Looking for recommendation for Phono Stage

What people are working on at the moment
RhythMick
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#16 Re: Looking for recommendation for Phono Stage

Post by RhythMick »

I have some 5842 which might be a good candidate.
simon
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#17 Re: Looking for recommendation for Phono Stage

Post by simon »

RhythMick wrote: Wed Jan 16, 2019 11:10 pm Lastly, I'm not averse to using solid state to help maximise the clean gain.
In which case it might be worth looking at Rod Coleman's shunt cascode boards on DIY Audio. Rod's posted circuits for phonos and is generally really helpful supporting his stuff - he'd no doubt suggest a circuit.

You're brave trying DHTs in a phono though. But we applaud you, it's the spirit of what the place is about. :-)
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IslandPink
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#18 Re: Looking for recommendation for Phono Stage

Post by IslandPink »

However do be aware of WC Fields' advice -
"If at first you don't succeed, try again..
then stop.
No point making a damn fool out of yourself"
"Once you find out ... the Circumstances ; then you can go out"
RhythMick
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#19 Re: Looking for recommendation for Phono Stage

Post by RhythMick »

IslandPink wrote: Thu Jan 17, 2019 11:30 pm However do be aware of WC Fields' advice -
"If at first you don't succeed, try again..
then stop.
No point making a damn fool out of yourself"
:D

Nice one
RhythMick
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#20 Re: Looking for recommendation for Phono Stage

Post by RhythMick »

D3a looks interesting too, but where to buy? A few sellers on eBay selling NOS NIB at £30 each plus postage (matched pairs or quads)
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izzy wizzy
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#21 Re: Looking for recommendation for Phono Stage

Post by izzy wizzy »

D3a are silly prices now. There are I think some Russian valves that are similar that might be worth a try at more sensible prices. Would have to look up what they are though.

E810f is another super hi gm valve. Not sure of their prices.

Cheers,
Stephen
RhythMick
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#22 Re: Looking for recommendation for Phono Stage

Post by RhythMick »

https://rover.ebay.com/rover/0/0/0?mpre ... 3063506600

10 for £42 Inc postage. I figure even if they are used I can experiment without worrying about them.
Ant
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#23 Re: Looking for recommendation for Phono Stage

Post by Ant »

This one sounded really nice

http://www.audio-talk.co.uk/phpBB2/view ... ilit=Dcc90

I did one with nuvistors that sounds good too
Also starring Rex Hamilton as Abraham Lincoln

www.bte-designs.weebly.com
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Nick
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#24 Re: Looking for recommendation for Phono Stage

Post by Nick »

RhythMick wrote: Fri Jan 18, 2019 7:27 pm https://rover.ebay.com/rover/0/0/0?mpre ... 3063506600

10 for £42 Inc postage. I figure even if they are used I can experiment without worrying about them.
They are npot d3s'a but the Russian equiv is good as well.
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RhythMick
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#25 Re: Looking for recommendation for Phono Stage

Post by RhythMick »

Wondering if it's worth experimenting with the grid connections on those pentode valves, perhaps connecting G2 to G1. That should increase the gain significantly? Would help to get that 8mV signal on the grids up to a less delicate level quickly.

Downside would be increased plate resistance I guess, making loading more difficult. Anyone tried that? Might experiment.
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Nick
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#26 Re: Looking for recommendation for Phono Stage

Post by Nick »

Depends how complex you want to be, this is the front end of the ref phono, it makes use of the d3a as a pentode with feedback via g2 to reduce and stabilise the gain, then the 5687 cathode follower will drive any riaa stage you want.
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RhythMick
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#27 Re: Looking for recommendation for Phono Stage

Post by RhythMick »

Very interesting thanks. I plan to spend a lot of time on the breadboard stage, experimenting and learning. I've steered away from any form of feedback, admittedly mostly because I just haven't wrapped my head around it. Perhaps it's time to grasp the nettle.
RhythMick
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#28 Re: Looking for recommendation for Phono Stage

Post by RhythMick »

Are cartridge outputs quoted in Vrms or Vpk?
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izzy wizzy
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#29 Re: Looking for recommendation for Phono Stage

Post by izzy wizzy »

Nick wrote: Sat Jan 19, 2019 10:17 am Depends how complex you want to be, this is the front end of the ref phono, it makes use of the d3a as a pentode with feedback via g2 to reduce and stabilise the gain, then the 5687 cathode follower will drive any riaa stage you want.
That looks fantastic and creative. How would you feel if I added it to my collection online? Would completely understand if you didn't want that.

Cheers,
Stephen
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Nick
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#30 Re: Looking for recommendation for Phono Stage

Post by Nick »

izzy wizzy wrote: Sat Jan 19, 2019 1:46 pm
Nick wrote: Sat Jan 19, 2019 10:17 am Depends how complex you want to be, this is the front end of the ref phono, it makes use of the d3a as a pentode with feedback via g2 to reduce and stabilise the gain, then the 5687 cathode follower will drive any riaa stage you want.
That looks fantastic and creative. How would you feel if I added it to my collection online? Would completely understand if you didn't want that.

Cheers,
Stephen
By all means, I have sold a few of them and I am rather pleased with the design itself so happy to see what people think.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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