cressy wrote:just a quick thought, im very happy with the nuvistor phono that andrew mike and others designed, the biggest expense involved being the nuvistor bases at about a tenner apiece. in all i think mine came to about 60 quid to build. might be worth a look
Thanks Ant, but Simon and I have decided to go down the LCR route, 600ohm version.
It was a tough decision for me, because Nick's new phono sounded really good in my system. But I planned to build an LCR phono years ago after hearing Nick's version of that. I bought most of the bits etc, but S&B didn't want to make the LCR modules. So I've been sitting on all these bits for years. Then James told me S&B were making a batch, and it just felt like the right way to go - I think it felt like unfinished business.
Do you have an LT spice model of the Mk 2 I could have a play with?
Thanks,
James.
Sorry I don't have any version of the T's circuit only the middle EQ section. If you get SBench's models for E810F and D3A, the rest is pretty easy. I am happy to help you replicate it, however.
Do you have an LT spice model of the Mk 2 I could have a play with?
Thanks,
James.
Sorry I don't have any version of the T's circuit only the middle EQ section. If you get SBench's models for E810F and D3A, the rest is pretty easy. I am happy to help you replicate it, however.
cheers,
Andrew
Thanks Andrew, that's just what we need! I was looking for the E810F and D3a models last night and couldn't find anything. I will have a better look now you have pointed me in the right direction!
Nick wrote:I have been musing that a 6c45p with 4 jfets in parallel underneath as a cascode would drive the 600R modules nicely.
What do you reckon the gm of that would be? It might in fact be an easier solution as the jfet is doing the heavy lifting and would potentially be quieter and cheaper.
I must get some jfets.....
Andrew
Analogue, the lost world that lies between 0 and 1.
They would increase the gm and reduce the noise, but the main reason for them in parallel in this case is they can collectively pass 20ma so the 6c45p can be run where it will have a low ra. An that will allow us to drive the RIAA with 600R termination.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
Nick wrote:They would increase the gm and reduce the noise, but the main reason for them in parallel in this case is they can collectively pass 20ma so the 6c45p can be run where it will have a low ra. An that will allow us to drive the RIAA with 600R termination.
A but, if you will allow an, ah but, if you terminate with 600R you need to couple with a large cap, unless you intend to DC couple, now, that might be an idea.
By sourcing with 600R you can use a small cap because its a large R that terminates.
Unless I'm missing something, wouldn't be the first time...
Last edited by Andrew on Fri Dec 02, 2011 8:13 am, edited 1 time in total.
Analogue, the lost world that lies between 0 and 1.
