@DAVADA,
That's good to know David. Yes, I think originally I was looking
to use the 49710 as the A1 U3 buffer, couldn't find any at the time
but then got some ops134s. : )
I'm wondering 49710 would be useful for the Notch amp at A3 U3?
As I go through this I keep reading y'alls R&D over on low distortion
thread along with Troubleshooting Analog Circuits, Robert Pease, Newnes, 1991.
I'm learning everyone keeps f-ing (fooling) with things until you get it the way
you want it and it works right, even the guys who write books.
Reminds me of a colleague of mine when he was in tech school and
their instructor was discussing ways to get things working called...
...while two of his black classmates were prompting him to say,
"we know what you mean come on and say it, say it so we
all can hear it, do you mean,
"Presidentially Modified"
BUT
"jury rigged", the instructor said.
That's good to know David. Yes, I think originally I was looking
to use the 49710 as the A1 U3 buffer, couldn't find any at the time
but then got some ops134s. : )
I'm wondering 49710 would be useful for the Notch amp at A3 U3?
As I go through this I keep reading y'alls R&D over on low distortion
thread along with Troubleshooting Analog Circuits, Robert Pease, Newnes, 1991.
I'm learning everyone keeps f-ing (fooling) with things until you get it the way
you want it and it works right, even the guys who write books.
Reminds me of a colleague of mine when he was in tech school and
their instructor was discussing ways to get things working called...
...while two of his black classmates were prompting him to say,
"we know what you mean come on and say it, say it so we
all can hear it, do you mean,
"Presidentially Modified"
BUT
"jury rigged", the instructor said.
@Sync -- I suggest using non-polar electrolytics in signal coupling positions, as they have been found to have the lowest distortion.
Tantalums are fine for RF bypassing, at the outputs of voltage regulators for example because of lots of C with very low inductance, or where the smallest size is desirable over other things, so don't toss 'em if they're good.
David was talking about why you might want to use a very good FET-input opamp instead of the LME parts at input amps, for example -- where the impedance is relatively high, current noise is the enemy, and higher voltage noise will still result in lower overall noise.
Tantalums are fine for RF bypassing, at the outputs of voltage regulators for example because of lots of C with very low inductance, or where the smallest size is desirable over other things, so don't toss 'em if they're good.
David was talking about why you might want to use a very good FET-input opamp instead of the LME parts at input amps, for example -- where the impedance is relatively high, current noise is the enemy, and higher voltage noise will still result in lower overall noise.
@RichEEM,
Ok, I'm trying to think this through, but I don't have the background nor
understanding of the circuits to know which part goes where. : (
I'm spending money for parts that I shouldn't be spending to begin with
for parts that I was planning to put in the wrong place or make things worse.
Yes, I saved those parts. One of the little 0.1uf tants popped on me,
but I can't tell which one looking at them. I don't want to measure it because
one of the leading manufacturers of tants said to never measure them
because you'll ruin them from meters voltages and you won't know
that you have problems.
So now I've got over $300 in parts for just these things alone and more in
other test gear so I know what to look for, and measure, etc.
I took people at their word for what they did, which is what I've started
and acquired the parts for, etc. Or at least that is what I thought.
I don't know which opAmps are the fet or bi polar ones, I guess
I'll have to print out all the data sheets, since we can only get this
stuff on line now now in print any more.
I've got 12 pages of schematics and every opamp looks
similar, some with more stuff hanging off it than others,
some are vertically stacked, some horizontally stacked,
some flipped, some backwards, some pointing the other
way...
I feel like I've fallen out from under the bell curve,
but on the wrong side.
I'm looking at a jigsaw puzzle with a lot of missing pieces,
I've started putting it together, I can't even tell which
pieces are lost.
I"m not feeling too well.
Thanks for the bandwidth.
Ok, I'm trying to think this through, but I don't have the background nor
understanding of the circuits to know which part goes where. : (
I'm spending money for parts that I shouldn't be spending to begin with
for parts that I was planning to put in the wrong place or make things worse.
