Apr 2010, 16:58

oldfatbubba wrote:
mictester wrote: Where did you get your H11F3s? I need some myself. The LDRs I used in my Mutron-alike were cheap 1M ones form Futurlec.
Hi, mictester. They're in-stock at Small Bear Electronics...
http://www.smallbearelec.com/Detail.bok?no=702

They must be the solid gold ones at that price! I used to pay $4.25 / 100 of them! I hate profiteering!

The price of all the components to make (for example) a TS9 was around $2.55 including the box and the assembly costs! When you factor in testing, packing, shipping, manufacturer profit, wholesaler profit, and profit for the dealer, the old price of £29.95 was sane (but there were some big profits in that figure!).

oldfatbubba · Post by **oldfatbubba** » 15 Apr 2010, 17:15

mictester wrote: The LDRs I used in my Mutron-alike were cheap 1M ones form Futurlec.

So, how is the sound of your Mutron-like pedal? Can you provide any details on the specific LDR?

Mich P · Post by **Mich P** » 15 Apr 2010, 17:23

I've tried LED/LDR, H11F3,NSL32
And the best were the combo HAMAMATSU p873-13
With higher Rx resistor than 4,7KOhm.
Small Bear have them bit it seems
they're out of stock !
Mich P.

oldfatbubba · Post by **oldfatbubba** » 15 Apr 2010, 19:29

Mich P wrote:I've tried LED/LDR, H11F3,NSL32
And the best were the combo HAMAMATSU p873-13
With higher Rx resistor than 4,7KOhm.
Small Bear have them bit it seems
they're out of stock !
Mich P.

Agreed that the original part is best but they're as rare as hen's teeth. How about anything else? Do the
CLM6000's work reasonably well?

theehman · Post by **theehman** » 15 Apr 2010, 19:40

oldfatbubba wrote:
Mich P wrote:I've tried LED/LDR, H11F3,NSL32
And the best were the combo HAMAMATSU p873-13
With higher Rx resistor than 4,7KOhm.
Small Bear have them bit it seems
they're out of stock !
Mich P.
Agreed that the original part is best but they're as rare as hen's teeth. How about anything else? Do the
CLM6000's work reasonably well?

You might try to get the unit used in the EHX Qtron (old style big box version).

oldfatbubba · Post by **oldfatbubba** » 15 Apr 2010, 23:21

theehman wrote:You might try to get the unit used in the EHX Qtron (old style big box version).

They used Vactrol VL5C3. Any other opinions?

chicago_mike · Post by **chicago_mike** » 16 Apr 2010, 05:43

Thats what I use.

Otherwise you spend too much money for the 0803 part off ebay.

oldfatbubba · Post by **oldfatbubba** » 16 Apr 2010, 14:02

chicago_mike wrote:Thats what I use.

Thanks, Mike... Does your pedal work well in every mode?

chicago_mike · Post by **chicago_mike** » 16 Apr 2010, 22:56

Yeah. I also used the 5C3's in my mcmeat.

oldfatbubba · Post by **oldfatbubba** » 17 Apr 2010, 13:08

okay, thanks. FWiW, I found someone selling the original 0805A for $20. Ugh.

jim50hertz · Post by **jim50hertz** » 18 May 2010, 11:25

Hey there oldfatbubba,

Been looking for that part on and off for years, where did you find it?

Any comments on whether the pedal will behave the same without that part? i.e. with the vactrol approach?

Peace

Jim

Kas · Post by **Kas** » 25 Sep 2010, 11:37

jim50hertz wrote:Hey there oldfatbubba,

Been looking for that part on and off for years, where did you find it?

Any comments on whether the pedal will behave the same without that part? i.e. with the vactrol approach?

Peace

Jim

Is there anyone with answes on this post? I have the same questions.

lerxst60 · Post by **lerxst60** » 28 Dec 2010, 00:24

ddavis510 · Post by **ddavis510** » 02 Jan 2011, 01:01

I have used the Hammatsu 873 from smallbear and VL5C3. Both provide good results. The vl5c3 seem to 'need matched'. I wish I knew a more efficient method of matching them. I have had to just place sip sockets and trial and use trial and error. Its tedious but it works.(anyone have a better way?) I've also replaced the 'Rx' with a pot and relocated it to the top of the build so I can adjust that on the fly. The Hammatsu has been the best so far. I built one for me and 2 for Christmas presents this year. I kept the one with the 873.

I hope it helps.

lerxst60 · Post by **lerxst60** » 24 Jan 2011, 22:24

Thank you sir.

pula58 · Post by **pula58** » 02 Oct 2014, 02:00

old post revisited:

I looked inside a few envelope filter pedals, one had two opto parts marked "NSL 7053" part, and the other had two parts marked "NSL 1053"

I tried looking these up, couldn't find much.

Anyone know which opto device they are?

chicago_mike · Post by **chicago_mike** » 02 Oct 2014, 02:25

Theres mods posted on a site...I forget the name of the site right now...so you can use the NSL32.

I used the VTL-5C3 and like those. I have 40 or more of those NSL-32's but haven't tried them.

*best* LDR for Mutron III / Neutron circuit [found/sold]

best LDR for Mutron III / Neutron circuit [found/sold]