Passive RIAA - single Vs double stage

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RhythMick
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#1 Passive RIAA - single Vs double stage

Post by RhythMick »

Planning my phono stage and I'm reading Merlin Blencowe's book. I'm considering

SUT 1:20
D3a triode
01A
112 long tailed pair into LL1660 for balanced output

That would appear to lend itself to 2 stage RIAA. Any views compared to single stage?
PXL_20210716_183453041~2_compress21.jpg
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IslandPink
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#2 Re: Passive RIAA - single Vs double stage

Post by IslandPink »

Steven will be your best bet for advice, i haven't tried it - but the DC link to the CF at the end allows you to avoid a second cap, so that's always good in my books.
"Once you find out ... the Circumstances ; then you can go out"
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izzy wizzy
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#3 Re: Passive RIAA - single Vs double stage

Post by izzy wizzy »

Never tried split eq although never had a 3 stage phono. I've not read or understood, a compelling reason why it would be a good idea other than it's. easier to calculate the values. There's an argument for hf overload relief in some circuits but that doesn't usually apply for valves.

Sure the all in one eq can be a bit tricky to do but spice is your friend so does the heavy lifting.

In my head doing the eq all in one place just seems right. But you can try both and tell us what you think :D
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Nick
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#4 Re: Passive RIAA - single Vs double stage

Post by Nick »

Yep I agree with Izzy. Bit more natural with single stage. But YMMV.
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RhythMick
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#5 Re: Passive RIAA - single Vs double stage

Post by RhythMick »

Ok I going to build the PSU and a prototyping amp with the valves and RIAA on interchangable turret boards. HM-3 inputs one end, HT & GND and valve heater connections along one edge, outputs to LL1660 other end. One per channel.

I should be able to prototype and swap in different amp modules to listen to. Hopefully.
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