Hi.
I've recently aquired some pearl pcbs (nice!), but I have a question about the riaa filtration capacitors.
Compared with other phono stages, the values of these caps is quite large (as large as .15uf !), ruling out the use of 1% capacitors (such as silvered mica, or those vishay polyester ones).
What's with the large values, and are there other recommended capacitors besides the panasonic 2% caps (which I'll have to source from overseas
)?
I've recently aquired some pearl pcbs (nice!), but I have a question about the riaa filtration capacitors.
Compared with other phono stages, the values of these caps is quite large (as large as .15uf !), ruling out the use of 1% capacitors (such as silvered mica, or those vishay polyester ones).
What's with the large values, and are there other recommended capacitors besides the panasonic 2% caps (which I'll have to source from overseas
)?
The important caps seem to be .12 and .33uF. I see no reason the RIAA network cannot be recalculated for higher resistance/ lower capacitance. Some people seem to have a preference for the sound of low resistance networks but i have never been convinced. Your other option is to hand select an accurate cap out of a large batch or using a parallel combination of smaller caps. Nothing wrong with either approach.
thanks analog_sa
for good info in this matter
Another thing I have read from some RIAA project:
- It is a bit more important
that the RC components for left and right channel are very close in match.
than
- The actual RC resulting value (... = how close the curve follows RIAA)
analog_sa
Can there be any valid point in this?
Of course, the ideal is
that BOTH channels match AND the riaa curve follows standard closely.
But sometimes, even if parallel or series components
is not possible to achieve absolute perfect values.
It is possibly, in my opinion,
a bit easier to select out two almost identical value Capacitors, for left resp. right channel
than is to find a combination that gives exactly 75uS performance in circuit.
I would say that listening, we may more easily detect difference between left right sound/phase
than detect if the RIAA is 1 or a couple dB from standard curve.
Human hearing is using left / right ear differences- like phase and delay, I guess,
to locate from what direction a sound is coming and the distance to sound source.
We have a developed apparatus for this.
( this is one good reason we have 2 ears and 2 eyes )
Old people with not much left in hearing in one ear
will have difficulty locate a sound source, without using vision.
And if they are half-blind, too.
Only sight of one eye, then is not very funny for them.
Regards
lineup
on his way gettin' old man, half deaf and half blind, hopefully!
(who would want to die too soon ...)
for good info in this matter
Another thing I have read from some RIAA project:
- It is a bit more important
that the RC components for left and right channel are very close in match.
than
- The actual RC resulting value (... = how close the curve follows RIAA)
analog_sa
Can there be any valid point in this?
Of course, the ideal is
that BOTH channels match AND the riaa curve follows standard closely.
But sometimes, even if parallel or series components
is not possible to achieve absolute perfect values.
It is possibly, in my opinion,
a bit easier to select out two almost identical value Capacitors, for left resp. right channel
than is to find a combination that gives exactly 75uS performance in circuit.
I would say that listening, we may more easily detect difference between left right sound/phase
than detect if the RIAA is 1 or a couple dB from standard curve.
Human hearing is using left / right ear differences- like phase and delay, I guess,
to locate from what direction a sound is coming and the distance to sound source.
We have a developed apparatus for this.
( this is one good reason we have 2 ears and 2 eyes )
Old people with not much left in hearing in one ear
will have difficulty locate a sound source, without using vision.
And if they are half-blind, too.
Only sight of one eye, then is not very funny
for them.Regards
lineup
on his way gettin' old man, half deaf and half blind, hopefully!(who would want to die too soon ...)
The argument for lower resistances is based on noise. Lower values contribute somewhat less noise than higher ones--this is one of several reasons that tube circuits are noisier than solid state ones; the resistances are much, much higher.
None of which stopped me from using higher resistances and lower value caps in a phono stage I did last winter, precisely because I wanted to use 1% caps in the RIAA eq. The RIAA is pretty close to perfect. There is some noise. In an ideal world, I'd have enough time to build another circuit using low resistance/higher capacitance for comparison purposes, but I've got other circuits that are more interesting to me at the moment.
