Dear All
I experimented with several separate phono stages, yesterday my bro took his NAD 3020 to my place. Just for fun, we took the signal out from the tape output to feed the line stage of my Audio Research SP9 Mk II
... I was shocked! The sound of my loved Shure V15 was too good to believe. Although I missed some of the fresh touch of the SP9 in the mids/highs, although the overall presentation is not as clean as from the SP9, the energy and realism of the NAD output is quite something.
I decided I want to experiment a bit further. So I'd like to modify the signal path to avoid the tape loop. I want to put a pair of RCA connectors on the back and take the phono output from an optimal location in the circuit.
I wonder whether this has been tried before. Any experience to share?
I experimented with several separate phono stages, yesterday my bro took his NAD 3020 to my place. Just for fun, we took the signal out from the tape output to feed the line stage of my Audio Research SP9 Mk II
... I was shocked! The sound of my loved Shure V15 was too good to believe. Although I missed some of the fresh touch of the SP9 in the mids/highs, although the overall presentation is not as clean as from the SP9, the energy and realism of the NAD output is quite something.
I decided I want to experiment a bit further. So I'd like to modify the signal path to avoid the tape loop. I want to put a pair of RCA connectors on the back and take the phono output from an optimal location in the circuit.
I wonder whether this has been tried before. Any experience to share?
This phono stage has an unbuffered RC low pass filter at its output, loaded by the 50k volume control.
Try to duplicate this loading when taking the phono signal from the output side of C422. Just deselect
the phono on the front panel, and its output will be disconnected from the rest of the following circuitry.
As it happens, the two ARC 100k balance and volume controls (in parallel) will load the phono stage
correctly when phono is deselected on the NAD.
Try to duplicate this loading when taking the phono signal from the output side of C422. Just deselect
the phono on the front panel, and its output will be disconnected from the rest of the following circuitry.
As it happens, the two ARC 100k balance and volume controls (in parallel) will load the phono stage
correctly when phono is deselected on the NAD.
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The 3020 phono stage is quite remarkable. The 3150 even more so. Strictly for mm. In the 80s I built a few clones of both with better/more power supplies and better parts and it was very hard to beat them. Humbling even.
A shame to hack a 3020 for that purpose. Since they tend to die early due to the goal of trying to keep it inexpensive you might just take the schema and start from scratch. I need to get a flaky channel fixed in my 7020.
dave
dave
Hi thanks!
let me see if I understood it correctly (I am not too much into active circuits):
(A) I take the phono signal on the output side of C422
(B) then, before the RCA outuput plugs (that I will add on the back) I load the previous signal with 50K.
What kind of resistor do you suggest for (B)?
let me see if I understood it correctly (I am not too much into active circuits):
(A) I take the phono signal on the output side of C422
(B) then, before the RCA outuput plugs (that I will add on the back) I load the previous signal with 50K.
What kind of resistor do you suggest for (B)?
now that you say so I feel myself less crazy 🙂, this means my impressions are likely not due to "hear loss" 🙂
Originally, I think the preamp was simply a 3020 minus the power amp section using the same pcb.
Pretty sure the 3030 uses the same circuit.
Pretty sure the 3030 uses the same circuit.
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Hey! the NAD phono is something I wanted to adopt too. I took the design and made some simulations and tweaked up the output driver and made a pcb for it. I didn’t have a chance to build it yet. If anybody wants a stand alone pcb for it I have spares. I included a dual rail shunt regulator on the board too. I looked at several NAD integrated amps as there were a few variations. I ended up taking the best from what I understand. I really must build it as I currently have no phono and vinyl sitting in wrappers.
TGMC - a modular control pre-amplifier
TGMC - a modular control pre-amplifier
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1) Yes, along with a ground wire. Twist them together.
2) No need for a resistor, the ARC will load the NAD properly by itself.
Just remember to "deselect" the phono function on the NAD's front panel.
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The NAD 3020 phono stage was quite popular in my country in the 80's. A lot of clones have been built (legally), thanks to a local audio magazine:
?j fono-el?er?s?t?
?j fono-el?er?s?t?