Yes, I saved those parts. One of the little 0.1uf tants popped on me,
but I can't tell which one looking at them. I don't want to measure it because
one of the leading manufacturers of tants said to never measure them
because you'll ruin them from meters voltages and you won't know
that you have problems.
So now I've got over $300 in parts for just these things alone and more in
other test gear so I know what to look for, and measure, etc.
I took people at their word for what they did, which is what I've started
and acquired the parts for, etc. Or at least that is what I thought.
I don't know which opAmps are the fet or bi polar ones, I guess
I'll have to print out all the data sheets, since we can only get this
stuff on line now now in print any more.
I've got 12 pages of schematics and every opamp looks
similar, some with more stuff hanging off it than others,
some are vertically stacked, some horizontally stacked,
some flipped, some backwards, some pointing the other
way...
I feel like I've fallen out from under the bell curve,
but on the wrong side.
I'm looking at a jigsaw puzzle with a lot of missing pieces,
I've started putting it together, I can't even tell which
pieces are lost.
I"m not feeling too well.
Thanks for the bandwidth.
The op amp that are in the signal path have a very high input R. I'm suggesting you observe this as well the earlier point on the current noise. Don't use the LME's in the notch filter. The loading to much. The data sheet for the 2625 is still floating around the net. Read up on it.
300 meg dif resistance, 0.16 pA/rtHz. Not to many op amps match this.
300 meg dif resistance, 0.16 pA/rtHz. Not to many op amps match this.
@Sync -- Everyone on this site has been where you are. Not a lot of comfort there, but at least with the web you're not completely alone like David and I were, for two, for years with no one to bounce things off of. You've decided to get into a fairly rarefied area of electronics without, it seems, a lot of background so of course the learning curve is *extremely* steep, not to mention a little pricey.
@ RichEEM,
@David,
Thanks gentlemen, yeah I'm over it.
AND
Yep, I do realize how lucky we are to have access to all this info
on the WWW. This 'puter also misses posts sometimes too.
I remember David discussing using the OPA1461 for A3 U3 and making a board for it. So no LME here, that leaves either LT1468 or the
OPS134. : ) At least for the moment. But I'm getting ahead of
myself here. Also recall the AM Detector, and isolating it from chassis
was thinking of grounding somewhere at the input around TP8...with the
mini coax.
This brings up a related question...as I'm sure y'all encountered before,
Who makes a chassis punch with the little hold down, anti rotation notch?
I also got that NULL really really deep, so the hand by the output
cable, or around the front of the HP339a was making it clack.
@RichEEM, Steep is right,kinda like Yosemite or Pinnicles a shear face,
not like the O/S...but now that I think about it, yeah it is a new thing.
I do have a little cap meter simple BK
that gives cap values, and a home made
Dick Smith ESR/Low Ohms meter. Then I have an old Navy
LCR Meter that looks like it was made by Hickock, which I cleaned
and fired up the other day. I have no way to calibrate it yet, and
didn't think it would power up, but it did with a variac to bring up
slowly.
It took a while but I did save up for a DER EE 5000 LCR meter
which does the Dfactor and other measurements, has sort function
and IR computer USB connection that will also help. Heck a few
folks say here that it is the same as or similar to the Agilent LCR
meter and it matches their calibrated LCR.
Anyway, I'm patient and look for good buys on test gear.
I also am going to need a laptop that will be usable for
testing also. Any suggestions? MAC/PC?
Thank's for your wisdom and keeping me on the wagon,
and not letting me put the wrong parts in the wrong place.
The next round's on me...
Chantal, would you be kind enough to bring to these gentlemen
what ever they are having.
Cheers
@David,
Thanks gentlemen, yeah I'm over it.
AND
Yep, I do realize how lucky we are to have access to all this info
on the WWW. This 'puter also misses posts sometimes too.
