Search found 247 matches

by IDM
Tue Oct 03, 2017 3:35 pm
Forum: News
Topic: Grim
Replies: 28
Views: 10155

Re: Grim

Nick,

I think it may be you that has the poor grasp of logic, though I suppose it doesn't surprise me as it the same poor grasp that is leading to the death of this site through your inability to understand how things actually work.

I think I am done here now.
by IDM
Tue Oct 03, 2017 3:18 pm
Forum: News
Topic: Grim
Replies: 28
Views: 10155

Re: Grim

No That would be ridiculous. Though it was you that started the debate with your absurd comparison of guns and cars. an argument that was basically laughable and simply had to be shown for what it was. I work as a research scientist and will find a ban on sulphuric acid an absolute pain in the arse ...
by IDM
Tue Oct 03, 2017 2:26 pm
Forum: News
Topic: Grim
Replies: 28
Views: 10155

Re: Grim

Yes, but was it for killing people or for food? Earliest records appears to be the Chines Fire lance which was a kind a flame thrower, that used black powder, to which shrapnel was added to make a more effective killing device. I would hazard that such a device was used in warfare not in hunting fo...
by IDM
Tue Oct 03, 2017 1:24 pm
Forum: News
Topic: Grim
Replies: 28
Views: 10155

Re: Grim

And just to continue your point, guns are designed to throw projectiles, they are not designed for any other purpose. If someone decides to use them to throw that projectile at people, then its not the gun or its design that does that. Sorry Nick that's not true. The gun was not developed and then ...
by IDM
Tue Oct 03, 2017 12:41 pm
Forum: News
Topic: Grim
Replies: 28
Views: 10155

Re: Grim

That's true Nick, but cars were designed for and have an alternative prime purpose. Gun's don't. So I don't think your logic follows.
by IDM
Fri Mar 31, 2017 6:24 pm
Forum: Speakers
Topic: Sub Woofer
Replies: 182
Views: 22278

Re: Sub Woofer

Hi Shane, How did you integrate the sub into your system. From the article (I admit I only scan read it) it looks like the sub is simply added to the existing stereo amplifier. If that's the case how did you adjust it's frequency range or set the level? If you couldn't set the level I am not surpris...
by IDM
Fri Mar 31, 2017 1:33 pm
Forum: Speakers
Topic: Sub Woofer
Replies: 182
Views: 22278

Re: Sub Woofer

I have sometimes considered a sub woofer, and wondered about this as a cheap DIY solution: http://www.transcendentsound.com/Subwoofer.html Maybe coupled with this D-amp as its cheap: https://www.amazon.co.uk/TDA8920-Subwoofer-Stereo-Digital-Amplifier/dp/B00HJKT366/ref=s9_simh_gw_g23_i1_r?_encoding=U...
by IDM
Wed Jan 18, 2017 2:21 pm
Forum: Computer Audio
Topic: RPi Reclocker
Replies: 9
Views: 3780

Re: RPi Reclocker

I bought a Kali re-clocker about a month ago and finally got round to building a linear PSU with 3A* capacity to try it out. The difference with and without is not subtle. The Kali offers a big leap forward in terms of micro-detail and imaging. I strongly recommend for anyone using an RPI. System it...
by IDM
Sat Dec 17, 2016 4:05 pm
Forum: Everyones Projects
Topic: j-FET / Triode Phono front-end
Replies: 287
Views: 83047

Re: j-FET / Triode Phono front-end

I certainly think that given I spent less than £20 on load of jFETS (needed several for the matching) that the schematic offers a very cheap way of getting very high performance out of a MC cartridge. I think some people have said they don't like the sound with the jFET, this might just be a taste t...
by IDM
Fri Dec 16, 2016 2:06 pm
Forum: Everyones Projects
Topic: j-FET / Triode Phono front-end
Replies: 287
Views: 83047

Re: j-FET / Triode Phono front-end

I thought that I should give some feedback on the performance of this phono-stage, particularly give the help and support I received to solve the issue with the second stage of the circuit. The circuit I have is slightly different to Marks in that I had to play with the value of the jFET source resi...
by IDM
Tue Nov 29, 2016 11:00 pm
Forum: Everyones Projects
Topic: j-FET / Triode Phono front-end
Replies: 287
Views: 83047

Re: j-FET / Triode Phono front-end

Hi, Yes I made the mistake of measuring the grid with the power off, just the battery bias. It was only when I simply couldn't get the thing to behave that I measured it with the power on. The caps were Jupiter beeswax. I had heard some adverse reports but never had the problem myself. I won't be us...
by IDM
Tue Nov 29, 2016 9:38 pm
Forum: Everyones Projects
Topic: j-FET / Triode Phono front-end
Replies: 287
Views: 83047

Re: j-FET / Triode Phono front-end

Hi, Finally found the problem. The 0.1uf caps coupling the RIAA to the second stage were leaking DC onto the grids and hence the valves was conducting really hard. I found a couple of other caps in the spares box and voltages are now about bang on. Gain is now much much greater and the bass is seems...
by IDM
Mon Nov 28, 2016 6:44 am
Forum: Everyones Projects
Topic: j-FET / Triode Phono front-end
Replies: 287
Views: 83047

Re: j-FET / Triode Phono front-end

I had an early morning teleconference to Australia so been up since god knows when, so had a look at the datasheet I have from Philips for the D3A, which includes triode curves. It indicates that -1.3V is about 19-20mA of current and that the bias for 12mA is -1.6V or 15mA -1.5V. I am off to work in...
by IDM
Sun Nov 27, 2016 8:57 pm
Forum: Everyones Projects
Topic: j-FET / Triode Phono front-end
Replies: 287
Views: 83047

Re: j-FET / Triode Phono front-end

Hi
I checked the battery bias and the grid definitely measures about -1.3V.

I faffed about and moved G3 to the cathode and still get 60V on the anode and a current of 19mA. I think I will stop tonight and try more tomorrow if I have time.

Cheers
Ian
by IDM
Sun Nov 27, 2016 6:20 pm
Forum: Everyones Projects
Topic: j-FET / Triode Phono front-end
Replies: 287
Views: 83047

Re: j-FET / Triode Phono front-end

Hi Mark,
On stage 2 I have both G2 and G3 connected to the anode via 100R grid stoppers. Is that the problem should I move G3 to the cathode? I must admit I did that part on auto-pilot!

Hi Nick, the problem is in stage 2 not stage . I agree that the IDSS guides the current of stage 1

Cheers
Ian