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*best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 13:52
by oldfatbubba
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

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 14:00
by mictester
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.

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 15:08
by oldfatbubba
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

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 16:58
by mictester
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! :evil:

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!).

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 17:15
by oldfatbubba
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?

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 17:23
by Mich P
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.

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 19:29
by oldfatbubba
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?

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 19:40
by theehman
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).

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 15 Apr 2010, 23:21
by oldfatbubba
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?

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 16 Apr 2010, 05:43
by chicago_mike
Thats what I use.

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

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 16 Apr 2010, 14:02
by oldfatbubba
chicago_mike wrote:Thats what I use.
Thanks, Mike... Does your pedal work well in every mode?

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 16 Apr 2010, 22:56
by chicago_mike
Yeah. I also used the 5C3's in my mcmeat. :)

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 17 Apr 2010, 13:08
by oldfatbubba
okay, thanks. FWiW, I found someone selling the original 0805A for $20. Ugh.

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 18 May 2010, 11:25
by jim50hertz
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

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 25 Sep 2010, 11:37
by Kas
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.

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 28 Dec 2010, 00:24
by lerxst60
bump

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 02 Jan 2011, 01:01
by ddavis510
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.

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 24 Jan 2011, 22:24
by lerxst60
Thank you sir.

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 02 Oct 2014, 02:00
by pula58
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?

Re: *best* LDR for Mutron III / Neutron circuit

Posted: 02 Oct 2014, 02:25
by chicago_mike
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.