I remember David discussing using the OPA1461 for A3 U3 and making a board for it. So no LME here, that leaves either LT1468 or the
OPS134. : ) At least for the moment. But I'm getting ahead of
myself here. Also recall the AM Detector, and isolating it from chassis
was thinking of grounding somewhere at the input around TP8...with the
mini coax.
This brings up a related question...as I'm sure y'all encountered before,
Who makes a chassis punch with the little hold down, anti rotation notch?
I also got that NULL really really deep, so the hand by the output
cable, or around the front of the HP339a was making it clack.
@RichEEM, Steep is right,kinda like Yosemite or Pinnicles a shear face,
not like the O/S...but now that I think about it, yeah it is a new thing.
I do have a little cap meter simple BK
that gives cap values, and a home made
Dick Smith ESR/Low Ohms meter. Then I have an old Navy
LCR Meter that looks like it was made by Hickock, which I cleaned
and fired up the other day. I have no way to calibrate it yet, and
didn't think it would power up, but it did with a variac to bring up
slowly.
It took a while but I did save up for a DER EE 5000 LCR meter
which does the Dfactor and other measurements, has sort function
and IR computer USB connection that will also help. Heck a few
folks say here that it is the same as or similar to the Agilent LCR
meter and it matches their calibrated LCR.
Anyway, I'm patient and look for good buys on test gear.
I also am going to need a laptop that will be usable for
testing also. Any suggestions? MAC/PC?
Thank's for your wisdom and keeping me on the wagon,
and not letting me put the wrong parts in the wrong place.
The next round's on me...
Chantal, would you be kind enough to bring to these gentlemen
what ever they are having.
Cheers
For testing you will want a PC. There are just a lot more options available. Laptops do not have good sound cards as a rule so you will need an external one. How heavy vs. how much you want it to do vs. how much you want to pay all matter. For a test system I would get an older Dell laptop like an e6410 (around $200 or so on eBay), get an SSD and either an EMU Tracker pre or a QA400. Its heavier than you would like (really around 5-6 Lbs.) but getting a i5 or an i7 for that price is pretty attractive. Dell parts are easy to get on eBay and usually cheap. The Dell manuals are really complete for opening them and replacing components.
Getting current gen tech is always way more expensive and the prices drop like a rock in 6 months.
@Demian,
I'm confused. Okay, Mac/PC therefore PC.
Desktop/Laptop Desktop, but then Laptop?
Typo?
Or not?
I was thinking of the new laptop for both here,
which I typically use (is an older PC-Laptop) and portable for using
for testing etc.
I did revise my older desktop PC which was an old Fry's Electronic's
unit, but now with a new O/S, Processor, motherboard, power supply,
video card, sound board, etc, etc.
i5, i7? Will look mmmm i7 for me.
EMU Tracker, I noticed them.
I've got the QA400 already along with the QA190.
I've also worked to have multiple references as y'all have
described their benefit for checking against other known references.
Some are not the best equipment but with upgrades as I'm performing
and your knowledge ( DIY Audio) I"ve made significant progress.
I've got a ways to go and am learning in leaps and bounds.
I'll continue to investigate, including the e6410.
Cheers,
I'm confused. Okay, Mac/PC therefore PC.
Desktop/Laptop Desktop, but then Laptop?
Typo?
Or not?
I was thinking of the new laptop for both here,
which I typically use (is an older PC-Laptop) and portable for using
for testing etc.
I did revise my older desktop PC which was an old Fry's Electronic's
unit, but now with a new O/S, Processor, motherboard, power supply,
video card, sound board, etc, etc.
i5, i7? Will look mmmm i7 for me.
EMU Tracker, I noticed them.
I've got the QA400 already along with the QA190.
I've also worked to have multiple references as y'all have
described their benefit for checking against other known references.
Some are not the best equipment but with upgrades as I'm performing
and your knowledge ( DIY Audio) I"ve made significant progress.
I've got a ways to go and am learning in leaps and bounds.
I'll continue to investigate, including the e6410.