Grey
None of which stopped me from using higher resistances and lower value caps in a phono stage I did last winter, precisely because I wanted to use 1% caps in the RIAA eq. The RIAA is pretty close to perfect. There is some noise. In an ideal world, I'd have enough time to build another circuit using low resistance/higher capacitance for comparison purposes, but I've got other circuits that are more interesting to me at the moment.
Grey
low noise riaa lineup analog_sa hansen grey grollins
Hello, Mister Grey
GRollins
I guess we both have to wait for
analog_sa ......... isn't this Mister C. Hansen ... ?
as you probably know as little as me
the answer to my follow up question (see post above)
in this subject
Regards
lineup 1st Chief Low Noise Engineer
at
Lineup Audio Phono Lab Designs Inc.
http://lineup.awardspace.com/
Hello, Mister Grey
GRollins
I guess we both have to wait for
analog_sa ......... isn't this Mister C. Hansen ... ?
as you probably know as little as me
the answer to my follow up question (see post above)
in this subject
Regards
lineup 1st Chief Low Noise Engineer
at
Lineup Audio Phono Lab Designs Inc.
http://lineup.awardspace.com/
Re: Re: low noise riaa lineup analog_sa hansen grey grollins
Charles 'Charlie' Hansen
... 24 matched (FET) transistors ...
... completely balanced from input to output ...
... as simple as we could make it ...
Yeah!
making a preamp
is pretty simple, isn't
lineup - simply
-----------------------------------------------
Reference.
( Weblink: http://stereophile.com/interviews/610/index1.html )
analog_sa said:
Charles 'Charlie' Hansen
... 24 matched (FET) transistors ...
... completely balanced from input to output ...
... as simple as we could make it ...
Yeah!
making a preamp
is pretty simple, isn't
lineup - simply
-----------------------------------------------
Reference.
( Weblink: http://stereophile.com/interviews/610/index1.html )
lineup,
I'm sorry, but I'm not clear on what your followup question actually is. If you can rephrase it, I'll try to answer it.
You can either have high resistance and low capacitance, or low resistance and high capacitance. One percent resistors aren't all that difficult (or expensive) to find, but tight tolerance caps are a problem--particularly if you want some sort of film caps. I went with the polypropylene/foil 1% WIMA caps. This allowed me to have virtually perfect RIAA eq, albeit at the expense of slightly higher noise.
I have yet to find a manufacturer who makes polypropylene or polystyrene capacitors in larger values in tight tolerances.
Grey
I'm sorry, but I'm not clear on what your followup question actually is. If you can rephrase it, I'll try to answer it.
You can either have high resistance and low capacitance, or low resistance and high capacitance. One percent resistors aren't all that difficult (or expensive) to find, but tight tolerance caps are a problem--particularly if you want some sort of film caps. I went with the polypropylene/foil 1% WIMA caps. This allowed me to have virtually perfect RIAA eq, albeit at the expense of slightly higher noise.
I have yet to find a manufacturer who makes polypropylene or polystyrene capacitors in larger values in tight tolerances.
Grey
steenoe
steenoe
i have read your post
i leave it to mr grey rollins to eventually report my post
or bother at all if he finds this necessary
he was kind enough to reply
and i am fully aware of his enormous knowledge
in some audio matters
anyway
he who knows it all
is not yet invented
lets not pretend he is
i am not shy to admit there are things i do not know
i am strong enough to admit my weakness
if i find it is there
as well as i am not shy to admit my ability my good knowledge
if i find it really is at hand
for sure,
i wont put my candle under cover
whatever anyone may try with me
at our 97.41% nice forum
of www.diyaudio.com
kindest regards you could imagine
from
lineup
steenoe
i have read your post
i leave it to mr grey rollins to eventually report my post
or bother at all if he finds this necessary
he was kind enough to reply
and i am fully aware of his enormous knowledge
in some audio matters
anyway
he who knows it all
is not yet invented
lets not pretend he is
i am not shy to admit there are things i do not know
i am strong enough to admit my weakness
if i find it is there
as well as i am not shy to admit my ability my good knowledge
if i find it really is at hand
for sure,
i wont put my candle under cover
whatever anyone may try with me
at our 97.41% nice forum
of www.diyaudio.com
kindest regards you could imagine
from
lineup
You can get 1% 50 V rated pp caps at digikey
For example,
http://www.digikey.com/scripts/DkSearch/dksus.dll?PName?Name=P3876-ND
For example,
http://www.digikey.com/scripts/DkSearch/dksus.dll?PName?Name=P3876-ND
I have found the Panasonic caps to be only average (at best) in sound quality, although they are certainly more widely available--at least here in the US--than, say, the WIMA. The WIMAs are available from Mouser, but the 1% polypropylene & foil caps I used are only available in small values. Bummer.
