Poor Serbian Man Optical Volume Control

Re: How does it sound?

wlowes said:
I am curious to know how it sounds... have you done a listening test vs George's MKII?


MKII means : series LDR , shunt LDR

PSM LS will sound same as George's ;

LDR is LDR , doesn't matter with which circuit you control it ;

maybe we have some more freedom in settings ......

main difference is in buffer stage , dedicated for PSM LS ........ hehe even if it is universal for anything you can think of ......
 
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Hi Choky,
I just finished the matching procedure of my (small) batch of 50.
I've encountered, however, a problem: my basement is quite cold (abt. 10° C), and the LDRs are veeeeery temperature-sensitive.
The R value (@ 30mA) vary of even 10% in a few minutes.
Could it preferable matching LDRs at a hottest ambient temperature? How much time do you wait for a correct reading?
Or can a reading "at the flight" after few (3-4) seconds be correct (for matching purposes)?
Thanks

Guido
 
GuidoR said:
Hi Choky,
I just finished the matching procedure of my (small) batch of 50.
I've encountered, however, a problem: my basement is quite cold (abt. 10° C), and the LDRs are veeeeery temperature-sensitive.
The R value (@ 30mA) vary of even 10% in a few minutes.
Could it preferable matching LDRs at a hottest ambient temperature? How much time do you wait for a correct reading?
Or can a reading "at the flight" after few (3-4) seconds be correct (for matching purposes)?
Thanks

Guido


that wasn't problem when I measure mine batch , maybe because temp in my workshop was ~22C ;
anyway - with higher currents , settling time is much shorter than for lower current points .
for lower currents you can count on settling time in range of 15~20sec at least ; I repeat - with adequate temp in room , that's less critical .

whatever temp is in your environment , you must measure them all at once .

tempco was one of the reasons why we planned and implemented temp bridge for all 8 (4) LDRs ...... and - when connected in series , driven with CCS , tempco is hardly of any relevance ....
 
Lego ....... continued

besides answer to Guiness - that is possible to use 4 channel buffer PCB02 as two stereo output buffers ( where one pair can be attenuated from various reasons ) .... there is another one :

Ulf asked - if using entire gadget in unbalanced - is it possible to use one pair of buffers as input buffers ?

yup - certainly - it's possible , either as buffer dedicated solely to one critical source ( read - with highish output impedance ) , or as general buffer - before LS stage itself .

something as G. Rollins's recent posting ...... somewhere in his threads.
 
;( ........... 😉

as some of you probably already know - I'm struggling last 10 or so days with my bad back ( hurt back , discus hernia , whatever ) ....

I already have sorted little bulbs , jfets , pcbs ...... but I just couldn't find a way to my workshop , to pack these little things in bubblie envelopes .

anyway - even if I'm now able to sit in front of my keyboard several times in 24h , I doubt that I'll be able to sit in workshop (tomorrow or day after ) , and have enough gray cell concentration to pack them and not mix addys .

so , I expect that Monday will be D Post Day ....

even if I will be more than happy to sort these ( longer awaited than I thought ) shipments ........ I'll be certainly even happier to finally grab solder again ..........

funny - every time ( few times a year ) when I finish episodes like this one , I'm always again surprised how I'm addicted to work bench 😉
 
Take your time and don't push yourself on my account. The only time I took out my back I spent a week on a friends couch taking the prescribed pain killers that made the week seem like a day. No hurry on my account. I hope you have a doctor to prescribe you the good stuff.
 
My first back pain struck me in 1987. Since then, it came back to haunt me once for a while. Sorry to hear you are in he same boat. I can feel your pain ..... Take care of yourself first. You need good health to support our endless questions 😉
 
I just got out of bed at 4:00 am because I couldn't sleep with my back & leg pain from herniated disc ( even though I've taken anti-inflammatory & codeine+Paracetemol). I see this thread - careful Zen - mine started out like yours with just back & leg pain when I worked for too long at the workbench - now I can't do any diy. Possibly an operation needed - I've seen the MRI & the lumbar disc is ruptured and completely engulfing the sciatic nerve on the right side. Agony for 2 -3 weeks - couldn't get out of bed - now I can but walking/standing/sitting is a problem for more than 5 min.

Sorry to go OT with this post but just thought I'd warn you to rest & take care before you do too much damage
 
It's DIYAudio's dirty little secret.
Too much bench time, and neck and lower back can go out!

It's sidelined me often. I try to spend no more than 45 minutes at the bench before taking a long break, like a day or two. I set my stove timer.

I think my problems are obvious, dad has problems with same area in his back, and neck issues are from driving and working behind a monitor for a living.

A pretty girl from the Netherlands has been teaching me yoga streches, and it helps if you do it before......consistently.

Best wishes Choky.
 
I had begun to notice how many here were suffering similar problems - I had thought it might be an age thing (I'm 54) as the profile of members in the DIY community tends to veer towards that end of the age range, I suspect (Actually, I suspect a bimodal distribution).

Maybe a good wiki about ways to avoid this problem/tips/techniques would be a good help to members?

I've never started a wiki - I'll look into it - nothing much else I can do