Cheers,
Last edited:
I guess it was confusion. I was only talking laptop. Desktop for measurement is a more involved topic.
Also I would seriously consider multiboot. XP for some of the older stuff that doesn't work well on win 7. And Win 7 for newer stuff. I have Win 8.1 on my main laptop but I would not use that for technical work. Its just too clumsy. I'm doing a lot of work on Bluetooth headphones and the only platform that works well with the software is XP. Everything else has many roadblocks, especially when drivers come into play. Same for most other tech software.
Also I would seriously consider multiboot. XP for some of the older stuff that doesn't work well on win 7. And Win 7 for newer stuff. I have Win 8.1 on my main laptop but I would not use that for technical work. Its just too clumsy. I'm doing a lot of work on Bluetooth headphones and the only platform that works well with the software is XP. Everything else has many roadblocks, especially when drivers come into play. Same for most other tech software.
Checking them out now.
Yeah, I see that Dell site isn't bad for bios upgrades etc.
I haven't seen the hardware stuff yet, but I do know that
the Fujitsu that I have is difficult to work on and not a lot
of information is out there and some of it is just plain
incorrect information about it and repairs/mods.
Please don't ask me how I know.
Yes, for the information that I've found and run,
having multi-boot capabilities is it. I kept that when
I upgrade my desktop...Still have XP capability and
Win 7. Win 7 was a major deal as lots of stuff doesn't
work with the some of the older software that I have.
Also, Microsoft is rearing it's ugly head...they want money
to develop etc...and won't license out some parts and have
stopped things from being used all together, etc.
Now they won't sell the OFFICE any more but want to
only license it's use and make people pay an annual fee
for it. Fine for big corps I guess but who want to keep
paying and paying....
Cheers,
Yeah, I see that Dell site isn't bad for bios upgrades etc.
I haven't seen the hardware stuff yet, but I do know that
the Fujitsu that I have is difficult to work on and not a lot
of information is out there and some of it is just plain
incorrect information about it and repairs/mods.
Please don't ask me how I know.
Yes, for the information that I've found and run,
having multi-boot capabilities is it. I kept that when
I upgrade my desktop...Still have XP capability and
Win 7. Win 7 was a major deal as lots of stuff doesn't
work with the some of the older software that I have.
Also, Microsoft is rearing it's ugly head...they want money
to develop etc...and won't license out some parts and have
stopped things from being used all together, etc.
Now they won't sell the OFFICE any more but want to
only license it's use and make people pay an annual fee
for it. Fine for big corps I guess but who want to keep
paying and paying....
Cheers,
Last edited:
Holy Smokes,
Yes, there is. I didn't pay close enough attention to it.
I was just looking through the specs sheet and noticed
the different chips.... not their function.
I was looking at the difference between the i5, i7,
then the SSD v HHD. SSD reduced latency, loading speed etc.
any one know how many times you can write to an address
space before you can't write to it any more? Was the major
limitation that was discussed in the article I read?
The Dells, for the price a couple hundred for a system that won't bank
rupt you if fried isn't too bad. For a 4 core processor to boot.
How well are they derated when you start overclocking them?
Yes, there is. I didn't pay close enough attention to it.
I was just looking through the specs sheet and noticed
the different chips.... not their function.
I was looking at the difference between the i5, i7,
then the SSD v HHD. SSD reduced latency, loading speed etc.
any one know how many times you can write to an address
space before you can't write to it any more? Was the major
limitation that was discussed in the article I read?
The Dells, for the price a couple hundred for a system that won't bank
rupt you if fried isn't too bad. For a 4 core processor to boot.
How well are they derated when you start overclocking them?
Last edited:
Don't worry about write life with your laptop SSD -- it may outlive you by a big margin. Only an issue with servers. Just get one that will stay about twice as much free space as you think you'll ultimately use. All my SSDs (5) happen to be 120GB at the moment, and since I don't store a lot of music or pictures or video, that's plenty.