Mallory used to make polystyrene & foil caps. I don't believe they make them any more, but back stock is still available here and there. Mouser has polystyrene & foil caps by Xicon, but I believe they're 5% tolerance. They sound okay. If you're willing to rematch them by hand, that might be an option.
I've built phono stages with tubes, chips, and discrete solid state. I find them endlessly fascinating...and annoying. One of the things on my to-do list is a phono stage using the Lovoltech JFETs at the outputs. I've got the topology in mind--just need time. At the moment, I'm feeding Wyatt with one hand and typing with the other. Unless I can grow a third hand, I won't be getting any electronics done in the next hour or so.
Grey
P.S.: There's something familiar about lineup's writing style. Methinks I'll let him dig his own grave.
Mallory used to make polystyrene & foil caps. I don't believe they make them any more, but back stock is still available here and there. Mouser has polystyrene & foil caps by Xicon, but I believe they're 5% tolerance. They sound okay. If you're willing to rematch them by hand, that might be an option.
I've built phono stages with tubes, chips, and discrete solid state. I find them endlessly fascinating...and annoying. One of the things on my to-do list is a phono stage using the Lovoltech JFETs at the outputs. I've got the topology in mind--just need time. At the moment, I'm feeding Wyatt with one hand and typing with the other. Unless I can grow a third hand, I won't be getting any electronics done in the next hour or so.
Grey
P.S.: There's something familiar about lineup's writing style. Methinks I'll let him dig his own grave.
First I would like to say that I am by no means an expert on anything, however, I have an opinion worth investigating. I currently am building a few different phono amps of various topologies and modifying an existing one I have. I have been experimenting with various parts and found three types of capacitors to use for my work. The best 1% I could find for sound, price, and precision in the low values are the Vishay Rod. MKP series. They are hard to get though, I had to order from over seas. The values are also limited. Wima has 1%, I liked them, though less so, and also only available in that precision in lower values. I tried the 1% Silver mica's and did not like the sound much, and had more trouble making up matched pairs than I expected.
The ones that I like best are not 1% but 5%, however for a fee of about $1 per pair of matched caps, you can have them matched to each other. Given the much higher cost per cap, I consider it worth while instead of buying a large lot of them. Anyway, I really like the Relcap RT series of caps available in a wide range of lower values, and I think they are one of the best choices for RIAA stages you can buy. Also I really like the Exotica Teflons and RTX's, though they are 10%, though according to Michael Percy, they are closer to 5% typical. I haven't used the exotica Teflon ones much at all, but I liked the two I used for the output of a dac. I want to try them in the larger values of a phonostage RIAA cuircit maybe, or if not, possibly elsewhere in the cuircit.
Thats my 2 cents, for what its worth. I would definatly check out the RT's, the others have a lot of competition and you can use what ever you like, but I found it hard to get nice small value caps, and the RT has been the answer to my prayer. If they werent so pricey they would be perfect. However, given what it costs me to buy the MKP's, its not so bad, and I like em better.
>>>Note on the above...
I just noticed that Parts Connection calls the ones I use RTE's not RT's, and claims they are 2% tolerance. I'm not sure, I should check when I get home what I bought, but that is probably the better choice.
Also noticed that TRT Wonder caps are available in 2% and smaller values, might be a nice option as well.
The ones that I like best are not 1% but 5%, however for a fee of about $1 per pair of matched caps, you can have them matched to each other. Given the much higher cost per cap, I consider it worth while instead of buying a large lot of them. Anyway, I really like the Relcap RT series of caps available in a wide range of lower values, and I think they are one of the best choices for RIAA stages you can buy. Also I really like the Exotica Teflons and RTX's, though they are 10%, though according to Michael Percy, they are closer to 5% typical. I haven't used the exotica Teflon ones much at all, but I liked the two I used for the output of a dac. I want to try them in the larger values of a phonostage RIAA cuircit maybe, or if not, possibly elsewhere in the cuircit.
