| Author |
Message |
TonyP
Guest
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 Posted:
Tue Nov 30, 2004 6:22 am Post subject:
Re: I have found a "reverse RIAA" module |
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"Isaac Wingfield" <isw@witzend.com> wrote in message
news:isw-8B55A3.19282028112004@netnews.comcast.net...
| Quote: | To have any hope at all of accuracy. the *only* way to test RIAA inputs
is using a proper RIAA test record.
If you don't include the cartridge in the test, it's worthless.
|
Not if you are testing the pre-amp!
TonyP.
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Mark D. Zacharias
Guest
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| Posted:
Tue Nov 30, 2004 5:32 pm Post subject:
Re: I have found a "reverse RIAA" module |
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"Isaac Wingfield" <isw@witzend.com> wrote in message
news:isw-0179D5.20340029112004@netnews.comcast.net...
| Quote: | In article <41AA9E78.C2DDFAFA@hotmail.com>,
Pooh Bear <rabbitsfriendsandrelations@hotmail.com> wrote:
Isaac Wingfield wrote:
In article <41AA4505.D79F26EA@hotmail.com>,
Pooh Bear <rabbitsfriendsandrelations@hotmail.com> wrote:
Bill wrote:
I found at http://www.hagtech.com/ a "reverse RIAA" module for
allowing line sources into phono inputs. It reverses the frequency
response curve and pads the level to around minus 50-60.
That's how we test RIAA inputs ! I didn't need some commercial
company
to tell me how to do it though.
To have any hope at all of accuracy. the *only* way to test RIAA inputs
is using a proper RIAA test record.
If you don't include the cartridge in the test, it's worthless.
And if you don't know what cartridge the user is going to attach....... ?
What then ?
Then you really don't know what the system's performance is going to be.
Surely you don't imagine that a "calibrated" RIAA preamp will have the
same frequency response *from a record* regardless of which cartridge
you attach?
It's a very interesting experiment to use an inverse-RIAA network to
"calibrate" a preamp, and then hook up the cartridge of your choice and
check the response using the test record.
Most RIAA preamps are "pretty close" without calibration anyway. The
only reason to use the inverse network is to "fine tune" things, and if
you ignore the cartridge's effect when you do the tuning, you may wind
up further off than when you started.
Isaac
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What about repairing and testing broken phono circuits?
Mark Z. |
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Arny Krueger
Guest
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| Posted:
Tue Nov 30, 2004 6:06 pm Post subject:
Re: I have found a "reverse RIAA" module |
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"Isaac Wingfield" <isw@witzend.com> wrote in message
news:isw-0179D5.20340029112004@netnews.comcast.net
| Quote: | In article <41AA9E78.C2DDFAFA@hotmail.com>,
Pooh Bear <rabbitsfriendsandrelations@hotmail.com> wrote:
Isaac Wingfield wrote:
In article <41AA4505.D79F26EA@hotmail.com>,
Pooh Bear <rabbitsfriendsandrelations@hotmail.com> wrote:
Bill wrote:
I found at http://www.hagtech.com/ a "reverse RIAA" module for
allowing line sources into phono inputs. It reverses the frequency
response curve and pads the level to around minus 50-60.
That's how we test RIAA inputs ! I didn't need some commercial
company to tell me how to do it though.
To have any hope at all of accuracy. the *only* way to test RIAA
inputs is using a proper RIAA test record.
If you don't include the cartridge in the test, it's worthless.
And if you don't know what cartridge the user is going to
attach....... ? What then ?
Then you really don't know what the system's performance is going to
be.
