Search found 5599 matches

by simon
Wed Feb 14, 2024 7:22 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

Great spots Mike, thanks! I'll see what difference they make.
by simon
Tue Feb 13, 2024 7:07 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

These are the settings. The 1.4V was a relic of another sim I modded. I didn't give it much thought as I figured I was interested in relative gain. I've tried 10mA and it didn't seem to make any difference. I'm not sure though what the small signal AC analysis is though? . TubeCAD Simple Pre-Preamp ...
by simon
Tue Feb 13, 2024 1:17 pm
Forum: Everyones Projects
Topic: RTZ SDM (DSD) DAC
Replies: 88
Views: 31550

Re: RTZ SDM (DSD) DAC

Hi Leon, I also Amazon Music Unlimited too. I don't know how it compares to other streaming services either but it sounds pretty good to me, and HD music is included not an extra cost option. (Perhaps the other streamers don't charge now either?) I'd hoped to use Linux, which I can through the Web r...
by simon
Tue Feb 13, 2024 9:48 am
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

I don't think I should be allowed to play with spice really. As far as I can see nothing's changed after fettling Q2, so there must be something fundamentally wrong in the model somewhere.
.
TubeCAD Simple Pre-Preamp 2.png
TubeCAD Simple Pre-Preamp 2.png (108.5 KiB) Viewed 1075 times
.
TubeCAD Simple Pre-Preamp Sim 2.png
TubeCAD Simple Pre-Preamp Sim 2.png (177.63 KiB) Viewed 1075 times
by simon
Mon Feb 12, 2024 10:33 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

Well that's quite amusing. No wonder it wasn't simming well. Sometimes you can't see for looking.
by simon
Mon Feb 12, 2024 8:11 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

I thought it might be fun to try to model the pre-preamp in spice to see if I could understand how it works. But I don't think I can have modelled it correctly. If I understand the output correctly then there's no gain but much attenuation. . TubeCAD Simple Pre-Preamp.png . The plots below are taken...
by simon
Mon Feb 12, 2024 5:11 pm
Forum: Everyones Projects
Topic: More RTZ DAC Fun.
Replies: 18
Views: 2047

Re: More RTZ DAC Fun.

I love the way you come up with something different with your chassis Steve, good inspiration.
by simon
Mon Feb 12, 2024 3:42 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

A quick check - the primaries are grounded to the same AC mains earth as the cans and screens. The secondaries are floating.
by simon
Sun Feb 11, 2024 10:47 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

It's that long ago I really can't remember what I did. I need to investigate.
by simon
Sun Feb 11, 2024 7:58 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

Mmm, good point. I need to check but I think I had to ground the step ups as I couldn't get rid of the hum years ago. Hopefully now I understand more I can get them balanced if they aren't.
by simon
Sun Feb 11, 2024 6:19 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

Okay, I've measured the voltages again and worked through the currents and I think I understand what you mean now Nick, and why the shunt reg should be connected, the return at least, close to the link to the output RCA phono. . 20240211_180624.jpg . The HV PS (shunt reg with Force and Sense + and -...
by simon
Sat Feb 10, 2024 11:31 pm
Forum: Your Fave Artists
Topic: What Are You Listening To Right This Minute?
Replies: 6152
Views: 1874311

Re: What Are You Listening To Right This Minute?

Top notch Dave! I award you the DIY Extreme Merit Award.

How do you like the Sowter TVCs?
by simon
Fri Feb 09, 2024 11:40 pm
Forum: Valves
Topic: Valve amplifier service
Replies: 176
Views: 84262

Re: Valve amplifier service

Hey, I was nearly right. Ish. :-)
by simon
Fri Feb 09, 2024 11:38 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

Ah right, not just a case of changing the ratio of the 100R and 330R resistors then?
by simon
Fri Feb 09, 2024 11:08 pm
Forum: Everyones Projects
Topic: C3g Aikido Phono
Replies: 319
Views: 81284

Re: C3g Aikido Phono

Looking at the Tubecad blog on the humming amp thread I noticed the SS phono preamps towards the bottom of the page suggested instead of step up transformers. https://www.tubecad.com/2019/11/blog0482.htm They look quite interesting, I'd need 10x gain rather 4x, but any thoughts on how good the circu...