Thats my 2 cents, for what its worth. I would definatly check out the RT's, the others have a lot of competition and you can use what ever you like, but I found it hard to get nice small value caps, and the RT has been the answer to my prayer. If they werent so pricey they would be perfect. However, given what it costs me to buy the MKP's, its not so bad, and I like em better.
>>>Note on the above...
I just noticed that Parts Connection calls the ones I use RTE's not RT's, and claims they are 2% tolerance. I'm not sure, I should check when I get home what I bought, but that is probably the better choice.
Also noticed that TRT Wonder caps are available in 2% and smaller values, might be a nice option as well.
Would you believe, that now when I finally got out of the bush and said my oppinion, this was the result:http://www.diyaudio.com/forums/showthread.php?postid=1082313#post1082313
He managed to dig out an almost 3 year old thread, in an attempt to smear me! Dooh! Dont even ask me, I am plenty tired of the posts this guy "Contributes with" Adding to confusion and never giving an answer to a posted question! Thats it for now, I dont want to get rude. I am very sorry to having to polute this thread.
Steen.
Steen,
If it's who I think it is, he's already been banned once, not to mention chased off from another site. Etc. He seems to be reverting to type.
The MIT caps are fabulous, but so expensive as to tempt me to steal lunch money from little old ladies. Once you get into the boutique caps, you can spend truly extraordinary amounts of money. On rare occasions I go ahead and drop the cash, but usually I stick with the more readily available and economical stuff.
Grey
If it's who I think it is, he's already been banned once, not to mention chased off from another site. Etc. He seems to be reverting to type.
The MIT caps are fabulous, but so expensive as to tempt me to steal lunch money from little old ladies. Once you get into the boutique caps, you can spend truly extraordinary amounts of money. On rare occasions I go ahead and drop the cash, but usually I stick with the more readily available and economical stuff.
Grey
Back in the day, someone (Arthur C. Clarke?) wrote a story wherein the phone system reached the point where it had so many nodes that it approached the complexity of the human brain, reached critical mass, and became self-aware. I shudder to think that the network might achieve the same end result. Given the amount of nonsense spam I receive, I suppose it's possible,
(Yes, I know it's pump-and-dump stock schemes, but jeez, what's a network to do when it finds that it needs money?)
Grey
(Yes, I know it's pump-and-dump stock schemes, but jeez, what's a network to do when it finds that it needs money?)
Grey
Cap testing
If you want to do some cap testing and have facility to etch your own board, you might find my layout for pearl interesting:
http://viller.org/audio/2006nov_pearl/pearlpcb.pdf
http://www.diyaudio.com/forums/showthread.php?s=&threadid=90136
You can fit almost any capacitor. I'll send the copperside on request by email. I have tested a revision earlier with very good results (made one mistake in schematics which is fixed now), but I'm not putting this layout online before someone tells me that they made it work!
I can change the output cap too, if I get some lengths.
If you want to do some cap testing and have facility to etch your own board, you might find my layout for pearl interesting:
http://viller.org/audio/2006nov_pearl/pearlpcb.pdf
http://www.diyaudio.com/forums/showthread.php?s=&threadid=90136
You can fit almost any capacitor. I'll send the copperside on request by email. I have tested a revision earlier with very good results (made one mistake in schematics which is fixed now), but I'm not putting this layout online before someone tells me that they made it work!
I can change the output cap too, if I get some lengths.
steenoe said:
http://www.diyaudio.com/forums/showthread.php?postid=1082313#post1082313
He managed to dig out an almost 3 year old thread, in an attempt to smear me! Dooh! Dont even ask me, I am plenty tired of the posts this guy "Contributes with" Adding to confusion and never giving an answer to a posted question! Thats it for now, I dont want to get rude. I am very sorry to having to polute this thread.
Steen.
steen-lineup have prehistory with diff nick,and If I remember correctly- he was banned once .....then...whatever
I just don't remember who was in question ...... halojoy....?
anyway
he's heavy
trying to be cozy and patronizing in same time
what he knows,and he knows about SS more than me,in any case is blurred with his heavy approach
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