Surely you don't imagine that a "calibrated" RIAA preamp will have the
same frequency response *from a record* regardless of which cartridge
you attach?
|
Agreed, but that is a different question.
| Quote: | It's a very interesting experiment to use an inverse-RIAA network to
"calibrate" a preamp, and then hook up the cartridge of your choice
and check the response using the test record.
|
Been there, done that.
| Quote: | Most RIAA preamps are "pretty close" without calibration anyway. The
only reason to use the inverse network is to "fine tune" things, and
if you ignore the cartridge's effect when you do the tuning, you may
wind up further off than when you started.
|
Agreed. |
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Pooh Bear
Guest
|
| Posted:
Thu Dec 02, 2004 6:08 am Post subject:
Re: I have found a "reverse RIAA" module |
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|
Isaac Wingfield wrote:
| Quote: | In article <41AA9E78.C2DDFAFA@hotmail.com>,
Pooh Bear <rabbitsfriendsandrelations@hotmail.com> wrote:
Isaac Wingfield wrote:
In article <41AA4505.D79F26EA@hotmail.com>,
Pooh Bear <rabbitsfriendsandrelations@hotmail.com> wrote:
Bill wrote:
I found at http://www.hagtech.com/ a "reverse RIAA" module for
allowing line sources into phono inputs. It reverses the frequency
response curve and pads the level to around minus 50-60.
That's how we test RIAA inputs ! I didn't need some commercial company
to tell me how to do it though.
To have any hope at all of accuracy. the *only* way to test RIAA inputs
is using a proper RIAA test record.
If you don't include the cartridge in the test, it's worthless.
And if you don't know what cartridge the user is going to attach....... ?
What then ?
Then you really don't know what the system's performance is going to be.
Surely you don't imagine that a "calibrated" RIAA preamp will have the
same frequency response *from a record* regardless of which cartridge
you attach?
It's a very interesting experiment to use an inverse-RIAA network to
"calibrate" a preamp, and then hook up the cartridge of your choice and
check the response using the test record.
Most RIAA preamps are "pretty close" without calibration anyway. The
only reason to use the inverse network is to "fine tune" things, and if
you ignore the cartridge's effect when you do the tuning, you may wind
up further off than when you started.
|
Well..... If you hadn't already noticed from my earlier posts, I've used an
inverse RIAA network to define testing of products at the manufacturing stage to
verify the correct equalisation.
The RIAA curve is well- known. It's a standard. If your cartridge has a lousy
response it's *not* a fault of the equipment that complies with the standard.
Nuff said.
Graham |
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Laurence Payne
Guest
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| Posted:
Fri Dec 03, 2004 5:17 am Post subject:
Re: I have found a "reverse RIAA" module |
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On Sun, 28 Nov 2004 09:10:00 -0500, Bill <bill2@mindspring.com> wrote:
| Quote: | I found at http://www.hagtech.com/ a "reverse RIAA" module for
allowing line sources into phono inputs. It reverses the frequency
response curve and pads the level to around minus 50-60.
|
Congratulations! Why? |
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Geoff Wood
Guest
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| Posted:
Sat Dec 04, 2004 6:19 am Post subject:
Re: I have found a "reverse RIAA" module |
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"Laurence Payne" <l@laurenceDELETEpayne.freeserve.co.uk> wrote in message
news:o4cvq0tg92hjlv286eqsfa17oll6qjn2lc@4ax.com...
| Quote: | On Sun, 28 Nov 2004 09:10:00 -0500, Bill <bill2@mindspring.com> wrote:
I found at http://www.hagtech.com/ a "reverse RIAA" module for
allowing line sources into phono inputs. It reverses the frequency
response curve and pads the level to around minus 50-60.
Congratulations! Why?
|
Wants to severely compromise gain staging, overload sensitivity, and freq
linearity.
geoff |
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TonyP
Guest
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| Posted:
Sat Dec 04, 2004 6:12 pm Post subject:
Re: I have found a "reverse RIAA" module |
|
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"Geoff Wood" <geoff@nospam-paf.co.nz> wrote in message
news:I9asd.13581$3U4.297492@news02.tsnz.net...
| Quote: | Congratulations! Why?
Wants to severely compromise gain staging, overload sensitivity, and freq
linearity.
|
Yes, but surely there are cheaper ways to do that :-)
TonyP. |
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